A   MANUAL 


OF 


BACTEBIOLOGIY 


BY 

GEOEGE   M.  STERNBEEG,  M.D. 

DEPUTY  SURGEON-GENERAL  U.  S.  ARMY 

Director  of  the  Hoagland  Laboratory  (Brooklyn,  N.  Y.);  Honorary  Member  of  the 

Epidemiological  Society  of  London,  of  the  Royal  Academy  of  Medicine  of 

Rome,  of  the  Academy  of  Medicine  of  Rio  de  Janeiro,  of  the 

American   Academy  of   Medicine,   etc.,  etc. 


ILLUSTRATED  BY  IIELIOTYPE  AND  CHROMO-LITHOGRAPIIIC  PLATES 

AND 
TWO  HUNDRED  AND  SIXTY-EIGHT  ENGRAVINGS 


-v 

X 


NEW  YORK 

WILLIAM  WOOD  &  COMPANY 
1893 


OUPLIC/JE 


BIOLOGY 

LIBRARY 

G 


COPYRIGHT  BY 

WILLIAM    WOOD    &    COMPANY 
1802. 


PREFACE. 


THE  progress  of  our  knowledge  relating  to  the  bacteria  has  been 
so  rapid  and  the  literature  of  the  subject  is  now  so  extensive  that  it 
is  no  small  task  to  keep  pace  with  this  progress,  even  when  one  has 
the  literature  at  hand  and  devotes  a  large  share  of  his  time  to  bac- 
teriological studies.  Fortunately,  recent  researches  in  this  depart- 
ment of  science  have  been  largely  made  by  exact  methods  and  by 
trained  investigators,  and  the  results  can  be  accepted  as  well  estab- 
lished. A  manual  of  bacteriology,  therefore,  which  fairly  represents 
the  present  state  of  knowledge,  will  consist  largely  of  a  statement  of 
facts  established  by  experimental  data,  and  cannot  fail  to  be  of  value 
to  physicians  and  to  advanced  students  of  bacteriology  as  a  work  of 
reference.  The  present  volume  is  an  attempt  to  supply  such  a 
manual,  and  at  the  same  time  a  text  book  of  bacteriology  for  stu- 
dents and  guide  for  laboratory  work.  That  portion  of  the  book 
which  is  printed  in  large  type  will,  it  is  hoped,  be  found  to  give  an 
accurate  and  sufficiently  extended  account  of  the  most  important 
pathogenic  bacteria,  and  of  bacteriological  technology,  to  serve  as  a 
text  book  for  medical  students  and  others  interested  in  this  depart- 
ment of  science.  The  descriptions  of  non-pathogenic  bacteria,  and 
of  the  less  important  or  imperfectly  described  species  of  pathogenic 
bacteria,  are  given  in  smaller  type.  In  the  preparation  of  this  man- 
ual various  text  books  in  foreign  languages  have  been  consulted,  and 
I  am  especially  indebted  to  the  works  of  Fliigge,  of  Baumgarten, 
and  of  Eisenberg.  But  the  descriptions  of  species  and  experimental 
data  have  been  very  largely  taken  from  original  memoirs.  '  The 
illustrations  also  are  to  a  considerable  extent  reproductions  from 
the  original  papars  of  those  engaged  in  research  work. 

NKW  YORK,  April  1st,  1892. 


268472 


TA.BLE    OF   CONTESTS. 


PART  FIRST. 

CLASSIFICATION,  MORPHOLOGY,  AND  GENERAL  BACTERIOLOGICAL 

TECHNOLOGY. 

PAGE 

I.  HISTORICAL, 3 

II.  CLASSIFICATION, .10 

III.  MORPHOLOGY, 20 

IV.  STAINING  METHODS, 25 

V.  CULTURE  MEDIA 37 

VI.  STERILIZATION  OF  CULTURE  MEDIA 50 

VII.  CULTURES  IN  LIQUID  MEDIA, CO 

VIII.  CULTURES  IN  SOLID  MEDIA,          .        .        .        ..       .        .        .67 

IX.  CULTIVATION  OF  ANAEROBIC  BACTERIA, 78 

X.  INCUBATING  OVENS  AND  THERMO-REGULATORS,          .        .        .86 

XI.  EXPERIMENTS  UPON  ANIMALS, 94 

XII.  PHOTOGRAPHING  BACTERIA,          ....  .  101 


PART   SECOND. 

GENERAL   BIOLOGICAL   CHARACTERS. 

I.  STRUCTURE,  MOTIONS,  REPRODUCTION, Ill 

II.  CONDITIONS  OF  GROWTH, 118 

III.  MODIFICATIONS  OF  BIOLOGICAL  CHARACTERS,     .        .        .        .122 

IV.  PRODUCTS  OF  VITAL  ACTIVITY, 126 

V.  PTOMAINES  AND  TOXALBUMINS,     ....  .  139 

VI.  INFLUENCE  OF  PHYSICAL  AGENTS,      .        .        .        .        .        .145 

VII.  ANTISEPTICS  AND  DISINFECTANTS  (GENERAL  ACCOUNT  OF  THE 

ACTION  OF), 156 

VIII.  ACTION  OF  GASES  AND  OF  THE  HALOID  ELEMENTS  UPON  BAC- 
TERIA,           164 

IX.  ACTION  OF  ACIDS  AND  ALKALIES 172 

X.  ACTION  OF  VARIOUS  SALTS,  .        .        .  * 178 

XI.  ACTION  OF  COAL-TAR  PRODUCTS,  ESSENTIAL  OILS,  ETC.,          .  189 

XII.  ACTION  OF  BLOOD  SERUM  AND  OTHER  ORGANIC  LIQUIDS,        .  198 

XIII.  PRACTICAL  DIRECTIONS  FOR  DISINFECTION,         .        .        .        .  201 


VI  TABLE   OP    CONTENTS. 

PART    THIRD. 
PATHOGENIC  BACTERIA. 

PAGB 

I.  MODES  OF  ACTION, ,     .  215 

II.  CHANNELS  OF  INFECTION 22.3 

III.  SUSCEPTIBILITY  AND  IMMUNITY,    .        .  .        .  .  226 

IV.  PYOGENIC  BACTERIA, 263 

V.  BACTERIA  IN  CROUPOUS  PNEUMONIA,  .        .        .  .  288 

VI.  PATHOGENIC   MICROOOCCI   NOT   DESCRIBED    IN    SECTIONS    IV. 

ANDV., 310 

VII.  THE  BACILLUS  OF  ANTHRAX,        ....  .  327 

VIII.  THS  BACILLUS  OF  TYPHOID  F  VER .  337 

IX.  BACTERIA  IN  DIPHTHERIA,     .        .        .-      .  .        .        .  356 

X.  BACTERIA  IN  INFLUENZA.       ,  .        .  370 

XI.  BACILLI  IN  CHRONIC  INFECTIOUS  Di  EASES,         .        .        .        .  374 
XII.  BACILLI   WHICH  PRODUCE   SEPTICAEMIA   ix  SUSCEPTIBLE    ANI- 
MALS,   .        .        .        .        ..       .        .        .        .        .      ,  .        .  407 

XIII.  PATHOGENIC  AEROBIC  BACILLI  NOT  DESCRIBED  IN    PREVIOUS 

SECTIONS,      .        .        .>-,'. 438 

XIV.  PATHOGENIC  ANAEROBIC  BACILLI,        .        .        .       ...        .482 

XV.  PATHOGENIC  SPIRILLA,    .        .        .        .        „        ,        .        .        .  497 

XVI.  BACTERIA  IN  INFECTIOUS  DISEASES  NOT  PROVED  TO  BE  DUE  TO 

SPECIFIC  MICROORGANISMS,         .        .        .       .        .        .        .  514 

XVII.  CLASSIFICATION  OF  PATHOGENIC  BACTERIA,         ...  .  533 


PART   FOURTH. 
SAPROPHYTES. 

I.  BACTERIA  IN  THE  AIR, .  541 

II.  BACTERIA  IN  WATER, 553 

III.  BACTERIA  IN  THE  SOIL, 567 

IV.  BACTERIA  OF  THE  SURFACE  OF  THE  BODY  AND  OF   EXPOSED 

Mucous  MEMBRANES, 573 

V.  BACTERIA  OF  THE  STOMACH  AND  INTESTINES,    ....  580 
VI.  BACTERIA  OF  CADAVERS  AND  OF  PUTREFYING  MATERIAL  FROM 

VARIOUS  SOURCES, 585 

VII.  BACTERIA  IN  ARTICLES  OF  FOOD, 588 

VIII.  NON-PATHOGENIC  MICROCOCCI, 593 

IX.   NON- PATHOGENIC   BACILLI, 620 

X.  NON-PATHOGENIC  SPIRILLA 694 

XI.  LEPTOTRICHE.E  AND  CLADOTRICHE^E, 703 

XII.  ADDITIONAL  SPECIES  OF  BACTERIA,  NOT  CLASSIFIED,       .        .  709 
XIII.  BACTERIOLOGICAL  DIAGNOSIS,      .  735 

BIBLIOGRAPHY,     . 769 

INDEX,  877 


LIST  OF  ILLUSTRATIONS. 


FIG.  PAGE 

1.  Staphylococci,           ...........  21 

2.  Zoogla-a 21 

3.  Ascococcus,       ............  21 

4.  Streptococci, 21 

5  Tetrads,    .        .                 22 

6.  Packets — sarciiia,      ...........  22 

7.  Bacilli, 23 

8.  Involution  forms,      ...........  23 

9.  Chains  formed  by  binary  division 23 

10.  Spirilla, 24 

11.  Cladothrix 24 

12.  Flagella, 24 

13.  Platinum  wire  in  glass  handle, 25 

14.  Flask  for  drawing  off  blood  serum, 38 

15.  Method  of  forcing  blood  serum  into  test  tube 38 

16.  Suction  pipette,        ...........  38 

17.  Hot- water  funnel 42 

18.  Karliuski's  agar  filter, 44 

19.  Unna's  agar  filter,     ...........  45 

20.  Glass  dishes  for  preserving  potato  cultures, 48 

21.  Test  tube  for  sterilizing  potato,         ........  48 

22.  Shape  of  potato  for  test-tube  culture, 48 

23.  Hot  air  oven, 52 

24.  Koch's  steam  sterilizer,     ..........  53 

25.  Koch's  steam  sterilizer, 53 

26.  Arnold's  steam  sterilizer,           ...                 .....  54 

27.  Miincke's  steam  sterilizer, 54 

28.  Koch's  apparatus  for  coagulating  blood  serum.       .....  56 

29.  Miincke  s  steam  sterilizer  and  coagulator,        ,        .         .:....         .        .  56 

30.  Pasteur  Chamberlain  filter 57 

31.  Pasteur- Chamberlain  filter  without  metal  case, 58 

32.  Modified  Pasteur-Chamberlain  filter 59 

33.  Erlenmeyer  flask 61 

34.  Flask  used  by  Pasteur, 61 

35.  Platinum  wire  loop, 62 

36.  Platinum  needle 63 

37.  Sternberg's  bulb, 64 

38.  Method  of  making  stick  culture, 67 


Vlll  LIST   OP   ILLUSTRATIONS. 

FIG.  PAGE 

39.  Sloping  surface  of  culture  medium,         .......  68 

40.  Growth  of  non-liquefying  bacteria  in  gelatin  stick  cultures,    .                 .  C8 

41.  Growth  of  same  along  line  of  puncture,  .......  69 

42.  Growth  of  liquefying  bacilli, 70 

43.  Colonies  of  bacteria, 71 

44.  Apparatus  for  gelatin  plates, 73 

45.  Esmarch  roll  tube, .  74 

46.  (See  Fig.  15). 

47.  Mode  of  development  of  a  facultative  anaerobic  bacillus,       .        .         .  78 

48.  Mode  of  development  of  strict  anaerobic  in  long  stick  culture,        .         .  78 

49.  Exhausted-air  flask  for  liquid  media ,  .         .         .  80 

50.  Method  of  displacing  air  with  hydrogen,          ......  80 

51.  Salomonson's  tube, HO 

53.  Friinkel's  method  of  cultivation, 81 

53.  Sternberg's  method  of  cultivation, .  81 

54.  Sternberg's  method  of  cultivation 82 

55.  Buchner's  method  of  cultivation,     .         .         .         .         .         .        .         .  83 

56.  Hydrogen  generator, 83 

57.  Hydrogen  apparatus  for  plate  cultures,   .......  85 

58.  Incubating  oven,       .        .     '  '.     \  .' 87 

59.  Thermo-regulator  for  gas,        .        .                 .        .         .        .         .         .  88 

60.  Moitessier's  pressure  regulator,         .                 ....        -.        .        .  88 

61.  Mica  screen  for  flame,       .        .        .        .        .        .'       .-       .        .        .  89 

62.  Koch's  device  for  cutting  off  flame,          -..''"-•«        •        •        >  "     •         •  89 

63.  Reichert's  thermo  regulator,     .        .         .                 .        .  '     .        .         .  89 

64.  Bohr's  thermo-regulator,          .         .        .         •  *      •        •        «'''.'.  89 

65.  Munckc's  thermo-regulator 4        .  90 

66.  Sternberg's  thermo-regulator, 90 

67.  Gas  valve  for  the  same, .  91 

68.  D'Arsonval's  incubating  apparatus, 91 

69.  Roux's  incubating  oven  and  thermo-regulator,        .....  91 

70.  Roux's  thermo-regulator, -.        .91 

71.  Koch's  syringe,         ...........  95 

72.  Sternberg's  glass  syringe,          .- .      9f 

73.  Pringle's  photomicrographic  apparatus 106 

74.  Sternberg's  photomicrographic  apparatus  for  gas,  .....  107 

75.  Spores  of  bacilli, 115 

76.  Method  of  germination  of  spores,     .        .         .         .         .        ,         .        .  116 

77.  Apparatus  for  cultivating  anaerobic  bacilli 131 

78.  Bacillus  of  mouse  septicaemia  in  leucocytes  from  blood  of  mouse,          .  245 

79.  Staphylococcus  pyogenes  aureus,     .        .         .        .        .         .         .        .  266 

80.  Gelatin  culture  of  Staphylococcus  pyogenes  aureus 267 

81.  Vertical  section  through  a  subcutaneous  abscess  caused  by  inoculation 

with  staphylococci  in  the  rabbit,          .......  269 

82.  Pus  containing  streptococci, 275 

83.  Streptococcus  of  erysipelas  in  nutrient  gelatin 276 

84.  Section  from  margin  of  an  erysipelatous  inflammation,  showing  strepto- 

cocci in  lymph  spaces, 277 

85.  Gouococci, 283 

86.  Gonococcus  in  gonorrhrcal  pus,        ........  284 

87.  Gonorrhooal  conjunctivitis,  second  day  of  sickness,         .        .                 .  286 


LIST   OF   ILLUSTRATIONS.  ix 

no.  PAGE 

88.  FriedlSnder's  bacillus, 296 

89.  Friedlander's  bacillus;  stick  culture  in  gelatin, 297 

90.  Micrococcus  pneumoniae  crouposae, 301 

91.  Micrococcus  pneumoniae  crouposae, 301 

92.  Micrococcus  pneumoniae  crouposae,          .......  301 

93.  Micrococcus  pneumoniae  crouposae,  showing  capsule 302 

94.  Single  colony  of  Micrococcus  pneumonise  crouposae  upon  agar  plate,     .  303 

95.  Micrococcus  pneumoniae  crouposae  in  blood  of  rabbit  inoculated  with 

sputum, 307 

96.  Micrococcus  of  progressive  tissue  necrosis  in  mice,          .         .        .         .  311 

97.  Micrococcus  of  pyaemia  in  rabbits, 312 

98.  Micrococcus  tetragenus, 314 

99.  Streptococcus  of  mastitis  in  cows, 321 

100.  Bacillus  anthracis,  showing  development  of  long  threads  in  convoluted 

bundles, 328 

101.  Bacillus  anthracis,  showing  formation  of  spores,     .        .        ...         .  329 

102.  Culture  of  Bacillus  anthracis  in  nutrient  gelatin 330 

103.  Colonies  of  Bacillus  anthracis  upon  gelatin  plates,           .         .        .        .  331 

104.  Bacillus  anthracis  in  liver  of  mouse,        .......  334 

105.  Bacillus  anthracis  in  kidney  of  rabbit, 335 

106.  Bacillus  of  typhoid  fever;  colonies  in  stained  sections  of  spleen,     .        .  340 

107.  Bacillus  of  typhoid  fever;  colonies  in  stained  sections  of  spleen,     .         .  340 

108.  Bacillus  typhi  abdominalis, 346 

109.  Bacillus  typhi  abdominalis, 346 

110.  Bacillus  typhi  abdominalis,  showing  flagella, 347 

111.  Single  colony  of  Bacillus  typhi  abdominalis  in  nutrient  gelatin,     .        .  348 

112.  Bacillus  typhi  abdominalis;  stick  culture  in  nutrient  gelatin,          .        .  348 

113.  Section  through  wall  of  intestine,  showing  invasion  by  typhoid  bacilli,  352 

114.  Bacillus  diphtheriae, 360 

115.  Colonies  of  Bacillus  diphtheriae  in  nutrient  agar, 361 

116.  Bacillus  tuberculosis, .  376 

117.  Bacillus  tuberculosis  in  sputum,       .        .        .'        »        .        .        ....  377 

118.  Section  through  a  tuberculous  nodule  in  the  lung  of  a  cow,  showing 

two  giant  cells, 379 

119.  Tubercle  bacilli  from  surface  of  culture  upon  blood  serum,    .         .        .  382 

120.  Culture  of  tubercle  bacillus  upon  glycerin-agar, 384 

121.  Limited  epithelioid-celled  tubercle  of  the  iris,          .        .        .        .        .  390 

122.  Section  of  a  recent  lepra  nodule  of  the  skin, 395 

123.  Bacillus  mallei 397 

124.  Section  of  a  glanders  nodule, .        . ,  397 

125.  Section  through  a  glanders  nodule  in  liver  of  field  mouse,      .        .        .  .  400 

126.  Migrating  cell  containing  syphilis  bacilli,        ......  402 

127.  Pus  from  hard  chancre  containing  syphilis  bacilli,           ....  402 

128.  Bacillus  of  rhinoscleroma  in  lymphatic  vessels  of  the  superficial  part  of 

tumor, 405 

129.  Bacillus  septicaemias  haemorrhagicae  in  blood  of  a  rabbit,        .        .        .  408 

130.  Bacillus  septicaemiae  haemorrhagicae;  stick  culture  in  nutrient  gelatin,  .  410 

131.  Bacillus  of  Schweineseuche, 410 

132.  Colonies  of  bacillus  of  swine  plague, 410 

133.  Bacillus  of  Schweineseuche  in  blood  of  rabbit,        .        .        .        .        .  412 

134.  Bacillus  of  hog  cholera,   ...                ...                .  414 


X  LIST   OF   ILLUSTRATIONS. 

PIG.  PAGE 

135.  Bacillus  of  mouse  septictemia  in  leucocytes  from  blood  of  mouse,          .  420 

136.  Bacillus  of  rouget, 421 

137.  Bacillus  of  mouse  septicaemia  ;  culture  in  nutrient  gelatin,     .        .         .  4'31 

138.  Bacillus  of  mouse  septicaemia;  single  colony  in  nutrient  gelatin,     .        .  422 

139.  Section  of  diaphragm  of  a  mouse  dead  from  mouse  septicaemia,     .         .  423 

140.  Bacillus  cavicida  Havaniensis,       " 425 

141.  Bacillus  crassus  sputigenus,     .        .        .        .       -.        .        .        .        .  426 

142.  Proteus  hominis  capsulatus,     .*       .        .        .        .        .     ,   .        .        .  428 

143.  Bacillus  capsulatus,          .        .        .        .        .  •     .        »        .        .        .  432 

144.  Bacillus  hydrophilus  fuscus,     .        .        ,        .        .        ...        .  433 

145.  Culture  of  Bacillus  hydrophilus  fuscus  in  nutrient  gelatin,     .  •      .        .  433 
14C.  Bacillus  coli  communis,    .        .        »        ;        .        .        .        .        .        .  440 

147.  Bacillus  coli  communis  in  nutrient  gelatin,      .        .        .                  .  442 

148.  A  portion  of  the  growth  shown  in  Fig.  147, 442 

149.  Bacillus  lactis  aerogenes,  .        .•-..-.        .        .  -               .        .        .  447 

150.  Bacillus  acidiformans,      .        .        ...        .        .         .        .        .        .  449 

151.  Culture  of  Bacillus  acidiformans  in  nutrient  gelatin,       .        .        .  '-     .  449 

152.  Bacillus  cuniculicida  Havaniensis, 450 

153.  Colonies  of  Bacillus  cuniculicida  Havaniensis,         .        .         .        .  -    '•'•.  451 

154.  Colonies  of  Bacillus  cuniculicida  Havaniensis,                                   ,  451 

155.  Bacillus  pyocyanus,          .        .  •     .        .•       .  '     .         .        .        .         .  454 

156.  Proteus  vulgaris,      .         .        .                 .        .        .        .'."..  457 

157.  "  Swarming  islands"  from  a  culture  of  Proteus  mirabilis,     .        .'       .  461 

158.  Spiral  zooglcea  from  a  culture  of  Proteus  mirabilis,        .        .        .        .  461 

159.  Tetanus  bacillus, '  .       '.        .        .   .    -V       .  483 

160.  Tetanus  bacillus,      .        .        .        .        .        •*"'"•    '    •        ;  '    "*   *  '•  483 

161.  Culture  of  Bacillus  tetani  in  nutrient  gelatin,          .....  484 

162.  Bacillus  cedematis  maligni,       . .  489 

163.  Bacillus  redematis  maligni,       .        ..               '.•       .        .        .        .        .  489 

164.  Cultures  of  Bacillus  oedematis  maligni  in  nutrient  gelatin,      .        .        .  490 

165.  Bacillus  cadaveris, -      .        .        . '•••'.        .  492 

166.  Bacillus  cadaveris, .        .        .492 

167.  Bacillus  of  symptomatic  anthrax, _  .  493 

168.  Bacillus  of  symptomatic  anthrax,    .  •      .        .        .         .         .        .        .  493 

169.  Culture  of  bacillus  of  symptomatic  anthrax,    ......  494 

170.  Spirillum  Obermeieri 498 

171.  Spirillum  Obermeieri,      ..........  498 

172.  Spirillum  cholerae  Asiaticae, 500 

173.  Spirillum  cholerae  Asiaticse, 500 

174.  Colonies  of  Spirillum  cholerae  Asiaticae.  .        .        .         .        .        .        ;  501 

175.  Spirillum  cholerae  Asiaticae, 501 

176.  Cultures  of  Spirillum  choleras  Asiaticae  in  nutrient  gelatin,     .         .        .  502 

177.  Spirillum  cholerae  Asiaticae, 502 

178.  Colonies  in  nutrient  gelatin  of  Spirillum  cholerae  Asiaticae,  Spirillum 

tyrogenum,  and  Spirillum  of  Finkler  and  Prior,         ....  503 

179.  Section  through  mucous  membrane  of  intestine  from  cholera  cadaver,  507 

180.  Spirillum  of  Finkler  and  Prior,       .                510 

181.  Colonies  of  Spirillum  of  Finkler  and  Prior, 510 

182.  Spirillum  of  Finkler  and  Prior  ;  culture  in  gelatin,         ....  510 

183.  Spirillum  tyrogenum 511 

184.  Colonies  of  Spirillum  tyrogenum, 511 


LIST   OF   ILLUSTRATIONS.  xj 

FIG.  PAGE 

185.  Spirillum  Metschnikovi, 512 

186.  Penicillum  glaucum, 542 

187.  Miquel's  aeroscope, 543 

188.  Hesse's  aeroscope 545 

189.  Miquel's  flask ' 547 

190.  Straus  and  Wurtz's  soluble  filter, 547 

191.  Petri's  sand  filter 548 

192.  Sugar  filter, 549 

193.  Sedgwick  and  Tuckers  apparatus, 549 

194.  Sternberg's  vacuum  tube, 554 

195.  Lepsius'  apparatus  for  collecting  water  at  various  depths,       .        .        .  555 

196.  Koch's  plate  method, 556 

197.  Smear  preparation  from  liver  of  yellow-fever  cadaver,    ....  586 

198.  Bacillus  cadaveris  grandis, 586 

199.  Micrococcus  of  Freire,  from  a  gelatin  culture, '  G09 

200.  Culture  of  Freire's  micrococcus  in  nutrient  gelatin,        ....  609 

201.  Streptococcus  coli  gracilis,       . 610 

202.  Streptococcus  cadaveris, 612 

203  Streptococcus  Ha vaniensis,      „ 612 

204.  Streptococcus  liquefaciens,  from  anaerobic  culture  in  nutrient  gelatin,  .  613 

205.  Streptococcus  liquefaciens  ;  culture  in  nutrient  gelatin,          .        .        .  613 

206.  Micrococcus  tetragenus  versatilis,  from  a  single  colony  in  nutrient 

gelatin, 614 

207.  Micrococcus  tetragenus  ;  culture  in  nutrient  gelatin,      ....  614 

208.  Sarcina  lutea, 616 

209.  Ascococcus  Billrothii, 618 

210.  Bacillus  cyanogenus, 627 

211.  Bacillus  arborescens,  from  a  gelatin  culture, 633 

212.  Colony  of  Bacillus  arborescens 633 

213.  Bacterium  termo  of  Vignal,  from  a  bouillon  culture 642 

214.  The  same  from  a  culture  fifteen  days  old 642 

215.  Bacillus  ubiquitus 644 

216.  Bacterium  Zopfii, 655 

217.  Bacillus  scissus, 657 

218.  Bacillus  scissus;  superficial  colony  on  gelatin  plate,        ....  657 

219.  Bacillus  circulans, 664 

220.  Bacillus  diffusus,  from  a  gelatin  culture 667 

221.  Bacillus  diffusus;  superficial  colony  in  nutrient  gelatin,          .        .        .  667 

222.  Bacillus  vermicularis, 668 

223.  Bacillus  mesentericus  vulgatus,  from  a  culture  in  bouillon,    .        .        .  673 

224.  Bacillus  mesenteriqus  vulgatus,  from  an  agar  culture 673 

225.  Bacillus  megatherium, 674 

226.  Bacillus  subtilis, 678 

227.  Bacillus  ulna  of  Vignal, 681 

228.  Bacillus  buccalis  maximus 683 

229.  Colonies  of  Bacillus  muscoides, 687 

230.  Colonies  of  Bacillus  polypiformis, 688 

231.  Bacillus  butyricus,  .                 689 

232.  Colonies  of  Bacillus  liquefaciens  magnus, 690 

233.  Colonies  of  Bacillus  liquefaciens  parvus, 691 

234.  Colony  of  Bacillus  radiatus, 691 


Xii  LIST   OF   ILLUSTRATIONS. 

FIG  PAGE 

235.  Culture  of  Bacillus  liquefacieus  magnus 692 

236.  Culture  of  Bacillus  radiatus, 692 

237.  Culture  of  Bacillus  spinosus, 692 

238.  Culture  of  Bacillus  liquefaciens  parvus, 692 

239.  Culture  of  Clostridium  fcetidum,      .    4   .        .        .        .        .        .        .  692 

240.  Colony  of  Bacillus  spiuosus 693 

241.  "  Spirochoete  dentium," .  694 

242.  "  Spirochaete  plicatilis,  vibrio  rugula,  and  other  bacteria,"     .        .        .  694 

243.  "  Spirillum  dentium," 694 

244.  Vibrio  rugula, 695 

245.  Spirillum  volutans,  .        . '      .        .        .        .        .        .        .        .        .  696 

246.  Spirillum  sanguineum,     .        .         .        .        ,        .        .        .        .        .  696 

247.  Spirillum  serpens, 696 

248.  Spirillum  tenue,       . 696 

249.  Spirillum  undula,     .        .        .....        .        .        .        .        .  696 

250.  Spirillum  linguae,     .  j ...  697 

251.  Spirillum  a  of  Weibel, .        .        .  698 

252.  Spirillum  ft  of  Weibel, .'....  698 

253.  Spirillum  y  of  Weibel,    .        .        .        .                .,       ....  699 

254.  Spirillum  aureum, 699 

255.  Crenothrix  Kuhniana,      .        .      -  .        . 704 

256.  Beggiatoa  alba, 704 

257.  Cladothrix  dichotoma 707 

258.  Nitrifying  bacillus  of  Winogradsky, 710 

259.  Bacillus  thalassophilus,    .        .        .        .        .        .        .        .        .  712 

260.  Bacillus  granulosus,          .        .        .        .        .        .        .        .        .     •    .  712 

261.  Bacillus  limosus, 713 

262.  Spirillum  marinum, ,         .  713 

263.  Bacillus  litoralis, 715 

264.  Bacillus  balophilus, 715 

265.  Bacillus  of  Dantec, 718 

266.  Bacillus  Havaniensis 718 

267.  Bacillus  gracilis  cadaveris, 733 

268.  Colonies  of  Bacillus  gracilis  cadaveris, 73C 


PART    FIRST. 


CLASSIFICATION,    MORPHOLOGY,  AND  GENERAL 
BACTERIOLOGICAL  TECHNOLOGY. 

I.  HISTORICAL.    II.   CLASSIFICATION.    III.   MORPHOLOGY.     IV.  STAINING 
METHODS.    V.   CULTURE  MEDIA.     VI.  STERILIZATION  OP  CULTURE 
MEDIA.    VII.   CULTURES  IN  LIQUID  MEDIA.    VIII.  CULTURES 
IN  SOLID  MEDIA.    IX.  CULTIVATION  OF  ANAEROBIC  BAC- 
TERIA.   X.  INCUBATING  OVENS  AND  THERMO  REGU- 
LATORS.    XI.  EXPERIMENTS  UPON  ANIMALS. 
XII.   PHOTOGRAPHING  BACTERIA. 


PART    FIRST. 


I. 

HISTORICAL. 

IT  is  probable  that  Leeuwenhoeck,  "  the  father  of  microscopy," 
observed  some  of  the  larger  species  of  bacteria  in  faeces,  putrid  in- 
fusions, etc.,  which  he  examined  with  his  magnifying  glasses  (1675), 
but  it  was  nearly  a  century  later  before  an  attempt  was  made  to  de- 
fine the  characters  of  these  minute  organisms  and  to  classify  them 
(0.  F.  Miiller,  1773). 

In  the  absence  of  any  reliable  methods  for  obtaining  pure  cultures, 
it  is  not  surprising  that  the  earlier  botanists,  in  their  efforts  to  classify 
microorganisms,  fell  into  serious  errors,  one  of  which  was  to  include 
under  the  name  of  infusoria  various  motile  bacteria.  These  are  now 
generally  recognized  as  vegetable  organisms,  while  the  Infusoria  are 
unicellular  animal  organisms. 

Ehrenberg  (1838),  under  the  general  name  of  Vibrioniens,  de- 
scribes four  genera  of  filamentous  bacteria,  as  follows  : 

1.  Bacterium — filaments  linear  and  inflexible  ;  three  species. 

2.  Vibrio — filaments  linear,  snake-like,  flexible  ;  nine  species. 

3.  Spirillum — filaments  spiral,  inflexible  ;  three  species. 

4.  Spirochcete — filaments  spiral,  flexible  ;  one  species. 

These  vibrioniens  were  described  by  Ehrenberg  as  "  filiform  ani- 
mals, distinctly  or  apparently  polygastric,  naked,  without  external 
organs,  with  the  body  uniform  and  united  in  chains  or  in  filiform 
series  as  a  result  of  incomplete  division." 

Dujardin  (1841)  also  placed  the  vibrioniens  of  Ehrenberg  among 
the  infusoria,  describing  them  as  ''filiform  animals,  extremely  slen- 
der, without  appreciable  organization,  and  without  visible  locomotive 
organs. " 

Charles  Robin  (1853)  suggested  the  relationship  of  Ehrenberg's 
vibrioniens  with  the  genus  Leptothrix,  which  belongs  to  the  algSB  ; 
and  Davaine  (1859)  insisted  that  the  vibrioniens  are  vegetable  organ- 


4  HISTORICAL. 

isms,  nearly  allied  to  the  algae.  His  classification  will  be  found 
in  the  "  Dictionnaire  Encyclop.  des  Sciences  Medicales,"  art.  "  Bac- 
teries  "  (18G8).  This  view  is  also  sustained  by  the  German  botanist 
Cohn  and  is  now  generally  accepted. 

Spallanzani,  in  1776,  endeavored  to  show  by  experiment  that  the 
generally  received  theory  of  the  spontaneous  generation  of  micro- 
organisms in  organic  liquids  was  not  true.  This  he  did  by  boiling 
putrescible  liquids  in  carefully  sealed  flasks.  The  experiment  was 
not  always  successful,  but  in  a  certain  number  of  instances  the 
liquids  were  sterilized  and  remained  unchanged  for  an  indefinite 
period.  The  objection  was  raised  to  these  experiments  that  the  oxy- 
gen of  the  air  was  excluded  by  hermetically  sealing  the  flasks,  and 
it  was  claimed,  in  accordance  with  the  views  of  Gay-Lussac,  that 
free  admission  of  this  gas  was  essential  for  the  development  of  fer- 
mentation. 

This  objection  was  met  by  Franz  Schulze  (1836),  who  admitted  air 
to  boiled  putrescible  liquids  by  drawing  it  through  strong  sulphuric 
acid,  in  which  suspended  microorganisms  were  destroyed.  He  thus 
demonstrated  that  boiled  solutions,  which,  when  exposed  to  the  air 
without  any  precautions,  quickly  fell  into  putrefaction,  remained  un- 
changed when  freely  supplied  with  air  which  had  been  passed  through 
an  agent  capable  of  quickly  destroying  all  living  organisms  con- 
tained in  it. 

Schwann  (1839)  demonstrated  the  same  fact  by  another  method. 
Air  was  freely  admitted  to  his  boiled  liquids  through  a  tube  which 
was  heated  to  a  point,  which  insured  the  destruction  of  suspended 
microorganisms.  The  same  author  is  entitled  to  the  credit  of  hav- 
ing first  clearly  stated  the  essential  relation  of  the  yeast  plant — 
Saccharomyces  cerevisice — to  the  process  of  fermentation  in  saccha- 
rine liquids,  which  results  in  the  formation  of  alcohol  and  carbonic 
acid. 

Helmholtz,  in  1843,  repeated  the  experiments  of  Schwann  with 
calcined  air,  and  arrived  at  similar  results — i.  e. ,  he  found  that  the 
free  admission  of  calcined  air  to  boiled  organic  infusions  did  not  pro- 
duce fermentation  of  any  kind. 

It  was  objected  to  these  experiments  that  the  air,  having  been 
subjected  to  a  high  temperature,  had  perhaps  undergone  some  chem- 
ical change  which  prevented  it  from  inaugurating  processes  of  fer- 
mentation. 

This  objection  was  met  by  Schroder  and  Von  Dusch  (1854)  by  a 
very  simple  device  which  has  since  proved  to  be  of  inestimable  value 
in  bacteriological  researches.  These  observers  showed  that  a  loose 
plug  of  cotton,  through  which  free  communication  with  the  external 
air  is  maintained,  excludes  all  suspended  microorganisms,  and  that 


HISTORICAL.  5 

air  passed  through  such  a  filter  does  not  cause  the  fermentation  of 
boiled  organic  liquids. 

The  experiments  of  Pasteur  and  of  Hoffman,  made  a  few  years 
later,  showed  that  even  without  a  cotton  filter,  when  the  neck  of  the 
flask  containing  the  boiled  liquid  is  long  drawn  out  and  turned  down- 
ward, the  contents  may  be  preserved  indefinitely  without  change. 
In  this  case  suspended  particles  do  not  reach  the  interior  of  the  flask, 
as  there  is  no  current  of  air  to  carry  them  upward  through  its  long- 
drawn-out  neck,  and  they  are  prevented  by  the  force  of  gravity  from 
ascending. 

Tyndall  showed  at  a  later  date  that  in  a  closed  chamber,  in  which 
the  air  is  not  disturbed  by  currents,  all  suspended  particles  settle  to 
the  floor  of  the  chamber,  leaving  the  air  optically  pure,  as  is  proved 
by  passing  a  beam  of  light  through  such  a  chamber. 

Notwithstanding  the  fact  that  the  experimenters  mentioned  had 
succeeded  in  keeping  boiled  organic  liquids  sterile  in  flasks  to  which 
the  oxygen  of  the  air  had  free  access,  the  question  of  the  possibility 
of  spontaneous  generation — heterogenesis — still  remained  unsettled, 
inasmuch  as  occasionally  a  development  of  bacterial  organisms  did 
occur  in  such  boiled  liquids. 

This  fact  was  explained  by  Pasteur  (1860),  who  showed  that  the 
generally  received  idea  that  the  temperature  of  boiling  water  must 
destroy  all  living  organisms  was  a  mistaken  one,  and  that,  especially 
in  alkaline  liquids,  a  higher  temperature  was  required  to  insure  ster- 
ilization. His  experiments  showed  that  a  temperature  of  110°  to 
112°  C.  (230°  to  233.6°  F.),  which  he  obtained  by  boiling  under  a 
pressure  of  one  and  a  half  atmospheres,  was  sufficient  in  every  case. 
These  experiments,  which  have  been  repeated  by  numerous  investi- 
gators since,  settled  the  spontaneous-generation  controversy  ;  and  it 
is  now  generally  admitted  that  no  development  of  microorganisms 
occurs  in  organic  liquids,  and  no  processes  of  putrefaction  or  fermen- 
tation occur  in  such  liquids,  when  they  are  completely  sterilized  and 
guarded  against  the  entrance  of  living  germs  from  without. 

Pasteur,  at  a  later  date  (1865)  showed  that  the  atmospheric  or- 
ganisms which  resist  the  boiling  temperature  are  in  fact  reproduc- 
tive bodies,  or  spores,  which  he  described  under  the  name  of  "  corpus- 
cles ovoides  "  or  "  corpuscles  brillants."  Spores  had  been  previously 
seen  by  Perty  (1852)  and  Robin  (1853),  but  it  was  not  until  1876  that 
the  development  of  these  reproductive  bodies  was  studied  with  care 
by  Cohn  and  by  Koch.  The  last-named  observer  determined  the 
conditions  under  which  spores  are  formed  by  the  anthrax  bacillus. 
Five  years  later  (1881)  Koch  published  his  valuable  researches  relat- 
ing to  the  resisting  power  of  anthrax  spores  to  heat  and  to  chemical 
agents. 


6  HISTORICAL. 

The  development  of  our  knowledge  relating  to  the  bacteria,, 
stimulated  by  the  controversy  relating  to  spontaneous  generation 
and  by  the  demonstration  that  various  processes  of  fermentation 
and  putrefaction  are  due  to  microorganisms  of  this  class,  has 
depended  largely  upon  improvements  in  methods  of  research. 
Among  the  most  important  points  in  the  development  of  bacterio- 
logical technique  we  may  mention,  first,  the  use  of  a  cotton  air 
filter  (Schroder  and  Von  Dusch,  1854)  ;  second,  the  sterilization  of 
culture  fluids  by  heat  (methods  perfected  by  Pasteur,  Koch,  and 
others)  ;  third,  the  use  of  the  aniline  dyes  as  staining  agents  (first 
recommended  by  Weigert  in  1877)  ;  fourth,  the  introduction  of 
solid  culture  media,  and  the  "  plate  method  "  for  obtaining  pure  cul- 
tures, by  Koch  in  1881. 

The  various  improvements  in  methods  of  research,  and  espe- 
cially the  introduction  of  solid  culture  media  and  Koch's  "plate 
method  "  for  isolating  bacteria  from  mixed  cultures,  have  placed 
bacteriology  upon  a  scientific  basis,  and  have  shown  that  many  of 
the  observations  and  inferences  of  the  earlier  investigators  were 
erroneous  owing  to  the  imperfection  of  the  methods  employed. 

Since  it  has  been  demonstrated  that  certain  infectious  diseases  of 
man  and  the  lower  animals  are  due  to  organisms  of  this  class,  phy- 
sicians have  been  especially  interested  in  bacteriological  researches, 
and  the  progress  made  during  the  past  fifteen  years  has  been  largely 
due  to  their  investigations.  It  was  a  distinguished  French  physi- 
cian, Davaine,  who  first  demonstrated  the  etiological  relation  of  a 
microorganism  of  this  class  to  a  specific  infectious  disease.  The  an- 
thrax bacillus  had  been  seen  in  the  blood  of  animals  dying  from  this 
disease  by  Pollender  in  1849  and  by  Davaine  in  1850,  but  it  was  sev- 
eral years  later  (1863)  before  the  last-named  observer  claimed  to 
have  demonstrated  by  inoculation  experiments  the  causal  relation  of 
the  bacillus  to  the  disease  in  question. 

The  experiments  of  Davaine  were  not  generally  accepted  as  con- 
clusive, because  in  inoculating  an  animal  with  blood  containing  the 
bacillus,  from  an  infected  animal  which  had  succumbed  to  the 
disease,  the  living  microorganism  was  associated  with  material 
from  the  body  of  the  diseased  animal.  This  objection  was  subse- 
quently removed  by  the  experiments  of  Pasteur,  Koch,  and  many 
others  with  pure  cultures  of  the  bacillus,  which  were  shown  to  have 
the  same  pathogenic  effects  as  had  been  obtained  in  inoculation  ex- 
periments with  the  blood  of  an  infected  animal. 

The  next  demonstration  of  the  causal  relation  of  a  parasitic  mi- 
croorganism to  an  infectious  malady  was  made  by  Pasteur,  who  de- 
voted several  years  to  the  study  of  an  infectious  disease  of  silkworms 
which  threatened  to  destroy  the  silk  industry  of  France — pebrine. 


HISTORICAL.  7 

In  1873  Obermeier,  a  German  physician,  announced  the  discov- 
ery, in  the  blood  of  patients  suffering  from  relapsing  fever,  of  a  mi- 
nute, spiral,  actively  motile  microorganism — the  Spirochcete  Ober- 
tneieri — which  is  now  generally  recognized  as  the  specific  infectious 
agent  in  this  disease. 

The  very  important  work  of  Koch  upon  traumatic  infectious 
diseases  was  published  in  1878. 

In  1879  Hansen  reported  the  discovery  of  bacilli  in  the  cells  of 
leprous  tubercles,  and  subsequent  researches  have  shown  that  this 
bacillus  is  constantly  associated  with  leprosy  and  presumably  bears 
an  etiological  relation  to  the  disease. 

In  the  same  year  (1879)  Neisser  discovered  the  "  gonococcus  "  in 
gonorrhceal  pus. 

The  bacillus  of  typhoid  fever  was  first  observed  by  Eberth,  and 
independently  by  Koch,  in  1880,  but  it  was  not  until  1884  that  Gaff- 
ky's  important  researches  relating  to  this  bacillus  were  published. 

In  1880  Pasteur  published  his  memoir  upon  fowl  cholera,  and  the 
same  year  appeared  several  important  communications  from  this 
pioneer  in  bacteriological  research  upon  the  "attenuation"  of  the 
virus  of  anthrax  and  of  fowl  cholera  and  upon  protective  inocula- 
tions in  these  diseases. 

In  1880  the  present  writer  discovered  a  pathogenic  micrococcus, 
which  he  subsequently  named  Micrococcus  Pasteuri,  and  which  is 
now  generally  recognized  as  the  usual  agent  in  the  production  of 
acute  croupous  pneumonia — commonly  spoken  of  as  the  "  diplococ- 
cus  pneumonia},"  but  described  in  the  present  volume  under  the 
name  of  Micrococcus  pneumonias  crouposce. 

In  1881  several  important  papers  by  Koch  and  his  colleagues  ap- 
peared in  the  first  volume  of  the  "  Mittheilungen  "  published  by  the 
Imperial  Board  of  Health  of  Germany. 

The  following  year  (1885)  Koch  published  his  discovery  of  the 
tubercle  bacillus. 

The  same  year  Pasteur  published  his  researches  upon  the  disease 
of  swine,  known  in  France  as  ronget. 

The  same  investigator  (Pasteur)  also  published  in  1883  his  first 
communication  upon  the  subject  of  rabies. 

Another  important  discovery  was  made  in  1882  by  the  German 
physicians  Loffler  and  Schiitz,  viz.,  that  of  the  bacillus  of  glan- 
ders. 

Koch  published  his  discovery  of  the  cholera  spirillum — * '  co*ima 
bacillus  "—in  1884. 

The  same  year  (1884)  Loffler  discovered  the  diphtheria  bacillus. 

Another  important  publication  during  the  same  year  was  that  of 
Rosenbach,  who,  by  the  application  of  Koch's  methods,  fixed  defi- 


8  HISTORICAL. 

nitely  the  characters  of  the  various  microorganisms  found  in  pus 
from  acute  abscesses,  etc. 

The  tetanus  bacillus  was  discovered  in  1884  by  Nicolaier,  a  stu- 
dent in  the  laboratory  of  Prof.  Flugge,  of  Gottingen.  That  this 
bacillus  is  the  cause  of  tetanus  in  man  has  been  demonstrated  by  the 
subsequent  researches  of  numerous  investigators.  For  an  exact  knowl- 
edge of  its  biological  characters  we  are  especially  indebted  to  Kitasato. 

So  far  as  human  pathology  is  concerned,  no  important  pathogenic 
microorganism  has  been  discovered  since  the  year  1884  until  the 
present  year  (1892).  After  numerous  unsuccessful  researches  by 
competent  bacteriologists,  a  bacillus  has  finally  been  discovered  by 
Pfeiffer,  of  Berlin,  and  independently  by  Canon,  which  is  believed 
to  be  the  specific  cause  of  influenza. 

Having  briefly  passed  in  review  some  of  the  principal  events  in 
the  progress  of  our  knowledge  in  this  department  of  scientific  inves- 
tigation, it  will  be  of  interest  to  students  to  know  something  more  of 
the  literature  of  bacteriology.  Important  papers  have  appeared  in 
medical  and  scientific  journals  in  all  countries,  and  research  work  of 
value  has  been  done  by  enthusiastic  investigators  of  nearly  every 
nation.  The  brilliant  pioneer  work  done  by  Pasteur  and  by  Koch 
has  attracted  to  them  many  pupils  and  has  made  France  and  Ger- 
many the  leading  countries  in  this  line  of  investigation.  The  very 
great  advantages  of  Koch's  methods  of  research,  introduced  at  the 
commencement  of  the  last  decade,  have  attracted  many  students 
from  various  parts  of  the  world  to  Berlin,  and  to  other  cities  of  Ger- 
many where  instruction  was  to  be  obtained  from  some  of  Koch's 
earlier  pupils.  But  to-day  bacteriological  laboratories  have  been 
established  in  all  parts  of  the  world,  and  it  is  no  longer  necessary  to 
go  to  Germany  to  obtain  such  instruction.  The  literature  of  the  sub- 
ject is,  however,  largely  in  the  German  and  French  languages.  We 
can  only  refer  here  to  such  periodicals  as  are  principally  devoted  to 
bacteriological  research  work. 

The  Zeitschrift  fur  Hygiene  has  been  published  since  188(3,  and 
contains  numerous  valuable  papers,  contributed  for  the  most  part  by 
the  pupils  of  Koch  and  of  Flugge,  who  are  the  editors  of  the  journal. 
Nine  volumes,  each  containing  three  numbers,  have  thus  far  been 
published  (1891). 

The  Annales  de  I'Institut  Pasteur  is  a  monthly  journal  which  has 
been  published  since  1888.  It  is  edited  by  Duclaux,  and  contains  many 
important  papers  and  reviews,  as  well  as  the  statistics  of  the  Pasteur 
Institute  relating  to  preventive  inoculations  against  hydrophobia. 

The  Annales  de  Micrography  is  a  monthly  journal,  published  in 
Paris.  It  is  now  (1892)  in  its  fourth  year.  The  principal  editor  is 
Miquel. 


HISTORICAL.  9 

The  Centralblatt  fiir  Bakteriologie  und  Parasitenkunde  is  a 
weekly  journal  which  has  been  published  by  Gustav  Fischer,  of 
Jena,  since  1887.  The  editors  are  Uhlworm,  of  Cassel;  Loffler,  at 
present  professor  at  Greifswald;  and  Leuckart,  professor  at  Leipzig. 

A  most  important  work  for  students  of  bacteriology  is  the  Jahres- 
bericht  of  Baumgarten,  which  has  been  published  since  1885  by 
Harald  Bruhn,  Braunschweig,  Germany.  This  gives  a  brief  abstract 
of  nearly  every  paper  of  importance  relating  to  the  subject  which 
has  been  published  during  the  year. 


II. 

CLASSIFICATION. 

THE  earlier  naturalists — Ehrenberg  (1838),  Dujardin  (1841) — 
placed  the  bacteria  among  the  infusoria;  but  they  are  now  recog- 
nized as  vegetable  microorganisms,  differing  essentially  from  the 
infusoria,  which  are  unicellular  animal  organisms.  One  of  the  prin- 
cipal points  in  differentiating  animal  from  vegetable  organisms 
among  the  lowest  orders  of  living  things  is  the  fact  that  animal 
organisms  receive  food  particles  into  the  interior  of  the  body,  assimi- 
lating the  nutritious  portion  and  subsequently  extruding  the  non- 
nutritious  residue  ;  vegetable  organisms,  on  the  other  hand,  are 
nourished  through  the  cell  wall  which  encloses  their  protoplasm,  by 
organic  or  inorganic  substances  held  in  solution. 

Ehrenberg  (1838),  under  the  name  of  vibrioniens,  established  four  gen- 
era, as  follows : 

1.  Bacterium — filaments  linear  and  inflexible. 

2.  Vibrio — filaments  linear,  snake-like,  flexible. 

3.  Spirillum — filaments  spiral,  inflexible. 

4.  'Spirochcete — filaments  spiral,  flexible. 

Dujardin  (1841)  united  the  two  genera  Spirillum  and  Spirochcete  of 
Ehrenberg,  and  added  to  the  description  of  the  generic  characters  as  fol- 
lows: 

1.  Bacterium — filaments  rigid,  with  a  vacillating  movement. 

2.  Vibrio — filaments  flexible,  with  an  undulatory  movement. 

3.  Spirillum — filaments  spiral,  movement  rotatorv. 

It  will  be  seen  that  this  classification  leaves  no  place  for  the  motionless 
bacilli,  such  as  the  anthrax  bacillus  and  many  others,  and  does  not  include 
the  spherical  bacteria,  now  called  micrococci. 

The  classification  of  Davaiue  (18G8)  provides  for  the  motionless,  fila- 
mentous bacteria,  but  does  not  include  the  micrococci.  This  author  first 
insisted  that  the  vibrioniens  of  Ehrenberg  are  truly  vegetable  organisms, 
allied  to  the  algae.  He  makes  four  genera,  as  follows: 

Filaments    straight    or    bent,  i  Moving    spontane-  \  Rigid  Bacterium. 
but  not  in  a  spiral,  ously,  )  Flexible  Vibrio. 

( Motionless,        .          Bacteridium. 
Filaments  spiral, Spirillum. 

Following  Davaine,  the  French  bacteriologists  frequently  speak  of  the 
motionless  anthrax  bacillus  as  la  bacteridie. 

Hoffman  in  1869  included  in  his  classification  the  spherical  bacteria, 
and  pointed  out  the  fact  that  motility  could  not  be  taken  as  a  generic  char- 
acter, as  it  was  not  constant  in  the  same  species  and  depended  to  some  ex- 
tent upon  temperature  conditions,  etc. 


CLASSIFICATION.  11 

Having  determined  that  the  bacteria  are  truly  vegetable  organ- 
isms, the  attention  of  botanists  has  been  given  to  the  question  as  to 
what  class  of  vegetable  organisms  they  are  most  nearly  related  to. 
There  are  decided  differences  of  opinion  in  this  regard.  While  Da- 
vaine,  Rabenhorst,  and  Cohn  insist  upon  their  affinities  with  the 
algae,  Robin,  Nageli,  and  others  consider  them  fungi.  One  of  the 
principal  characters  which  distinguish  the  algae  from  the  fungi  is 
the  presence  of  chlorophyll  in  the  former  and  its  absence  in  the  latter. 
Now,  the  bacteria  are  destitute  of  chlorophyll,  and  in  this  regard 
resemble  the  fungi;  yet  in  others  their  affinities  with  the  Palmellacece 
and  Oscillator iacece  are  unmistakable.  It  is  not  necessary,  how- 
ever, that  we  should  consider  them  as  belonging  to  either  of  these 
classes  of  the  vegetable  kingdom.  By  considering  them  a  distinct 
class  of  unicellular  vegetable  organisms,  under  the  general  name  of 
bacteria,  we  may  avoid  the  difficulties  into  which  the  botanists  have 
fallen. 

We  must  refer  briefly,  however,  to  the  classification  proposed  by  some 
of  the  leading  German  botanists. 

Nageli,  placing  the  bacteria  among  the  lower  fungi,  which  give  rise  to 
the  decomposition  of  organic  substances,  divides  these  into  three  groups: 

1.  The  Mucorini,  or  mould  fungi. 

2.  The  Saccharomycetes,  or  budding  fungi,  which  produce  alcoholic  fer- 
mentation in  saccharine  liquids. 

3.  The  Schizomycetes,  or  fission  fungi,  which  produce  putrefactive  pro- 
cesses, etc. 

Cohn,  under  the  name  of  Schizophytes,  has  grouped  these  low  vegetable 
organisms,  whether  provided  or  not  with  chlorophyll,  into  two  tribes  hav- 
ing the  following  characters: 

1.  GL^OGENES — cells  free  or  united   into  glairy  families  by  an  intercel- 
lular substance. 

2.  NEMA.TOGENES— cells  disposed  in  filaments. 

In  the  first  tribe  he  has  placed  the  genera  Micrococcus  (Hallier),  Bacte- 
rium (Dujardin),  Merismopedia  (Meyer),  Sarciita  (Goodsir),and^lscococcM6f 
(Billroth),  with  various  genera  of  unicellular  algae  containing  chlorophyll. 

In  the  second  tribe  we  have  the  genera  Bacillus  (Cohn),  Leptothrix 
(Kg.),  Vibrio  (Ehr.),  Spirillum  (Ehr.),  Spirochcete  (Ehr.),  Streptococcus 
(Billr.),  Cladothrix  (Cohn),  and  Streptothrix  (Cohn),  associated  with  gen- 
era of  green  filamentous  algae. 

The  German  botanist  Sachs  unites  the  fungi  and  the  algae  into  a  single 
group,  the  Thallophytes,  in  which  he  establishes  two  parallel  series,  one  in- 
cluding those  containing  chlorophyll,  and  the  other  without,  as  follows: 


THALLOPHYTES. 

Forms  with  chlorophyll.  Forms  without  chlorophyll. 

Class  I. — Protophytes. 

A.  Cyanophyceae     (Oscillatoria-  A.  Schizomycetes  (Bacteria), 
ceae,  etc.). 

B.  Palmellaceae.  B.  Saccharomycetes. 


12  CLASSIFICATION. 

Zopf,  who  insists  upon  the  polymorphism  of  these  low  organisms,  divides 
the  bacteria  into  four  groups : 

Genera. 

Streptococcus, 
Merismopedia, 


1.   COCCKCE^E. — Up   to  the    pre- 
sent time,  only  known  in  the  form  of 


cocci. 


Sarcina, 
Micrococcus, 


Ascococcus. 

2.  BACTERIACE.E. — Have  for  the  1  Bacterium, 
most    part    spherical,   rod-like,   and  j  Spirillum, 
filamentous  forms  ;  the  first  (cocci)   •  vibrio, 
may  be  wanting  ;  the  last  are  not  j  Leuconostoc, 
different  at  the  two  extremities;  fila-  Bacillus, 
ments  straight  or  spiral.  Clostridium. 

3.  LEPTOTRICHE^.  —  Spherical,  ]  Crmnnriv 
rod-shaped,  and  filamentous  forms;  Beaaiatoa 

the  last  show  a  difference  between  the  \  p*S™  ,v//o/7i  w-r 

two  extremities  ;   filaments  straight  |  LevSrix 

orspiral;  spore  formation  not  known.  J  ^ 

4.  CLADOTRICHE.E.  —  Spherical,  1 
rod-shaped,  filamentous,  and   spiral  | 

forms  ;  the  filamentous    form    pre-  \  Cladothrix. 
sents  pseudo-branches  ;  spore  forma- 
tion not  known. 

The  main  objection  to  this  classification  is  that  it  assumes  a  pleomorph- 
ism  for  the  bacteria  of  the  second  group — Bact?riacese — which  has  only  been 
established  for  a  few  species,  and  which  appears  not  to  be  general  among  the 
rod- shaped  and  spiral  bacteria. 

De  Bary  divides  the  bacteria  into  two  principal  groups,  one  including 
those  which  form  endospores,  and  the  other  those  which  are  reproduced  by 
arthrospores.  But  our  knowledge  is  yet  too  imperfect  to  make  this  classifi- 
cation of  value,  and  the  same  may  be  said  of  Hueppe's  recent  attempt  at 
classification,  in  which  the  mode  of  reproduction  is  a  principal  feature. 

The  classification  of  Baumgarten  (1890)  appears  to  us  to  have 
more  practical  value,  and,  with  slight  modifications,  we  shall  adopt 
it  in  the  present  volume.  This  author  divides  the  bacteria  into  two 
principal  groups,  as  follows  : 

GROUP  I.  Species  relatively  monomorphous. 

GROUP  II.  Species  pleomorphous. 

The  first  group  includes  the  micrococci,  the  bacilli,  and  the 
spirilla;  the  second  group  the  spirulina  of  Hueppe,  leptotrichece 
(Zopf),  and  cladotrichece. 

The  pleomorphous  species  described  by  Hauser  under  the  generic 
name  Proteus  are  included  in  the  second  group  among  the  spirulina. 
In  the  present  volume  we  have  described  these  pleomorphous  species 
among  the  bacilli. 

The  Cocci,  in  the  classification  of  Baumgarten,  constitute  a  single 
genus  with  the  following  subgenera  :  1,  Diplococcus  ;  2,  Strepto- 
coccus; 3,  Merismopedia  (Zopf) — "Merista"  (Hueppe);  4,  Sar- 
cina (Goodsir)  ;  5,  Micrococcus  ("  staphylococci"). 

The  BACILLI  are  included  in  a  single  genus  embracing  all  of 


CLASSIFICATION.  13 

those  species  which  only  form  rod-shaped  cells,  and  filaments  com- 
posed of  red-like  segments ;  or  straight  filaments  not  distinctly  seg- 
mented, which  may  be  rigid  or  flexible. 

The  SPIRILLA  are  also  included  in  a  single  genus,  embracing  all 
of  those  species  in  which  the  filaments  are  spiral  in  form  and  the 
segments  more  or  less  spiral  or  "comma-shaped" — filaments  either 
rigid  or  flexible. 

This  simple  morphological  classification  of  the  monomorphous 
group  of  Baumgarten  corresponds  with  the  nomenclature  now  gene- 
rally in  use  among  bacteriologists.  We  speak  of  the  spherical  bac- 
teria as  cocci  or  as  micrococci,  of  the  rod-shaped  bacteria  as  bacilli, 
and  of  the  spiral  bacteria  as  spirilla, 

It  is  true,  however,  that  we  are  sometimes  embarrassed  to  decide 
whether  a  particular  microorganism  belongs  to  one  or  the  other  of 
these  morphological  groups  or  so-called  genera.  Among  the  bacilli, 
for  example,  we  may  have,  in  the  same  pure  culture,  rods  of  very 
different  lengths,  some  being  so  short  that  if  alone  they  might  be 
taken  for  cocci,  while  others  may  have  grown  out  into  long  fila- 
ments. But  if  we  are  assured  that  the  culture  is  pure  the  presence 
of  rod  forms  establishes  the  diagnosis,  and  usually  the  cocci-like 
elements,  when  carefully  observed,  will  be  seen  to  be  somewhat 
longer  in  one  diameter  than  in  the  other.  The  German  bacterio- 
logists generally  insist  upon  placing  among  the  bacilli  all  straight  bac- 
teria in  which,  as  a  rule,  one  diameter  is  perceptibly  greater  than 
that  transverse  to  it ;  and  several  species  of  well-known  bacteria 
which  were  formerly  classed  as  micrococci  are  now  called  bacilli — 
e.  g. ,  Friedlander's  bacillus  ("pneumococcus"),  Bacillus prodigiosus. 

The  distinction  made  by  Cohn  and  others  between  the  genus 
Bacterium  (Duj.)  and  the  genus  Bacillus  (Cohn)  cannot  be  main- 
tained, inasmuch  as  we  may  have  short  rods  and  quite  long  fila- 
ments in  the  same  pure  culture  of  a  single  species ;  and,  again,  the 
character  upon  which  the  genus  Vibrio  (Ehr.)  was  established — 
viz.,  the  fact  that  the  filaments  are  flexible  and  the  movements 
sinuous — is  not  a  sufficient  generic  or  even  specific  character,  for  in 
a  pure  culture  there  may  be  short  rods  which  are  rigid,  and  long 
filaments  which  are  flexible  and  have  a  sinuous  movement.  We 
therefore  to-day  speak  of  all  the  elongated  forms  as  bacilli,  unless 
they  are  spiral  and  have  a  corkscrew-like  motion,  in  which  case  they 
are  known  as  spirilla. 

The  bacteria  are  also  classified  according  to  their  biological  char- 
acters, and  it  will  be  necessary  to  consider  the  various  modes  of 
grouping  them  from  different  points  of  view  other  than  that  which 
relates  to  their  form.  This  is  the  more  important  inasmuch  as  we 
are  not  able  to  differentiate  species  by  morphological  characters 


14  CLASSIFICATION. 

alone.  Thus,  for  example,  there  are  among  the  spherical  bacteria,  or 
micrococci,  numerous  well-established  species  which  the  most  expert 
microscopist  could  not  differentiate  by  the  use  of  the  microscope 
alone  ;  the  same  is  true  of  the  rod-shaped  bacteria.  The  assump- 
tion often  made  by  investigators  who  are  not  sufficiently  impressed 
with  this  fact,  that  two  microorganisms  from  different  sources,  or 
even  from  the  same  source,  are  the  same  because  stained  prepara- 
tions examined  under  the  microscope  look  alike,  has  led  to  serious 
errors  and  to  much  confusion.  As  an  example  of  what  is  meant  we 
may  refer  to  the  pus  organisms.  Before  the  introduction  of  Koch's 
"plate  method"  micrococci  had  been  observed  in  the  pus  of  acute 
abscesses.  Some  of  these  were  grouped  in  chains — streptococci — 
and  some  were  single,  or  in  pairs,  or  in  groups  of  four  ;  but  whether 
these  were  simply  different  modes  of  grouping  in  a  single  species,  or 
whether  the  chain  micrococci  represented  a  distinct  species,  was  not 
determined  with  certainty.  That  there  were  in  fact  four  or  more 
distinct  species  to  be  found  in  the  pus  of  acute  abscesses  was  not 
suspected  until  Rosenbach  and  Passet  demonstrated  that  this  is  the 
case,  and  showed  that  not  only  is  the  streptococcus  a  distinct  species, 
but  that  among  the  cocci  not  associated  in  chains  there  are  three 
species  which  are  to  be  distinguished  from  each  other  by  their  color 
when  grown  on  the  surface  of  a  solid  culture  medium.  One  of  these 
has  a  milk-white  color,  one  is  of  a  lemon-yellow  color,  while  the  third 
is  a  golden-yellow. 

Those  microorganisms  which  form  pigment  are  called  chromo- 
genes,  or  chromogenic ;  those  which  produce  fermentations  are 
spoken  of  as  zymogenes,  or  zymogenic  ;  those  which  give  rise  to  dis- 
ease processes  in  man  or  the  lower  animals  are  denominated  patho- 
genes,  or  pathogenic.  We  cannot,  however,  classify  bacteria  under 
the  three  headings  chromogenes,  zymogenes,  and  pathogenes,  for 
some  of  the  chromogenic  species  are  also  pathogenic,  as  are  some 
of  the  zymogenes.  These  characters  must  therefore  be  considered 
separate^  as  regards  each  species,  and  in  studying  its  life  history  and 
distinguishing  characters  we  determine  whether  it  is  chromogenic 
or  noii-chromogenic  ;  whether  it  produces  special  fermentations  ; 
and  whether  it  is  or  is  not  pathogenic  when  inoculated  into  the 
lower  animals.  In  making  the  distinction  between  pathogenic 
and  non-pathogenic  microorganisms  we  must  remember  that  a 
certain  species  may  be  pathogenic  for  one  animal  and  not  for  an- 
other. Thus  the  anthrax  bacillus,  which  is  fatal  to  cattle,  sheep, 
rabbits,  guinea-pigs,  and  mice,  does  not  kill  white  rats  ;  the  bacillus 
of  mouse  septica3mia  kills  house  mice,  but  field  mice  are  fully  im- 
mune from  its  pathogenic  effects  ;  on  the  other  hand,  the  bacillus  of 
glanders  is  fatal  to  field  mice  but  not  to  house  mice. 


CLASSIFICATION.  15 

Again,  it  must  be  remembered  that  pathogenic  power  also  de- 
pends, to  a  greater  or  less  extent,  upon  the  dose  injected  into  an 
animal  as  compared  to  its  body  weight.  Some  pathogenic  organ- 
isms in  very  minute  doses  give  rise  to  a  fatal  infectious  malady ; 
others  are  only  able  to  overcome  the  vital  resisting  power  of  the 
tissues  and  fluids  of  the  body  when  introduced  into  the  circulation, 
or  into  the  subcutaneous  tissue  or  abdominal  cavity,  in  considerable 
amounts.  Some  pathogenic  bacteria  invade  the  blood  ;  others  mul- 
tiply only  in  certain  tissues  of  the  body  ;  and  others  again  multiply 
in  the  intestine  and  by  the  formation  of  poisonous  products  which 
are  absorbed  show  their  pathogenic  power. 

Another  classification  of  the  bacteria  relates  to  the  environment 
favorable  to  their  development.  Thus  we  speak  of  saprophytic  and 
parasitic  bacteria,  or  of  SAPROPHYTES  and  PARASITES. 

The  saprophytes  are  such  as  exist  independently  of  a  living  host, 
obtaining  their  supply  of  nutriment  from  dead  animal  or  vegetable 
material  and  from  water  containing  organic  and  inorganic  matters 
in  solution.  The  strict  parasites,  on  the  other  hand,  depend  upon 
a  living  host,  in  the  body  of  which  they  multiply,  sometimes  without 
injury  to  the  animal  upon  which  they  depend  for  their  existence,  but 
frequently  as  harmful  invaders  giving  rise  to  acute  or  chronic  infec- 
tious diseases.  Microorganisms  which  ordinarily  lead  a  saprophy- 
tic existence,  but  which  can  also  thrive  within  the  body  of  a  living 
animal,  are  called  facultative  parasites.  Thus  the  leprosy  bacillus, 
which  is  only  found  in  leprous  tissues,  is  a  strict  parasite  ;  while  the 
typhoid  bacillus,  the  cholera  spirillum,  etc. ,  are  facultative  parasites, 
inasmuch  as  they  are  capable  of  maintaining  an  independent  exist- 
ence, for  a  time  at  least,  external  to  the  bodies  of  living  animals. 

It  seems  probable  that  the  pathogenic  organisms  which  are  only 
known  to  us  to-day  as  strict  parasites  were,  at  some  time  in  the  past, 
saprophytes,  which  gradually  became  accustomed  to  a  parasitic 
mode  of  existence,  and,  under  the  changed  conditions  of  their  envi- 
ronment, finally  lost  the  power  of  living  in  association  with  other 
saprophytes  exposed  to  variations  of  temperature,  etc.  The  tubercle 
bacillus,  for  example,  is  known  to  us  only  as  a  parasite  which  has  its 
habitat  in  the  lungs,  lymphatic  glands,  etc. ,  of  man  and  of  certain 
of  the  lower  animals.  But  we  are  able  to  cultivate  it  in  artificial 
media  external  to  the  body  ;  and  it  is  in  accord  with  modern  views 
relating  to  the  development  of  species  to  suppose  that  at  some  time 
in  the  past  it  was  able  to  lead  a  saprophytic  existence.  Not  to  admit 
this  forces  us  to  the  conclusion  that,  at  some  time  subsequent  to  the 
appearance  of  man  and  the  lower  animals  in  which  it  is  now  found 
as  a  parasite,  it  was  created  with  its  present  biological  characters, 
which  restrict  it  to  a  parasitic  existence  in  the  bodies  of  these  ani- 


10  CLASSIFICATION. 

mals,  and  that,  consequently,  the  immense  destruction  of  human  life 
which  has  resulted  from  its  parasitic  invasion  of  successive  genera- 
tions was  designed  when  it  was  created.  The  opposite  view  is  sup- 
ported by  numerous  facts  which  show  that  these  low  organisms,  like 
those  higher  in  the  scale,  are  subject  to  modifications  as  a  result  of 
changed  conditions  of  environment,  and  that  such  modifications,  in 
the  course  of  time,  may  become  well-established  specific  characters. 

Again,  the  bacteria  may  be  grouped  into  aerobic  and  anaerobic 
species.  This  is  a  very  important  distinction,  which  was  first  estab- 
lished by  Pasteur,  who  found  that  certain  bacteria  will  only  grow 
when  freely  supplied  with  oxygen,  while  others  absolutely  decline  to 
grow  in  the  presence  of  this  gas.  The  latter,  which  are  spoken  of  as 
strict  anaerobics,  may  be  cultivated  in  a  vacuum  or  in  an  atmo- 
sphere of  hydrogen.  Those  species  which  grow  either  in  the  pre- 
sence of  oxygen  or  when  it  is  excluded  are  called  facultative  an- 
aerobics. 

Certain  bacteria  produce  a  peptonizing  ferment  which  has  the 
power  of  liquefying  gelatin.  This  has  led  to  the  classification  of 
those  microorganisms  of  this  class  which  grow  in  Koch's  flesh-pep- 
tone-gelatin as  liquefying  and  non-liquefying  bacteria. 

Again,  we  speak  of  them  as  motile  or  non-motile. 

It  is  evident  that  these  biological  characters,  although  all-im- 
portant in  the  definition  of  species,  cannot  serve  us  in  an  attempt  to 
establish  natural  genera  ;  for  the  lines  are  not  sharply  drawn  between 
the  saprophytes  and  the  parasites,  the  aerobics  and  the  anaerobics, 
etc. ,  inasmuch  as  we  have  facultative  parasites  and  facultative  an- 
aerobics which  we  cannot  include  in  either  class,  and  which  yet  do 
not  form  a  distinct  class  by  themselves.  We  therefore  adhere  to  the 
morphological  classification,  although  this  is  open  to  criticism.  For 
example,  among  the  rod-shaped  organisms  which  we  call  bacilli  and 
describe  under  the  generic  name  Bacillus  there  are  some  which 
multiply  by  binary  division  only,  while  others  form  endogenous  re- 
productive bodies  known  as  spores.  Certainly  so  important  a  differ- 
ence in  the  mode  of  reproduction  should  be  sufficient  to  separate 
these  rod-shaped  organisms  into  two  natural  groups  or  genera. 

As  heretofore  stated,  the  German  bacteriologist  Hueppe  has  at- 
tempted a  classification  based  upon  the  mode  of  reproduction,  in 
which  he  makes  two  groups,  or  "  tribes,"  one  in  which  reproduction 
occurs  by  the  formation  of  endogenous  spores — "  endospores  " — the 
other  in  which  it  occurs  by  the  formation  of  "•  ar  thro  spores." '  The 
latter  group  includes  all  of  those  bacteria  in  which  no  other  mode  of 
multiplication  is  known  than  that  by  binary  division,  which  is  com- 
mon to  all.  In  the  present  state  of  our  knowledge  this  classification 
1  An  account  of  this  mode  of  reproduction  is  given  on  page  19. 


CLASSIFICATION.  17 

is  scarcely  to  be  considered  of  practical  value,  inasmuch  as  the  ques- 
tion of  spore  formation  is  still  undetermined  for  a  large  number  of 
species. 

In  the  following  table  we  shall  give  the  characters  of  the  dif- 
ferent genera  which  have  been  described  by  recent  botanists  and 
bacteriologists,  arranged  under  the  three  headings,  MiCROCOCCi, 
BACILLI,  SPIRILLA.  Where  we  doubt  the  propriety  of  maintaining 
a  distinct  generic  name  upon  the  supposed  distinguishing  characters, 
the  description  will  be  printed  in  small  type. 

MICROCOCCI. 

General  Characters. — Spherical  bacteria  which  are  reproduced 
by  binary  division  ;  usually  without  spontaneous  movements  ;  do  not 
form  endogenous  spores.  (According  to  some  authors,  certain  cells, 
known  as  arthrospores,  may  be  distinguished  by  their  greater  size 
and  refractive  power,  and  these  are  supposed  to  have  greater  resist- 
ance to  desiccation  than  the  ordinary  cocci  resulting  from  binary 
division,  and  to  serve  as  reproductive  bodies.)  Some  micrococci  are 
not  precisely  round,  but  are  somewhat  oval  in  form  ;  and  when  in 
process  of  division  the  cocci,  necessarily,  are  more  or  less  elongated 
in  one  diameter  before  a  complete  separation  into  two  spherical  ele- 
ments has  occurred. 

MICROCOCCUS. — Division  in  one  direction  ;  cocci  single,  in  pairs, 
or  accidentally  associated  in  irregular  groups  ;  sometimes  held  to- 
gether in  irregular  masses  by  a  transparent,  glutinous,  intercellular 
substance.  (Micrococci  belonging  to  this  genus  are  frequently  de- 
scribed as  "  staphylococci,"  and  Staphylococcus  is  used  by  Rosen- 
bach  as  a  generic  name  for  the  pus  cocci  described  by  him,  which 
are  solitary  or  associated  in  irregular  groups,  as  above  described. ) 

Ascococcus. — Cocci  associated  in  globular  or  lobulated,  zooglcea 
masses  by  a  rather  firm  intercellular  substance. 

LEUCONOSTOC. — Cocci,  solitary  or  in  chains,  surrounded  by  a 
thick,  gelatinous  envelope  arid  forming  zooglcea  of  cartilaginous 
consistence. 

STREPTOCOCCUS. — Division  in  one  direction  only ;  cocci  associ- 
ated in  chains. 

Diplococcus. — Division  in  one  direction  only  ;  cocci  associated  in  pairs. 

Association  in  pairs  is  common  to  all  of  the  micrococci,  inasmuch  as 
they  multiply  by  binary  division.  When  such  association  has  rather  a  per- 
manent character,  it  is  customary  to  speak  of  the  microorganism  as  a  diplo- 
coccus,  but  we  doubt  the  propriety  of  recognizing  this  mode  of  association 
as  a  generic  character. 

MERISMOPEDIA. — Division  in  two  directions,  forming  groups  of 
four,  which  remain  associated  in  a  single  plane — "tetrads." 

SARCINA. — Division  in  three  directions,  forming  packets  of  eight 


18  CLASSIFICATION. 

or  more  elements,  which  remain  associated  in  more  or  less  regular 
cubical  masses. 

BACILLI. 

General  Characters. — Rod-shaped  and  filamentous  (not  spiral) 
bacteria  in  which  there  is  no  differentiation  between  the  extremities 
of  the  rods  ;  reproduction  by  binary  division  in  a  direction  trans- 
verse to  the  long  axis  of  the  rods,  or  by  binary  division  and  the  for- 
mation of  endogenous  spores  ;  rigid  or  flexible  ;  motile  or  non-motile. 

BACILLUS. — Characters  as  given  above. 

Bacterium.—  This  genus,  established  by  Dujardin,  is  now  generally 
abandoned,  the  species  formerly  included  in  it  being  transferred  to  the  genus 
Bacillus.  As  denned  by  Cohn,  the  generic  characters  were  :  Cells  cylindri- 
cal or  elliptical,  free  or  united  in  pairs  during  their  division,  rarely  in 
fours,  never  in  chains,  sometimes  in  zoogloea  (differing  from  the  zoogloea 
of  spherical  bacteria  by  a  more  abundant  aud  firmer  intercelluar  substance), 
having  spontaneous  movements,  oscillatory  and  very  active,  especially  in 
media  rich  in  alimentary  material  and  in  presence  of  oxygen. 

Clostridium. — Rod-shaped  bacteria  which  form  large,  endogenous,  and 
usually  oval  spores  ;  these  are  centrally  located,  and  during  the  stage  of 
spore  formation  the  rods  become  fusiform. 

SPIRILLA. 

General  Characters. — Curved  rods  or  spiral  filaments  ;  rigid  or 
flexible  ;  reproduction  by  binary  division,  or  by  binary  division  and 
the  formation  of  endogenous  spores  (or  by  arthrospores  ?)  ;  move- 
ments rotatory  in  the  direction  of  the  long  axis  of  the  filaments. 

SPIRILLUM. — Characters  as  above. 

Spirochcete. — Flexible,  spiral  filaments;  movements  rotatory. 

vibrio, — Filaments  flexible,  straight  or  sinuous;  movements  sinuous. 

A  considerable  number  of  bacteria  which  are  usually  seen  as  short,  curved 
rods,  but  which  may  grow  out  into  long,  spiral  filaments,  are  desci-ibed  by 
some  authors  under  the  generic  name  Vibrio,  e.g.,  the  so-called  ''comma 
bacillus"  of  Koch—"  Spirillum  cholerae  Asiatic*";  the  spirillum  of  Finkler 
and  Prior — "Vibrio  proteus" ;  the  spirillum  described  by  Gameleia — "  Vibrio 
Metschnikovi,"etc.  These  microorganisms  have  not  the  characters  which 
distinguished  the  genus  Vibrio  as  established  by  Ehrenberg,  and  we  prefer  to 
follow  Fliigge  in  describing  them  under  the  generic  name  Spirillum. 

The  pathogenic  bacteria  now  known  belong  to  one  or  the  other 
of  the  above-described  genera,  and  the  attention  of  bacteriologists 
has  been  given  chiefly  to  the  study  of  micrococci,  bacilli,  and  spirilla. 
But  the  botanists  place  among  the  bacteria  certain  other  forms  which 
are  found  in  water,  and  which,  in  a  systematic  account  of  this  class 
of  microorganisms,  demand  brief  attention  at  least.  These  are  in- 
cluded in  Baumgarten's  second  group,  which  includes  the  pleomor- 
phous  bacteria. 

SPIRULINA  (Hueppe). — The  vegetative  cells  are  sometimes  rod- 
shaped  and  sometimes  spiral ;  in  suitable  media  they  may  grow  out 


CLASSIFICATION.  19 

into  long,  straight,  wavy,  or  spiral  filaments.  These  filaments  may 
break  up  into  cocci -like  reproductive  elements — "  arthrospores. " 

LEPTOTRiCHEyE  (Zopf). — The  vegetative  cells  present  rod-shaped 
and  spiral  forms,  and  grow  out  into  straight,  wavy,  or  spiral  fila- 
ments ;  these  may  show  a  difference  between  the  two  extremities, 
of  base  and  apex.  Cocci-like  reproductive  bodies  are  formed  by  seg- 
mentation of  the  rod-shaped  elements  in  these  filaments.  In  some 
of  the  species  the  segments  are  enclosed  in  a  common  sheath.  Sub- 
genera:  LEPTOTHRIX,  BEGGIATOA,  CRENOTHRIX,  PHRAGMIDIO- 
THRIX  (for  generic  characters  see  page  12). 

CLADOTRICHE^E  (Zopf). — The  vegetative  cells  are  rod-shaped 
or  spiral,  and  grow  out  into  straight  or  spiral  filaments,  which  may 
present  pseudo-ramifications.  A  single  genus,  CLADOTHRIX  (see 
page  12). 


III. 

MORPHOLOGY. 

IN  the  present  chapter  we  shall  give  a  general  account  of  the 
morphology,  modes  of  grouping,  and  dimensions  of  the  bacteria. 

The  standard  of  measurement  used  by  bacteriologists  is  the  micro- 
millimetre,  or  the  one-thousandth  part  of  a  millimetre.  This  is 
represented  by  the  Greek  letter  yw.  One  >M  (micromillimetre)  is  equal 
to  about  one-twenty-five-thousandth  of  an  English  inch. 

The  spherical  bacteria,  or  micrococci,  differ  greatly  in  size,  and 
also  in  the  mode  of  grouping  when,  as  a  result  of  binary  division, 
they  remain  associated  one  with  another.  The  smallest  may  mea- 
sure no  more  than  0.1  >w,  while  some  of  the  larger  species  are  from 
one  to  two  yw  in  diameter.  The  enormous  number  of  these  minute 
organisms  which  may  be  contained  in  a  small  drop  of  a  pure  culture 
may  be  easily  estimated  in  a  rough  way.  Compare  a  single  micro- 
coccus,  for  example,  with  a  sphere  having  a  diameter  of  one-twenty- 
fifth  of  an  inch.  If  our  micrococcus  is  one  of  the  larger  sort,  having 
a  diameter  of  one  >w,  it  would  take  a  chain  of  one  thousand  to  reach 
across  the  diameter  of  such  a  sphere,  and  its  mass,  as  compared 
to  the  larger  sphere,  would  be  as  1  to  523,600,000. 

The  number  of  cocci  in  a  milligramme  of  a  pure  culture  of  Staphy- 
lococcus  pyogenes  aureus  has  been  estimated  by  Bujwid,  by  count- 
ing, at  8,000,000,000. 

Not  only  do  different  species  differ  in  dimensions,  but  consider- 
able differences  in  size  may  be  recognized  in  the  individual  cocci  in  a 
pure  culture  of  the  same  species.  On  the  other  hand,  there  are 
numerous  species  which  so  closely  resemble  each  other  in  size  and 
mode  of  association  that  they  cannot  be  differentiated  by  a  micro- 
scopic examination  alone,  and  we  must  depend'upon  other  characters, 
such  as  color,  growth  in  various  culture  media,  pathogenic  power, 
etc. ,  to  decide  the  question  of  identity  or  non-identity. 

When  in  active  growth  the  micrococci  necessarily  depart  from  a 
typical  spherical  form  just  before  dividing,  and  under  these  circum- 
stances may  be  of  a  short  or  long  oval.  When  division  has  taken 
place,  if  the  two  members  of  a  pair  remain  associated  they  are  often 
more  or  less  flattened  at  the  point  of  contact  (Fig.  1,  a). 


MORPHOLOGY.  21 

The  staphylococci  are  characterized  by  the  fact  that,  for  the 
most  part,  the  individual  cocci  in  a  culture  are  solitary  (Fig.  1,  6). 
But,  inasmuch  as  multiplication  occurs  by  binary  division,  we  also 
have  pairs  and  occasionally  a  group  of  four — probably  from  the 
accidental  apposition  of  two  pairs  (Fig.  1,  c).  When  in  a  culture 
the  cocci  are  for  the  most  part  associated  in  pairs  (Fig.  1,  d),  we 
speak  of  the  organism  as  a  diplococcus.  Frequently  after  staining 

00       OQO 

00    o 

a        8° 
b 

&83      8Soo 

C  ficbQ} 


FIG.  1. 


and  mounting  a  preparation  we  find  that  the  cocci  are  associated  in 
irregular  groups,  although  we  may  have  endeavored  to  distribute 
them  in  a  drop  of  distilled  water.  This  results  from  the  fact  that 
they  are  surrounded  by  a  glutinous  material  which  causes  them  to 


FIG.  2. 


FIG.  3. 


FIG.  4. 


adhere  to  each  other  (Fig.  1,  e).  A  mass  of  cocci  held  together 
in  this  way  by  a  transparent,  ;glutinous,  intercellular  substance  is 
spoken  of  as  a  zoogloea  (Fig.  2).  In  the  genus  Ascococcus  the  in- 
tercellular substance  is  quite  firm  and  the  zooglcea  are  in  the  form 
of  spherical  or  irregularly  lobulated  masses  surrounded  by  a  resist- 
ant envelope  of  jelly-like  material  (Fig.  3). 

When,  as  a  result  of  division  in  one  direction  only,    the  cocci 


22  MORPHOLOGY. 

remain  united  in  chains  (Fig.  4,  a),  they  are  described  as  streptococci, 
and  are  sometimes  spoken  of  as  in  chaplets  or  in  torula  chains.  In 
such  chains  we  frequently  find  the  evidence  of  recent  division  of  the 
cocci,  as  shown  by  the  grouping  of  the  elements  of  the  chain  into 
pairs  (Fig.  4,  b). 

When  division  occurs  habitually  in  two  directions,  groups  of  four 
result,  which  are  spoken  of  as  tetrads.  This  is  the  distinguishing 
character  of  the  genus  Merismopedia.  In  these  groups  of  four  the 
individual  cocci  are  often  flattened  at  the  points  of  contact,  as  in 
Fig.  5,  b.  We  also  find  pairs  and  groups  of  three  in  pure  cultures  of 
species  belonging  to  this  genus,  as  shown  in  Fig.  5,  c.  In  these, 
transverse  division  has  not  yet  occurred  in  one  or  in  both  elements  of 
a  pair.  This  association  of  micrococci  in  tetrads  seems  to  be  main- 
tained, in  some  species  at  least,  by  the  fact  that  each  group  of  four  is 
enclosed  in  a  jelly-like  capsule.  The  extent  of  this  capsule  differs  in 
the  same  species  under  different  circumstances;  as  a  rule,  it  is  most 
apparent  when  a  culture  has  been  made  in  a  liquid  medium.  Some  of 


88 


00  S 

e 

Fia.  5. 


the  diplococci  have  a  similar  capsule.  The  jelly-like  substance  does 
not  stain  well  with  the  aniline  colors  and  is  seen  as  a  transparent 
halo  around  the  stained  cocci.  Some  authors  (Frankel  and  Pfeiffer) 
believe  that  this  capsule  is  formed  by  the  swelling  up  of  the  cell 
membrane  as  a  result  of  the  imbibition  of  water. 

When  division  occurs  in  three  directions  packets  of  eight  or 
more  elements  are  formed.  This  mode  of  association  characterizes 
the  genus  Sarcina.  The  "packet  form  "is  best  seen  in  an  un- 
stained preparation  from  a  fresh  culture,  in  which  a  little  material 
suspended  in  water  is  examined  under  a  comparatively  low-power 
objective — one-sixth  (Fig.  G). 

Among  the  bacilli  there  is  room  for  a  wider  range  of  morphologi- 
cal characters.  They  differ  not  only  in  dimensions  and  in  modes  of 
grouping,  but  in  form.  The  relation  of  the  transverse  to  the  longi- 
tudinal diameters  affords  a  great  variety  of  forms,  varying  from  a 
short  oval  element  to  a  slender  rod  or  elongated  filament.  But  it 
must  be  remembered  that  we  may  have  short  rods  and  long  filaments 
in  a  pure  culture  of  the  same  bacillus — the  typhoid  bacillus,  for 


MORPHOLOGY.  23 

example.  There  are  also  considerable  differences  in  the  transverse 
diameter  of  bacilli  belonging  to  the  same  species  when  cultivated  in 
different  media,  or  even  in  the  same  medium,  although,  as  a  rule, 
the  transverse  diameter  is  tolerably  uniform  in  pure  cultures. 

Again,  the  form  of  the  extremities  of  the  rods  is  to  be  observed 
(Fig.  7).  This  may  be  square,  or  the  corners  may  be  slightly 
rounded,  or  the  extremities  may  be  quite  round  or  lance-oval,  or 
the  outlines  of  the  rod  may  be  spindle-shaped  from  the  formation  of 


CO  CTXZD  CO   CO 


a  large  central  spore — "clostridium" — or  one  end  may  be  dilated 
from  the  formation  of  a  large  terminal  spore. 

In  old  cultures  we  frequently  find  irregular  forms  due  to  swellings 
and  constrictions,  which  probably  occur  in  bacilli  which  have  but 
little  vitality  or  are  already  dead.  'These  are  spoken  of  as  involution 
forms  (Fig.  8). 

The  bacilli  multiply  by  binary  division  in  a  direction  transverse 
to  the  longitudinal  axis,  and,  as  a  result  of  such  binary  division,  long 


FIG.  9. 

chains  in  which  the  elements  remain  associated  may  be  formed 
(Fig.  0)  ;  or  the  rods  may  be  for  the  most  part  solitary  or  united  in 
pairs.  Like  the  micrococci,  the  bacilli  are  sometimes  surrounded  by 
a  gelatinous  envelope  or  capsule.  They  may  also  be  united  by  a 
glutinous  material  into  zooglcea  masses. 

Bacilli  which  under  certain  conditions  are  seen  as  short  rods 
may,  under  other  circumstances,  grow  out  into  long  filaments,  and 
these  may  be  associated  in  bundles  or  in  tangled  masses. 

The  spirilla  differ  from  the  bacilli  in  the  form  of  the  rods  and  fila- 


MORPHOLOGY. 


merits,  which  are  curved  or  spiral.  The  shorter  elements  in  a  pure 
culture  may  be  simply  curved,  as  in  a,  Fig.  10,  while  the  spiral  form 
becomes  apparent  in  those  which  are  longer,  and  we  may  have  one 
or  several  turns  of  the  spiral  (Fig.  10,  b).  The  spiral  form  may  be 
but  slightly  marked  (Fig.  10,  c),  or  the  turns  may  be  close  and  deep 
as  in  a  corkscrew  (Fig.  10,  d).  Again,  the  curved  filaments  may  be 
short  and  rigid,  or  long  and  flexible  (Fig.  10,  e). 

In  the  genus  Cladothrix,  which  is  placed  by  botanists  among 
the  bacteria,  the  filaments  appear  to  branch  ;  but  this  branching  is 
only  apparent,  and  there  is  no  true  dichotomous  branching  in  this 
class  of  microorganisms.  The  false  branching  of  Cladothrix 
dichotoma,  Cohn,  is  shown  in  Fig.  11.  The  fact  that  some  of  the 
larger  species  of  bacilli  and  spirilla  are  provided  with  slender,  whip- 
like  appendages  called  flagella  has  been  known  for  many  years,  and 
it  has  for  some  time  been  suspected  that  all  of  the  motile  organisms 


FIG.  10. 


FIG.  11. 


FIG.  12. 


of  this  class  are  provided  with  similar  appendages  and  that  these  are 
organs  of  locomotion.  Recently,  by  improvements  in  methods  of 
staining,  Loffler  has  demonstrated  the  presence  of  flagella  in  many 
species  in  which  they  had  heretofore  escaped  observation.  They  are 
sometimes  single,  at  the  ends  of  the  rods  (Fig.  12,  a);  or  there  may 
be  several  at  the  extremity  of  a  single  rod  (Fig.  12,  6);  again,  they 
are  seen  in  considerable  numbers  around  the  periphery  of  the  rod 
(Fig.  12,  c). 

The  bacilli  and  spirilla  sometimes  contain  in  the  interior  of  the 
cells  granules  of  different  kinds.  These  may  appear  like  little  oil 
drops  or  they  may  be  more  opaque.  In  the  genus  Beggiatoa  grains 
of  sulphur  are  found  in  the  interior  of  the  cells.  Again,  we  may 
find  vacuoles  in  the  protoplasm  ;  or,  in  stained  preparations,  deeply 
stained  granules,  which  are  not  spores,  may  be  seen  at  the  extremi- 
ties of  the  rods — end-staining.  The  morphological  characters  de- 
pending upon  the  formation  of  endogenous  spores  will  be  referred  to 
hereafter. 


IV. 

STAINING  METHODS. 

THE  rapid  development  of  our  knowledge  with  reference  to  the 
minute  microorganisms  under  consideration  depends  very  largely 
upon  the  discovery  that  they  may  be  stained  by  various  dyes,  and  es- 
pecially by  the  aniline  colors.  Weigert  (1876)  was  the  first  to  employ 
these  colors  in  studying  the  bacteria,  and  Koch  at  once  recognized 
the  value  of  the  method  and  made  use  of  it  in  his  researches. 

The  basic  aniline  colors  are  those  employed,  and  among  these  the 
most  useful  are  fuchsin,  methylene  blue,  gentian  violet,  Bismarck 
brown,  and  vesuvin. 

Staining  upon  the  Cover  Crlass  or  Slide. — By  a  "  cover-glass 
preparation "  we  mean  that  material  supposed  to  contain  bacteria 
has  been  spread  out  upon  a  thin  glass  cover,  dried,  and  stained  for 
microscopical  examination.  A  small  drop  of  a  liquid  culture  may,  for 


FIG  13. 

example,  be  spread  upon  a  perfectly  clean  cover  glass  by  means  of  a 
platinum  wire  held  in  a  glass  handle  (Fig.  13).  Or  we  may  place  a 
drop  of  water  in  the  centre  of  the  thin  glass  cover,  and  by  means  of 
the  same  instrument  take  a  little  material  from  a  culture  made  upon 
the  surface  of  a  solid  medium  and  distribute  it  through  the  drop. 
In  this  case  we  must  be  careful  to  take  very  little  of  the  material,  as 
the  smallest  quantity  will  contain  an  immense  number  of  bacteria, 
and  for  a  satisfactory  view  of  the  individual  cells  it  is  necessary  that 
they  be  well  separated  from  each  other,  in  some  parts  of  the  prepa- 
ration at  least,  and  not  massed  together. 

Where  the  object  is  to  make  a  cabinet  preparation  for  permanent 
preservation,  special  care  should  be  taken  to  distribute  the  bacteria 
unif ormly  through  the  drop  of  water.  The  next  step  consists  in  eva- 
porating the  liquid  so  that  the  bacteria  may  remain  attached  to  the 
surface  of  the  glass  cover.  This  may  be  done  by  simple  exposure  to 
the  air  or  by  the  application  of  gentle  heat.  When  the  bacteria  are 


20  STAINING   METHODS. 

suspended  in  an  albuminous  medium  it  will  be  necessary,  after  the 
film  is  dry,  to  heat  the  preparation  sufficiently  to  coagulate  the  albu- 
men, in  order  that  it  may  not  ba  washed  off  in  the  subsequent  stain- 
ing process.  This  is  best  done,  in  accordance  with  Koch's  directions 
for  the  preparation  of  tuberculous  sputum,  by  passing  the  cover 
glass,  held  in  slender  forceps,  rather  quickly  through  the  flame  of  an 
alcohol  lamp  three  times  in  succession.  In  this  operation  it  must 
be  remembered  that  too  much  heat  will  destroy  the  preparation, 
while  too  little  will  fail  to  accomplish  the  object  in  view — coagu- 
lation of  the  albumen.  In  passing  the  cover  glass  through  the 
flame  the  smeared  side  is  to  be  held  upward.  The  time  required 
will  be  about  three  seconds  for  passing  it  three  times  as  directed  ;. 
but  this  will  vary  according  to  the  intensity  of  the  flame,  and  some 
little  experience  is  neoessary  in  order  to  .obtain  the  best  results. 

The  operation  of  "  fixing,"  or  coagulating  the  albumen,  may  also 
be  effected  by  exposure  in  a  dry-air  oven,  heated  to  120°  to  130°  C., 
for  a  few  minutes  (two  to  ten  minutes),  as  directed  by  Ehrlich. 

Bacteria  simply  suspended  in  distilled  water  adhere  very  well  to 
the  cover  glass  when  treated  as  directed,  but  if  they  have  been  taken 
from  a  liquefied  gelatin  culture  the  film  is  very  apt  to  be  washed 
away  during  the  staining  process.  This  is  best  avoided  by  taking  as 
little  as  possible  of  the  gelatin  medium  and  suspending  the  bacteria 
to  be  examined  in  a  drop  of  water,  which  dilutes  the  gelatin  and 
washes  it  away  from  the  surface  of  the  cells. 

Smear  Preparations. — In  various  infectious  diseases  bacteria  are 
found  in  the  blood  and  tissues  of  the  body,  and  their  presence  may 
be  demonstrated  by  making  what  is  called  a  smear  preparation.  A 
little  drop  of  blood  may  be  spread  upon  the  thin  glass  cover,  or  it 
may  be  brought  in  contact  with  the  freshly  cut  surface  of  one  of  the 
vascular  organs,  as  the  liver  or  spleen.  It  is  especially  desirable  that 
the  material  used  for  such  a  preparation  be  small  in  amount  and  dis- 
tributed evenly  in  a  very  thin  layer.  In  Germany  it  is  the  custom, 
in  making  smear  preparations,  to  press  the  material  between  two  glass 
covers,  which  are  then  separated  by  sliding  them  apart,  thus  leaving 
a  thin  layer  upon  each.  This  answers  very  well,  but  the  writer  pre- 
fers to  spread  the  material  by  drawing  across  the  face  of  the  cover 
glass  the  end  of  a  well-ground  and  polished  glass  slide.  This  method 
is  especially  useful  for  spreading  blood  in  a  uniform  layer,  in  which 
the  corpuscles  are  evenly  distributed  and  retain  their  normal  form. 
A  very  small  drop  of  blood  is  placed  near  one  edge  of  the  cover  glass, 
which  is  placed  upon  a  smooth  surface  ;  the  glass  slide  is  held  at  a 
very  acute  angle  and  is  gently  drawn  across  the  cover  glass,  without 
any  pressure. 

Most  bacteriologists  make  their  preparations  upon  the  cover  glass, 


STAINING   METHODS.  27 

as  above  described,  but  the  writer  has  for  a  number  of  years  made 
his  mounts  of  bacteria  upon  the  glass  slide,  and  believes  that  this 
method  has  some  advantages  for  every-day  work.  The  thin  glass 
covers  required  when  a  preparation  is  to  be  examined  with  an  im- 
mersion objective  of  high  power,  are  easily  broken  and  often  dropped 
from  the  fingers  or  forceps.  When  the  material  to  be  examined  is 
spread  and  dried  directly  upon  the  glass  slide,  the  operation  is  at- 
tended with  less  difficulty  and  fewer  accidents  and  the  results  are 
quite  as  good.  In  this  case  the  slide  is  held  in  the  fingers  during  the 
various  steps  in  the  operation  of  distributing,  drying,  and  staining, 
while  the  thin  glass  cover  must  be  held  in  delicate  forceps. 

Contact  Preparations. — When  a  dry  and  clean  cover  glass  is 
brought  in  contact  with  a  colony  or  surface  culture  we  may  often 
obtain  a  very  pretty  preparation,  showing  the  bacteria  in  a  single 
layer,  and  preserving  the  arrangement,  as  regards  growth,  which 
characterizes  the  species.  Similar  preparations  may  sometimes  be 
obtained  from  the  surface  of  liquid  cultures,  when  the  bacteria  grow 
upon  the  surface  as  a  thin  film.  The  cover  glass  is  to  be  gently 
brought  into  contact  with  this  surface  growth,  which  adheres  to  it 
and  is  dried  and  stained  by  the  usual  methods. 

Staining  of  the  dried  film  is  quickly  effected  by  using  an  aqueous 
solution  of  one  of  the  aniline  colors  above  mentioned.  For  general 
use  the  writer  prefers  a  solution  of  f  uchsin,  on  account  of  the  prompt- 
ness of  its  staining  action,  and  because,  in  preparations  for  permanent 
preservation,  it  is  not  as  likely  to  fade  as  methylene  blue  or  gentian 
violet.  It  is  also  a  better  color  than  blue  or  violet  in  case  a  photo- 
micrograph is  to  be  made  from  the  preparation. 

It  is  best  to  keep  on  hand  saturated  alcoholic  solutions  of  the 
staining  agents  named,  and  to  make  an  aqueous  solution  whenever 
required  by  the  addition  of  a  few  drops  to  a  little  "water  in  a  watch 
glass  or  test  tube  ;  for  the  aqueous  solutions  do  not  keep  well  on  ac- 
count of  the  precipitation  of  the  dye  as  a  fine  powder,  which  ren- 
ders the  solution  opaque.  The  addition  of  ten  per  cent  of  alcohol 
to  the  aqueous  solution  will,  however,  prevent  this  precipitation ; 
but,  as  a  rule,  freshly  prepared  solutions  are  the  best.  These  should 
be  filtered  before  use.  We  may  place  a  few  drops  of  the  filtered 
solution  upon  the  dried  film  on  the  slide  or  cover  glass,  or  the  thin 
cover  may  be  floated  upon  a  little  of  the  solution  in  a  watch  glass. 
In  some  cases  it  is  best  to  use  heat  to  expedite  the  staining,  and  this 
may  be  done  by  holding  the  slide  or  the  watch  glass  over  the  flame 
of  an  alcohol  lamp  until  steam  commences  to  be  given  off.  If  the 
heating  is  carried  too  far  the  preparation  is  likely  to  be  spoiled  by 
the  precipitation  of  the  staining  agent.  As  a  rule,  heating  will  not 
be  necessary,  and  when  an  aqueous  solution  of  fuchsin  (one  part  to 


28  STAINING   METHODS. 

one  hundred  of  water)  is  used  most  bacteria  are  stained  within  a 
few  seconds  to  a  minute.  At  the  end  of  this  time  the  staining  solu- 
tion is  to  be  washed  away  by  means  of  a  gentle  stream  of  water,  or 
by  moving  the  cover  glass  about  in  a  vessel  containing  distilled 
water. 

Decolorization. — It  often  happens  that  the  albuminous  material 
associated  with  the  bacteria  which  we  propose  to  examine  is  stained 
so  deeply  as  to  obscure  the  view  of  these  ;  and,  generally,  we  will 
obtain  more  satisfactory  preparations  by  the  use  of  a  decolorizing 
agent,  by  which  the  background  is  cleared  up  and  the  outlines  of  the 
cells  more  clearly  defined.  The  agents  chiefly  used  for  this  purpose 
are  alcohol,  diluted  acids,  and  solution  of  iodine  with  potassium 
iodide  (Gram's  solution). 

Koch  recommends  a  solution  containing  sixty  parts  of  alcohol  to 
forty  parts  of  water.  The  cover  glass  is  to  be  quickly  passed 
through  this  solution  two  or  three  times.  Some  bacteriologists  pre- 
fer to  use  absolute  alcohol. 

Or  we  may  use  dilute  acetic  acid  (one-half  to  one  per  cent)  or 
very  dilute  hydrochloric  acid  (ten  drops  to  half  a  litre  of  water). 

For  decolorizing  preparations  containing  the  tubercle  bacillus 
strong  solutions  of  the  mineral  acids  are  employed  (one  part  of  ni- 
tric or  of  sulphuric  acid  to  three  parts  of  water). 

Gram's  solution  contains  one  part  of  iodine  and  two  parts  of 
potassic  iodide  in  three  hundred  parts  of  water.  Special  directions 
will  be  given  for  the  use  of  these  agents  when  we  give  an  account 
of  the  staining  methods  most  useful  for  the  various  pathogenic 
organisms. 

Double  Staining. — After  decolorizing  the  background  of  albu- 
minous material  we  may  again  stain  this  with  a  contrast  stain, 
such  as  eosin  or  vesuvin.  In  mounts  made  from  pure  cultures, 
either  liquid  or  solid,  a  single  stain,  for  the  bacteria  only,  is  all  that 
we  require,  and  our  aim  is  to  have  the  background  as  free  as  possi- 
ble from  any  material  which  would  obscure  the  view. 

After  staining,  decolorizing,  and  washing  the  preparation  the 
cover  glass  or  slide  is  again  dried  by  exposure  to  the  air  or  gentle 
heat,  and  is  then  ready  for  the  permanent  mounting  in  Canada  bal- 
sam. If  the  bacteria  have  been  stained  upon  the  slide,  a  small  drop 
of  balsam  dissolved  in  xylol  is  placed  in  the  middle  of  the  prepara- 
tion and  a  clean,  thin  glass  cover  applied. 

If  it  is  the  intention  to  make  the  microscopical  examination  with 
an  immersion  objective  of  high  power,  or  to  make  photomicro- 
graphs from  it,  only  the  thinnest  glass  covers  should  be  used — one- 
two-hundredths  of  an  inch  or  less. 

If  the  preparation  is  not  intended  for  permanent  preservation, 


STAINING   METHODS.  29 

the  examination  may  be  made  without  drying  the  surface  upon 
which  the  stained  bacteria  are  spread,  the  water  taking  the  place  of 
balsam  in  a  permanent  mount ;  or  we  may  dry  the  film  and  use  a 
drop  of  cedar  oil  between  the  slide  and  cover. 

While  simple  aqueous  solutions  of  the  aniline  colors,  when 
freshly  prepared,  will  promptly  stain  most  bacteria,  certain  agents 
may  be  added  to  these  which  aid  in  the  preservation  of  the  solution, 
or  which  act  as  mordants,  and  are  useful  in  special  cases. 

We  shall  only  give  here  a  few  of  the  standard  solutions  which 
are  most  frequently  employed  by  experienced  bacteriologists  : 

1.  Aniline-Gentian-Violet  (Ehrlich). 

Saturated  alcoholic  solution  of  gentian  violet,          .  .  5  cc. 

Aniline  water,       .  .  .  .          .  .  .  100  cc. 

2.  Aniline-Methyl-Violet  ( Ehrlich- Weigert). 

Saturated  alcoholic  solution  of  methyl  violet,          .          .          11  cc. 
Absolute  alcohol,  ......  lf)  cc. 

Aniline  water,  .......          100  cc. 

Aniline  water  for  the  above  solutions  is  prepared  by  shaking  in  a 
test  tube  one  part  of  aniline  oil  with  twenty  parts  of  distilled  water, 
and,  after  allowing  it  to  stand  for  a  short  time,  filtering  the  saturated 
aqueous  solution  through  a  moistened  filter.  If  the  solution  is  not 
perfectly  transparent  it  should  be  filtered  a  second  time. 

3.   C  arbol-Fuchsin  (Ziehl's  solution). 

Fuchsin,          .  .          .          .          .  ...  .          .      1  cc. 

Alcohol,  . 10  cc. 

Dissolve  and  add  100  cc.  of  a  five-per-cent  solution  of  carbolic  acid. 

4.  Alkaline  Blue  Solution  (Loffler's  solution). 

Saturated  solution  of  methylene  blue,         ...  30  cc. 

Solution  of  caustic  potash  of  1:10,000,  .  100  cc. 

These  solutions  keep  better  than  the  simple  aqueous  solutions, 
but  after  having  been  kept  for  a  time  they  are  likely  to  lose  their 
staining  power  as  a  result  of  the  precipitation  of  the  aniline  color. 

The  following  special  methods  of  staining  cover-glass  prepara- 
tions will  be  found  useful  in  certain  cases: 

Gram's  Method.— The  dried  film  upon  a  slide  or  cover  glass  is 
stained,  with  an  aqueous  solution  of  methyl  violet  or  with  aniline- 
gentian-violet  solution  (No.  1);  it  is  then  placed  in  the  iodine  solution 
for  a  minute  or  two  (iodine  one  part,  potassio  iodide  two  parts,  water 


30  STAINING   METHODS. 

three  hundred  parts) ;  then  washed  in  alcohol,  dried,  and,  if  for  per- 
manent preservation,  mounted  in  balsam. 

METHODS  OF  STAINING  THE  TUBERCLE  BACILLUS. — Numerous 
methods  of  staining  the  tubercle  bacillus  in  sputum  dried  upon  a 
cover  glass  have  been  proposed,  but  we  shall  only  give  here  two  or 
three  of  the  most  approved  methods,  either  one  of  which  may  be 
relied  upon  for  satisfactory  results  if  carefully  followed. 

1.  The  Ehrlich-Weigert  Method. — Place  in  a  watch  glass  a  little 
of  the  aniline-methyl-violet  solution  (No.   2);  float  upon  the  surface 
of  this  the  cover  glass  with  the  dried  film  downward  ;  heat  over  a 
small  flame  until  it  begins  to  steam,  then  allow  it  to  stand  for  from 
two  to  five  minutes  ;  decolorize  in  a  tray  containing  one  part  of  nitric 
acid  to  three  parts  of  water — the  cover  glass,  held  in  forceps,  is  gently 
moved  about  in  the  decolorizing  solution  for  a  few  seconds.     It  is 
then  washed  off  in  sixty-per-cent  alcohol  to  remove  the  remaining 
blue  color — this  usually  takes  but  a  second  or  two — and  then  in  water. 
For  a  contrast  stain  a  saturated  aqueous  solution  of  vesuvin  may  bs 
used,  a  few  drops  being  left  upon  the  cover  glass  for  five  minutes. 
The  stained   preparation  is  then  washed,  dried,    and  mounted  in 
balsam. 

2.  The  Ziehl-Neelson  Method. — Float  the  cover  glass  upon  the 
carbol-fuchsiii  solution  (No.  3) ;  heat  gently  until  steam  commences 
to  rise — from  three  to  five  minutes'  time  will  usually  be  sufficient ; 
wash  off  in  water,  and  decolorize  in  nitric  or  sulphuric  acid,  twenty- 
five-per-cent  solution,  then  in  sixty-per-cent  alcohol  for  a  very  short 
time  to  remove  remaining  color  from  albuminous  background;  wash 
well  in  water  and  mount  in  Canada  balsam. 

3.  Friedlander's  Method. — Spread  and  dry  the  sputum  upon 
the  slide ;  fix  by  passing  the  slide  three  times  through  the  flame  of 
an  alcohol  lamp  or  Bunsen  burner  ;  place  upon  the  dried  film  three  or 
four  drops  of  carbol-fuchsin  (No.  3);  heat  gently  over  a  flame  until 
steam  is  given  off  ;  wash  in  a  dish  of  distilled  water  ;  drain  off  excess 
of  water,  and  add  a  few  drops  of  the  following  decolorizing  solution : 

Acid,  nitric,  pure,          .  .  .  ...  .          5  cc. 

Alcohol  (eighty  per  cent),  .  .  .to  100  cc. 

— usually  the  preparation  will  be  decolorized  in  about  half  a  minute  ; 
wash  in  water  ;  add  a  few  drops  of  an  aqueous  solution  of  methylene 
blue  as  a  contrast  stain  ;  allow  the  stain  to  act  for  about  five  minutes, 
without  heating ;  wash  again  in  water,  dry,  and  mount  in  balsam, 
or  for  a  temporary  mount  use  a  drop  of  cedar  oil. 

4.  Gabbett's  Method. — This  is  a  slight  modification  only  of  a 
very  useful  method  recommended  by  B.  Frankel  in  1884.     The  con- 
trast stain  is  added  to  the  decolorizing  solution.     After  staining  with 


STAINING   METHODS.  31 

carbol-f  uchsin  solution  (No.  3)  the  cover  glass  is  placed  for  one  or 
two  minutes  in  a  solution  containing: 

Sulphuric  acid  (twenty-five-per-cent  solution),         .  .       100  cc. 

Methylene  blue,      ......  2  cc. 

Wash,  dry,  and  mount  in  cedar  oil  or  balsam. 

METHODS  OF  STAINING  SPORES. — When  preparations  containing 
the  spores  of  bacilli  are  stained  by  any  of  the  methods  above  given, 
these  remain  unstained  and  appear  as  highly  refractive  bodies  in  the 
interior  of  the  rods  or  filaments  in  which  they  have  been  formed,  or 
scattered  about  in  the  field  if  they  have  been  set  free.  Owing  to 
the  contrast  with  the  stained  protoplasm  of  the  rod  or  spore-bearing 
filament,  they  are  especially  well  seen  in  recent  cultures ;  while  in 
older  cultures  the  bacilli  often  do  not  stain  well,  or  are  entirely  dis- 
integrated and  spores  only  are  to  be  seen.  The  discovery  was  made 
at  about  the  same  time  by  Buchner  (1884)  and  by  Hueppe  that 
spores  may  be  stained  if  they  are  first  exposed  to  an  elevated  tem- 
perature for  some  time.  This  may  be  accomplished  by  placing  the 
slide  or  cover  glass,  upon  which  the  spore-containing  culture  has 
been  dried,  in  a  hot-air  oven  at  a  temperature  of  120°  C.  for  an 
hour;  or  a  higher  temperature  (180°  C.)  may  be  employed  for  a 
shorter  time  (fifteen  minutes) ;  or  the  cover  glass  may  be  passed 
through  the  flame  of  an  alcohol  lamp  or  Bunsen  burner  eight  or  ten 
times,  instead  of  three  times  as  is  customary  when  the  object  in 
view  is  simply  to  coagulate  the  albumen  and  fix  the  film  upon  the 
cover  glass.  After  such  treatment  the  spores  may  be  stained  with 
an  aqueous  solution  of  one  of  the  basic  aniline  colors — fuchsin, 
methyl  violet,  etc. — but  the  bacilli  no  longer  take  the  stain  so  well. 

To  obtain  satisfactory  double-stained  preparations,  showing 
both  spores  and  bacilli,  a  different  method  is  employed. 

The  film  upon  the  cover  glass  is  passed  through  the  flame  three 
times,  as  heretofore  directed  ;  it  is  then  floated  upon  aniline-f uchsin 
solution  in  a  watch  glass,  and  this  is  heated  to  near  the  boiling  point 
for  an  hour — Neisser's  method.  The  aniline-f  uchsin  solution  is 
prepared  by  shaking  an  excess  of  aniline  oil  in  a  test  tube  with  dis- 
tilled water,  filtering  the  saturated  solution  into  a  watch  glass,  and 
then  adding  a  few  drops  of  a  saturated  alcoholic  solution  of  fuchsin. 
After  this  prolonged  action  of  the  hot  staining  fluid  the  spores  of 
some  bacilli  are  deeply  stained,  while  others  do  not  take  the  stain  so 
well.  The  cover  glass  is  next  washed  in  water  and  then  placed  in 
a  decolorizing  solution  containing  twenty-five  parts  of  hydrochloric 
acid  to  seventy-five  parts  of  alcohol.  This  removes  the  stain  from 
the  bacilli,  but,  if  not  allowed  to  act  too  long,  leaves  the  spores  still 
stained.  The  preparation  is  next  stained  in  a  saturated  aqueous 


32  STAINING   METHODS. 

solution  of  methylene  blue  ;  and  if  the  operation  has  been  successfully 
carried  out  the  spores  will  be  stained  red  and  the  protoplasm  of  the 
bacilli  in  which  they  are  present  will  be  blue. 

Moller  has  recently  (1891)  published  the  following  new  method 
of  staining  spores : 

The  cover-glass  preparation,  dried  in  the  air,  is  passed  three  times 
through  a  flame  or  placed  for  two  minutes  in  absolute  alcohol ;  it  is 
then  placed  in  chloroform  for  two  minutes  and  washed  in  water  ;  it 
is  now  immersed  in  a  five-per-cent  solution  of  chromic  acid  for  from 
half  a  minute  to  two  minutes  and  again  thoroughly  washed  in 
water ;  next  a  solution  of  carbol-fuchsin  is  poured  upon  it  and  it 
is  heated  over  a  flame  until  it  commences  to  boil,  for  sixty  seconds  ; 
the  carbol-fuchsin  solution  is  then  poured  off  and  the  cover  glass  is 
immersed  in  a  five-per-cent  solution  of  sulphuric  acid  until  the 
film  is  decolorized,  after  which  it  is  again  thoroughly  washed  in 
water.  It  is  then  placed  for  thirty  seconds  in  an  aqueous  solution  of 
methylene  blue  or  of  malachite  green,  and  again  washed  in  water, 
after  which  the  preparation  should  be  dried  and  mounted  in  balsam. 
As  a  result  of  this  procedure  the  spores  are  stained  dark  red  and  the 
protoplasm  of  the  bacilli  blue  or  green. 

METHODS  OF  STAINING  FLAGELLA. — Koch  first  succeeded  in  de- 
monstrating the  flagella  of  certain  bacilli  and  spirilla  by  staining  them 
with  an  aqueous  solution  of  hsematoxylon,  and  dilute  chromic  acid 
as  a  mordant.  Recently  Loffler  (1889)  has  succeeded  in  demonstrat- 
ing, by  an  improved  staining  method,  the  presence  of  flagella  in  a  con- 
siderable number  of  species  in  which  they  had  not  previously  been  seen, 
although  generally  suspected  to  be  present.  His  method  is  as  follows : 

Loffler 's  Method. — The  following  solution  is  used  as  a  mordant : 

No.  1. 

Solution  of  tannin  of  twenty  per  cent,  .  .  .       10  cc. 

Saturated  (cold)  solution  of  ferrous  sulphate,       .  .  5  cc. 

Aqueous  or  alcoholic  solution  of  fuchsin,       .  .  1  cc. 

(Or  one  cubic  centimetre  alcoholic  solution  of  methyl  violet.) 

No.  2. 

A  one  per-eent  solution  of  caustic  soda. 

No.  3. 

A  solution  of  sulphuric  acid  of  such  strength  that  one  cubic  centi- 
metre is  exactly  neutralized  by  one  cubic  centimetre  of  the  soda 
solution. 

According  to  Loffler,  solution  No.  1  is  just  right  for  staining  the 
flagellum  of  Spirillum  concentricum,  but  for  certain  other  bacteria  it 
is  necessary  to  add  to  this  some  of  No.  2  or  of  No.  3.  Thus,  for  the 
cholera  spirillum  from  half  a  drop  to  a  drop  of  the  acid  solution  is 


STAINING   METHODS.  33 

added  to  sixteen  cubic  centimetres  of  No.  1.  For  the  bacillus  of 
typhoid  fever  one  cubic  centimetre  of  No.  2  is  added  to  sixteen  cubic 
centimetres  of  No.  1.  Bacillus  subtilis  requires  twenty-eight  to 
thirty  drops  of  No.  2  ;  the  bacillus  of  malignant  oedema  thirty-six  to 
thirty-seven  drops,  etc. 

By  carefully  conducted  experiments  Loffler  has  found  that  suc- 
cess in  staining  the  flagella  depends  upon  adding  just  the  right  quan- 
tity of  acid  or  alkali,  a  very  slight  variation  from  the  proper  quantity 
being  sufficient  to  give  an  imperfect  or  negative  result.  In  general, 
those  bacilli  which  produce  an  acid  reaction  in  a  neutral  culture 
medium  require  the  addition  of  the  alkaline  solution,  and  those 
which  cause  an  alkaline  reaction  require  the  addition  of  an  acid — 
acetic  or  sulphuric. 

Loffler  gives  the  following  detailed  account  of  his  method  : 

A  small  quantity  of  a  pure  culture  is  suspended  in  a  few  drops  of 
distilled  water.  Upon  perfectly  clean  glass  covers  small  drops  of 
water  are  distributed  by  means  of  a  platinum  wire  loop  ;  these  are 
sowed  with  bacilli  from  the  first  drop.  These  little  drops  are  spread 
out  upon  the  cover  with  a  platinum  wire  and  allowed  to  dry  in  the 
air,  after  which  they  are  passed  through  the  flame  in  the  usual  way 
to  fix  the  bacteria  to  the  cover  glass.  Great  care  must  be  taken  not 
to  heat  the  preparation  too  much,  as  this  prevents  the  flagella  from 
taking  the  stain.  Loffler  recommends  that  the  cover  glass  be  held 
between  the  thumb  and  forefinger  in  passing  it  through  the  flame, 
instead  of  in  forceps,  as  this  insures  it  from  being  overheated. 

The  mordant  (solution  No.  1)  is  now  placed  upon  the  cover  glass 
so  as  to  completely  cover  it  as  an  arched  drop.  The  cover  glass  is 
then  carefully  heated  over  a  flame  until  steam  commences  to  be  given 
off ;  too  much  heat  causes  a  precipitate  which  cannot  be  washed 
away.  The  mordant  is  left  upon  the  cover  glass  for  from  half  a 
minute  to  a  minute,  and  during  this  time  it  is  gently  moved  to  and 
fro.  The  cover  glass  is  then  washed  by  means  of  a  stream  of  dis- 
tilled water.  All  remnants  of  the  mordant  attached  to  the  margins 
of  the  cover  glass  should  then  be  washed  away  with  absolute  alco- 
hol. The  staining  solution  is  now  dropped  upon  the  surface  of  the 
glass  cover  so  as  to  completely  cover  it,  and  heat  is  applied  as  before 
for  about  a  minute  until  steam  commences  to  be  given  off.  The 
staining  solution  recommended  is  a  neutral,  saturated  aniline- 
water-fuchsin  solution. 

METHODS  OF  STAINING  BACTERIA  IN  TISSUES. — The  solutions  re- 
commended for  staining  cover-glass  preparations  are  also  used  in 
staining  bacteria  in  thin  sections  of  the  various  organs,  in  which 
they  are  found  in  certain  infectious  diseases ;  but,  in  general,  a 
longer  time  is  required  to  stain  sections,  and  it  is  best  not  to  hasten 
3 


34  STAINING   METHODS. 

the  process  by  the  use  of  heat.  To  obtain  good  thin  sections,  the 
material,  cut  in  small  cubes,  must  be  very  thoroughly  hardened  in 
absolute  alcohol.  The  piece  selected  for  cutting  may  be  attached  to 
a  cork  by  the  use  of  melted  glycerin  jelly,  which  is  hardened  by 
placing  the  cork  and  attached  piece  of  tissue  in  alcohol.  This  an- 
swers for  well-hardened  pieces  of  liver,  kidney, , etc.,  but  the  hollow 
viscera  and  tissues  of  loose  structure  will  require  embedding  in 
paraffin  or  celloidin.  Any  well-made  sledge  microtome  will  answer 
for  cutting  the  sections,  if  the  knife  is  properly  sharpened.  The  sec- 
tions should,  of  course,  be  cut  under  alcohol,  and  they  can  scarcely 
be  too  thin  when  the  object  is  to  ^demonstrate  the  presence  or  ab- 
sence of  bacteria.  Very  thin  sections  ma}T  be  cut  dry  by  embedding 
in  paraffin  having  a  melting  point  of  50°  C.  In  this  case  the  knife 
is  set  at  a  right  angle  to  the  material  to  be  cut,  and  the  sections 
are  spread  out  upon  and  attached  to  the  glass  slide  for  staining. 

One  of  the  most  useful  solutions  for  staining  tissues  is  Lofflers 
alkaline  solution  of  methylene  blue  (No.  4).  A  freshly-prepared  so- 
lution will  stain  sections  in  four  or  five  minutes.  Superfluous  color 
is  removed  by  immersing  the  sections  in  diluted  alcohol  or  in  a  one- 
half-per-cent  solution  of  acetic  acid  for  a  few  seconds.  The  sectiofis 
are  dehydrated  in  absolute  alcohol,  cleared  up  with  oil  of  cedar,  and 
mounted  in  a  drop  of  cedar  oil  'for  examination,  or.  in  balsam  if 
they  are  to  be  preserved. 

Gram's  method  may  be  used  as  directed  for  cover-glass  prepara- 
tions, the  sections  being  first  stained  in  aniline-gentian-violet  solu- 
tion (No.  1),  then  washed  in  water,  or  in  aniline  water  as  recently 
(1892)  recommended  by  Botkin,  then  decolorized  in  the  iodine  solu- 
tion (see  page  29).  The  sections  when  decolorized  are  again  washed 
in  water,  dehydrated  in  absolute  alcohol,  cleared  in  cedar  oil,  and 
mounted  in  balsam. 

Weigert's  Method, — This  is  a  modification  of  Gram's  method  in 
which  the  sections  are  dehydrated  by  the  use  of  aniline  oil.  The 
stained  section,  after  having  been  washed,  is  transferred  to  a  clean 
glass  slide,  the  excess  of  water  is  removed  by  the  use  of  filtering 
paper,  and  the  iodine  solution  is  placed  upon  it  in  sufficient  quantity 
to  cover  the  entire  section.  When  sufficiently  decolorized  this  is  re- 
moved in  the  same  way.  The  section  is  then  dehydrated  by  placing 
a  few  drops  of  aniline  oil  upon  it,  removing  this  with  filtering  paper, 
and  repeating  the  operation  once  or  twice.  The  aniline  oil  must 
then  be  completely  removed  by  the  use  of  xylol,  after  which  the  sec- 
tion is  mounted  in  balsam. 

Kiihne's  Method. — The  object  of  this  method  is  to  prevent  the 
removal  of  the  color  from  stained  bacteria  in  sections  during  the 
treatment  which  such  sections  usually  receive  before  they  are  ready 


STAINING   METHODS.  35 

for  mounting — i.  e. ,  during  the  washing  and  dehydrating  processes 
usually  employed.  For  staining,  Kiihne  prefers  a  methylene-blue 
solution  prepared  as  follows  :  Methylene  blue,  1.5  parts;  absolute 
alcohol,  ten  parts  ;  triturate  in  a  watch  glass  and  add  gradually  one 
hundred  parts  of  a  solution  of  carbolic  acid  containing  five  parts  in 
one  hundred  of  water.  The  section  is  placed  in  this  solution  for  about 
half  an  hour,  then  washed  in  water  and  decolorized  in  a  weak  solution 
of  hydrochloric  acid — ten  drops  to  five  hundred  grammes  of  water. 
This  part  of  the  operation  must  be  conducted  very  carefully,  and 
usually  thin  sections  will  only  require  to  be  dipped  in  the  acid  solu- 
tion for  an  instant,  after  which  they  must  be  at  once  immersed  in  a 
solution  of  lithium — eight  drops  of  a  saturated  solution  of  carbonate 
of  lithium  in  ten  grammes  of  water.  They  are  then  allowed  to  re- 
main in  a  bath  of  distilled  water  for  a  few  minutes,  after  which  they 
are  dipped  into  absolute  alcohol,  which  Kiihne  colors  by  the  addition 
of  methylene  blue.  The  sections  are  then  placed  in  aniline  oil  which 
contains  a  little  methylene  blue  in  solution,  where  they  are  dehy- 
drated without  the  color  being  extracted  from  the  stained  bacteria 
present.  The  aniline-oil  blue  solution  is  prepared  by  adding  an  ex- 
cess of  dry  methylene  blue  to  a  small  quantity  of  clarified  aniline 
oil.  The  undissolved  pigment  settles  to  the  bottom,  and  a  few  drops 
of  the  colored  solution  are  added  to  a  little  aniline  oil  in  a  watch 
glass  to  make  the  colored  dehydrating  bath.  The  section  is  next 
washed  out  in  pure  aniline  oil — not  colored — after  which  every  trace 
of  aniline  oil  is  to  be  removed  by  the  use  of  xylol.  The  section  is 
cleared  up  in  turpentine  and  mounted  in  balsam. 

Ziehl-Neelson  Method,  for  the  tubercle  bacillus  in  tissues. — 
Leave  the  sections  for  fifteen  minutes  in  carbol-fuchsin  solution 
(No.  3)  ;  decolorize  in  sulphuric  or  nitric  acid,  twenty-five-per-cent 
solution  ;  wash  in  sixty-per-cent  alcohol ;  place  in  a  saturated  aque- 
ous solution  of  methylene  blue  for  contrast  stain  ;  wash,  dehydrate, 
and  mount  in  balsam. 

The  following  method  of  staining  sections  for  the  purpose  of 
demonstrating  bacteria  present  in  the  tissues  is  recommended  by 
Pregl  (1891)  as  a  substitute  for  the  method  of  Kiihne.  The  results 
are  said  to  be  excellent,  and  it  is  much  simpler  and  more  expeditious. 

The  sections  are  made  from  tissues  embedded  in  paraffin,  and  are 
attached  to  clean  glass  slides  with  albumen-glycerin.  Or  they  may 
be  attached  to  a  cover  glass  by  the  following  method  when  not  em- 
bedded in  paraffin  :  The  sections,  completely  dehydrated,  are  taken 
out  of  absolute  alcohol  on  a  thin  glass  cover,  upon  which  they  are 
extended  ;  a  piece  of  filter  paper  is  applied  to  the  side  of  the  cover 
glass  to  absorb  the  alcohol,  and  before  the  section  is  completely  dry 
a  drop  of  aceton-celloidin  solution  is  placed  upon  it  by  means  of  a 


36  STAINING   METHODS. 

glass  rod.  The  cover  glass  is  now  moved  about  in  the  air  to  promote 
rapid  evaporation  of  the  alcohol,  and  is  then  placed  in  water.  The 
section  now  remains  attached  to  the  cover  glass  during  subsequent 
manipulations.  The  aceton-celloidin  solution  referred  to  is  pre- 
pared by  adding  celloidin  in  small,  dry  pieces  to  aceton  until  a  con- 
centrated solution  is  obtained.  A  large  drop  of  this  added  to  five 
cubic  centimetres  of  absolute  alcohol  makes  a  suitable  solution  for 
use.  This  must  be  kept  in  a  glass-stoppered  bottle,  and  will  require 
to  be  frequently  renewed,  as  it  is  not  suitable  for  use  after  having 
absorbed  moisture  from  the  air.  The  aceton  as  obtained  from  dealers 
contains  considerable  water  and  must  be  dehydrated  by  adding  to  it 
red-hot  sulphate  of  copper. 

The  sections,  attached  to  a  slide  or  cover  glass  by  one  of  the 
methods  mentioned,  are  stained  with  Kiihne's  carbol-methylene-blue 
solution,  which  is  dropped  upon  them  from  a  pipette.  Usually  they 
will  be  sufficiently  stained  at  the  end  of  half  a  minute  to  a  minute, 
but  in  some  cases  a  longer  time  and  the  application  of  heat  will  be  de- 
sirable. They  are  then  washed  in  water  and  immediately  placed  in 
fifty-per-cent  alcohol,  where  they  remain  until  the  sections  have  a 
pale-blue  color  with  a  greenish  tinge.  They  are  now  completely 
dehydrated  in  absolute  alcohol  and  subsequently  cleared  up  in  xylol. 

STAINING  SECTIONS  OP  GELATIN  STICK  CULTURES. — Fischl,  Wei- 
gert,  and  Neisser  have  given  an  account  of  methods  for  staining 
stick  cultures  in  gelatin  of  non-liquefying  bacteria.  The  object  of 
this  is  to  show  the  mode  of  growth  and  the  association  of  individual 
cells  in  undisturbed  cultures.  Neisser  gives  the  following  direc- 
tions :  The  gelatin  cultures  are  inoculated,  by  several  punctures, 
with  the  microorganism  to  be  studied.  When  the  development  is 
deemed  sufficient  the  cylinder  of  gelatin  is  removed  from  the  test 
tube  by  gently  warming  its  walls.  It  is  then  placed  for  several  days 
— one  to  eight,  according  to  its  size  and  thickness — in  a  one-per-cent 
solution  of  bichromate  of  potassium.  While  in  this  solution  it  must 
be  exposed  to  the  light,  which  causes  a  change  in  the  gelatin,  ren- 
dering it  insoluble.  The  gelatin  cylinder  is  thoroughly  washed  and 
then  hardened  in  alcohol,  first  of  seventy  per  cent  and  then  of  ninety- 
six  per  cent.  It  is  then  cut  into  suitable  pieces,  and  these  are  attached 
to  a  cork  in  the  usual  manner  and  placed  for  twenty-four  hours  in  ab- 
solute alcohol.  Thin  sections  may  now  be  made  with  a  microtome, 
and  these  are  attached  to  a  glass  slide  and  stained  by  Gram's  or 
Weigert's  method  or  by  the  use  of  Loffler's  solution  (No.  4). 
The  decolorization  should  be  effected  by  the  use  of  alcohol  and  not 
with  an  acid  solution.  When  Gram's  method  is  used  decolorize  by 
the  alternate  use  of  alcohol  and  oil  of  cloves.  Clear  the  preparation 
with  oil  of  bergamot. 


V. 
CULTURE  MEDIA. 

To  obtain  a  satisfactory  knowledge  of  the  biological  characters 
of  the  different  species  of  bacteria,  it  is  necessary  to  isolate  them  in 
"  pure  cultures  "  and  to  study  their  growth  in  various  culture  media. 
By  a  pure  culture  we  mean  a  cultivation  containing  a  single  species 
only ;  and  to  be  absolutely  sure  that  we  have  a  pure  culture  it  is 
desirable  that  all  of  the  bacteria  in  a  culture  shall  be  the  progeny  of 
a  single  cell.  The  methods  of  obtaining  pure  cultures  will  be  given 
later.  At  present  we  propose  to  give  an  account  of  the  various  cul- 
ture media  commonly  employed  by  bacteriologists,  and  the  methods 
of  preparing  them  for  use. 

By  a  natural  culture  medium  we  mean  one  which,  as  obtained  in 
nature,  contains  the  necessary  pabulum  for  the  development  of  one 
or  more  species  of  bacteria.  An  artificial  culture  medium  is  one 
which  is  prepared  artificially  by  adding  nutritive  material  to  water. 
A  sterile  medium  is  one  which  does  not  contain  any  living  micro- 
organisms. We  may  obtain  natural  media  in  a  sterile  condition,  but 
artificial  media  require  sterilization,  as  they  are  infallibly  contami- 
nated with  living  "  germs  "  from  the  atmosphere  during  the  process 
of  preparing  them.  Sterilization  is  usually  effected  by  heat.  For- 
ceps, glass  tubes,  etc. ,  may  be  sterilized  by  passing  them  through 
the  flame  of  an  alcohol  lamp  or  Bunsen  burner. 

NATURAL,  CULTURE  MEDIA. — The  most  important  natural  cul- 
ture medium  is  blood  serum,  which  may  be  obtained  from  one  of 
the  lower  animals — preferably  from  oxen  or  calves.  This  is  to  be 
collected  in  a  sterilized  jar,  with  every  precaution  to  insure  cleanli- 
ness, at  the  moment  of  slaughtering  the  animal.  Or  the  blood  of  a 
calf,  sheep,  or  dog  may  be  collected  at  the  laboratory  by  a  carefully 
conducted  operation,  in-  which  the  femoral  or  carotid  artery  is  con- 
nected with  a  sterilized  glass  tube  leading  into  a  sterilized  receptacle, 
such  as  a  Woulf 's  bottle,  into  one  neck  of  which  a  cotton  plug  has 
been  placed  to  permit  the  air  to  escape  as  the  bottle  fills  with 
blood  through  a  tube  which  is  secured  in  the  other  neck.  "When 
blood  is  passed  directly  from  an  artery  into  a  sterilized  receptacle 
the  serum  will  not  subsequently  require  sterilization.  The  writer  is  in 


38 


CULTURE   MEDIA. 


the  habit  of  collecting  it  in  this  way,  and,  after  the  serum  has  sepa- 
rated, of  drawing  it  off  in  little  flasks  having  a  long  neck,  as  shown 
in  Fig.  14.  The  neck  of  the  flask,  previously  sterilized  by  heat,  is 
slipped  into  the  Woulf's  bottle  beside  the  cotton  plug,  the  bulb  (a) 
having  been  previously  gently  heated  to  expand  the  contained  air. 
As  the  heated  air  cools  a  partial  vacuum  is  formed  and  the  clear 
serum  mounts  into  the  little  flask.  One  after  another  is  filled  in 
this  way,  and  each  one  is  hermetically  sealed  in  the  flame  of  a  lamp 


—  a 


FIG.  14. 


FIG.  15. 


FIG.  18. 


as  soon  as  it  is  withdrawn.  The  sterile  blood  serum  may  be  pre- 
served indefinitely  in  this  way,  and  may  be  used  as  a  liquid  culture 
medium  in  the  little  flask,  or  it  may  be  transferred  to  a  test  tube 
and  solidified  by  heat  whenever  a  solid  blood-serum  medium  is  re- 
quired. The  advantage  of  preserving  blood  serum  and  other  liquid 
media  in  these  little  flasks  is  in  the  fact  that  they  may  be  preserved 
indefinitely  without  becoming  contaminated  or  drying  up,  and  that 
they  are  easily  transported,  while  a  liquid  medium  in  a  test  tube 
must  be  kept  upright.  The  contents  of  one  of  these  flasks  are  readily 


CULTURE   MEDIA.  39 

transferred  to  a  test  tube  by  breaking  off  the  sealed  extremity  with 
sterile  forceps  and  slipping  it  past  the  cotton  plug,  which  must  be 
partly  withdrawn  for  the  purpose.  Upon  applying  gentle  heat  to 
the  bulb  its  contents  are  forced  out  into  the  test  tube  (Fig.  15). 
Blood  serum  which  is  collected  without  these  special  precautions 
will  require  sterilization  by  heat,  for  which  directions  will  be  given 
later. 

To  obtain  the  clear  serum  from  blood  collected  as  above  directed, 
the  jars  containing  it  are  set  aside  in  a  cool  place  in  order  that  a  firm 
clot  may  form,  care  being  taken  not  to  shake  them.  After  the  clot 
has  formed  they  may  be  transported  to  the  laboratory,  where  they 
are  placed  in  an  ice  box  or  in  a  cool  cellar  for  from  twenty-four  to 
forty-eight  hours.  By  this  time  the  serum  has  separated  from  the 
clot,  and  it  may  be  transferred  to  sterilized  test  tubes  by  means  of  a 
suction  pipette  (Fig.  16),  or  may  be  distributed  in  little  flasks  as 
above  directed, 

Milk  is  largely  used  as  a  culture  medium,  and  is  especially  useful 
in  studying  the  biological  characters  of  various  microorganisms,  as 
shown  by  their  causing  coagulation  of  the  casein,  or  otherwise  ;  or 
an  acid  or  alkaline  reaction  of  the  liquid  ;  or  peptonization  of  the 
precipitated  casein,  etc.  In  the  udder  of  healthy  cows  milk  is  quite 
sterile,  and  by  proper  precautions  it  may  be  drawn  into  sterilized 
flasks  without  any  contamination  and  kept  indefinitely  without  un- 
dergoing coagulation  or  any  other  change.  But  in  practice  it 
is  easier  to  sterilize  it  in  test  tubes  or  small  flasks  by  the  use  of 
heat  than  to  obtain  it  in  a  sterile  condition  from  the  udder  of  the 
cow. 

Urine  has  been  used  to  some  extent  as  a  culture  medium,  and 
many  bacteria  multiply  in  it  abundantly,  although,  on  account  of  its 
acid  reaction,  other  species  fail  to  grow  in  it.  As  contained  in  the 
healthy  bladder  it  is  sterile,  but  the  mucous  membrane  of  the  mea- 
tus  urinarius  always  contains  numerous  bacteria  upon  its  surface,  and 
some  of  these  are  sure  to  be  carried  away  with  the  current  when 
urine  is  passed. 

A  culture  fluid  which  the  writer  has  found  extremely  useful,  in 
tropical  countries  where  it  is  to  be  obtained,  is  the  transparent  fluid 
contained  in  the  interior  of  unripe  cocoanuts — called  agua  coco  by 
the  Spaniards.  In  countries  where  the  cocoanut  is  indigenous  this 
cocoanut  water  is  largely  used  as  a  refreshing  drink.  It  contains 
about  four  per  cent  of  glucose  in  solution,  together  with  some  vege- 
table albumen  and  salts.  Some  microorganisms  multiply  in  it  with- 
out appropriating  the  glucose,  while  others  split  this  up,  producing 
an  abundant  evolution  of  carbon  dioxide  and  giving  to  the  fluid 
a  very  acid  reaction.  The  following  are  the  results  of  an  analysis 


40  CULTURE   MEDIA. 

made  for  me  by  Dr.  L.  L.  Van  Slyke  in  the  chemical  laboratory  of 
Johns  Hopkins  University  :  The  weight  of  the  fluid  obtained  from 
six  nuts  averaged  339.1  grammes.  The  specific  gravity  averaged 
1.02285.  The  amount  of  water  averaged  95  percent;  the  amount 
of  inorganic  ash,  0.618  per  cent;  the  amount  of  glucose,  3.97  per 
cent ;  the  amount  of  fat,  0.119  per  cent ;  the  amount  of  albuminoids, 
0. 133  per  cent. 

As  this  fluid  is  contained  in  a  germ-proof  receptacle,  no  steriliza- 
tion is  required  when  it  is  drawn  off  with  proper  precautions  in  the 
little  flasks  heretofore  described. 

Hydrocele  fluid  has  been  used  as  a  culture  medium,  and  many 
bacteria  multiply  in  it  abundantly. 

Other  natural  culture  media  are  found  in  the  animal  and  vege- 
table kingdoms,  which  are  used,  either  cooked  or  raw,  as  solid  sub- 
strata upon  which  bacteria  may  be  cultivated.  One  of  the  most  use- 
ful of  these  is  the  potato,  which  is  a  favorable  medium  for  the  de- 
velopment of  numerous  species,  and  upon  which  (cooked)  many  of 
them  present  characters  of  growth  which  are  so  distinctive  as  to  aid 
greatly  in  the  differentiation  of  species. 

Other  tubers,  roots,  or  fruits  may  also  be  used  as  solid  media,  or 
their  juices  extracted  and  employed  as  liquid  media.  Cooked  fish 
and  meats  of  various  kinds  are  also  suitable  media  for  certain  spe- 
cies— e.g.,  the  phosphorescent  bacteria  grow  very  well  upon  the  sur- 
face of  boiled  fish,  and  in  a  dark  room  give  off  a  bright,  phosphores- 
cent light. 

Eggs,  sterilized  by  boiling,  have  been  used  by  some  bacteriolo- 
gists, especially  for  the  cultivation  of  anaerobic  species. 

ARTIFICIAL  CULTURE  MEDIA. — A  great  variety  of  liquid  media 
have  been  employed  by  bacteriologists,  the  most  useful  of  which  are 
infusions  of  beef  or  mutton,  with  the  addition  of  a  little  peptone. 
But  Pasteur  has  shown  that  some  species  of  bacteria  will  grow  in  a 
medium  which  does  not  contain  any  albuminous  material,  nitrogen 
being  obtained  from  salts  containing  ammonia. 

Pasteur's  solution,  which  is  rarely  used  at  present,  contains  : 
Distilled  water,  one  hundred  parts  ;  cane  sugar,  ten  parts  ;  tartrate 
of  ammonia,  one  part,  with  the  addition  of  the  ashes  from  one 
gramme  of  yeast. 

Cohn  modified  this  by  leaving  out  the  cane  sugar,  which  favors 
the  development  of  moulds.  These  fluids  are  not,  however,  in- 
tended for  general  use  in  the  cultivation  of  bacteria,  but  to  demon- 
strate certain  facts  relating  to  their  physiology. 

Infusions  of  meat,  or  "  flesh  water,"  are  made  by  chopping  fine 
lean  beef  or  mutton  (one  pound)  and  covering  it  with  water  (one 
litre).  This  is  placed  in  an  ice  chest  for  twenty-four  hours,  and  the 


CULTURE   MEDIA.  41 

aqueous  extract  is  then  obtained  by  filtration  through  muslin  by 
pressure.  This  extract  is  cooked,  filtered,  and  carefully  neutralized 
by  the  addition  of  a  solution  of  carbonate  of  sodium,  which  is  added 
drop  by  drop.  Usually  we  add  to  this  one-half  per  cent  of  chloride 
of  sodium.  The  addition  of  ten  grammes  of  peptone  to  a  litre  of 
this  meat  infusion  constitutes  the  flesh-peptone  solution  which  is 
largely  used  in  the  preparation  of  solid  culture  media,  to  be  described 
hereafter. 

The  addition  of  five  per  cent  of  glycerin  to  the  above  infusion 
makes  a  useful  liquid  medium  for  the  cultivation  of  the  tubercle  ba- 
cillus (Roux  and  Nocard).  The  liquid  should  be  again  neutralized 
after  adding  the  glycerin,  which  commonly  has  an  acid  reaction. 

Bouillon  is  made  by  cooking  the  chopped  meat — one  pound  in  a 
litre  of  water — for  about  half  an  hour  in  a  large  glass  flask  or  an 
enamelled  iron  kettle.  The  filtered  bouillon  is  then  carefully  neu- 
tralized with  sodium  carbonate,  and  again  boiled  for  an  hour  to  pre- 
cipitate all  coagulable  albuminoids.  It  is  again  filtered  and  dis- 
tributed in  test  tubes  or  small  flasks,  in  which  it  is  subsequently 
sterilized.  For  certain  pathogenic  bacteria  a  bouillon  made  from  the 
flesh  of  a  fowl  or  of  a  rabbit  is  preferable  to  beef  bouillon. 

Flesh  infusion  may  also  be  made  from  one  of  the  standard  beef 
extracts,  such  as  Liebig's  (five  grammes  to  a  litre  of  water). 

Various  vegetable  infusions  may  also  be  used  as  culture  media, 
such  as  yeast  water,  potato  water,  infusion  of  hay,  of  barley,  or  of 
wheat,  of  dried  fruits,  beer  wort,  etc. 

SOLID  CULTURE  MEDIA. — The  introduction  of  solid  culture 
media,  and  especially  the  use  of  gelatin  and  agar-agar,  as  first 
recommended  by  Koch  (1881),  for  the  isolation  and  differentiation  of 
species,  was  a  most  important  advance  in  bacteriological  technology. 
We  are  concerned  here  only  with  the  composition  and  preparation 
of  these  media. 

Flesli-Peptone<-Gelatin. — This  is  made  by  adding  ten  per  cent 
of  the  best  French  gelatin  to  the  flesh-peptone  solution  above  de- 
scribed. This  is  the  standard  gelatin  medium,  but  more  or  less 
gelatin  may  be  added  to  serve  a  special  purpose.  Thus,  in  Havana 
during  the  summer  months  the  writer  used  a  medium  containing 
twenty  per  cent  of  gelatin,  because  when  but  ten  per  cent  was  used 
the  gelatin  was  liquefied  by  the  normal  temperature  of  the  atmo- 
sphere. Ten-per-cent  gelatin,  of  good  quality  and  carefully  pre- 
pared, will  stand  a  temperature  of  20°  to  22°  C.  (68°  to  71.6°  F.) 
without  melting.  When  twenty  per  cent  of  gelatin  is  used  the 
melting  point  is  about  8°  C.  higher.  It  must  be  remembered  that 
exposure  to  a  boiling  temperature  reduces  the  melting  point  of  gela- 
tin. It  is  therefore  desirable  to  accomplish  the  operations  of  cook- 


42  CULTURE   MEDIA. 

ing  and  sterilizing  in  as  short  a  time  as  is  practicable.  The  French 
gelatin  used  comes  in  thin  sheets  ;  this  is  broken  up  and  added  to 
the  flesh-peptone  solution. 

Usually  we  prepare  a  litre  of  nutrient  gelatin  at  one  time,  and  for 
this  quantity  one  hundred  grammes  of  gelatin  will  be  required  for  the 
standard  preparation  (ten  per  cent).  It  is  well  to  allow  it  to  soak  for 
a  time  in  the  liquid  before  applying  heat  for  the  purpose  of  dissolving 
it.  Then  apply  gentle  heat  until  it  is  completely  dissolved.  The  gela- 
tin of  commerce  usually  has  an  acid  reaction,  and  it  will  be  necessary 
to  carefully  neutralize  the  medium  after  it  has  been  added.  A  slightly 
alkaline  reaction  is  usually  no  disadvantage,  but  certain  pathogenic 
bacteria  will  not  grow  when  there  is  a  trace  of  acid  present.  The 


FIG.  17. 


next  step  consists  in  clarifying  the  nutrient  medium.  It  is  allowed 
to  cool  to  about  50°  C.,  and  an  egg,  previously  broken  into  one 
hundred  grammes  of  water,  is  gradually  added  while  stirring  the 
liquid  with  a  glass  rod.  A  whole  egg  is  used  for  a  litre  of  the  solu- 
tion. Heat  is  again  applied  and  the  solution  is  kept  at  the  boiling 
point  for  about  ten  minutes,  during  which  time  the  egg  albumen  is 
precipitated  apd  carries  down  with  it  all  insoluble  particles,  which 
without  this  clarifying  process  would  have  interfered  with  the  trans- 
parency of  the  medium,  even  when  carefully  filtered.  The  hot 
solution  is  then  filtered,  A  hot- water  funnel  (Fig.  17)  is  usually 
employed,  as  the  gelatin  solution  does  not  pass  through  filtering 
paper  very  rapidly,  and  when  cooled  to  near  the  point  of  solidifying 
ceases  to  pass. 


CULTURE   MEDIA.  43 

The  advantages  of  the  gelatin  medium  are  that  it  is  perfectly 
transparent,  that  it  is  easily  melted  for  making  ''plates,"  and  that 
many  bacteria  exhibit  in  it  special  characters  of  growth  by  which  they 
may  be  differentiated  from  others  which  resemble  them  in  form. 
The  principal  disadvantage  is  the  low  melting  point,  which  prevents 
us  from  making  use  of  this  medium  for  cultivating  bacteria  in  an  in- 
cubating oven  at  a  higher  temperature  than  about  22°  C.  for  ten-per- 
cent gelatin. 

This  disadvantage  is  overcome  by  using  agar-agar  instead  of 
gelatin.  This  is  prepared  in  Japan  and  other  Eastern  countries 
from  certain  species  of  gelatinous  algae.  It  comes  to  us  in  the  form 
of  bundles  of  dried  strips,  which  form  a  stiff  jelly  when  dissolved  in 
water  in  the  proportion  of  one  to  two  per  cent.  This  jelly  remains 
solid  at  a  temperature  of  40°  C.  and  above.  It  was  first  employed 
by  Hesse,  one  of  Koch's  collaborators  in  the  office  of  the  imperial 
board  of  health  of  Berlin.  Koch,  who  was  in  search  of  a  trans- 
parent jelly  which  would  stand  the  temperature  required  for  the  cul- 
tivation of  certain  pathogenic  bacteria  (37°  to  38°  C.),  quickly  recog- 
nized its  value  and  introduced  it  into  general  use. 

The  agar-agar  jelly  is  more  difficult  to  filter  than  the  gelatin 
medium,  and  some  skill  is  required  in  order  to  obtain  a  transparent 
solution.  It  will  bear  long  boiling  without  losing  its  quality  of 
forming  a  stiff  jelly.  From  ten  to  twenty  grammes  are  added  to  a 
litre  of  flesh  infusion,  or  we  may  make  a  peptonized  agar  in  accor- 
dance with  the  following  formula  which  is  given  by  Salomonson  : 
Add  to  one  litre  of  distilled  water  five  grammes  Liebig's  extract, 
thirty  grammes  peptone,  five  grammes  cane  sugar,  fifteen  grammes 
agar.  Cook  for  an  hour,  render  slightly  alkaline,  and  cool  to  below 
60°  C.  Clarify  and  cook  again  for  an  hour  or  more. 

Glycerin-agar  is  made  by  adding  five  per  cent  of  glycerin  to 
the  peptonized  agar  made  by  the  above  formula  or  by  the  use  of  the 
flesh-peptone  infusion.  This  is  a  very  favorable  medium  for  the  cul- 
tivation of  the  tubercle  bacillus — first  used  by  Roux  and  Nocard. 

Agar-gelatin,  a  medium  which  has  recently  come  into  favor  and 
is  said  to  be  very  useful,  as  it  resembles  gelatin  in  transparency  and 
has  a  considerably  higher  melting  point  than  ten-per-cent  gelatin,  is 
made  by  adding  fifty  grammes  of  gelatin  and  7. 5  grammes  of  agar 
to  a  litre  of  flesh-peptone  solution.  Care  should  be  taken  not  to  cook 
this  longer  than  is  necessary. 

In  making  all  of  these  agar  culture  media  the  main  difficulties 
encountered  result  from  the  difficulty  of  dissolving  the  agar  and  the 
slowness  with  which  the  solution  passes  through  filtering  paper. 
These  difficulties  are  best  met  as  follows  :  Break  up  the  sticks  of  agar 
into  small  fragments  and  allow  them  to  soak  in  cold  water  for  twenty- 


44 


CULTURE   MEDIA. 


four  hours.  Pour  off  the  water  and  add  the  flesh-peptone  solution. 
Boil  for  several  hours  until  the  agar  is  completely  dissolved.  Neu- 
tralize by  adding  gradually  a  solution  of  carbonate  of  soda  (or  render 
slightly  alkaline).  Filter. 

The  last  operation  is  the  most  troublesome,  and  various  plans 
have  been  proposed  to  avoid  the  tedious  nitration  through  filtering 
paper  in  a  hot-water  filter.  A  method  which  gives  satisfactory  re- 
sults is  to  place  the  filter  containing  the  hot  agar  solution,  and  the 
flask  which  is  to  receive  the  filtrate,  in  a  steam  sterilizing  apparatus, 
where  it  is  left  in  an  atmosphere  of  streaming  steam  until  the  filtra- 


FIQ.  18. 


tion  is  completed.  Or  the  solution  may  be  put  in  a  tall  jar  and  left 
in  the  steam  sterilizer  for  several  hours  until  it  is  clear  as  a  result  of 
sedimentation.  The  clear  solution  is  then  obtained  by  decantation. 
Or  by  conducting  the  operation  in  a  tall  cylindrical  vessel,  and  al- 
lowing sedimentation  to  occur  in  the  steam  sterilizer  and  the  agar 
subsequently  to  solidify  by  cooling,  the  cylinder  of  jelly  may  be  re- 
moved from  the  jar  and  the  part  containing  the  sediment  can  be  cut 
away.  The  transparent  portion  is  then  melted  again  and  distributed 
in  test  tubes  for  use. 

In  the  present  volume  we  frequently  refer  to  the  nutrient  medium 
made  by  adding  one  to  two  per  cent  of  agar-agar  to  the  standard 
flesh-peptone  solution  as  "  nutrient  agar"  or  simply  as  "agar." 


CULTURE   MEDIA. 


45 


The  following  method  of  filtering  agar  has  recently  (1890)  been 
proposed  by  Karlinsky.  It  is  a  modification  of  the  method  previously 
described  by  Jakobi  and  depends  upon  the  use  of  pressure. 

In  Fig.  18,  a  is  a  cylindrical  vessel  of  tin,  which  is  closed  above  by 
a  perforated  rubber  cork,  through  which  is  passed  a  glass  tube,  b. 
This  is  enclosed  in  a  larger  tin  cylinder,  c,  which  contains  water, 
which  may  be  kept  hot  by  placing  an  alcohol  lamp  under  the  pro- 
jecting arm  d.  The  central  cylinder  has  a  tube,  e,  passing  through 
the  bottom  of  the  hot-water  cylinder,  and  which  is  provided  with  a 


Fio.  19. 

stopcock  for  drawing  off  the  filtered  solution.  Before  pouring  the 
hot  agar  solution  into  the  cylinder  a,  a  cotton  filter  about  ten  centi- 
metres thick  is  placed  at  the  bottom  of  this  cylinder  and  hot  water 
is  poured  upon  it  while  the  stopcock  of  the  outlet  tube  is  open.  This 
washes  out  the  cotton  and  prepares  the  filter  for  the  agar  solution. 
The  apparatus  is  supported  upon  a  tripod,  not  shown  in  the  figure. 
Filtration  is  said  to  occur  rapidly  when  the  air  in  the  central  cylinder 
is  compressed  by  means  of  the  hand  bellows  attached  to  the  tube  b. 
Unna  (1891)  has  devised  a  filtering  apparatus  for  agar  which  is 
shown  in  Fig.  19.  In  this  the  pressure  of  steam  is  utilized.  A  hollow 


46  CULTURE   MEDIA. 

sphere  of  copper,  supported  upon  a  tripod,  is  so  constructed  that  an 
upper  hemispherical  segment  can  be  removed  to  give  access  to  the 
interior.  An  opening  at  the  bottom  contains  a  perforated  rubber 
cork,  through  which  the  stem  of  an  enamelled  iron  funnel  passes. 
A  simple  filter  of  filtering  paper  is  used  in  this  funnel,  and  this  is 
filled  to  a  depth  of  two  centimetres  with  well-burned  kieselgur  (dia- 
tomaceous  earth  in  which  the  organic  matter  has  been  destroyed  by 
heat).  The  hot  solution  of  agar  is  poured  into  the  funnel,  and  hot 
water  into  the  space  between  it  and  the  copper  vessel ;  this  must  not 
come  too  near  the  top  of  the  funnel — not  nearer  than  three  centi- 
metres. The  hemispherical  cover  is  then  secured  in  its  place  by 
means  of  a  clamp  screw  shown  in  the  figure.  By  placing  a  Bunsen 
burner  under  the  projecting  arm  the  water  is  made  to  boil  and  a 
sufficient  steam  pressure  secured.  A  small  stopcock  attached  to  the 
cover  of  the  copper  vessel  permits  the  escape  of  steam  if  the  pressure 
is  too  great.  According  to  Unna,  solutions  containing  as  much  as 
three  per  cent  of  agar  can  be  filtered  by  means  of  this  apparatus,  and 
a  litre  of  two-per-ceiit  agar  will  pass  through  it  in  about  two  hours. 

For  special  purposes  various  substances  are  added  to  the  above- 
described  solid  and  liquid  media.  A  favorable  addition  for  the 
growth  of  a  considerable  number  of  bacteria  is  from  one  to  three  per 
cent  of  glucose.  The  phosphorescent  bacteria  grow  best  in  a  medium 
containing  two  to  three  per  cent  of  sodium  chloride.  The  addition 
of  three  to  four  per  cent  of  potassium  nitrate  is  made  in  conducting 
experiments  designed  to  test  the  reducing  power  of  certain  bacteria, 
by  which  this  salt  is  decomposed  with  the  production  of  nitrites. 
Acids  are  also  added  in  various  proportion  to  test  the  ability  of 
bacteria  under  investigation  to  grow  in  an  acid  medium.  From 
1  : 2,000  to  1  : 500  of  hydrochloric  acid  may  be  used  for  this  purpose. 
The  addition  of  litmus  to  milk  or  other  culture  media  is  fre- 
quently resorted  to  for  the  purpose  of  ascertaining  whether  acids  or 
alkalies  are  developed  during  the  growth  of  bacteria  under  investi- 
gation. The  addition  of  aniline  colors  which  are  variously  changed 
by  the  products  of  growth  of  certain  species  has  also  been  resorted 
to  in  the  differentiation  of  species.  Various  disinfecting  agents,  such 
as  carbolic  acid,  etc. ,  have  also  been  used  for  the  same  purpose,  and 
it  has  been  shown  by  experiment  that  some  bacteria  will  grow  in  a 
medium  containing  such  agents  in  a  proportion  which  would  entirely 
restrain  the  development  of  others. 

Quite  recently  the  soluble  silicates  which  form  a  jelly-like  mass 
have  been  proposed  as  a  culture  medium  for  certain  bacteria  which 
do  not  grow  in  the  usual  media.  Kiihne  (1890),  Winogradsky 
(1891),  and  Sleskin  (1891)  have  made  experiments  which  indicate 
that  this  medium  has  considerable  value. 


CULTURE   MEDIA.  47 

Winogradsky  uses  in  the  preparation  of  his  silicate  jelly  the 
following  salts  : 

Ammonium  sulphate,          ....  0.4  gramme. 

Magnesium  sulphate,     .  .  .  .  0.05 

Potassium  phosphate,         .  .  .  ~  0.1 

Calcium  chloride,          ....  a  trace. 

Sodium  carbonate,  .  .  .  0.6  to  0.9  gramme. 

Distilled  water,  .  .  .  .  100  grammes. 

To  this  he  adds  a  solution  of  silicic  acid.  According  to  Kiihne,  a 
solution  containing  3.4  per  cent  of  silicic  acid  and  having  a  specific 
gravity  of  1.02  may  be  preserved  in  a  liquid  condition.  To  this  the 
salts  are  added  in  greater  or  less  amount,  according  to  the  consis- 
tence desired. 

Sleskin  states  that  a  suitable  jelly  is  formed  by  the  addition  of 
1.15  to  1.45  per  cent  of  the  salts,  and  recommends  that  concentrated, 
sterilized  solutions  be  added  to  the  acid.  He  dissolves  separately,  in 
as  little  water  as  possible,  the  sulphates,  the  potassium  phosphate 
and  sodium  carbonate,  and  the  calcium  chloride. 

The  use  of  a  culture  medium  containing  an  extract  from  the 
jequirity  seeds  has  recently  been  recommended  by  Kaufmann  (1891), 
who  has  found,  by  experimenting  upon  various  bacteria,  that  such  a 
medium  is  useful  in  differentiating  species. 

'The  jequirity  solution,  which  may  be  used  as  a  liquid  medium 
"or  may  be  employed  in  the  preparation  of  nutrient  gelatin  or  agar,  is 
prepared  as  follows  :  Ten  grammes  of  jequirity  seeds  are  bruised  in 
a  mortar  and  the  shells  removed  ;  they  are  then  placed  in  one  hun- 
dred cubic  centimetres  of  water  and  cooked  for  two  hours  in  the  steam 
sterilizer  ;  after  allowing  the  infusion  to  cool  it  is  filtered.  The  fil- 
tered liquid  has  a  pale-yellow  color  and  a  neutral  or  slightly  alkaline 
reaction.  Certain  bacteria  grow  in  this  solution  without  producing 
any  change  in  its  color ;  others,  which  produce  an  acid  reaction, 
cause  it  to  be  decolorized  ;  others,  which  produce  an  alkaline  reac- 
tion of  the  medium,  change  the  color  to  green. 

Cooked  Potato. — Schroter  first  used  cooked  potato  as  a  culture 
medium  for  certain  chromogenic  bacteria  (1872),  and  Koch  subse- 
quently called  attention  to  the  great  value  of  potato  cultures  for 
differentiating  species.  His  plan  of  preparing  potatoes  is  as  follows: 
Sound  potatoes  are  chosen  in  which  the  epidermis  is  intact.  These 
are  thoroughly  washed  and  scrubbed  with  a  brush  to  remove  all 
dirt.  The  "  eyes"  and  any  bruised  or  discolored  spots  are  removed 
with  a  sharp-pointed  knife.  They  are  again  thoroughly  washed  in 
water,  and  are  then  placed  for  an  hour  in  a  bath  containing 
mercuric  chloride  in  the  proportion  of  1 :  500,  to  thoroughly  disinfect 
the  surface.  They  are  then  placed  in  a  steam  sterilizer  for  about 
three-quarters  of  an  hour,  and  after  an  interval  of  twenty-four  hours 


48 


CULTURE   MEDIA. 


are  again  steamed  for  fifteen  minutes.  It  is  well  to  wrap  each 
potato  in  tissue  paper  before  placing  it  in  the  bichloride  bath,  and  to 
leave  it  in  this  protecting  envelope  until  it  is  placed  in  the  glass  dish 
in  which  it  is  preserved  from  contamination  by  atmospheric  germs 
after  being  inoculated  with  some  particular  microorganism.  Just 
before  such  inoculation  the  potato  is  cut  in  halves  with  a  sterilized 
(by  heat)  table  knife.  The  bacteria  to  be  cultivated  are  placed  upon 
the  cut  surface  and  the  potato  is  preserved  in  a  glass  dish  (Fig.  20). 


FIG.  20. 


FIG.  21. 


FIG.  22. 


A  more  convenient  method,  and  one  which  secures  the  potato  more 
effectually  from  atmospheric  organisms,  is  to  cut  a  cylinder,  about 
an  inch  in  diameter,  from  a  sound  potato,  by  means  of  a  tin  instru- 
ment resembling  a  cork  borer  or  apple  corer.  This  cylinder  is  cut 
obliquely  into  two  pieces  having  the  form  shown  in  Fig.  22,  and 
each  piece  is  placed  in  a  large  test  tube  having  a  cotton  air  filter,  in 
which  it  is  sterilized.  This  method,  first  employed  by  Bolton,  has 
been  slightly  modified  by  Roux,  who  recommends  that  a  receptacle 
for  catching  the  water  which  separates  during  the  sterilizing  process 
be  formed  by  making  a  constriction  around  the  test  tube  an  inch 
above  its  lower  extremity.  This  is  done  by  the  use  of  a  blowpipe. 


CULTURE   MEDIA.  40 

The  cylinder  of  potato  rests  upon  the  constricted  portion  of  the  tube, 
as  shown  in  Fig.  21. 

Sometimes  a  potato  paste  is  employed.  The  potatoes  are  boiled 
for  an  hour  and  the  skins  removed,  after  which  they  are  mashed 
with  a  little  sterilized  water,  placed  in  suitable  plates,  and  sterilized 
by  exposure  for  half  an  hour  on  three  successive  days  in  the  steam 
sterilizer.  Bread  paste  may  be  made  in  the  same  way,  and  is  a  very 
favorable  medium  for  the  growth  of  certain  bacteria  and  also  for  the 
common  moulds. 
4 


VI. 
STERILIZATION   OF   CULTURE   MEDIA. 

A  MOST  important  part  of  bacteriological  technology  consists  in 
the  sterilization  of  the  various  culture  media  employed.  A  sterile 
medium  is  essential  for  maintaining  a  pure  culture,  and  we  can  only 
obtain  an  exact  knowledge  of  the  biological  characters  of  a  species 
by  studying  its  growth  in  various  media,  its  physiological  reactions, 
its  pathogenic  power,  etc.,  independently  of  all  other  microorgan- 
isms— i.  e. ,  in  pure  cultures. 

We  may  sterilize  a  culture  medium  either  by  heat  or  by  filtration 
through  a  substance  which  does  not  permit  bacteria  to  pass.  The 
last-mentioned  method  is  useful  for  certain  special  purposes  ;  but,  in 
general,  sterilization  of  culture  media,  and  of  the  vessels  in  which 
they  are  preserved,  is  effected  by  heat. 

The  scientific  use  of  heat  as  an  agent  for  sterilizing  our  culture 
media  depends  upon  a  knowledge  of  the  thermal  death-point  of  the 
various  microorganisms  which  are  liable  to  be  present  in  them,  and 
upon  various  facts  relating  to  the  manner  in  which  heat  is  applied. 
All  this  has  been  determined  by  experiment,  and  before  giving 
practical  directions  for  sterilization  it  will  be  well  to  consider  the 
experimental  data  upon  which  our  methods  are  based. 

As  a  rule,  bacteria  which  do  not  form  spores  are  killed  at  a  com- 
paratively low  temperature.  Thus,  in  a  series  of  experiments  made 
by  the  writer  upon  the  thermal  death-point  of  various  pathogenic 
organisms,  the  pus  cocci  were  found  to  be  the  most  resistant,  and  all 
of  these  were  killed  by  exposure  for  ten  minutes  to  a  temperature 
of  62°  C.  (143. 6°  F.).  There  are  several  species  of  bacteria  known, 
however,  which  not  only  are  not  killed  by  this  temperature,  but  are 
able  to  grow  and  multiply  at  a  temperature  of  65°  to  70°  C.  (Miquel, 
Van  Tieghem,  Globig).  But  it  is  safe  to  say  that  exposure  to  a 
boiling  temperature  for  a  minute  or  two  will  infallibly  destroy  all 
microorganisms  in  the  absence  of  spores,  when  they  are  in  a  moist 
condition  or  moist  heat  is  used — i.e.,  when  they  are  directly  ex- 
posed to  the  action  of  boiling  water  or  of  steam.  The  power  of  dry 
heat  to  destroy  microorganisms  in  a  desiccated  condition  is  a  differ- 
ent matter  and  will  require  special  consideration. 


STERILIZATION  OF   CULTURE   MEDIA.  51 

The  spores  of  bacilli  have  a  much  greater  resisting  power,  and 
the  vitality  of  some  of  these  reproductive  bodies,  from  known  spe- 
cies, is  not  destroyed  by  a  boiling  temperature  maintained  for  sev- 
eral hours.  Thus  Globig  found  that  the  spores  of  a  certain  bacillus 
from  the  soil — his  "  red  potato  bacillus  " — required  six  hours'  exposure 
to  streaming  steam  in  order  to  destroy  it.  Steam  under  pressure,  at 
a  temperature  of  115°  C.,  killed  it  in  half  an  hour  ;  at  125°  C.  in  five 
minutes.  This  extreme  resisting  power  is  exceptional,  however, 
and  many  spores  are  destroyed  in  a  few  minutes  by  the  boiling  tem- 
perature of  water. 

In  practice  we  assume  that  some  of  the  more  resistant  spores, 
which  are  frequently  present  in  the  atmosphere,  may  have  fallen 
into  our  culture  material,  and  to  insure  its  sterilization  we  subject  it 
to  a  temperature  which  can  be  depended  upon  to  destroy  these  ;  or 
we  resort  to  the  method  of  discontinuous  heating.  This  method 
was  first  employed  by  Tyndall  (1877),  and  is  now  in  general  use  in 
the  bacteriological  laboratories  of  Germany,  having  been  adopted  by 
Koch  and  his  pupils  ;  while  in  France  a  single  sterilization  by  means 
of  steam  under  pressure,  securing  a  higher  temperature,  is  still  the 
favorite  method  with  many. 

In  the  method  by  discontinuous  heating  we  subject  the  culture 
material  for  a  short  time  to  the  temperature  of  boiling  water,  thus 
destroying  all  bacteria  in  the  vegetative  stage.  After  an  interval, 
usually  of  twenty-four  hours,  we  repeat  the  operation  for  the  pur- 
pose of  destroying  those  which  in  the  meantime  have  developed 
from  spores  which  may  have  been  present.  Again  the  material  is 
put  aside,  and  after  twenty-four  hours  it  is  again  heated  to  the 
boiling  point.  This  is  usually  repeated  from  three  to  five  times. 
The  object  in  view  is  to  kill  the  growing  bacteria  which  are  de- 
veloped from  spores  which  were  present ;  and,  as  a  matter  of  expe- 
rience, we  find  that  this  method  of  sterilization  is  more  reliable  than 
a  single  prolonged  boiling,  unless  this  be  effected  at  a  higher  tem- 
perature than  that  of  boiling  water  at  the  ordinary  pressure  of  the 
atmosphere.  Discontinuous  heating  is  especially  useful  for  the  sterili- 
zation of  liquids  which  would  be  injured  by  prolonged  boiling — as  is 
the  case  with  solutions  of  gelatin — or  which  are  coagulated  by  the 
boiling  temperature.  By  means  of  a  water  bath,  the  temperature 
of  which  is  regulated  automatically,  we  may  conduct  the  operation 
at  any  desired  degree.  Thus  in  sterilizing  blood  serum  we  use  a 
temperature  a  little  below  that  at  which  coagulation  occurs  (about 
70°  C.). 

Test  tubes,  flasks,  and  apparatus  of  various  kinds  are  commonly 
sterilized  by  dry  heat  in  a  hot-air  oven.  This  is  usually  made  of 
.sheet  iron,  with  double  walls,  and  shelves  for  supporting  the  articles 


52  STERILIZATION   OF   CULTURE   MEDIA. 

to  be  sterilized.  The  form  shown  in  Fig.  23  is  commonly  used  in 
bacteriological  laboratories. 

It  must  be  remembered  that  a  much  higher  temperature  is  re- 
quired for  the  destruction  of  microorganisms  when  dry  heat  is  em- 
ployed than  is  the  case  with  moist  heat.  The  experiments  of  Koch 
and  Wolffhugel  (1881)  show  that  a  temperature  of  120°  to  128°  C. 
(248°  to  262°  F.)  is  required  to  destroy  the  spores  of  mould  fungi,  and 
micrococci  or  bacilli  in  the  absence  of  spores.  For  the  spores  of  ba- 
cilli a  temperature  of  140°  C.  (284°  F.),  maintained  for  three  hours, 
was  required. 

In  practice  we  usually  maintain  a  temperature  of  about  150°  C. 


FIG.  23. 

(302°  F.)  for  an  hour  or  more ;  and  it  is  customary  to  sterilize  all 
test  tubes  and  flasks,  which  are  to  be  used  as  receptacles  for  culture 
media,  in  the  hot-air  sterilizer.  This  procedure  could  no  doubt,  how- 
ever, be  dispensed  with  in  many  cases  and"  reliance  be  placed  upon 
the  sterilization  of  the  flask,  together  with  its  contents,  in  the  steam 
sterilizer,  especially  with  such  culture  media  as  are  not  injured  by 
long  exposure  to  a  boiling  temperature — e.  g. ,  bouillon  and  agar-agar. 
When  we  propose  to  cultivate  aerobic  bacteria,  or  such  as  require 
oxygen  for  their  development,  a  cotton  air  filter  is  placed  in  the 
mouth  of  each  test  tube  and  flask  before  it  is  sterilized  in  the  hot-air 
oven.  This  is  a  loose  plug  of  cotton,  pushed  into  the  neck  of  the 
flask  for  an  inch  or  more,  and  projecting  from  its  mouth  for  a  short 
distance.  These  cotton  filters  should  fill  the  tube  completely  and 


STERILIZATION   OF   CULTURE   MEDIA. 


53 


uniformly,  but  should  not  be  packed  so  closely  that  there  is  difficulty 
is  removing  them. 

Steam  Sterilizers. — Steam  at  the  ordinary  pressure  of  the  atmo- 
sphere has  the  same  temperature  as  boiling  water,  and  in  practice  is 
preferable  to  a  water  bath  for  several  reasons.  The  form  of  steam 
sterilizer  adopted  by  Koch,  after  extensive  experiments  made  in  col- 
laboration with  Loftier  and  Gaffky,  is  now  generally  used  in  bacte- 
riological laboratories.  This  is  shown  in  Fig.  24.  It  consists  of  a 
cylindrical  vessel  of  zinc  which  is  covered  with  a  jacket  of  felt. 
The  cover,  also  covered  with  non-conducting  material,  has  an  aper- 
ture at  the  top  for  the  escape  of  steam.  A  glass  tube,  which  is  in 
communication  with  the  interior  of  the  vessel,  serves  to  show  the 


FIG.  24. 


FIB.  55 


height  of  the  water  when  the  apparatus  is  in  use.  The  bottom  of 
the  cylindrical  vessel  should  be  of  copper.  A  Bunsen  burner  having 
three  jets  will  commonly  be  required  to  keep  the  water  in  ebullition 
and  the  upper  part  of  the  steam  sterilizer  filled  with  "live  steam," 
which  should  escape  freely  from  the  aperture  in  the  cover  to  insure 
a  temperature  of  100°  C.  in  the  steam  chamber.  A  perforated  zinc 
or  copper  shelf  in  the  interior  of  the  cylinder  serves  to  support  the 
flasks,  etc.,  which  are  to  be  sterilized.  Usually  they  are  lowered 
into  the  cylinder  in  a  light  wire  basket,  or  tin  pail  with  perforated 
bottom,  of  proper  diameter  to  sli-p  easily  into  the  sterilizer. 

Fig.  25  is  a  sectional  view  of  this  sterilizer. 

The  steam  sterilizer  shown  in  Fig.  26  '  is  an  American  invention, 

1  The  Arnold  steam  sterilizer,  manufactured  at  Rochester,  N.  Y. 


54 


STERILIZATION   OF   CULTURE   MEDIA. 


which  answers  the  purpose  admirably,  and  which  has  the  advantage 
of  getting  up  steam  very  quickly  and  also  of  using  comparatively 
little  gas. 

The  use  of  steam  under  pressure,  by  which  higher  temperatures 
are  obtained,  requires  a  more  expensive  apparatus,  made  on  the 
principle  of  Papin's  digester.  The  form  manufactured  by  Miincke 
is  one  of  the  best.  This  is  shown  in  Fig.  27.  It  is  provided  with  a 
pressure  gauge  and  a  safety  yalve.  A  single  sterilization  in  this  ap- 
paratus, at  a  temperature  of  115°  C.,  for  half  an  hour,  will  usually 


FIG.  26. 


Fro.  27. 


suffice,  and  for  liquid  culture  media  or  for  agar-agar  this  method  is 
entirely  satisfactory  ;  but  a  gelatin  medium  which  is  exposed  to  this 
temperature  loses  its  property  of  forming  a  jelly  at  20°  to  22°  C.,  and 
consequently  its  value  as  a  solid  culture  medium.  In  practice  the 
simpler  form  of  apparatus  in  which  streaming  steam  is  used  will  be 
found  to  answer  every  requirement.  To  insure  sterilization  with 
this  it  is  customary  to  resort  to  discontinuous  heating,  as  heretofore 
described.  The  standard  flesh-peptone-gelatin  medium  should,  as 
a  rule,  be  subjected  to  a  temperature  of  100°  C.  for  ten  minutes,  at 
intervals  of  twenty-four  hours,  four  days  in  succession.  Bouillon, 
flesh  infusions,  and  agar-agar  jelly  may  be  steamed  for  an  hour  at  a 
time  two  or  three  days  in  succession. 


STERILIZATION   OF   CULTURE   MEDIA.  55 

It  is  always  advisable  to  test  the  sterilization  of  culture  material 
before  making  use  of  it.  This  is  done  by  placing  it  for  a  few  days 
in  an  incubating  oven  at  30°  to  35°  C.  If  a  considerable  quantity  of 
material  in  test  tubes  has  been  prepared  at  one  time,  it  will  be  suffi- 
cient to  put  a  few  tubes  in  the  incubating  oven  to  test  sterilization. 

Failure  to  make  this  test  often  leads  to  serious  complications  in 
experimental  investigations.  A  laboratory  sometimes  becomes  in- 
fected with  resistant  spores,  which  are  not  all  destroyed  by  the  usual 
methods  of  sterilization,  and  these  may  not  develop  until  some  time 
has  elapsed  after  the  supposed  sterilization. 

Sterilized  ion  of  Blood  Serum. — Blood  serum  which  has  been 
collected  in  test  tubes  or  small  flasks,  as  heretofore  directed,  is 


FIG.  28. 

sterilized  in  a  water  bath  at  GO0  C.  (140°  F.)  by  the  method  of  dis- 
continuous heating.  It  is  usually  left  in  the  hot-water  bath  for 
about  an  hour,  and  this  is  repeated,  at  intervals  of  twenty-four  hours, 
for  five  to  seven  days.  This  rather  tedious  process  may  be  avoided 
by  collecting  the  serum  in  the  first  instance  with  proper  precautions 
to  prevent  it  from  becoming  contaminated  with  atmospheric  organ- 
isms. A  special  apparatus  was  devised  by  Koch  for  sterilizing  blood 
serum,  but  an  improvised  hot-water  bath  which  is  regulated  to  a 
temperature  of  00°  C.  by  an  automatic  thermo-regulator  will  answer 
the  purpose.  After  being  sterilized  the  serum  is  solidified  by  careful 
exposure  to  a  temperature  of  about  08°  C.,  which  causes  it  to  co- 
agulate, forming  a  transparent,  jelly-like  mass.  When  coagulated 
at  a  higher  temperature  it  becomes  opaque.  The  time  required  for 
this  operation  varies  from  half  an  hour  to  an  hour,  and  it  is  best  to 
remove  the  tubes  from  the  receptacle  in  which  they  are  exposed  to 


56 


STERILIZATION   OF   CULTURE   MEDIA. 


heat  as  soon  as  the  serum  is  solidified.  Koch's  apparatus  for  coagu- 
lating blood  serum  is  shown  in  Fig.  28.  It  is  customary  to  place  the 
test  tubes  in  an  oblique  position,  so  that  a  large  surface  may  be  ex- 
posed upon  which  to  cultivate  the  tubercle  bacillus  or  whatever 
microorganism  may  be  under  investigation.  A  form  of  apparatus 
designed  for  both  sterilizing  and  coagulating  blood  serum  is  shown 
in  Fig.  29.  It  is  manufactured  by  Miincke  in  accordance  with  the 
directions  of  Hueppe,  and  special  precautions  have  been  taken  to  se- 
cure a  uniform  temperature  in  all  parts  of  the  air  chamber.  We 


FIG.  29. 


may  remark  that  since  it  has  been  shown  by  Roux  and  Nocard  that 
the  tubercle  bacillus  grows  very  well  in  agar-agar  jelly  to  which 
five  per  cent  of  glycerin  has  been  added,  blood  serum  is  not  so 
largely  used  as  a  culture  medium  in  bacteriological  laboratories. 

Sterilization  by  Filtration.— This  method  is  especially  useful 
for  separating  the  soluble  substances  contained  in  a  liquid  culture  of 
bacteria  from  the  living  cells.  It  has  been  demonstrated  that  several 
of  the  most  important  pathogenic  bacteria  produce  toxic  substances 
during  their  growth  which  may  cause  the  death  of  susceptible  ani- 
mals independently  of  the  living  bacteria ;  and  this  demonstration 


STERILIZATION   OF   CULTURE   MEDIA.  57 

has  been  made  either  by  sterilizing  a  pure  culture  by  means  of  heat, 
or  by  separating  the  bacteria  from  the  culture  liquid  by  filtration. 
Some  of  these  toxic  products  of  bacterial  growth  are  destroyed  by  a 
comparatively  low  temperature  ;  the  method  of  sterilization  by  fil- 
tration is  therefore  very  important  in  researches  relating  to  the 
composition  and  pathogenic  power  of  these  soluble  products.  Pas- 
teur, in  his  earlier  experiments,  used  plaster  of  Paris  as  a  filter,  and 


Fig.  30. 


subsequently  resorted  to  the  use  of  unglazed  porcelain,  through 
which  a  liquid  may  be  forced  by  pressure,  but  which  does  not  per- 
mit of  the  passage  of  suspended  particles,  however  small. 

As  the  porcelain  filter  is  the  most  reliable  and  convenient  for 
accomplishing  the  object  in  view,  we  shall  not  describe  other  methods 
of  filtration  which  have  been  proposed  and  successfully  used.  The 
porcelain  used  is  a  very  fine  paste,  manufactured  at  Sevres,  which  is 
moulded  into  cylinders  (bougies)  of  the  form  proposed  by  Chamber- 
lain and  baked  at  a  high  temperature. 


58 


STERILIZATION   OF   CULTURE   MEDIA. 


In  Fig.  30  the  Pasteur-Chamberlain  filter  is  shown  as  arranged 
for  the  filtration  of  water.  A  is  the  hollow  porcelain  cylinder,  which 
is  enclosed  in  a  metal  case,  D.  The  metal  case  is  tightly  clamped 
against  a  projecting  shoulder  at  the  lower  part  of  the  porcelain  filter, 
a  ring  of  rubber  being  interposed  to  secure  a  tight  joint.  When 
water  under  pressure  is  admitted  to  the  space  E,  between  the  cylin- 
der of  porcelain  and  the  metal  case,  it  slowly  filters  through,  and, 
running  down  the  inner  wall  of  the  filter,  escapes  at  B  into  a  recep- 
tacle placed  to  receive  it.  If  we  fill  the  space  E  with  a  liquid  cul- 
ture of  bacteria  and  apply  sufficient  pressure  (one  or  two  atmo- 
spheres), a  clear  filtrate  is  obtained  which  is  entirely  sterile  if  the 
porcelain  filter  is  sound  and  made  of  proper  material.  After  the 


Fio.  31. 

filter  has  been  in  use  for  some  time,  however,  it  may  permit  the  pas- 
sage of  bacteria,  and  it  will  be  necessary  to  subject  it  to  a  high  tem- 
perature for  the  purpose  of  destroying  all  organic  matter  contained 
in  the  porous  porcelain. 

We  may  use  the  Chamberlain  filter  without  a  metal  case  by  im- 
mersing it  in  a  cylindrical  glass  vessel  containing  the  liquid  to  be  fil- 
tered, as  shown  in  Fig.  31.  The  porcelain  cylinder  is  connected  with 
an  aspirator  bottle,  a,  and  a  small  Erlenmeyer  flask,  6,  is  interposed 
to  catch  the  filtrate  when  it  overflows  from  the  interior  of  the  filter. 
Of  course  all  the  necessary  precautions  must  be  taken  with  reference 
to  the  sterilization  of  the  interior  of  the  bougie,  of  the  flask  b,  and  of 
the  rubber  tube  connecting  the  two. 

Another  arrangement  of  the  Pasteur-Chamberlain  filter  for  labora- 
tory purposes  is  shown  in  Fig.  32.  In  this  form  of  apparatus  a 


STERILIZATION   OF   CULTURE   MEDIA.  59 

receptacle,  R,  is  provided  for  the  liquid  to  be  filtered,  and  a  pump  for 
compressing  air  is  attached  to  it  by  a  rubber  tube.  Instead  of  this 
pump,  water  pressure  may  be  used  indirectly  by  attaching  a  strong 
bottle  to  the  water  supply  and  allowing  it  to  fill  slowly  with  water, 
and  at  the  same  time  to  force  out  the  air  through  a  tube  connected 
with  the  filtering  apparatus.  For  this  purpose  the  bottle,  having  a 
capacity  of  a  quart  or  more,  should  be  provided  with  a  rubber  stop- 
per through  which  two  short  tubes  are  passed.  One  of  these  is  con- 
nected with  the  water  supply  and  the  other  with  the  filter.  Of 
course  this  is  only  practicable  when  a  water  supply  with  sufficient, 
pressure  is  available. 


FIG.  32. 

As  a  rule,  filtration  cannot  be  substituted  with  advantage  for  ster- 
ilization by  heat  in  the  preparation  of  culture  media.  Albuminous 
liquids  pass  through  the  filter  with  difficulty,  and  the  process  of 
sterilization  by  discontinued  heating  will  usually  prove  more  satis- 
factory than  filtration,  which  requires  extreme  precautions  to  pre- 
vent accidental  contamination  of  the  filtered  liquid.  Moreover,  the 
filter  may  change  the  composition  of  the  medium  passed  through  it 
by  preventing  the  passage  of  colloid  and  albuminous  material  in  so- 
lution. Thus,  in  an  attempt  to  separate  blood  corpuscles  from  the 
serum  by  filtration  through  a  Chamberlain  filter,  the  writer  obtained 
a  transparent  liquid  which  did  not  coagulate  by  heat — i.e.,  the  albu- 
minous constituents  of  the  serum  did  not  pass  through  the  filter. 


VII. 

CULTURES   IN   LIQUID   MEDIA. 

to  the  introduction  of  gelatinous  media  by  Koch  in  1881, 
cultures  were  made  in  various  organic  liquids,  and  these  are  still 
largely  used,  being  for  certain  purposes  preferable  to  solid  media. 
The  method  of  preparing  and  sterilizing  the  flesh  infusions  and 
other  organic  liquids  commonly  used  has  already  been  given.  We 
are  here  concerned  with  the  various  modes  of  using  these  nutritive 
liquids  in  cultivating  bacteria. 

Flasks  and  tubes  of  various  forms  have  been  employed  by  differ- 
ent investigators,  but  the  most  useful  receptacle  for  liquid  as  well  as 
for  solid  culture  media  is  the  ordinary  test  tube.  These  are  care- 
full}'  cleaned,  plugged  with  a  cotton  air  filter,  sterilized  in  the  hot-air 
oven  at  150°  C.,  and  are  then  ready  to  receive  the  filtered  liquid. 
Usually  the  tube  should  not  be  filled  to  more  than  one-third  to  one- 
half  of  its  capacity.  Sterilization  of  the  culture  liquid  is  then  effected 
by  placing  the  tubes  in  the  steam  sterilizer  for  half  an  hour  on  three 
successive  days.  Before  using,  the  tubes  should  be  placed  for  a  few 
days  in  an  incubating  oven  at  30°  to  35°  C.  to  test  the  sterilization. 
This  is  especially  important  with  liquid  media,  for  if  a  single  living 
spore  is  present  it  may  give  rise  to  an  abundant  progeny,  which  will 
be  distributed  through  the  liquid  in  association  with  the  species 
which  has  been  planted.  In  solid  cultures,  on  the  contrary,  such  a 
spore  would  give  rise  to  a  colony,  which  by  its  locality  and  characters 
of  growth  would  probably  be  recognized  as  different  from  the  species 
planted,  and  consequently  accidental.  This  is  the  great  danger  in 
the  use  of  liquid  media  ;  imperfect  sterilization,  or  accidental  contami- 
nation by  atmospheric  germs,  may  lead  the  inexperienced  student 
into  serious  errors  resulting  from  the  assumption  that  the  micro- 
organisms present  in  his  cultures  are  all  derived  from  the  seed  he 
planted. 

On  the  other  hand,  liquid  media  are  more  convenient  than  solid 
when  it  is  the  intention  to  isolate  by  filtration  the  soluble  products  of 
bacterial  growth;  for  injection  into  animals  to  test  pathogenic  power; 
for  experiments  on  the  germicidal  or  antiseptic  power  of  chemical 
agents,  etc. 


CULTURES   IN   LIQUID   MEDIA. 


61 


For  larger  quantities  of  liquid  than  can  be  held  in  an  ordinary 
test  tube  the  small  flasks  with  a  flat  bottom,  known  as  Erlenmeyer 
flasks,  are  very  convenient  (Fig.  33). 

In  his  earlier  researches  Pasteur  used  flasks  and  tubes  of  various 
forms,  which  served  a  useful  purpose,  but  have  been  displaced  in  his 
laboratory  by  the  simpler  form  of  apparatus  shown  in  Fig.  34. 
This  is  a  little  flask  having  a  cover  which  is  ground  to  fit  the  neck. 
This  cover  is  drawn  out  above  into  a  narrow  tube  which  admits 
oxygen  to  the  flask  through  a  cotton  air  filter.  To  obtain  access 
to  the  interior  of  the  flask  for  the  purpose  of  introducing  bacteria 
to  start  a  culture,  or  to  obtain  material  for  microscopical  examina- 
tion, the  cover  is  detached  at  the  ground  joint  by  a  gentle  twisting 
motion. 

There  is  much  less  danger  that  a  sterile  culture  liquid  will  become 


FIG.  33. 


FIG.  31. 


contaminated  during  the  momentary  removal  of  the  cover  from, 
one  of  these  little  flasks,  or  of  the  cotton  plug  from  a  test  tube,  than 
is  usually  supposed.  Abundant  laboratory  experience  demonstrates 
that  such  contamination  by  bacteria  floating  in  the  atmosphere  rarely 
occurs.  The  spores  of  mould  fungi  are  commonly  more  abundant 
in  the  air,  but  even  these  do  not  very  frequently  fall  into  the  culture 
liquid  when  the  tube  is  opened  to  inoculate  it  with  the  bacteria  it  is 
proposed  to  cultivate.  This  inoculation  is  best  made  with  a  platinum 
wire,  bent  into  a  loop  at  the  free  extremity,  and  sealed  fast  into  the 
end  of  a  glass  rod  (Fig.  35).  This  is  sterilized  in  the  flame  of  a 
Bunsen  burner  or  alcohol  lamp  by  bringing  the  platinum  wire  to  a 
red  heat  and  passing  the  end  of  the  glass  rod  which  carries  it 
through  the  flame  several  times.  With  this  instrument  we  may 
transfer  a  little  drop  from  a  culture  to  the  sterile  fluid  in  another 


32  CULTURES   IN   LIQUID   MEDIA. 

tube  for  the  purpose  of  starting  a  new  culture.  Or  we  may  start  a 
pure  culture  from  a  drop  of  blood  taken  from  the  veins  of  an  animal 
-which  has  been  inoculated  Math  anthrax,  or  any  similar  infectious 
disease  in  which  the  blood  is  invaded  by  a  bacterial  parasite. 

But  if  we  have  not  a  pure  culture  to  start  with  our  liquid  media 
do  not  afford  us  the  means  of  obtaining  one  ;  and  if  two  or  more 
bacteria  which  resemble  each  other  in  their  morphology  are  associated 
in  such  a  culture  we  cannot  differentiate  them,  and  are  likely  to  infer 
that  we  have  a  pure  culture  of  a  single  microorganism  when  this  is 
not  really  the  case. 

But  if  we  have  pure  stock  to  start  with  we  may  maintain  pure 
cultures  in  liquid  media  without  any  special  difficulty. 

Various  characters  of  growth,  etc.,  are  to  be  observed  in  culti- 
vating different  microorganisms  in  liquid  media.  Thus  some  grow 
at  the  surface  in  the  form  of  a  thin  film  or  membranous  layer — "  my- 
coderma  " — while  others  are  distributed  uniformly  through  the  liquid, 
rendering  it  opalescent  or  more  or  less  milky  and  opaque  ;  others, 
again,  form  little  flocculi  which  are  suspended  in  the  transparent 


FIG.  35. 


fluid.  Usually,  when  active  growth  has  ceased,  the  bacteria  fall  to 
the  bottom  of  the  tube  as  a  more  or  less  abundant,  white  or  colored, 
pulverulent  or  glutinous  deposit.  In  some  cases  the  liquid  is  colored 
with  a  soluble  pigment  formed  during  the  growth  of  the  bacteria, 
and  usually  this  is  formed  most  abundantly  at  the  surface,  where 
there  is  free  access  of  oxygen.  The  reaction  of  the  medium  is  often 
changed  as  a  result  of  the  growth  of  bacteria  in  it.  From  being  neu- 
tral it  may  become  decidedly  alkaline  or  acid  in  its  reaction.  These 
changes  may  be  observed  by  adding  a  litmus  solution  before  sterili- 
zation of  the  culture  medium,  and  observing  the  change  of  color 
when  an  acid-producing  bacterium  is  under  cultivation.  The  re- 
ducing power  of  bacteria  upon  various  aniline  colors  may  also  be 
studied  ;  also  their  power  to  break  up  various  organic  substances,  as 
shown  by  the  evolution  of 'gas  or  other  volatile  products  which 
may  be  collected,  or  by  substances  which  remain  in  solution  and 
can  be  studied  by  ordinary  chemical  methods. 

Drop  Cultures. — When  we  desire  to  study  the  life  history  of  a 
microorganism  and  to  witness  its  development  from  spores,  for  ex- 
ample, its  motions,  etc. ,  the  method  of  cultivation  in  a  hanging  drop 


CULTURES   IN   LIQUID   MEDIA.  63 

of  culture  fluid,  attached  to  a  thin  glass  cover  and  suspended  over  a 
circular  excavation  ground  out  of  a  glass  slide,  is  very  useful. 
Such  a  drop  culture  may  be  left  under  the  microscope  and  kept 
under  observation  for  hours  or  days. 

In  making  these  drop  cultures  it  is  necessary  to  sterilize  the  glass 
slides  and  thin  glass  covers  by  heat,  and  to  take  every  precaution  to 
prevent  the  inoculation  of  the  drop  of  culture  liquid  with  any  other 
bacteria  than  those  which  are  to  be  studied. 

The  simplest  form  of  moist  chamber  for  drop  cultures  consists  of 
an  ordinaiy  glass  slide  having  a  concave  depression,  about  fifteen 
millimetres  in  diameter,  ground  out  in  its  centre.  This  and  the  thin 
glass  cover,  having  been  sterilized  by  exposure  in  the  hot-air  oven  at 
150°  C.  for  an  hour  or  more,  or  by  passing  them  through  the  flame 
of  an  alcohol  lamp,  are  ready  for  use.  The  cover  glass  is  held  in 
sterile  forceps,  and  a  little  drop  of  the  culture  fluid  containing  the 
bacterium  to  be  studied  is  transferred  to  its  centre  by  means  of  the 
platinum  loop  heretofore  described.  It  is  best  to  spread  the  drop 
out  as  thin  as  possible,  and  it  may  be  inoculated,  from  a  pure  cul- 


FIG.  86. 


ture,  with  a  platinum  needle  (Fig.  36)  after  it  has  been  placed  upon 
the  cover.  This  is  then  inverted  over  the  hollow  place  in  the  glass 
slide,  and  it  is  customary  to  prevent  the  entrance  of  air  and  attach 
the  cover  by  spreading  a  little  vaseline  around  the  margin  of  the 
"  excavation. 

Another  form  of  moist  chamber  is  made  by  attaching  a  glass 
ring,  having  parallel,  ground  surfaces,  to  the  centre  of  a  glass  slide 
by  a  suitable  cement. 

In  Ranvier's  moist  chamber  there  is  a  central  eminence  sur- 
rounded by  a  groove  ground  into  the  glass  slide,  and  the  drop  of 
culture  fluid  is  in  contact  with  a  polished  glass  surface  below  as  well 
as  above.  This  affords  a  more  satisfactory  view  under  the  micro- 
scope. 

The  Author's  Culture  Method. — In  a  paper  read  at  the  meeting 
of  the  American  Association  for  the  Advancement  of  Science,  in 
August,  1881,  the  writer  described  a  method  of  conducting  culture 
experiments  which  he  has  since  used  extensively  and  with  very  satis- 
factory results.  The  liquid  culture  medium  is  preserved  in  little  flasks 
having  a  long  neck  which  is  hermetically  sealed.  The  principal  ad- 
vantages connected  with  the  use  of  these  little  flasks,  or  "  Stern- 


64  CULTURES   IN   LIQUID   MEDIA. 

berg's  bulbs,"  as  they  are  sometimes  called,  are  that  a  culture  me- 
dium may  be  preserved  in  them  indefinitely  and  that  they  are  easily 
transported  from  place  to  place;  whereas  test  tubes,  Pasteur's  flasks, 
and  similar  receptacles  must  be  kept  upright,  and  after  a  time  the 
culture  liquid  in  them  is  changed  in  its  composition  by  evaporation. 
They  are  also  liable  to  be  contaminated  by  the  entrance  of  mould 
fungi  when  kept  in  a  damp  place.  The  spores  of  these  fungi,  falling 
upon  the  surface  of  the  cotton  air  filter,  germinate,  and  the  myce- 
lium grows  down  through  the  cotton  into  the  interior  of  the  tube, 
where  a  new  crop  of  spores  is  quickly  formed.  It  is,  therefore,  a 
convenience  to  have  sterile  culture  liquids  always  ready  for  use  in 
a  receptacle  which  can  be  packed  in  a  box  and  transported  from 
place  to  place  ;  but  for  every-day  use  in  the  laboratory  the  ordinary 


FIG.  37. 

test  tube,  with  its  cotton  air  filter,  is  the  most  economical  and  conve- 
nient receptacle  for  culture  liquids  as  well  as  for  solid  media.  With 
reference  to  the  method  of  making  and  using  these  little  flasks,  I 
quote  from  a  paper  published  in  the  American  Journal  of  the 
Medical  Sciences  in  1883  :' 

The  culture  flasks  employed  contain  from  one  to  four  fluidrachms. 
They  are  made  from  glass  tubing  of  three-  or  four- tenths  inch  diameter,  and 
those  which  the  writer  has  used  in  his  numerous  experiments  have  all  been 
"  home-made."  It  is  easier  to  make  new  flasks  than  to  clean  old  ones,  and 
they  are  thrown  away  after  being  once  used.  Bellows  operated  by  foot,  and 
a  flame  of  considerable  size — gas  is  preferable — will  be  required  by  one  who 
proposes  to  construct  these  little  flasks  for  himself.2  After  a  little  practice 
they  are  made  rapidly ;  but  as  a  large  number  are  required,  the  time  and 
labor  expended  in  their  preparation  are  no  slight  matter.  After  blowing  a 
bulb  at  the  extremity  of  a  long  glass  tube,  of  the  diameter  mentioned,  this 
is  provided  with  a  slender  neck,  drawn  out  in  the  flame,  and  the  end  of  this 

1  "  The  Germicide  Value  of  Certain  Therapeutic  Agents,"  op.  cit.,  vol.  clxx. 
9  A  glass-blower  ought  to  make  them  for  two  or  three  dollars  per  hundred. 


CULTURES   IN   LIQUID   MEDIA.  65 

is  hermetically  sealed.  Thus  one  little  flask  after  another  is  made  from  the 
same  piece  of  tubing  until  this  becomes  too  short  for  further  use.  To  intro- 
duce a  culture  liquid  into  one  of  these  little  flasks,  heat  the  bulb  slightly, 
break  off  the  sealed  extremity  of  the  tube  and  plunge  it  beneath  the  surface 
of  the  liquid  (Fig.  37).  The  quantity  which  enters  will  of  course  depend 
upon  the  heat  employed  and  the  consequent  rarefaction  of  the  enclosed  air. 
Ordinarily  the  bulb  is  filled  to  about  one-third  of  its  capacity  with  the  cul- 
ture liquid,  leaving  it  two-thirds  full  of  air  for  the  use  of  the  microscopic 
plants  which  are  to  be  cultivated  in  it.  ...  Sterilization  is  effected  by  heat 
after  the  liquid  has  been  introduced  and  the  neck  of  the  flask  hermetically 
sealed  in  the  flame  of  an  alcohol  lamp. 

Sterilization  may  be  effected  by  boiling  for  an  hour  in  a  bath  of  paraffin 
or  of  concentrated  salt  solution,  by  which  a  temperature  considerably  above 
that  of  boiling  water  is  secured.  The  writer  is  in  the  habit  of  preparing  a 
considerable  number  of  these  flasks  at  one  time,  and  leaving  them,  in  a  suit- 
able vessel  filled  with  water,  for  twenty  four  hours  or  longer  on  the  kitchen 
stove.1 

To  inoculate  the  liquid  contained  in  one  of  these  little  flasks  with  mi- 
croorganisms from  any  source,  the  end  of  the  tube  is  first  heated  to  destroy 
germs  attached  to  the  exterior;  the  extremity  is  then  broken  off  with  steril- 
ized (by  heat)  forceps;  the  bulb  is  very  gently  heated,  so  as  to  force  out  a 
little  air,  and  the  open  end  is  plunged  into  the  liquid  containing  the  organ- 
ism to  be  cultivated  (or  into  a  vein,  or  one  of  the  solid  viscera  of  an  animal 
dead  from  an  infectious  germ  disease,  such  as  anthrax). 

Inoculation  from  one  tube  to  another  may  also  be  effected  by  means  of 
the  ordinary  platinum  wire  needle. 

Before  the  introduction  of  Koch's  plate  method  for  isolating  bac- 
teria in  pure  cultures,  certain  methods  had  been  proposed,  and  em- 
ployed to  some  extent,  which  at  present  have  a  historical  value  only. 

Thus  Klebs  (1873)  proposed  to  take  from  a  first  culture  in  which 
two  or  more  species  were  associated  a  minute  quantity,  by  means  of  a 
capillary  tube,  and  with  this  to  inoculate  a  second  culture.  By  re- 
peating this  procedure  several  times  he  expected  to  exclude  all  except 
the  species  which  was  present  in  the  greatest  abundance  and  which 
multiplied  most  rapidly  in  the  medium  employed. 

The  method  by  dilution,  first  employed  with  precision  by  Brefeld 
(1872)  in  obtaining  pure  cultures  of  mould  fungi,  and  subsequently 
by  Lister  for  the  isolation  of  bacteria,  consists  in  so  diluting  a  minute 
quantity  of  the  mixed  culture  that  the  number  of  bacteria  in  the  dilu- 
tion may  be  less  than  one  for  each  drop  of  the  liquid.  If  now  a 
single  drop  be  added  to  each  of  a  series  of  tubes  containing  a  small 
quantity  of  sterile  bouillon,  some  of  the  inoculations  made  may  give 
a  pure  culture,  as  the  drop  may  have  contained  but  a  single  vege- 
tative cell. 

Another  method  of  obtaining  a  pure  culture  in  liquid  media,  when 
several  microorganisms  are  associated  which  have  a  different  ther- 

1  Where  a  steam  sterilizer  is  at  hand  they  will  be  most  conveniently  sterilized  in 
the  usual  way,  by  subjecting  them  to  the  boiling  temperature  for  an  hour  at  a  time 
on  three  successive  days. 


66  CULTURES   IN   LIQUID    MEDIA. 

mal  death-point,  consists  in  the  application  of  heat  and  thus  destroy- 
ing all  except  the  most  resistant  species.  This  method  io  especially 
applicable  when  one  of  the  species,  only,  forms  spores.  By  subject- 
ing the  mixed  culture  to  a  temperature  which  is  sufficient  to  destroy 
all  the  vegetative  cells  in  it,  the  more  resistant  spores  are  left  and, 
under  favorable  conditions,  may  subsequently  vegetate  and  give  us 
a  pure  culture  of  the  species  to  which  they  belong. 


VIII. 
CULTURES  IN  SOLID  MEDIA. 

THE  introduction  of  solid  culture  media  in  1881  by  the  famous 
German  bacteriologist,  Robert  Koch,  inaugurated  a  new  era  in  the 
progress  of  our  knowledge  relating  to  the  bacteria.  His  methods 
enable  us  to  obtain  pure  cultures  with  ease  and  certainty,  and  to 
study  the  morphological  and  biological  characters  of  each  species 
free  from  the  complications  which  led  to  so  much  error  and  confusion 
before  these  methods  were  introduced.  We  have  already  given  an 
account  of  the  method  of  preparing  and  sterilizing  the  various  solid 
culture  media,  and  are  here  concerned  with  the  manner 
in  which  they  are  used  and  the  special  advantages  which 
they  afford. 

Koch's  flesh-peptone-gelatin,  which  contains  ten  per 
cent  of  gelatin,  is  a  transparent  jelly  which  liquefies  at 
from  22°  to  2-t°  C.  It  is  a  favorable  culture  medium  for 
a  great  number  of  bacteria,  and  many  species  show  de- 
finite characters  of  growth  in  this  medium  which  serve  to 
differentiate  them.  One  of  the  most  prominent  of  these 
characters  depends  upon  the  fact  that  some  bacteria  liquefy 
gelatin  and  others  do  not.  This  is  made  apparent  when 
we  make  stick  cultures — also  called  "stab  cultures." 
This  is  the  usual  manner  of  inoculating  a  solid  culture 
medium,  and  is  illustrated  in  Fig.  38.  A  platinum  needle, 
consisting  of  a  piece  of  platinum  wire  inserted  into  a  glass 
rod  which  serves  as  a  handle,  is  passed  through  the  flame 
of  an  alcohol  lamp  to  sterilize  it.  When  cooled,  which 
occurs  very  quickly,  the  point  is  introduced  into  the  ma- 
terial containing  the  bacteria  to  be  planted  in  the  gelatin 
medium.  We  may  obtain  our  seed  for  a  pure  culture  FlG  ^ 
from  a  single  colony,  from  another  stick  culture,  from  the 
blood  of  an  infected  animal,  etc.  The  point  of  the  needle  is  then 
carried  into  the  sterilized  jelly,  as  shown  in  the  figure,  care  being 
taken  to  introduce  it  in  the  central  line  and  in  a  direction  parallel 


68 


CULTURES   IN   SOLID   MEDIA. 


with  the  sides  of  the  tube.  It  is  best  always  to  hold  the  tube  in- 
verted during  the  inoculation,  and  not  to  remove  the  cotton  air  filter 
until  we  are  ready  to  make  it.  The  cotton  plug  is  then  returned  to 
its  place  and  the  platinum  needle  again  brought  to  a  red  heat  to 
destroy  any  bacteria  which  remain  attached  to  it. 

Sometimes  it  is  an  advantage  to  have  the  culture  medium  with  a 


FIQ.  39. 


sloping  surface,  as  shown  in  Fig.  39.     We  may  then  draw  the  nee- 
dle over  the  surface  in  a  longitudinal  direction,  and  by  this  means 
distribute  the  seed  in  a  line  along  which  development  will  take  place. 
The  characters  of  growth  in  these  stick  cultures  in  gelatin  are 


very  various.  Non-liquefying  bacteria  may  grow  only  on  the  sur- 
face, as  at  a,  Fig.  40;  or  both  on  the  surface  and  along  the  line 
of  puncture,  as  at  b;  or  only  at  the  bottom,  as  at  c.  In  the  first 
case  the  microorganism  is  aerobic — that  is,  it  requires  oxygen,  and 
grows  only  in  the  presence  of  this  gas.  In  the  second  case  it  is 
not  strictly  aerobic,  but  may  grow  either  in  the  presence  of  oxygen 


CULTURES   IN   SOLID   MEDIA. 


69 


or  in  its  absence — a  facultative  anaerobic.  In  the  third  case  the 
microorganism  is  an  anaerobic,  which  cannot  grow  in  the  presence 
of  oxygen,  and  consequently  does  not  grow  upon  the  surface  of  the 
culture  medium  or  along  the  upper  portion  of  the  line  of  puncture. 

Again,  we  have  differences  as  to  the  character  of  growth  upon  the 
surface  or  along  the  line  of  puncture.  The  surface  growth  may  be 
a  little  mass  piled  up  at  the  point  where  the  needle  entered  the  gela- 
tin ;  or  it  may  form  a  layer  over  the  entire  surface,  and  this  may 
be  thin  or  thick,  dry  or  moist,  viscid  or  cream-like,  and  of  various 
colors — green,  blue,  red,  or  yellow,  of  different  shades — or  more  fre- 
quently of  a  milk-white  color. 


The  growth  along  the  line  of  puncture  also  differs  greatly  with 
different  species.  We  may  have  a  number  of  scattered  spherical 
colonies  (a,  Fig.  41),  and  these  maybe  translucent  or  opaque  ;  or  we 
may  have  little  tufts,  like  moss,  projecting  from  the  line  of  puncture 
(b,  Fig.  41)  ;  or  slender,  filamentous  branches  may  grow  out  into  the 
gelatin  (c,  Fig.  41). 

The  liquefying  bacilli  also  present  different  characters  of  growth. 
Thus  liquefaction  may  take  place  all  along  the  line  of  puncture, 
forming  a  long  and  narrow  funnel  of  liquefied  gelatin  (a,  Fig.  42)  ; 
or  we  may  have  a  broad  funnel,  as  at  b  ;  or  a  cup-shaped  cavity,  as 
at  c;  or  the  upper  liquefied  portion  may  be  separated  from  that 
which  is  not  liquefied  by  a  horizontal  plane  surface,  as  at  d. 


70 


CULTURES   IN   SOLID   MEDIA. 


The  characters  of  growth  in  agar-agar  jelly  are  not  so  varied, 
but  this  medium  possesses  the  advantage  of  not  liquefying  at  a  tem- 
perature of  35°  to  38°  C.,  which  is  required  for  the  development  of 
certain  pathogenic  bacteria.  Variations  in  mode  of  growth  are 
also  manifested  in  nutrient  agar  similar  to  those  referred  to  as  pro- 
duced by  non-liquefying  bacteria  in  flesh-peptone-gelatin.  These 
relate  to  the  surface  growth  and  to  growth  along  the  line  of  punc- 
ture. One  character  not  heretofore  mentioned  consists  in  the  for- 
mation of  gas  bubbles  in  stick  cultures  either  in  gelatin  or  agar. 

Colonies. — If  we  melt  the  gelatin  or  agar  in  a  test  tube,  pour 
the  liquid  medium  into  a  shallow  glass  dish  previously  sterilized, 


L'J 


FIG.  42. 

and  allow  it  to  cool  while  properly  protected  by  a  glass  cover,  we 
will  have  a  broad  surface  of  sterile  nutrient  material.  If  now  we  ex- 
pose it  to  the  air  for  ten  or  fifteen  minutes,  and  again  cover  it  and 
put  it  aside  for  two  or  three  days  at  a  favorable  temperature,  we  can 
scarcely  fail  to  have  a  number  of  colonies  upon  the  surface  of  the 
culture  medium,  which  have  been  developed  from  atmospheric  germs 
which  were  deposited  upon  it  during  the  exposure.  Each  of  these 
colonies,  as  a  rule,  is  developed  from  a  single  bacterium  or  spore, 
and  consequently  the  little  mass,  visible  to  the  naked  eye,  which  we 
call  a  colony,  is  a  pure  culture  of  a  particular  species.  In  this  ex- 
periment we  are  more  apt  to  have  colonies  of  mould  fungi  than  of 
bacteria,  but  the  principle  is  the  same,  viz.,  that  a  colony  developed 
from  a  single  germ  is  a  pure  culture.  By  touching  our  platinum. 


CULTURES   IN   SOLID   MEDIA.  71 

needle,  then,  to  such  a  colony,  which  is  quite  independent  of,  and 
well  separated  from,  all  others,  we  may  make  a  stick  culture  in  gela- 
tin or  agar,  and  preserve  the  pure  culture  for  further  study.  This 
is  a  most  important  advantage  which  psrtains  to  the  use  of  -solid 
culture  media.  It  is  a  singular  fact  that,  as  a  rule,  colonies  of  bac- 
teria which  lie  near  each  other  do  not  grow  together,  but  each  re- 
mains distinct.  If  there  are  but  few  colonies,  each  one,  having 
plenty  of  room,  may  grow  to  considerable  size  ;  if  there  are  many 
and  they  are  crowded,  they  remain  small,  but  are  still  independent 
colonies. 

Now,  these  colonies  differ  greatly  in  their  appearance  and  char- 
acters of  growth,  according  to  the  species  (Fig.  43).  Some  are 
spherical,  and  these  may  be  translucent  or  opaque,  or  they  may  have 
an  opaque  nucleus  surrounded  by  a  transparent  zone.  Again,  the 


FIG.  48.— Colonies  of  Bacteria. 

outlines  may  be  irregular,  giving  rise  to  amoeba-like  forms,  or  to  a 
fringed  or  plaited  margin,  or  the  form  may  ba  that  of  a  rosette,  etc.  ; 
or  the  colony  may  appear  to  be  made  up  of  overlapping  scales  or 
masses,  or  of  tangled  filaments ;  or  it  may  present  a  branching 
growth.  In  the  case  of  liquefying  bacteria,  when  the  colonies  have 
developed  in  a  gelatin  medium  they  commonly  do  not  at  once  cause 
liquefaction  of  the  gelatin,  but  at  the  end  of  twenty-four  hours  or 
more  the  gelatin  about  them  commences  to  liquefy  and  they  are 
seen  in  a  little  funnel  of  transparent  liquefied  gelatin  ;  or  in  other 
cases  little  opaque  drops  of  liquefied  gelatin  are  seen,  which,  as  the 
liquefaction  extends,  run  together.  All  of  these  characters  are  bast 
studied  under  a  low-power  lens,  with  an  amplification  of  five  to 
twenty  diameters  ;  and  by  a  careful  observation  of  the  differences  in 
the  form  and  development  of  colonies  we  are  greatly  assisted  in  the 
differentiation  of  species. 

Single,  isolated  colonies  do  not  always  contain  a  single  species, 
for  they  are  not  always  develops!  from  a  single  cell.     We  may  have 


72  CULTURES   IN   SOLID   MEDIA. 

deposited  upon  our  plate,  exposed  as  above  described,  a  little  mass 
of  organic  material  containing  two  or  more  different  bacteria,  and 
this  would  serve  as  the  nucleus  of  a  colony  from  which  we  could  not 
obtain  a  pure  culture. 

Koch's  Plate  Method. — In  the  experiment  above  described, 
colonies  were  obtained  from  air-borne  germs  which  were  deposited 
upon  the  surface  of  our  gelatin  medium.  By  Koch's  famous  ' '  plate 
method  "  we  obtain  colonies  of  any  particular  microorganism  which 
we  desire  to  study,  or  of  two  or  more  associated  bacteria  which  we 
desire  to  study  separately  in  pure  cultures.  Evidently,  when  we 
have  obtained  separate  colonies  of  different  bacteria  upon  the  sur- 
face of  a  solid  culture  medium,  we  can  easily  obtain  a  pure  culture 
of  each  by  inoculating  stick  cultures  from  single  colonies. 

To  obtain  separate  colonies  we  resort  to  the  ingenious  method  of 
Koch.  Three  test  tubes  containing  a  small  quantity  of  nutrient 
gelatin  (or  of  agar)  are  commonly  employed.  The  tubes  are  num- 
D3red  1,  2,  and  3.  The  first  step  consists  in  liquefying  the  nutrient 
jelly  by  heat,  and  it  will  be  well  for  beginners  to  place  the  tubes  in 
a  water  bath  having  a  temperature  of  about  40°  C.  (104°  F.)  for  the 
purpose  of  keeping  the  culture  material  liquid,  and  at  the  same  time 
at  a  temperature  which  is  not  high  enough  to  destroy  the  vitality  of 
the  bacteria  which  are  to  be  planted.  We  next,  by  means  of  a 
platinum-wire  loop  or  the  platinum  needle  used  for  stick  cultures, 
introduce  into  tube  No.  1  a  small  amount  of  the  culture,  or  material 
from  any  source,  containing  the  bacteria  under  investigation.  Care 
must  be  taken  not  to  introduce  too  much  of  this  material,  and  it 
must  be  remembered  that  the  smallest  visible  amount  may  contain 
many  millions  of  bacteria.  The  reason  for  using  three  tubes  will 
now  be  apparent.  It  is  usually  impossible  to  introduce  a  few  bac- 
teria into  tube  No.  1,  but  we  effect  our  object  by  dilution,  as  follows  : 
With  the  platinum-wire  loop  we  take  up  a  minute  drop  of  the  fluid  in 
tube  No.  1,  through  which  the  bacteria  have  been  distributed  by 
stirring,  and  carry  it  over  to  tube  No.  2.  Washing  off  the  drop  by 
stirring,  we  may  repeat  this  a  second  or  third  time — this  is  a  matter 
of  judgment  and  experience ;  often  it  will  suffice  to  carry  over  a 
single  ose  (the  German  name  for  the  platinum- wire  loop).  Next 
we  carry  over  one,  or  two,  or  three  ose  from  tube  No.  2  to  tube  No. 
3.  By  this  procedure  we  commonly  succeed  in  so  reducing  the  num- 
ber of  bacteria  in  tube  No:  3  that  only  a  few  colonies  will  develop 
upon  the  plate  which  we  subsequently  make  from  it;  or  it  may  happen 
that  the  dilution  has  been  carried  too  far  and  that  no  colonies  de- 
velop upon  the  plate  made  from  this  tube,  in  which  case  we  are 
likely  to  get  what  we  want  from  tube  No.  2.  The  next  step  is  to 
pour  the  liquid  gelatin  upon  sterilized  glass  plates,  which  are  num- 


CULTURES   IN   SOLID   MEDIA.  73 

bered  to  correspond  with  the  tubes.  The  plates  used  by  Koch  are 
from  eight  to  ten  centimetres  wide  and  ten  to  twelve  centimetres 
long.  They  must  be  carefully  cleaned  and  sterilized  in  the  hot-air 
oven,  at  150°  C.,  for  two  hours.  They  may  be  wrapped  in  paper  be- 
fore sterilization,  or  placed  in  a  metal  box  especially  made  for  the 
purpose.  In  order  that  the  liquid  gelatin  may  be  evenly  distributed 
upon  the  plate  the  apparatus  shown  in  Fig.  44  is  used.  This  con- 
sists of  a  glass  plate,  g,  supported  by  a  tripod  having  adjustable  feet. 
By  means  of  the  spirit  level  I  the  glass  plate  is  adjusted  to  a  hori- 
zontal position.  The  sterilized  glass  plate  is  placed  in  a  glass  tray, 
shown  in  the  figure,  and  the  gelatin  from  one  of  the  tubes  is  care- 
fully poured  upon  it  and  distributed  upon  its  surface  with  a  steril- 
ized glass  rod,  care  being  taken  not  to  bring  it  too  near  the  edge  of 
the  plate.  The  glass  tray  in  then  covered  until  the  gelatin  has 
cooled  sufficiently  to  become  solid,  after  which  plate  No.  1  is  re- 
moved and  plates  Nos.  2  and  3  are  made  in  the  same  way.  In 


FIG.  44. 

order  to  save  time  it  is  customary  to  fill  the  glass  tray  shown  in  the 
figure  with  ice  water,  to  place  a  second  glass  support  upon  it,  and 
upon  this  the  sterilized  glass  plate  upon  which  the  liquid  gelatin  is 
poured.     This  is  protected  by  a  glass  cover,  as  before,  until  the  gela- ' 
tin  becomes  solid. 

The  three  plates,  prepared  as  directed,  are  put  aside  in  a  glass 
jar  of  the  form  shown  in  Fig.  44,  one  being  supported  above  the 
other  by  a  bench  of  sheet  zinc  or  glass. 

Petri's  Dishes. — A  modification  of  the  plate  method  of  Koch, 
which  has  some  advantages,  consists  in  the  use  of  three  small  glass 
dishes  of  the  same  form  as  the  larger  one  used  by  Koch  to  contain 
the  plates.  These  dishes  of  Petri  are  about  ten  to  twelve  centime- 
tres in  diameter  and  one  to  1.5  centimetres  high,  the  cover  being  of 
the  same  form  as  the  dish  into  which  the  gelatin  is  poured.  These 
dishes  take  less  room  in  the  incubating  oven  than  the  larger  glass 
jar  used  in  the  plate  method,  and  they  do  not  require  the  use  of  a 
levelling  apparatus.  The  colonies  also  may  be  examined  and 
counted,  if  desired,  without  removing  the  cover,  and  consequently 


74 


CULTURES   IN   SOLID   MEDIA. 


without  the  exposure  which  occurs  when  a  plate  prepared  by  Koch's 
method  is  under  examination. 

In  agar-agar  cultures  or  in  gelatin  cultures  of  non-liquefying 
bacteria  made  in  Petri's  dishes,  we  may  examine  and  count  colonies, 
without  removing  the  cover,  by  inverting  the  dish. 

In  pouring  the  liquefied  gelatin  from  the  test  tubes  in  which  the 
dilution  has  been  made  into  sterilized  Petri's  dishes,  care  must  be 
taken  to  first  sterilize  the  lip  of  the  test  tube  by  passing  it  through 
the  flame  of  a  lamp.  We  may  at  the  same  time  burn  off  the  top  of 
the  cotton  plug,  then  remove  the  remaining  portion  with  forceps, 
when  the  lip  has  cooled,  for  the  purpose  of  pouring  the  liquid  into  the 
shallow  dish. 

Von  Esinarch's  Roll  Tubes. — Another  very  useful  modification 
of  Koch's  plate  method  is  that  of  von  Esmarch.  Instead  of  pouring 
the  liquefied  gelatin  or  agar  medium  upon  plates  or  in  shallow 


FIG.  45. 

dishes,  it  is  distributed  in  a  thin  layer  upon  the  walls  of  the  test  tube 
containing  it.  This  is  done  by  rotating  the  tube  upon  a  block  of  ice 
or  in  iced  water.  Esmarch  first  used  a  tray  containing  iced  water, 
and  to  prevent  the  wetting  of  the  cotton  filter  a  cap  of  thin  rubber 
was  placed  over  the  end  of  the  tube.  It  is  more  convenient  to  turn 
the  tubes  upon  a  block  of  ice  having  a  horizontal  flat  surface,  in 
which  a  shallow  groove  is  first  made  by  means  of  a  test  tube  con- 
taining hot  water  (Fig.  45).  Or,  in  the  winter,  we  may  turn  the 
tube  under  a  stream  of  cold  water  from  the  city  supply — i.e.,  from  a 
faucet  in  the  laboratory.  A  little  practice  will  enable  the  student  to 
distribute  the  culture  medium  in  a  uniform  layer  on  the  walls  of  the 
test  tube,  and  as  soon  as  it  is  quite  solidified  these  may  be  placed 
aside  for  the  development  of  colonies  from  the  bacteria  which  had 
been  introduced.  When  roll  tubes  are  made  from  the  agar  jelly  it  is 
best  to  place  the  tubes  in  a  nearly  horizontal  position,  for  if  placed 
upright  at  once  the  film  of  jelly  is  likely  to  slip  from  the  walls  of  the 


CULTURES   IN   SOLID    MEDIA.  75 

tube.  This  is  due  to  the  fact  that  a  little  fluid  is  pressed  out  of  the 
jelly,  probably  by  a  slight  contraction  while  cooling.  If  the  tubes 
are  slightly  inclined  from  the  horizontal  the  film  does  not  slip  and 
the  fluid  accumulates  at  the  bottom.  After  a  day  or  two  they  may 
be  placed  in  an  upright  position. 

These  roll  tubes  possess  several  advantages.  They  are  quickly 
made  and  take  but  little  space  in  the  incubating  oven,  and  the  film 
of  jelly  is  protected  from  contamination  by  atmospheric  germs. 
When  colonies  have,  formed  we  may  examine  them  through  the  thin 
walls  of  the  tube,  either  with  a  pocket  lens  or  a  low-power  objective. 
In  making  a  stick  culture  from  a  single  colony  in  one  of  these  roll 
tubes,  we  invert  the  tube,  remove  the  cotton  air  filter,  and  pass  the 
point  of  a  sterilized  platinum  needle  up  to  the  selected  colony.  In 
the  same  way  we  obtain  material  for  microscopical  examination. 

Streak  Cultures. — In  his  earlier  experiments  with  solid  culture 
media  Koch  made  "  streak  cultures"  by  drawing  the  point  of  a  plati- 
num needle,  charged  with  bacteria,  over  the  surface  of  a  gelatin  or 
agar  plate  ;  and  this  method  is  still  useful  in  certain  cases.  If  we 
draw  the  needle  over  the  moist  surface  several  times  in  succession 
the  greater  number  of  bacteria  will  be  deposited  in  the  first  streak, 
and  in  the  second  or  third  single  cells  are  likely  to  be  left  at  such 
intervals  from  each  other  that  each  will  develop  an  independent 
colony.  If  the  streaks  were  made  with  impure  stock  we  may  thus 
succeed  in  getting  separate  colonies  of  the  several  bacteria  contained 
in  it,  so  that  this  method  may  be  employed  for  obtaining  pure  cul- 
tures. But  for  this  purpose  it  is  much  inferior  to  the  plate  method, 
and  it  is  chiefly  used  for  observing  the  growth  of  bacteria  on  the  sur- 
face of  solid  culture  media.  Thus  we  commonly  make  a  streak  upon 
the  surface  of  cooked  potato  or  solidified  blood  serum  in  studying  the 
development  of  various  bacteria  on  these  culture  media. 

Cultures  upon  Blood  Serum. — The  use  of  blood  serum  as  a 
solid  medium  is  practically  restricted  to  stick  cultures  and  streak 
cultures,  for  we  cannot  substitute  it  for  the  gelatin  and  agar  media 
in  making  plates  and  roll  tubes.  This  is  because  it  only  becomes  solid 
at  a  temperature  which  would  be  fatal  to  most  bacteria  (70°  C.),  and 
when  once  made  solid  by  heat  cannot  again  be  liquefied.  Its  use  is, 
therefore,  restricted  mainly  to  the  cultivation  of  bacteria  for  which 
it  is  an  especially  favorable  medium.  It  may  be  used,  however,  in 
combination  with  a  gelatin  or  agar  medium.  For  this  purpose  it  is 
most  conveniently  kept  in  a  fluid  condition  in  the  little  flasks  hereto- 
fore described  ("  Sternberg's  bulbs  "). 

The  gelatin  or  agar  jelly  in  test  tubes  is  liquefied  by  heat  and 
cooled  in  a  water  bath  to  about  40°  C.  The  desired  amount  of  ste- 
rile blood  serum  is  then  forced  into  each  tube  by  passing  the  slender 


76 


CULTURES   IN    SOLID    MEDIA. 


neck  of  the  little  flask  along  the  side  of  the  cotton  filter  (see  Fig.  4G) 
and  applying  gentle  heat  to  the  bulb.  The  slender  neck  is  first  ste- 
rilized by  passing  it  through  a  flame,  and  the  point  is  broken  off 
with  sterile  forceps.  After  inoculating  the  liquefied  medium  in  the 
test  tubes  in  the  usual  manner  we  may  make  plates  or  roll  tubes. 

Cultures  on  Cooked  Potato. — The  method  of  preparing  pota- 
toes for  surface  cultures  has  already  been  given  (page  48).  It  was 
in  using  them  that  Koch  first  got  his  idea  of  the  importance  of  solid 
media,  which  led  to  his  introduction  of  the  use  of  gelatin  and  agar- 
agar  and  the  invention  of  the  plate  method.  By  means  of  streak 


FIG.  46. 

cultures  upon  potato  he  had  succeeded  in  obtaining  isolated  colonies 
and  pure  cultures.  We  now  use  the  potato  chiefly  for  the  purpose 
of  differentiating  species.  Some  bacteria  grow  on  the  surface  of 
cooked  potato  and  some  do  not.  Those  which  do  present  various 
characters  of  growth.  Thus  we  have  differences  as  to  color,  as  to 
rapidity  of  growth,  as  to  the  character  of  the  mass  formed — thick 
or  thin,  viscid,  moist  or  dry,  restricted  to  line  of  inoculation  or  ex- 
tending over  the  entire  surface,  etc. 

Instead  of  using  a  cut  section  of  the  potato  in  the  manner  here- 
tofore described,  we  may  make  a  puree  by  mashing  the  peeled  and 
cooked  tubers  and  distributing  the  mass  in  Erlenmeyer  flasks.  After 


CULTURES   IN   SOLID    MEDIA.  77 

thorough  sterilization  by  steam  the  culture  medium  is  ready  for  use. 
In  the  same  way  other  vegetables,  or  bread,  etc. ,  may  be  used  for 
special  purposes,  and  especially  for  cultures  of  the  mould  fungi. 

Potatoes  usually  have  a  slightly  acid  reaction,  and  on  this  ac- 
count certain  bacteria  will  not  grow  upon  them.  This  acid  reaction 
is  not  constant  and  differs  in  degree,  and  as  a  result  we  may  have 
decided  differences  in  the  growth  of  the  same  species  upon  different 
potatoes.  To  overcome  this  objection  the  writer  has  sometimes  neu- 
tralized the  cones  of  potato  in  test  tubes  (see  Fig.  21,  page  48)  by 
first  boiling  them  in  water  containing  a  little  carbonate  of  soda. 
The  liquid  is  poured  off  after  they  have  been  in  the  steam  sterilizer 
for  half  an  hour,  and  they  are  returned  for  sterilization. 

Salomonson's  Method  of  cultivation  in  capillary  tubes  has  a  his- 
torical value  only  since  the  introduction  of  Koch's  plate  method. 


IX. 


CULTIVATION  OF  ANAEROBIC   BACTERIA. 

PASTEUR  (1861)  first  pointed  out  the  fact  that  certain  species  of 
bacteria  not  only  grow  in  the  entire  absence  of  oxygen,  but  that  for 
some  no  growth  can  occur  in  the  presence  of  this  gas.  Such  bacteria 
are  found  in  the  soil,  and  in  the  intestines  of  man  and  the  lower  ani- 
mals. The  cultivation  of  "strict  anaerobics"  calls  for  methods  by 
which  oxygen  is  excluded.  The  "facultative  anae'robics''  grow 


FIG.  47.  FIG.  48. 

either  in  the  presence  or  absence  of  oxygen.  There  are  various  gra- 
dations in  this  regard,  from  the  strictly  aerobic  species  which  re- 
quire an  abundance  of  oxygen  and  will  not  grow  in  its  absence,  to 
the  strictly  anaerobic  species  which  will  not  grow  if  there  is  a  trace 
of  oxygen  in  the  medium  in  which  we  propose  to  cultivate  them. 
Among  the  most  interesting  pathogenic  bacteria  which  are  strictly 
anaerobic  are  the  bacillus  of  tetanus,  the  bacillus  of  malignant 
oedema,  and  the  bacillus  of  symptomatic  anthrax. 


CULTIVATION   OF   ANAEROBIC   BACTERIA.  79 

If  we  make  an  inoculation  of  one  of  the  species  which  is  not 
strictly  anaerobic  into  a  test  tube  containing  nutrient  gelatin  or  agar- 
agar,  we  may  have  a  development  all  along  the  line  of  puncture, 
and  this  may  be  more  abundant  below,  as  in  Fig.  47.  But  when  we 
make  a  long  stick  culture  with  a  strict  anaerobic  the  development 
occurs  only  near  the  bottom  of  the  line  of  puncture  (Fig.  48). 

We  may  then,  if  we  have  a  pure  culture  to  start  with,  propagate 
these  anaerobic  bacilli  in  long  stick  cultures.  It  is  best  to  use  tubes 
which  have  been  recently  sterilized,  as  boiling  expels  the  air  from 
the  culture  medium  ;  and  a  very  slender  needle  should  be  used  in 
making  the  inoculation.  To  prevent  the  absorption  of  oxygen  a 
layer  of  sterilized  olive  oil  may  be  poured  into  the  tube  after  the  in- 
oculating puncture  has  been  made,  or  it  may  be  filled  up  with  agar 
jelly  which  has  been  cooled  to  about  40°  C.  Roux  has  proposed  to  • 
prevent  the  absorption  of  oxygen  by  the  culture  medium  by  plant- 
ing an  aerobic  bacterium — Bacillus  subtilis — upon  the  surface,  after 
making  a  long  stick  culture  with  the  anaerobic  species.  The  agar 
jelly  is  first  boiled  and  quickly  cooled  ;  the  inoculation  is  then  made 
with  a  slender  glass  needle  ;  some  sterile  agar  cooled  to  40°  C.  is 
poured  into  the  tube,  and  when  this  is-  solid  the  aerobic  species  is 
planted  upon  the  surface.  The  top  of  the  test  tube  is  then  closed 
hermetically  and  it  is  placed  in  the  incubating  oven.  The  aerobic 
species  exhausts  the  oxygen  in  the  upper  part  of  the  tube  by  its 
growth  on  the  surface  of  the  culture  medium,  and  the  anaerobic 
species  grows  at  the  bottom  of  the  tube.  To  obtain  material  for  a 
new  culture  or  for  microscopical  examination  the  test  tube  is  broken 
near  its  bottom. 

Cultures  in  liquid  media  may  be  made  by  exhausting  the  air  in 
a  suitable  receptacle  or  by  displacing  it  with  hydrogen  gas.  The 
first-mentioned  method  has  been  largely  used  in  Pasteur's  laboratory, 
but  methods  in  which  hydrogen  gas  takes  the  place  of  atmospheric 
air  in  the  culture  tube  are  more  easily  applied  and  require  simpler 
apparatus.  The  flask  shown  in  Fig.  49  may  be  used  in  connection 
with  an  air  pump.  The  sterile  culture  liquid  is  first  introduced  into 
a  long-necked  flask  and  inoculated  with  the  anaerobic  bacillus  to  be 
cultivated.  The  neck  of  the  flask  is  then  drawn  out  in  a  flame  at  c. 
The  open  end  is  then  connected  .with  a  Sprengle's  pump  or  some 
other  apparatus  for  exhausting  the  air.  The  flask  is  placed  in  a 
water  bath  at  40°  C. ,  which  causes  ebullition  at  the  diminished  pres- 
sure, and  the  exhaustion  is  continued  for  about  half  an  hour.  The 
narrow  neck  is  then  sealed  at  c  by  the  use  of  a  blowpipe  flame. 

The  flask  shown  in  Fig.  49,  which  can  be  made  from  a  test  tube, 
may  also  be  used  in  connection  with  a  hydrogen  apparatus.  In  this 
case  a  slender  glass  tuba  is  passed  into  the  flask,  as  shown  in  Fig. 


80 


CULTIVATION    OF    ANAEROBIC    BACTERIA. 


50,  and  this  is  connected  with  a  hydrogen  apparatus  by  a  rubber 
tube,  The  hydrogen  is  allowed  to  bubble  through  the  culture 
liquid  in  a  full  stream  for  ten  to  fifteen  minutes,  in  order  that  all  of 
the  oxygen  in  the  flask  may  be  removed  by  displacement.  Then, 
while  the  gas  is  still  flowing,  the  flask  is  sealed  at  a  with  a  blow- 
pipe flame,  the  hydrogen  tube  being  left  in  position  and  melted  fast 
to  the  flask.  Some  little  skill  is  required  in  the  successful  perform- 
ance of  the  last  step  in  this  procedure,  and  it  will  be  easier  for  those 


FIG.  49. 


Fia.  51. 


who  are  not  skilful  in  the  use  of«the  blowpipe  to  use  Salomonson's 
tube,  shown  in  Fig.  51.  In  this,  hydrogen  is  admitted  through  the 
arm  b,  and  escapes  through  the  cotton  plug  a.  The  vertical  tube  is 
sealed  at  c  while  the  gas  is  flowing,  and  then  the  horizontal  tube  at  b. 
Frdnkel's  Method. — Instead  of  these  tubes  specially  made  for 
the  purpose,  an  ordinary  test  tube  may  be  used,  as  recommended  by 
Frankel.  This  is  closed  by  a  soft  rubber  cork  through  which  two 
glass  tubes  pass — one,  reaching  nearly  to  the' bottom  of  the  test  tube, 


CULTIVATION   OF   ANAEROBIC    BACTERIA. 


81 


for  the  admission  of  hydrogen,  which  passes  through  the  liquefied 
culture  medium  ;  and  the  other  a  short  tube  for  the  escape  of  the  gas. 
The  outlet  tube  is  sealed  in  the  flame  of  a  lamp  while  the  gas  is 
freely  flowing,  and  after  sufficient  time  has  elapsed  to  insure  the 
complete  expulsion  of  atmospheric  oxygen — which,  when  the  hydro- 
gen flows  freely,  requires  about  four  minutes  (Frankel) — melted 
paraffin  is  applied  freely  to  the  rubber  stopper  to  prevent  leakage  of 
the  hydrogen  and  entrance  of  oxygen.  A  roll  tube  may  then  be 
made  after  the  manner  of  Esmarch,  and,  after  colonies  have  de- 
veloped, the  anaerobic  culture  will  appear  as  shown  in  Fig.  52. 

To  isolate  anaerobic  bacteria  in  pure  cultures  it  is  well  to  make  a 


FIG.  52. 


^sV 
hJji 


-t 


FIG.  53. 


series  of  dilutions  as  heretofore  described  for  aerobic  cultures  ;  we 
will  then  usually  obtain  isolated  colonies  in  tube  No.  2  or  No.  3  of  a 
series,  and  by  removing  the  rubber  stopper  we  may  transplant  bac- 
teria from  these  colonies  to  deep  stick  cultures  in  nutrient  gelatin  or 
agar. 

The  Writer's  Method. — The  following  simple  method  has  been 
successfully  employed  by  the  writer: 

Three  Esmarch  roll  tubes  are  prepared  as  is  usual  for  aerobic  cul- 
tures. The  cotton  air  filter,  or  a  portion  of  it,  is  then  pushed  down 
the  tubes  for  a  short  distance,  as  shown  at  a,  Fig.  53.  A  section  of 
a  soft  rubber  stopper  carrying  two  glass  tubes  is  then  pushed  into  the 


82  CULTIVATION   OF   ANAEROBIC   BACTERIA. 

test  tube  for  about  half  an  inch,  as  shown  at  b,  Fig.  53.  The  space 
above  the  cork  is  then  filled  with  melted  sealing  wax,  which  I  have 
found  to  prevent  leakage  better  than  paraffin,  which  contracts  upon 
cooling.  The  test  tube  is  inverted  while  hydrogen  is  passed  through 
the  tube  c,  and  by  reason  of  its  levity  the  gas  quickly  passes  through 
the  cotton  air  filter  and  displaces  the  oxygen  in  the  test  tube  (Fig. 
54).  After  allowing  the  gas  to  flow  for  a  few  minutes  the  outlet 
tube  is  first  sealed  in  a  flame  and  then  the  inlet  tube.  As  the  cotton 
filter  is  interposed  between  the  rubber  stopper  and  the  culture  mate- 
rial, no  special  precautions  need  be  taken  for  the  sterilization  of  the 
rubber  cork  and  the  glass  tubes  which  it  carries. 


FIG.  54. 


FIG.  55. 


This  method  is  more  convenient  than  that  previously  described, 
and  the  only  objection  to  it  is  that  the  oxygen  is  not  completely  re- 
moved from  the  film  of  solid  gelatin  or  agar  attached  to  the  walls  of 
the  test  tube.  But  by  passing  the  hydrogen  for  a  long  time  it  would 
seem  that  by  diffusion  the  oxygen  remaining  in  this  thin  layer 
would  be  gotten  rid  of.  At  all  events,  this  method  will  serve  for  all 
except  the  very  strict  aiiaerobics. 

Method  of  Esmarcli. — The  following  method  has  been  proposed 
by  Esmarch  :  Three  roll  tubes  are  made  in  the  usual  way,  and  into 
these  liquid  gelatin,  that  is  nearly  cooled  to  the  point  of  becoming 
solid,  is  poured.  This  fills  the  tube  without  melting  the  layer  of 


CULTIVATION  OF   ANAEROBIC   BACTERIA. 


83 


gelatin,  previously  cooled  upon  its  walls,  which  contains  the  bacteria 
under  investigation.  When  the  anaerobic  colonies  have  developed 
the  test  tube  must  be  broken  to  get  at  them,  or  the  cylinder  of  gela- 
tin may  be  removed  by  first  warming  the  walls  of  the  tube. 

Another  method,  recommended  by  Liborius,  consists  in  distri- 
buting the  bacteria  in  test  tubes  nearly  filled  with  nutrient  gelatin  or 
agar  which  has  been  recently  boiled  to  expel  air.  Colonies  of  anaero- 
bic bacteria  will  develop  near  the  bottom  of  such  a  tube,  while  the 
aerobic  species  will  only  grow  near  the  surface.  The  cylinder  of 
jelly  is  removed  by  heating  the  walls  of  the  Ihbe,  and  sections  are 


'f  a 


FIG.  P6. 


made  with  a  sterilized  knife  for  the  purpose  of  'obtaining  material 
from  individual  colonies  for  further  cultures,  etc. 

Koch  and  his  pupils  are  in  the  habit  of  testing  the  aerobic  char- 
acter of  bacteria  in  plate  cultures  by  covering  the  recently  made 
plates  with  a  thin  sheet  of  mica  which  has  been  sterilized  by  heat. 
The  strictly  aerobic  species  do  not  grow  under  such  a  plate  ;  but, 
according  to  Liborius,  the  exclusion  of  oxygen  is  not  sufficiently 
complete  for  the  growth  of  strict  anaerobics. 

Buchners  Method  consists  in  the  removal  of  oxygen  by  means 
of  pyrogallic  acid.  The  anaerobic  species  under  investigation  is 
planted  in  recently  boiled  agar  jelly  in  a  small  test  tube.  This  is 
placed  in  a  larger  tube  having  a  tightly  fitting  rubber  stopper,  as 
shown  in  Fig.  55.  The  small  tube  is  supported  by  a  bent-wire 


CULTIVATION   OF   ANAEROBIC   BACTERIA. 

stand,  and  in  the  lower  part  of  the  large  tube  are  placed  ten  cubic 
centimetres  of  a  ten-per-cent  solution  of  caustic  potash,  to  which  one 
gramme  of  pyrogallic  acid  is  added.  The  absorption  of  the  oxygen 
takes  some  time,  but,  according  to  Buchner,  it  is  finally  so  complete 
that  strict  anaerobics  grow  in  the  small  tube. 

In  practice,  cultivation  in  an  atmosphere  of  hydrogen  will  be 
found  the  most  convenient  method,  and  for  this  any  form  of  hydro- 
gen generator  may  be  used.  The  writer  is  in  the  habit  of  using  the 
form  shown  in  Fig.  56.  A  perforation  a  quarter  of  an  inch  in 
diameter  is  drilled  through  the  bottom  of  a  wide-mouthed  bottle. 
Some  fragments  of  broken  glass  are  then  put  into  the  bottle,  form- 


FIG.  57. 

ing  a  layer  two  or  three  inches  thick.  Upon  this  is  placed  a  quan- 
tity of  granulated  zinc.  This  bottle  has  a  tightly  fitting  cork, 
through  which  passes  a  metal  tube  having  a  stopcock.  The  bottle 
is  placed  in  a  glass  jar  containing  diluted  sulphuric  acid  (one  part 
by  weight  of  sulphuric  acid  to  eight  parts  of  water).  The  acid,  ris- 
ing through  the  perforation  in  the  bottom  of  the  bottle,  when  it 
comes  in  contact  with  the  zinc  gives  rise  to  an  abundant  evolution 
of  hydrogen,  which  escapes  by  the  tube  a  when  the  stopcock  is 
open.  When  this  is  closed  the  gas  forces  the  acid  back  from  con- 
tact with  the  zinc.  To  remove  any  trace  of  oxygen  present  the 
gas  may  be  passed  through  a  solution  of  pyrogallic  acid  in  caustic 
potash. 

Evidently  plates  prepared   by  Koch's  method,  or  Esmarch  roll 


CULTIVATION   OF   ANAEROBIC    BACTERIA.  85 

tubes,  may  be  placed  in  a  suitable  receiver  and  the  air  exhausted,  or 
hydrogen  substituted  for  atmospheric  air.  Such  an  apparatus  for 
hydrogen  has  been  devised  by  Blucher  and  is  shown  in  Fig.  57.  A 
glass  dish,  A,  contains  a  smaller  dish,  B,  which  has  a  diameter  of 
about  seven  centimetres.  The  small  dish  is  kept  in  its  position  in 
the  centre  of  the  larger  one  by  the  wire  ring,  having  three  project- 
ing arms,  'which  is  shown  in  the  figure.  The  culture  medium  con- 
taining the  anaerobic  bacteria  to  be  cultivated  is  poured  into  the 
small  dish  and  the  glass  funnel  D  is  put  in  position.  This  is  held 
in  its  place  by  a  weight  of  lead  which  encircles  the  neck  of  the  fun- 
nel at  F.  A  mixture  of  glycerin  and  water  (twenty  to  twenty-five 
per  cent)  is  poured  into  the  dish  A  to  serve  as  a  valve  to  shut  off 
the  atmospheric  air  from  the  interior  of  the  funnel  D.  Hydrogen 
gas  is  introduced  through  the  tube  E,  which  is  connected  by  a  rub- 
ber tube  with  a  hydrogen  apparatus. 

A  somewhat  similar  apparatus  has  been  devised  by  Botkin,  in 
which  the  hydrogen  is  admitted  beneath  a  bell  jar  covering  small 
glass  dishes  containing  the  culture  medium.  We  believe  that  in 
practice  the  writer's  method  (page  81),  in  which  Esmarch  roll  tubes 
are  first  made,  will  be  found  more  convenient  than  either  of  the  last- 
mentioned  methods  of  preserving  plates  in  an  atmosphere  of  hydro- 
gen ;  or  roll  tubes  may  be  prepared  in  the  way  usually  practised  in 
cultivating  aerobic  bacteria,  and  these  may  be  placed  in  a  suitable 
receptacle  which  can  be  filled  with  hydrogen. 


X. 
INCUBATING  OVENS  AND   THERMO-REGULATORS. 

THE  saprophytic  bacteria  generally,  and  many  of  the  pathogenic 
species,  grow  at  the  ordinary  temperature  of  occupied  apartments 
(20°  to  25°  C. )  ;  but  some  pathogenic  species  can  only  be  cultivated 
at  a  higher  temperature,  and  many  of  those  which  grow  at  the 
"  room  temperature  "  develop  more  rapidly  and  vigorously  when 
kept  in  an  incubating  oven  at  a  temperature  of  35°  to '38°  C.  Every 
bacteriological  laboratory  should  therefore  be  provided  with  one  or 
more  brood  ovens  provided  with  thermo-regulators  to  maintain  a 
constant  temperature.  These  incubating  ovens  are  made  with  dou- 
ble walls  surrounding  an  air  chamber.  The  space  between  the  dou- 
ble walls  is  filled  with  water,  which  is  usually  heated  by  a  small  gas 
flame.  The  gas  passes  through  the  thermo-regulator,  and  its  flow 
is  automatically  controlled  for  any  temperature  to  which  this  is  ad- 
justed. The  exterior  of  the  incubating  oven  is  covered  with  felt  or 
asbestos  to  prevent  the  loss  of  heat  by  radiation.  A  simple  and 
cheap  form  which  answers  every  purpose  is  shown  in  Fig.  58.  The 
quadrangular  box  with  double  walls  should  be  made  of  zinc  or  cop- 
per. An  outer  metal  door  covered  with  non-conducting  material, 
and  an  inner  door  of  glass,  give  access  to  the  interior  space  ;  and  a 
thermometer  introduced  through  an  aperture  in  the  top  (Fig.  58,  b) 
shows  the  temperature  of  this  space  when  the  door  is  closed.  The 
stopcock  e  permits  the  drawing  off  of  the  water  from  the  space  be- 
tween the  double  walls,  and  the  glass  tube  d  shows  the  height  of 
the  water,  as  it  is  connected  with  the  space  containing  it.  The 
thermo-regulator  passes  through  an  aperture  at  one  side  of  the  oven 
into  the  water,  the  temperature  of  which  controls  the  flow  of  gas. 

The  ordinary  thermo-regulator  is  shown  in  Fig.  59  as  manufac- 
tured by  Rohrbeck.  A  glass  receptacle,  shaped  like  an  ordinary 
test  tube,  has  an  arm,  c,  for  the  escape  of  the  gas,  which  enters  by 
the  bent  tube  a,  which  passes  through  a  perforated  cork  and  is  ad- 
justable up  and  down.  Tube  a  is  connected  with  the  gas  supply  and 
tube  c  with  the  burner  by  means  of  rubber  tubing.  A  glass  parti- 
tion extending  downward  as  a  tube,  g,  makes  an  enclosed  space  in 


INCUBATING  OVENS   AND   THERMO-REGULATORS. 


87 


the  lower  part  of  the  instrument,  and  this,  when  immersed  in  water, 
acts  as  a  thermometer  bulb.  This  space  contains  mercury  below 
and  air  or  the  vapor  of  ether  above.  When  the  air  is  expanded  by 
heat  the  mercury  is  forced  up  the  tube  g  until  it  meets  the  end  of 
the  inlet  tube  for  gas  at  h,  and  by  shutting  off  the  flow  of  gas  pre- 
vents the  temperature  from  going  any  higher.  A  small  opening  in 
the  inlet  tube  at  e  permits  a  small  amount  of  gas  to  flow,  so  that  the 
flame  under  the  brood  oven  ( Fig.  58,  /)  may  not  be  entirely  extin- 
guished. The  lower  end  of  the  bent  tube  a  is  bevelled,  so  that  a  tri- 
angular opening  is  formed,  which  is  closed  gradually  by  the  rising 


FIG.  58. 

mercury,  instead  of  abruptly  as  would  be  the  case  if  the  lower  end 
of  the  tube  a  were  cut  off  square.  To  adjust  the  temperature  in 
the  air  space  of  the  incubating  oven  when  the  thermo-regulator  is  in 
position,  a  full  flow  of  gas  is  admitted  to  the  burner  until  the  ther- 
mometer (Fig.  58,  b)  shows  the  desired  temperature ;  then  the  bent 
tube  a  is  pushed  down  through  the  cork  until  its  lower  extremity 
meets  the  mercury  and  the  flame  /  is  somewhat  reduced.  The  ap- 
paratus is  then  left  for  a  time,  to  see  whether  the  flame  runs  too  high 
or  too  low,  and  a  further  adjustment  is  made.  When  the  changes 
in  the  exterior  temperature  are  slight  and  the  gas  pressure  regular 
the  temperature  in  the  air  chamber  is  controlled  with  great  precision. 
But  this  is  not  the  case  under  the  reverse  conditions.  Changes  in 


INCUBATING   OVENS   AND    THERMO-REGULATORS. 


the  pressure  of  gas,  especially,  interfere  with  the  maintenance  of  a 
constant  temperature,  and  for  this  reason  a  pressure  regulator  will 
be  required  when  great  precision  is  desired.  That  of  Moitessier  is 
commonly  used  in  bacteriological  laboratories  (Fig.  60).  But  for 
most  purposes  variations  of  temperature  of  1°  to  2°  C.  are  not  of 
great  importance.  For  ordinary  use  a  brood  oven  should  be  regu- 
lated to  about  35°  to  37°  C.  It  is  best  to  have  a  little  cylindrical 
screen  of  mica  around  the  gas  jet  beneath  the  incubating  oven,  for 
the  purpose  of  preventing  the  flame  from  being  extinguished  by  cur- 
rents of  air  (Fig.  61). 

Koch's  ingenious  automatic  device  for  shutting  off  the  gas  if  the 
flame  is  accidentally  extinguished  is  shown  in  Fig.  62. 


Fia.  59. 

Another  form  of  thermo-regulator,  which  answers  very  well,  is 
that  of  Reichert  (Fig.  63).  In  this  the  gas  enters  at  a  and  escapes 
at  c.  The  mercury,  which  fills  the  bulb,  shuts  off  the  gas  at  the 
point  for  which  the  instrument  is  regulated.  By  means  of  the 
screw  d  the  height  of  the  mercury  in  the  tube  may  be  very  accu- 
rately adjusted  for  any  desired  temperature. 

The  regulator  of  Bohr,  shown  in  Fig.  64,  is  more  sensitive  than 
that  of  Reichert,  and  rather  simpler  in  construction  than  the  usual 
form  shown  in  Fig.  59.  The  thermometer  bulb  a  contains  only  air, 
and  the  gas  which  passes  through  the  tube  /  is  shut  off  at  the 
proper  temperature  by  the  mercury  in  the  U-shaped  tube  c.  The 
stopcock  b  is  left  open  when  the  bulb  a  is  immersed  in  the  water 


INCUBATING   OVENS  AND    THERMO-REGULATORS. 


89 


bath,  and  when  the  proper  temperature  is  reached  is  closed  so  as  to 
confine  the  air  in  the  bulb.     An  increase  of  temperature  now  causes 


FIG.  61.  FIG.  63. 

ihe  air  in  the  bulb  to  expand,  the  mercury  in  the  U-tube  is  forced  up 


FIG.  63. 


FIG.  64. 


and  shuts  off  the  gas  flowing  through  the  tube /at  its  lower  ex- 
tremity, d.     A  small  opening,  e,  permits  sufficient  gas  to  pass  to 


90 


INCUBATING   OVENS   AND    THERMO-REGULATORS. 


maintain  a  small  flame  which  must  not  be  sufficient  by  itself  to  keep 
up  the  desired  temperature  in  the  water  bath. 

Altmann  has  recently  (1891)  described  a  thermo-regulator  which 
is  made  by  Miincke,  of  Berlin,  and  which  is  shown  in  Fig.  65.  This 
is  said  to  act  with  great  precision.  It  is  a  modification  of  Reichert's 


FIG.  65. 


FIG.  G6. 


regulator.     Its  mode  of  action  will  be  readily  understood  by  a  refe- 
rence to  the  figure. 

A  thermo-regulatQr  which  gives  very  accurate  results,  which  are 
not  influenced  by  differences  in  pressure,  is  that  invented  by  the 


FIG.  67. 


writer  over  twenty  years  ago.  The  regulating  thermometer  may 
contain  mercury  only,  or  air  and  mercury,  as  shown  in  the  thermo- 
regulator  for  gas  (Fig.  59).  In  the  simplest  form  a  large  bulb  con- 
taining mercury  is  used,  and  a  platinum  wire  is  hermetically  sealed 
in  the  glass  so  as  to  have  contact  with  the  mercury  (Fig.  60,  a). 


INCUBATING    OVENS    AND    THERMO-REGULATORS. 


9L 


Another  platinum  wire  passes  down  the  tube  of  the  thermometer,  b, 
and  is  adjustable  for  any  desired  temperature.  The  gas  passes 
through  a  valve  which  is  controlled  by  an  electro-magnet.  A 
simple  form  of  valve  is  shown  in  Fig.  67.  The  bent  tube  a  is  con- 
nected with  the  gas  supply  by  a  piece  of  rubber  tubing.  The  up- 
right arm  of  this  tube  is  enclosed  in  a  larger  tube,  b,  having  an  out- 


FIG.  68.  FIG.  69. 

let,  e,  which  is  connected  with  the  burner  under  the  incubating 
oven.  The  upper  end  of  this  larger  tube  is  closed  by  means  of  a 
piece  of  sheet  rubber,  which  prevents  the  escape  of  gas.  When  this 
is  depressed  by  means  of  the  lever  c,  the  flow  of  gas  through  the 
valve  is  arrested.  The  lever  c  has  attached  to  it  the  armature  d, 
and  is  operated  by  an  electro-magnet  under  the  control  of  the  regu- 
lating thermometer. 


INCUBATING   OVENS   AND    THERMO-REGULATORS. 

When  the  thermometer  is  immersed  in  a  water  bath  the  tem- 
perature of  which  it  is  desired  to  regulate,  and  the  proper  electric 
connections  are  made,  it  acts  as  a  circuit  breaker.  When  the  de- 
sired temperature  is  reached  the  mercury  in  the  tube  of  the  ther- 
mometer touches  the  wire  b  (Fig.  66),  an  electric  circuit  is  com- 
pleted, and  the  valve  is  closed,  shutting  off  the  gas  supply  and 
preventing  the  temperature  from  going  any  higher.  When  contact 
is  broken  in  the  thermometer  tube  the  valve  opens  and  permits  the 
gas  to  flow  again.  A  small  opening,  o  (Fig.  67),  permits  the  con- 
stant flow  of  a  sufficient  amount  of  gas  to  prevent  the  flame  from 
being  extinguished.  In  practice,  however,  it  is  better  to  have  a 
small  side  jet  of  gas,  quite  independent  of  that  which  passes  through 
the  valve,  which  burns  constantly  and  relights  the  principal  jet  when 


FIG.  70. 

the  valve  is  opened.  This  apparatus  is  very  well  adapted  for  regu- 
lating the  temperature  of  a  water  bath  with  precision,  but  for  gene- 
ral use  in  connection  with  incubating  ovens  the  ordinary  gas  regu- 
lator is  preferable,  on  account  of  the  trouble  connected  with  keeping 
a  galvanic  battery  in  order  when  it  is  required  to  act  at  frequent 
intervals  "  on  a  closed  circuit,"  for  weeks  and  months  together. 

The  incubating  apparatus  of  D' Arson val  is  shown  in  Fig.  68.  It 
is  a  cylindrical  vessel  of  copper  having  double  walls,  and  is  provided 
with  the  thermo-regulator  of  D' Arson val,  by  which  very  accurate 
regulation  is  maintained  at  any  desired  temperature.  In  its  form 
this  apparatus  is  not  as  convenient  as  are  the  brood  ovens  made 
in  the  form  shown  in  Fig.  58,  with  a  swinging  door  which  gives 
easy  access  to  the  interior,  which  is  provided  with  one  or  more 
shelves  upon  which  the  cultures  are  placed.  Various  modifications 


INCUBATING   OVENS   AND   THERMO-REGULATORS.  9& 

of  this  simple  and  convenient  incubating  oven  are  manufactured  by 
Rohrbeck  and  by  Miincke,  of  Berlin.  The  apparatus  of  D'Arson- 
val,  and  other  forms  in  favor  at  the  French  capital,  may  be  obtained 
from  Wiesnegg,  of  Paris.  The  last-named  manufacturer  also  sup- 
plies the  incubating  oven  and  thermo-regulator  recently  described  by 
Roux  (1891).  This  is  shown  in  Fig.  G9.  The  regulator  is  formed  of 
two  metallic  bars,  one  of  steel  and  the  other  of  zinc  ;  these  are 
soldered  together  in  the  shape  of  a  letter  U  ;  the  regulator  is  seen  in 
position  in  the  cut  (Fig.  69).  The  most  dilatable  metal  (zinc)  is  on 
the  outside.  When  the  temperature  is  raised  the  arms  of  the  U  ap- 
proach each  other,  and  the  reverse  when  it  falls.  The  method  by 
which  regulation  is  effected  is  shown  in  Fig.  70.  The  U-shaped 
regulator  is  placed  vertically,  and  one  of  its  branches,  A,  is  firmly 
fixed  to  the  wall  of  the  incubating  oven  ;  the  other,  free  arm  car- 
ries a  horizontal  bar  which  projects  through  the  wall  of  the  incu- 
bator in  an  opening  which  permits  it  to  move  freely  under  the  influ- 
ence of  a  change  in  the  temperature  within.  The  end  of  this 
projecting  bar  is  turned  up  at  a  right  angle  and  the  screw  p  passes 
through  it ;  this  can  be  fixed  at  any  desired  point  by  means  of  the 
nut  e.  The  end  of  the  screw  p  rests  against  the  stem  of  a  conical 
brass  valve  which  controls  the  flow  of  gas.  The  valve  is  closed  by  a 
spiral  spring  and  opened  by  the  screw  p  under  the  control  of  the 
thermo-regulator. 


XL 
EXPERIMENTS   UPON  ANIMALS. 

THE  pathogenic  power  of  various  bacteria  has  been  demonstrated 
by  injecting  pure  cultures  into  susceptible  animals.  As  a  rule,  the 
herbivora  are  more  susceptible  than  the  caniivora,  and  this  is  per- 
haps to  be  explained  in  accordance  with  the  theory  of  natural  selec- 
tion. Carnivorous  animals  often  feed  upon  the  bodies  of  animals 
which  have  succumbed  to  infectious  diseases,  and  upon  dead  animals 
in  which  putrefactive  changes  have  commenced.  In  their  struggles 
with  each  other  they  are  wounded  by  teeth  and  claws  soiled  with  in- 
fectious material  which  would  cause  a  fatal  disease  if  inoculated  into 
the  more  susceptible  herbivorous  animals.  As  this  has  been  going 
on  for  ages,  we  may  suppose  that,  by  survival  of  the  fittest,  a  race 
tolerance  has  been  acquired.  The  lower  animals  have  their  own  in- 
fectious diseases,  some  of  which  are  peculiar  to  certain  species  and 
some  common  to  several.  As  a  rule,  the  specific  infectious  diseases 
of  man  cannot  be  transmitted  to  lower  animals,  and  man  is  not  sub- 
ject to  the  diseases  of  the  same  class  which  prevail  among  animals. 
But  certain  diseases  furnish  an  exception  to  this  general  rule.  Thus 
tuberculosis  is  common  to  man  and  several  of  the  lower  animals ; 
relapsing  fever  may  by  inoculation  be  transmitted  to  monkeys  ; 
diphtheria  may  be  transmitted  to  pigeons  and  guinea-pigs.  On  the 
other  hand,  anthrax  and  glanders  may  be  contracted  by  man  as  a 
result  of  accidental  inoculation  or  contact  with  an  infected  animal. 

Nearly  allied  species  sometimes  present  very  remarkable  differ- 
ences as  to  susceptibility.  Thus  the  bacillus  of  mouse  septicaemia  is 
fatal  to  house  mice  but  not  to  field  mice,  while,  on  the  other  hand, 
field  mice  are  killed  by  the  bacillus  of  glanders  and  house  mice  are 
immune  from  this  pathogenic  bacillus. 

The  animals  most  commonly  used  for  testing  the  pathogenic 
power  of  bacteria  are  the  mouse,  the  guinea-pig,  and  the  rabbit. 
Domestic  fowls  and  pigeons  are  also  useful  for  certain  experiments. 
The  dog  and  the  rat  are  of  comparatively  little  use  on  account  of 
their  slight  susceptibility. 


EXPERIMENTS   UPON   ANIMALS. 


95 


Inoculations  are  made  directly  into  the  circulation  through  a 
vein,  into  the  subcutaneous  connective  tissue,  or  into  one  of  the 
serous  cavities — usually  the  peritoneal. 

The  ordinary  hypodermic  syringe  may  be  used  in  making  injec- 
tions, but  this  is  difficult  to  sterilize  on  account  of  the  leather  piston, 
and  complications  are  liable  to  arise  from  its  use  which  it  is  best  to 
avoid.  The  best  way  to  sterilize  a  piston  syringe  is  to  wash  it  thor- 
oughly with  a  solution  of  bichloride  of  mercury  of  1  : 1,000,  and  then 
to  remove  every  trace  of  bichloride  by  washing  in  alcohol.  But  one 
never  feels  quite  sure  that  the  most  careful  washing  will  insure  steril- 
ization, and  it  is  best  to  use  a  syringe  which  may  be  sterilized  by 


Fia.  71. 


heat,  such  as  that  of  Koch,  shown  in  Fig.  71.  In  this  the  metal  point 
and  glass  tube  are  easily  sterilized  in  a  hot-air  oven.  Fluid  is  drawn 
into  the  syringe  and  forced  out  of  it  by  a  rubber  ball  which  has  a 
perforation  to  be  covered  by  the  finger. 

The  writer  has  for  some  years  been  in  the  habit  of  making  injec- 
tions in  animals  with  an  improvised  glass  syringe.  This  is  made 
from  a  piece  of  glass  tubing  in  the  same  form  as  the  collecting  tubes 
heretofore  described.  A  bulb  is  blown  at  one  end  of  the  tube,  and 
the  other  end  is  drawn  out  to  form  a  slender  tube  which  serves  as  the 


Fm.  72. 

needle  of  the  syringe  (Fig.  72).  By  gently  heating  the  bulb  in  an 
alcohol  lamp  and  immersing  the  open  end  of  the  capillary  tube  in 
the  fluid  to  be  injected,  this  rises  into  the  syringe  as  the  expanded  air 
cools.  Having  introduced  the  glass  point  beneath  the  skin  or  into 
the  cavity  of  the  abdomen  of  the  animal  to  be  injected,  the  contents 
of  the  tube  are  forced  out  by  again  heating  the  bulb  by  means  of  a 
small  alcohol  lamp.  The  glass  point  is  easily  forced  through  the 
thin  skin  of  a  mouse  or  of  a  young  rabbit ;  but  for  animals  with  a 
thicker  skin  it  is  necessary  to  cut  through,  or  nearly  through,  the 
skin  with  some  other  instrument.  A  small  pair  of  curved  scissors 
answers  very  well  for  this  purpose. 


9(5  EXPERIMENTS   UPON   ANIMALS. 

Generally,  in  making  injections  into  animals,  it  is  customary  to 
remove  the  hair  for  some  distance  around  the  point  of  inoculation 
with  scissors  and  razor,  and  then  to  sterilize  the  surface  by  careful 
washing  with  a  solution  of  bichloride  of  mercury.  This  precaution 
is  necessary  in  researches  in  which  pathogenic  bacteria  are  being 
tested,  in  order  to  remove  any  possibility  of  accidental  inoculation 
with  germs  other  than  those  under  investigation,  and,  as  a  conse- 
quence, a  mistaken  inference  as  to  the  pathogenic  action  of  the  spe- 
cies under  investigation.  But  when  we  know  the  specific  pathogenic 
power  of  a  certain  microorganism  it  is  hardly  necessary  to  take  this 
precaution,  as  a  few  drops  of  culture  will  contain  millions  of  the  bac- 
teria, while  contamination,  if  it  occurs  from  the  surface  of  the  body, 
must  be  by  a  comparatively  small  number  of  bacteria,  which  are 
likely  to  be  of  a  harmless  kind  which  will  have  no  influence  on  the 
result  of  the  experiment. 

Instead  of  sterilizing  the  surface,  the  writer  usually  clips  away  a 
small  portion  of  skin  with  curved  scissors,  not  cutting  deep  enough 
to  draw  blood,  but  leaving  a  bare  surface  through  which  the  point  of 
the  syringe  can  be  introduced  with  very  little  danger  of  carrying  bac- 
teria into  the  connective  tissue  other  than  those  contained  in  the 
syringe. 

In  making  injections  into  the  peritoneal  cavity  care  must  be  taken 
not  to  wound  the  liver  or  the  distended  stomach.  The  intestine  is 
not  very  likely  to  be  wounded,  as  it  slips  out  of  the  way.  By  seizing 
a  longitudinal  fold  of  the  abdominal  wall  and  pushing  the  point  of 
the  syringe  quite  through  it,  and  then  releasing  the  fold  and  care- 
fully withdrawing  the  instrument  until  the  point  remains  in  the 
cavity,  the  danger  of  wounding  the  intestine  will  be  reduced  to  a 
minimum. 

Injections  into  the  circulation  are  made  by  exposing  a  vein  and 
carefully  introducing  the  needle  of  the  syringe  in  the  direction  of 
the  blood  current.  Care  must  of  course  be  taken  not  to  inject  air. 
In  the  rabbit  one  of  the  large  veins  of  the  ear  may  be  conveniently 
penetrated  by  the  point  of  a  hypodermic  syringe  without  any  pre- 
vious dissection.  The  ear  is  first  washed  with  a  solution  of  bichloride 
of  mercury  or  simply  with  warm  water.  The  animal  had  better  be 
carefully  wrapped  in  a  towel  to  control  its  movements.  The  veins 
are  distended  by  compressing  them  near  the  base  of  the  ear.  When 
the  point  of  the  needle  has  not  been  properly  introduced,  and  the 
fluid  to  be  injected  escapes  in  the  surrounding  connective  tissue,  it 
will  commonly  be  best  to  withdraw  the  syringe  and  make  the 
attempt  upon  another  vein.  As  pointed  out  by  Abbott,  the  needle 
of  the  syringe  should  be  ground  flat  at  the  point,  and  not  curved  as 
is  commonly  the  case. 


EXPERIMENTS   UPON   ANIMALS.  97 

Large  quantities  of  fluid  may  be  injected  into  the  cavity  of  the 
abdomen  or  into  the  circulation  by  slowly  forcing  the  fluid  through 
a  slender  canula,  properly  introduced,  which  is  coupled  with  a  large 
syringe  by  means  of  rubber  tubing,  or  with  a  glass  receptacle  from 
which  the  fluid  is  forced  by  the  pressure  of  air  pumped  in  with  a 
rubber  hand  ball. 

Mice  are  usually  injected  subcutaneously  near  the  tail.  The 
little  animal  is  first'  seized  by  a  long  pair  of  forceps,  or  "mouse 
tongs,  and  the  hair  is  clipped  away  on  the  back  just  above  the  tail. 
If  solid  material  is  to  be  introduced  a  little  pocket  is  made  with  scis- 
sors or  with  a  lancet,  into  which  the  infectious  material  is  carried  by 
means  of  a  platinum  needle  or  slender  forceps.  Liquids  may  be  in- 
jected by  the  little  glass  syringe  heretofore  described,  the  point  of 
which  is  easily  forced  through  the  skin. 

Pasteur's  method  of  inoculating  rabbits  with  the  virus  of  hydro- 
phobia consists  in  trephining  the  skull  and  injecting  the  material 
beneath  the  dura  mater.  An  incision  through  the  skin  is  first  made 
to  one  side  of  the  median  line  a  short  distance  back  of  the  eyes. 
The  edges  of  the  wound  are  separated,  and  a  small  trephine  (five  or 
six  millimetres  in  diameter)  is  used  to  remove  a  button  of  bone.  The 
emulsion  of  spinal  cord  from  a  hydrophobic  animal  is  then  carefully 
injected  beneath  the  dura  mater — two  or  three  drops  will  be  sufficient. 
The  wound  is  washed  out  with  a  two-per-cent  solution  of  carbolic 
acid  and  closed  with  a  couple  of  sutures. 

Injections  into  the  intestine  are  made  by  carefully  opening  the 
abdomen  with  antiseptic  precautions,  gently  seizing  a  loop  of  the  in- 
testine, and  passing  the  point  of  the  syringe  through  its  walls  ;  the 
loop  is  then  returned  and  the  incision  in  the  walls  of  the  abdomen 
carefully  closed  with  sutures  and  dressed  antiseptically. 

Inoculations  into  the  anterior  chamber  of  the  eye  of  rabbits  and 
other  animals  have  frequently  been  practised,  and  offer  certain  ad- 
vantages in  the  study  of  the  local  effects  of  pathogenic  microorgan- 
isms. The  animal  should  be  fastened  to  an  operating  board,  belly 
down,  and  its  head  held  by  an  assistant,  who  at  the  same  time  holds 
the  eyelids  apart.  The  conjunctiva  is  seized  with  forceps  to  steady 
the  eye,  and  an  incision  about  two  millimetres  long  is  made  through 
the  cornea  with  a  cataract  knife.  Through  this  opening  a  small 
quantity  of  a  liquid  culture  may  be  injected,  or  a  bit  of  solid  material 
introduced  with  slender  curved  forceps. 

Ordinary  injections  give  but  little  pain  and  do  not  call  for  the  use 
of  an  anaesthetic.  When  anaesthesia  is  required  ether  will  usually 
be  preferable  to  chloroform.  Rabbits,  especially,  are  very  apt  to  die 
from  chloroform,  no  matter  how  carefully  it  may  be  administered. 
Dog3,  rats,  and  mice  stand  ether  very  well.  The  smaller  animals 
7 


98  EXPERIMENTS  UPON  ANIMALS. 

may  be  brought  under  the  anaesthetic  by  placing  them  in  a  covered 
jar  into  which  a  pledget  of  cotton  wet  with  ether  has  been  dropped. 
Before  making  injections  into  the  anterior  chamber  of  the  eye  it  is 
well  to  use  a  two-per-cent  solution  of  cocaine  as  a  local  anaesthetic. 

Mice  which  have  been  inoculated  are  usually  kept  in  a  glass  jar 
having  a  wire-gauze  cover.  A  quantity  of  cotton  is  put  into  the  jar 
to  serve  as  a  shelter  for  the  little  animal,  and  it  is  well  to  partly  fill 
the  jar  with  dry  sawdust.  Larger  animals  are  kept  in  suitable  cages 
of  wire  or  wood,  and,  as  a  rule,  each  one  should  be  kept  in  a  separate 
cage  while  under  observation  after  an  inoculation  experiment. 

In  experimenting  upon  animals  the  following  points  should  be 
kept  in  view  and  noted  : 

(a)  The  age  and  weight  of  the  animal.     Young  animals  are,  as 
a  rule,  more  susceptible  than  older  ones,  and  with  many  pathogenic 
bacteria  the  lethal  dose  of  a  culture  bears  some  relation  to  the  size 
of  the  animal. 

(b)  The  point  of  inoculation.     Injections  into  the  circulation 
are  generally  more  promptly  fatal  and  require  a  smaller  dose  than 
those  into  a  serous  cavity  or  into  the  connective  tissue.     Pathogenic 
bacteria  introduced  into  the  abdominal  cavity  reach  the  circulation 
more  promptly  than  those  injected  subcutaneously.     But  certain 
microorganisms  owe  their  pathogenic  power  to  the  local  effect  about 
the  point  of  inoculation  and  the  absorption  of  toxic  products  formed 
in  the  limited  area  invaded,  and  do  not  enter  the  general  circulation, 
or  at  least  do  nqt  multiply  in  the  circulating  fluid,  and  quickly  dis- 
appear from  it. 

(b)  The  age  of  the  culture  injected.  Old  cultures  sometimes 
have  greater  and  sometimes  less  pathogenic  potency  than  recent  cul- 
tures. Some  kinds  of  virus  become  "attenuated"  when  kept.  But 
when  the  pathogenic  power  depends  chiefly  upon  toxic  products 
formed  during  the  growth  of  the  bacteria,  old  cultures  are,  as  a  rule, 
more  potent  than  those  recently  made. 

(d)  The  medium  in  which  the  pathogenic  bacteria  are  sus- 
pended.    Cultures  in  albuminous  media,  like  blood  serum,  are  in 
some  cases  more  potent  than  bouillon  cultures  ;  and  the  virulence  of 
several  pathogenic  bacteria  is  greatly  intensified  by  successive  cul- 
tures— by  inoculation — in  the  bodies  of  susceptible  animals.     Ogston 
found  that  pus  cocci  cultivated  in  the  interior  of  eggs  had  an  in- 
creased virulence.     According  to  Arloing,  Cornevin,  and  Thomas, 
the  activity  of  a  culture  of  the  bacillus  of  symptomatic  anthrax  is 
doubled  by  adding  one-five-hundredth  part  of  lactic  acid  to  the  cul- 
ture fluid. 

(e)  The  quantity  injected  is  evidently  an  essential  point  when 
the  result  depends  largely  upon  the  toxic  products  formed  in  the  cul- 


EXPERIMENTS   UPON  ANIMALS.  99 

ture  medium.  It  is  also  an  essential  point  when  pathogenic  bacteria 
are  injected  which  kill  susceptible  animals  in  very  minute  doses,  for 
it  has  been  shown  by  the  experiments  of  Watson  Cheyne  and  others 
that  in  the  case  of  some  of  these,  at  least,  there  is  a  limit  below 
which  infection  does  not  occur. 

Inoculated  animals  should  be  carefully  observed,  and  a  note 
made  of  every  symptom  indicating  a  departure  from  the  usual  con- 
dition of  health,  such  as  fever,  less  of  activity,  loss  of  appetite, 
weakness,  emaciation,  diarrhoea,  convulsions,  dilated  pupils,  the  for- 
mation of  an  abscess  or  a  diffuse  cellulitis  extending  from  the  point 
of  inoculation,  etc.  The  temperature  is  usually  taken  in  the  rectum. 
The  temperature  of  small  animals,  like  rabbits  and  guinea-pigs,  va- 
ries considerably  as  a  result  of  external  conditions.  In  the  rabbit 
the  normal  temperature  may  be  given  as  about  102°  to  103°  F.  ;  in 
the  guinea-pig  it  is  a  little  lower. 

In  making  a  post-mortem  examination  of  an  inoculated  animal  it 
is  best  to  stretch  it  out  on  a  board,  belly  up,  by  tying  its  legs  to  nails 
or  screws  fastened  in  the  margin  of  the  board.  When  the  abdomen 
is  dirty,  as  is  usually  the  case,  it  should  be  carefully  washed  with  a 
disinfecting  solution.  An  incision  through  the  skin  is  then  made  in 
the  median  line  the  full  length  of  the  body,  and  the  skin  is  dis- 
sected back  so  as  to  expose  the  anterior  walls  of  the  abdomen  and 
thorax.  These  cavities  are  then  carefully  opened  with  a  sterilized 
knife  or  scissors,  and  the  various  organs  and  viscera  examined.  At- 
tention should  also  be  given  to  the  appearances  at  the  point  of  in- 
oculation. To  ascertain  whether  the  microorganism  injected  has 
invaded  the  blood,  smear  preparations  should  be  made  with  blood 
obtained  from  a  vein  or  from  one  of  the  cavities  of  the  heart.  It 
will  be  well  also  to  make  a  smear  preparation  from  a  cut  surface  of 
the  liver  and  spleen.  In  the  various  forms  of  acute  septicaemia  the 
spleen  is  usually  found  to  be  enlarged.  If  but  few  microorganisms 
are  present  in  the  blood  and  tissues  they  may  escape  observation  in 
stained  smear  preparations,  and  it  will  be  necessary  to  make  cultures 
to  demonstrate  their  presence.  A  little  blood  from  a  vein  or  from 
one  of  the  cavities  of  the  heart  is  transferred,  by  means  of  a  plati- 
num loop  (ose)  or  a  sterilized  collecting  tube  (see  page  38),  to  a 
test  tube  containing  liquefied  nutrient  gelatin  or  agar-agar,  and  an 
Esmarch  roll  tube  is  made.  This  is  put  aside  for  the  development  of 
colonies  from  any  scattered  bacteria  which  may  be  present.  As  a 
rule,  it  will  be  best  to  make  agar  cultures,  as  these  can  be  placed  in 
the  incubating  oven  at  35°  to  38°  C.  Stick  cultures  may  also  be 
made  and  will  serve  to  show  the  presence  of  microorganisms,  but 
will  not  give  information  as  to  how  numerous  they  may  be.  The 
roll  tube  also  has  the  advantage  of  showing  whether  there  is  a 


100  EXPERIMENTS   UPON   ANIMALS. 

mixed  infection  or  whether  a  pure  culture  of  a  single  microorganism 
is  obtained  from  the  blood.  In  the  same  way  cultures  may  be  made 
from  material  obtained  from  the  liver  or  spleen,  and  it  may  happen 
that  one  or  both  of  these  organs  contain  bacteria  when  none  are 
found  in  the  blood.  Before  passing  the  platinum  needle  or  collect- 
ing tube  into  the  organ,  the  surface,  which  has  been  more  or  less  ex- 
posed to  contamination,  should  be  sterilized  by  applying  to  it  a  hot 
spatula  ;  then  at  the  moment  of  lifting  the  spatula  the  sterilized 
needle  is  introduced  into  the  interior  of  the  organ,  and  the  blood  and 
crushed  tissue  adhering  to  it  at  once  carried  over  to  the  culture  me- 
dium. Or  blood  obtained  with  proper  precautions  from  a  vein,  a 
cavity  of  the  heart,  or  the  interior  of  the  spleen  or  liver,  may  be 
used  to  inoculate  another  animal. 

Animals  are  also  sometimes  inoculated  by  excoriating  the  cutis 
as  in  vaccination.  They  may  also,  in  rare  cases,  be  infected  by  in- 
troducing cultures  into  the  stomach,  either  mixed  with  the  food  in- 
gested or  by  injection  through  a  tube.  Infection  by  inhalation  is 
accomplished  by  causing  the  animal  to  respire  an  atmosphere,  in  a 
properly  enclosed  space,  in  which  the  pathogenic  organism  is  sus- 
pended, by  the  use  of  a  spray  apparatus  for  liquid  cultures,  or 
some  form  of  powder  blower  for  powders  containing  the  bacteria  in 
a  desiccated  condition. 

One  method  of  obtaining  a  pure  culture  of  pathogenic  bacteria 
consists  in  the  inoculation  of  susceptible  animals  with  material  con- 
taining a  pathogenic  species  in  association  with  others  which  are  not. 
When  the  blood  is  invaded  by  the  pathogenic  species  and  the  animal 
dies  from  an  acute  septicaemia,  we  may  usually  obtain  a  pure  cul- 
ture by  inoculating  a  suitable  culture  medium  with  a  minute  drop  of 
blood  taken  from  a  vein  or  from  one  of  the  cavities  of  the  heart. 
Sometimes,  however,  a  mixed  infection  occurs  and  some  other  mi- 
croorganism is  associated  in  the  blood  with  that  one  which  was  the 
immediate  cause  of  the  death  of  the  animal. 


XII. 
PHOTOGRAPHING  BACTERIA. 

WELL-MADE  photomicrographs  are  unquestionably  superior  to 
drawings  made  by  hand  as  a  permanent  record  of  morphological 
characters.  This  being  the  case,  bacteriologists  would  no  doubt  re- 
sort to  this  method  more  generally  but  for  the  technical  difficulties 
and  the  time  and  patience  required  in  overcoming  these.  Koch,  in 
his  earlier  studies,  gave  much  time  to  photographing  bacteria,  and 
with  very  remarkable  success.  In  his  work  on  "Traumatic  Infec- 
tive Diseases  "  (1878)  he  says  : 

"With  respect  to  the  illustrations  accompanying  this  work,  I 
must  here  make  a  remark.  In  a  former  paper '  on  the  examination 
and  photographing  of  bacteria  I  expressed  the  wish  that  observers 
would  photograph  pathogenic  bacteria  in  order  that  their  representa- 
tions of  them  might  be  as  true  to  nature  as  possible.  I  thus  felt 
bound  to  photograph  the  bacteria  discovered  in  the  animal  tissues  in 
traumatic  infective  diseases,  and  I  have  not  spared  trouble  in  the 
attempt.  The  smallest,  and  in  fact  the  most  interesting  bacteria, 
however,  can  only  be  made  visible  in  animal  tissues  by  staining 
them  and  by  thus  gaining  the  advantage  of  color.  But  in  this  case 
the  photographer  has  to  deal  with  the  same  difficulties  as  are  expe- 
rienced in  photographing  colored  objects — e.g.,  colored  tapestry. 
These  have,  as  is  well  known,  been  overcome  by  the  use  of  colored 
collodion.  This  led  me  to  use  the  same  method  for  photographing 
stained  bacteria,  and  I  have,  in  fact,  succeeded,  by  the  use  of  eosin- 
collodion,  and  by  shutting  off  portions  of  the  spectrum  by  colored 
glasses,  in  obtaining  photographs  of  bacteria  which  had  been  stained 
with  blue  and  red  aniline  dyes.  Nevertheless,  from  the  long  ex- 
posure required  and  the  unavoidable  vibrations  of  the  apparatus,  the 
picture  does  not  have  sharpness  of  outline  sufficient  to  enable  it  to  be 
of  use  as  a  substitute  for  a  drawing,  or,  indeed,  even  as  evidence  of 
what  one  sees.  For  the  present,  therefore,  I  must  abstain  from  pub- 
lishing photographic  representations ;  but  I  hope,  at  a  subsequent 
period  when  improved  methods  allow  a  shorter  exposure,  to  be  able 
to  remedy  this  defect." 

1  The  paper  referred  to  is  published  in  Colm's  "Beitrage  zur  Biologie  d.  Pflanzen." 


102  PHOTOGRAPHING  BACTERIA. 

Since  the  above  was  written  considerable  progress  has  been  made 
in  removing  the  technical  difficulties,  and  a  few  bacteriologists  have 
succeeded  in  making  very  satisfactory  photomicrographs.  As  speci- 
mens of  what  may  be  done  with  the  best  apparatus  and  the  highest 
degree  of  skill,  we  may  call  attention  to  the  photomicrographs  in 
the  Atlas  der  Bakterienkunde  of  Frankel  and  Pfeiffer,  and  those 
of  Roux  in  the  Annales  of  the  Pasteur  Institute.  The  writer,  also, 
has  devoted  much  time  to  making  photomicrographs  which  have 
served  as  illustrations  for  several  of  his  published  works. 

Those  who  have  had  no  practical  experience  in  making  photo- 
micrographs are  apt  to  expect  too  much  and  to  underestimate  the 
technical  difficulties.  Objects  which  under  the  microscope  give  a 
beautiful  picture,  which  we  desire  to  reproduce  by  photography,  may 
be  entirely  unsuited  for  the  purpose.  In  photographing  with  high 
powers  it  is  necessary  that  the  objects  to  be  photographed  be  in  a 
single  plane  and  not  crowded  together  or  overlying  each  other. 
For  this  reason  photographing  bacteria  in  sections  presents  special 
difficulties,  and  satisfactory  results  can  only  be  obtained  when  the 
sections  are  extremely  thin  and  the  bacteria  well  stained.  Even 
with  the  best  preparations  of  this  kind  much  care  must  be  taken  in 
selecting  a  field  for  photography.  It  must  be  remembered  that  the 
expert  microscopist,  in  examining  a  section  with  high  powers,  has 
his  finger  on  the  fine  adjustment  screw  and  focuses  up  and  down  to 
bring  different  planes  into  view.  He  is  in  the  habit  of  fixing  his  at- 
tention on  that  part  of  the  field  which  is  in  the  focus  and  disregard- 
ing the  rest.  But  in  a  photograph  the  part  of  the  field  not  in  focus 
appears  in  a  prominent  way  which  mars  the  beauty  of  the  picture. 
In  a  cover-glass  preparation  made  from  a  pure  culture,  when  the 
bacteria  are  well  distributed,  this  difficulty  does  not  present  itself,  as 
the  bacteria  are  all  lying  in  a  single  plane;  but  the  portion  of  the  field 
which  can  be  shown  at  one  time  is  limited  by  the  spherical  aberra- 
tion of  the  objective,  which  the  makers  do  not  seem  able  to  overcome 
in  high-power  lenses  of  wide  angle,  at  least  not  without  loss  of  de- 
fining power. 

Usually  preparations  of  bacteria  are  stained  for  photography, 
but  with  some  of  the  larger  forms,  such  as  the  anthrax  bacillus, 
very  satisfactory  photomicrographs  may  be  made  from  unstained 
preparations.  In  this  case  a  small  quantity  of  a  recent  culture  is 
put  upon  a  slide,  covered  with  a  thin  cover  glass,  and  placed  at  once 
upon  the  stage  of  the  microscope.  The  main  difficulty  to  be  encoun- 
tered results  from  the  change  of  location  of  the  suspended  bacteria 
resulting  from  the  pressure  of  the  objective  in  focussing.  Motile 
bacteria,  of  course,  cannot  be  photographed  in  this  way  without  first 
arresting  their  movements  by  means  of  some  germicidal  agent ; 


PHOTOGRAPHING  BACTERIA.  103 

and  in  general  it  will  be  found  more  satisfactory  to  fix  the  micro- 
organisms to  be  photographed  to  a  slide  or  cover  glass  by  desiccation 
and  heat,  and  to  stain  them  with  one  of  the  aniline  colors. 

Objects  which  are  opaque  cannot  be  photographed  by  transmitted 
light,  and  objects  which  have  a  deep  orange  or  red  color  are  practi- 
cally opaque  for  the  actinic  rays  which  are  at  the  violet  end  of  the 
spectrum.  Such  objects  simply  intercept  the  light,  but  this  gives 
the  outlines,  and,  where  there  are  no  details  of  structure,  is  all  that 
is  required  to  illustrate  the  form  and  mode  of  grouping.  Softer  and 
more  satisfactory  photomicrographs  of  bacteria  are  made  when  the 
staining  is  not  such  as  to  entirely  arrest  the  actinic  rays.  Among 
the  aniline  colors  Bismarck  brown  and  vesuvin  are  the  most  suitable, 
care  being  taken,  with  the  larger  bacteria  especially,  not  to  make 
the  staining  too  intense.  Objects  which  are  transparent  for  the  ac- 
tinic rays,  or  nearly  so,  give  a  very  feeble  photographic  image,  or 
none  at  all,  on  account  of  the  want  of  contrast  in  the  impression 
made  upon  the  sensitive  plate.  This  is  the  case  when  we  attempt  to 
photograph,  by  ordinary  white  light,  objects  which  are  stained  violet 
or  blue.  But  this  want  of  contrast  in  the  negative  can  be  overcome 
by  the  use  of  specially  prepared  plates  and  colored  screens  of  glass 
interposed  between  the  object  and  the  source  of  light.  The  so-called 
orthochromatic  plates  are  more  sensitive  to  the  rays  toward  the  red 
end  of  the  spectrum  than  ordinary  plates.  They  are  prepared  by 
treating  the  plates  with  a  solution  of  eosin,  of  erythrosin,  or  of  rose 
bengal  (Vogel),  and  may  now  be  purchased  in  this  country  from 
dealers  in  dry  plates.  If  we  shut  off  the  violet  rays  by  the  use  of  a 
yellow  screen,  objects  having  a  yellow  or  orange  color  may  be  pho- 
tographed upon  orthochromatic  plates,  although  the  time  of  exposure 
will  be  quite  long  owing  to  the  comparatively  feeble  actinic  power 
of  the  yellow  rays. 

We  may  also  make  photomicrographs  of  objects  stained  with 
methylene  blue  or  with  fuchsin,  because  objects  stained  with  these 
colors  are  opaque  for  the  rays  from  the  red  end  of  the  spectrum,  and 
sufficiently  so  with  yellow  light  to  give  a  good  photographic  con- 
trast. Frankel  and  Pfeiffer  recommend  the  use  of  a  green  light-fil- 
ter (green  glass  screen)  for  all  preparations  stained  with  methyl  vio- 
let, fuchsin,  or  methylene  blue;  and  for  brown-stained  preparations  a 
pure  blue  light.  The  writer  has  been  in  the  habit  of  using  a  yellow 
glass  screen  for  fuchsin-stained  preparations,  and  has  had  excellent 
results,  but  the  time  of  exposure  is  necessarily  long.  A  yellow  glass 
screen  may  be  prepared  by  dissolving  tropjeolin  in  negative  varnish, 
and  pouring  this  upon  a  clean  glass  slide,  where  it  is  permitted  to 
dry. 

To  show  bacteria  in  photographs  in  a  satisfactory  manner  we 


104:  PHOTOGRAPHING   BACTERIA. 

require  an  amplification  of  five  hundred  to  one  thousand  diameters  ; 
and  as  it  is  often  desirable  to  make  comparisons  as  to  the  dimen- 
sions of  microorganisms  which  resemble  each  other  in  form,  it  is 
best  to  adopt  a  standard  amplification.  The  writer  has  himself 
adopted,  and  would  recommend  to  others,  a  standard  amplification 
of  one  thousand  diameters.  This  is  about  as  high  a  magnifying 
power  as  we  can  get  with  satisfactory  definition,  or  as  we  require, 
and  it  is  a  convenient  number  when  measurements  are  made  from 
the  photograph.  The  beginner,  after  having  put  his  apparatus  in 
position,  should  focus  the  lines  of  a  stage  micrometer  upon  the 
screen  with  the  optical  apparatus  which  he  proposes  to  use  ;  then  by 
moving  the  screen  forward  or  back  as  required,  and  carefully  focus- 
sing the  lines,  he  will  ascertain  what  is  the  position  of  the  screen  for 
exactly  one  thousand  diameters.  If  the  stage  micrometer  is  ruled 
with  lines  which  are  one  one-thousandth  of  an  inch  apart,  it  is  evi- 
dent that  when  projected  upon  the  screen  they  should  be  one  inch 
apart  to  make  the  amplification  one  thousand  diameters.  But  it 
must  be  remembered  that  any  change  in  the  position  of  the  optical 
combination  will  change  the  amplification.  If,  therefore,  the  cover 
correction  of  the  objective  is  changed,  or  the  position  of  the  eyepiece 
— if  one  is  used — it  will  be  necessary  to  again  adjust  the  distance  of 
the  screen. 

Apparatus  required. — A  first-class  immersion  objective  of  one- 
twelfth  of  an  inch  or  higher  power,  a  substantial  stand  which  can  be 
placed  in  a  horizontal  position,  and  a  camera  which  can  be  coupled 
with  the  microscope  tube,  are  the  essential  pieces  of  apparatus.  If 
sunlight  is  to  be  used  a  heliostat  will  also  be  required. 

The  oil-immersion  objectives  of  any  good  maker  may  be  used, 
but  the  apochromatic  objectives  and  projection  eyepieces  of  Carl 
Zeiss,  of  Jena,  are  especially  to  be  recommended.  Indeed,  those  who 
can  afford  it  will  do  well  to  get  Zeiss'  complete  apparatus,  which 
includes  a  stand  having  a  mechanical  stage  and  a  camera  mounted 
upon  a  metal  frame  conveniently  provided  with  focussing  appliances, 
etc.  However,  good  work  may  be  done  with  less  expensive  appa- 
ratus. 

The  stand  should  be  substantial  and  well  made,  with  a  delicate, 
fine  adjustment.  A  mechanical  stage  is  not  essential,  but  is  a  great 
convenience  in  finding  and  adjusting  to  the  centre  of  the  screen  a 
satisfactory  field  to  photograph.  The  substage  should  be  provided 
with  a  good  apochromatic  condenser,  and  with  appliances  for  moving 
the  condensing  lens  forward  and  back  and  for  centring  it,  with  dia- 
phragms, etc. 

By  the  use  of  a  high-power  objective,  like  the  one-eighteenth-inch 
oil-immersion  of  Zeiss,  the  desired  amplification  may  be  obtained 


PHOTOGRAPHING  BACTERIA.  105 

without  the  use  of  an  eyepiece  ;  and,  as  a  rule,  it  is  best  not  to  use 
an  ordinary  eyepiece  to  secure  increased  amplification,  as  this  is  ob- 
tained at  the  expense  of  definition.  But  an  amplifier  may  be  used  in 
the  tube  of  the  microscope,  as  first  recommended  by  Woodward.  In 
this  case  the  amplifier  must  be  carefully  adjusted  with  reference  to 
the  distance  of  the  screen,  to  secure  the  best  possible  definition. 

The  projection  eyepieces  of  Zeiss  are  constructed  especially  for 
photography  and  possess  a  decided  advantage.  By  the  use  of  his 
three-millimetre  apochromatic  oil-immersion  objective  and  projec- 
tion eyepiece  No.  3  we  may  obtain  an  amplification  of  one  thousand 
diameters  with  excellent  definition. 

Light. — Sunlight  is  in  many  respects  the  most  satisfactory  for 
photography,  but  has  the  disadvantage  that  it  is  not  always  available. 
In  some  sections  of  the  country  weeks  may  pass  without  a  single 
clear  day  suitable  for  making  photomicrographs.  In  addition  to  the 
uncertainty  arising  from  cloudy  weather,  we  have  to  contend  with 
the  fact  that  the  sun  is  only  available  for  use  with  a  heliostat  for  a 
limited  time  during  each  day,  and  that  this  time  is  greatly  restricted 
in  Northern  latitudes  during  the  winter  months.  When  sunlight  is 
to  be  employed  the  microscope  and  camera  must  be  set  up  in  a  room 
having  a  southern  exposure  on  a  line  corresponding  with  the  true 
meridian  of  the  place.  The  heliostat  is  placed  outside  the  window  in 
such  a  position  that  when  properly  adjusted  the  light  of  the  sun  will 
fall  upon  the  condenser  attached  to  the  substage  of  the  microscope. 
The  condenser  must  be  carefully  centred,  so  that  the  circle  of  light 
falling  upon  the  screen  shall  be  uniform  in  intensity  and  outline. 

The  calcium,  magnesium,  or  electric  light  may  be  used  as  a  sub- 
stitute for  sunlight,  but  they  are  all  rather  expensive,  unless,  in  the 
case  of  the  electric  light,  a  suitable  current  is  available  without  the 
expense  of  generating  it  for  the  special  purpose  in  view.  The  writer 
has  obtained  very  good  results  with  the  calcium  light,  but  has  no  ex- 
perience in  the  use  of  the  electric  light.  Woodward,  as  a  result  of 
extended  experiments,  arrived  at  the  conclusion  that  "the  electric 
light  is  by  far  the  best  of  all  artificial  lights  for  the  production  of 
photomicrographs."  He  used  a  Grove  battery  of  fifty  elements  to 
generate  the  current,  and  a  Duboscq  lamp.  The  current  from  a 
dynamo  would  no  doubt  be  much  cheaper  and  more  conveniently 
used,  if  an  electric-lighting  plant  was  in  the  vicinity. 

The  apparatus  shown  in  Fig.  73  was  designed  by  Mr.  Pringle  for 
the  use  of  the  calcium  light.  It  will  serve  to  illustrate  the  arrange- 
ment of  the  microscope  and  camera  in  connection  with  any  other 
light  as  well.  An  oil  lamp  may  be  placed  in  the  position  of  the  oxy- 
hydrogen  burner  ;  or,  if  sunlight  is  to  be  employed,  a  heliostat  will 
be  placed  in  the  same  position. 


106 


PHOTOGRAPHING   BACTERIA. 


When  a  colored  screen  is  used  this  may  be  placed  either  before 
or  behind  the  condensing  lens — we  prefer  to  place  it  behind,  although 


Neuhauss  has  shown  that  it  makes  no  difference  in  the  length  of  the 
exposure. 

We  cannot  in  the  present  volume  give  full  details  with  reference 


PHOTOGRAPHING    BACTERIA.  107 

to  the  technique  of  making  photomicrographs,  but  append  an  account 
of  a  form  of  apparatus  which  we  have  used  with  great  satisfaction  : 

"Photomicrography  by  Gaslight. — Those  who  have  had  much  experience 
in  making  photomicrographs  will  agree  with  me  that  one  of  the  most  essen- 
tial elements  of  success  is  the  use  of  a  suitable  source  of  illumination. 

"  Without  question  the  direct  light  of  the  sun,  reflected  in  a  right  line  by 
the  mirror  of  a  heliostat,  is  the  most  economical  and,  in  some  respects,  the 
most  satisfactory  light  that  can  be  used.  But  we  cannot  command  this  light 
at  all  times  and  places,  and  it  often  happens  that,  when  we  are  ready  to  de- 
vote a  day  to  making  photomicrographs,  the  sun  is  obscured  by  clouds  or 
the  atmosphere  is  hazy.  Indeed,  in  some  latitudes  and  at  certain  seasons  of 
the  year  a  suitable  day  for  the  purpose  is  extremely  rare.  The  use  of  sun- 
light also  requires  a  room  having  a  southern  exposure  and  elevated  above  all 
.surrounding  buildings  or  other  objects  by  which  the  direct  rays  of  the  sun 
would  be  intercepted.  For  these  reasons  a  satisfactory  artificial  light  is  ex- 
tremely desirable. 

"  The  oxyhydrogeu  lime  light,  the  magnesium  light,  and  the  electric  arc 
light  have  all  been  employed  as  a  substitute  for  the  light  of  the  sun,  and  all 
give  satisfactory  results.  I  have  myself  made  rather  extensive  use  of  the 
'lime  light,' and  think  it  the  best  substitute  for  solar  light  with  which  I 
am  familiar.  But  to  use  it  continuously,  day  after  day,  is  attended  with 
considerable  expense,  and  the  frequent  renewal  of  the  supply  of  gas  which 
it  calls  for  is  an  inconvenience  which  one  would  gladly  dispense  with. 

"  These  considerations  have  led  some  microscopists  to  use  an  oil  lamp  as 
the  source  of  illumination,  and  very  satisfactory  photomicrographs  with 
comparatively  high  power  have  been  made  with  this  cheap  and  convenient 
light.  But  in  my  experience  the  best  illumination  which  I  have  been  able 
to  secure  with  an  oil  lamp  has  called  for  very  long  exposures  when  working 
with  high  powers,  and,  as  most  of  my  photomicrographs  of  bacteria  are 
made  with  an  amplification  of  one  thousand  diameters,  I  require  a  more 
powerful  illumination  than  I  have  been  able  to  secure  in  this  way.  And 
especially  so  because  of  the  fact  that  a  colored  screen  must  be  interposed, 
which  shuts  off  a  large  portion  of  the  actinic  rays,  on  account  of  the  staining 
agent  usually  employed  in  making  my  mounts.  The  most  satisfactory 
staining  agents  for  the  bacteria  are  an  aqueous  solution  of  fuchsin,  or  of 
methylene  blue,  or  of  gentian  violet ;  and  all  of  these  colors  are  so  nearly 
transparent  for  the  actinic  rays  at  the  violet  end  of  the  spectrum  that  a 
satisfactory  photographic  contrast  cannot  be  obtained  unless  we  shut  off 
these  rays  by  a  colored  screen. 

"  I  am  in  the  habit  of  using  a  yellow  screen  for  my  preparations  stained 
with  fuchsin  or  methylene  blue,  and  have  obtained  very  satisfactory  results 
with  the  orthochromatic  plates  manufactured  by  Carbutt,  of  Philadelphia, 
and  a  glass  screen  coated  with  a  solution  of  tropteolin  dissolved  in  gelatin. 

"  But  with  such  a  screen,  which  shuts  off  a  large  portion  of  the  actinic 
light  and  increases  the  time  of  exposure  three-  or  fourfold,  the  use  of  an 
oil  lamp  becomes  impracticable  with  high  powers,  on  account  of  the  feeble- 
ness of  the  illumination. 

"These  considerations  have  led  me  to  experiment  with  gaslight,  and  the 
simple  form  of  apparatus  which  I  am  about  to  describe  is  the  result  of  these 
experiments.  I  have  now  had  the  apparatus  in  use  for  several  months, 
during  which  time  I  have  made  a  large  number  of  very  satisfactory  photo- 
micrographs of  bacteria  from  fuchsin-stained  preparations  with  an  amplifica- 
tion of  one  thousand  diameters.  My  photographs  have  been  made  with  the 
three-millimetre  oil-immersion  apochromatic  objective  of  Zeiss  and  his  pro- 
jection eyepiece  No.  3.  I  use  a  large  Powell  and  Lealand  stand,  upon  the 
substage  of  which  I  have  fitted  an  Abbe  condenser.  The  arrangement  of 
the  apparatus  will  be  readily  understood  by  reference  to  the  accompanying 
figure. 

"A  is  the  camera,  which  has  a  pyramidal  bellows  front  supported  by  the 


108 


PHOTOGRAPHING   BACTERIA. 


heavy  block  of  wood  B ;  this  can  be  pushed  back  upon  the  baseboard  which 
supports  it,  so  as  to  allow  the  operator  to  place  his  eye  at  the  eyepiece  of  the 
microscope.  When  it  is  brought  forward  an  aperture  of  the  proper  size  ad- 
mits the  outer  extremity  of  the  eyepiece  and  shuts  off  all  light  except  that, 
coming  through  the  objective.  C  is  the  microscope,  and  D  the  Abbe  con- 
denser, supported  upon  the  substage.  E  is  a  thick  asbestos  screen  for  pro- 
tecting the  microscope  from  the  heat  given  off  by  the  battery  of  gas  burners 
F.  This  asbestos  screen  has  an  aperture  of  proper  dimensions  to  admit  the 
light  to  the  condenser  D.  The  gas  burners  are  arranged  in  a  series,  with 
the  flat  portion  of  the  flame  facing  the  aperture  in  the  asbestos  screen  E. 
The  concave  metallic  mirror  G  is  properly  placed  to  reflect  the  light  in  the 
desired  direction.  I  have  not  found  any  advantage  in  the  use  of  a  condens- 
ing lens  other  than  the  Abbe  condenser  upon  the  substage  of  the  microscope. 
The  focussing  is  accomplished  by  means  of  the  rod  I,  which  carries  at  one 
extremity  a  grooved  wheel,  H,  which  is  connected  with  the  fine  adjustment 
screw  of  the  microscope  by  means  of  a  cord. 

' '  The  focussing  wheel  J  may  be  slipped  along  the  rod  I  to  any  desired 
position,  and  is  retained  in  place  by  a  set  screw.     The  rod  I  is  supported 


FIG.  74. 

above  the  camera  by  arms  depending  from  the  ceiling,  or  by  upright  arms 
attached  to  the  baseboard. 

"  I  have  lost  many  plates  from  a  derangement  of  the  focal  adjustment 
resulting  from  vibrations  caused  by  the  passing  of  loaded  wagons  in  the 
street  adjoining  the  laboratory  in  which  I  work.  This  has  been  overcome 
to  a  great  degree  by  placing  soft  rubber  cushions  under  the  whole  appa- 
ratus."1 

Students  who  desire  to  perfect  themselves  in  the  art  of  making 
photomicrographs  are  advised  to  first  make  themselves  familiar  with 
the  technique  of  photography  with  a  landscape  or  portrait  camera, 
and  not  to  undertake  the  more  difficult  task  of  photographing  bac- 
teria until  they  know  how  to  make  a  good  negative  and  to  judge 
whether  an  exposure  has  been  too  long  or  too  short,  etc. 

1  From  Johns  Hopkins  University  Circulars,  vol.  ix.,  No.  81,  p.  72. 


PLATE    I. 
STERNBERG'S  BACTERIOLOGY. 


V 


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•          -   T\ 


PHOTOMICROGRAPHS   BY   GAS   LIGHT. 


PLATE    II. 
STERNBERG'S  BACTERIOLOGY. 


COLONIES   ANI 


PLATE  I. 

PHOTOMICROGRAPHS  OF  BACTERIA  MADE   BY  GASLIGHT. 

FIG.  1. — Streptococcus  cadaveris,  from  a  culture  in  agua  coco;  stained 
with  fuchsin.  x  1,000.  (Steruberg.) 

FIG.  2. — Streptococcus  Ha vaniensis.  x  1,000.  From  a  photomicrograph. 
(Sternberg.) 

FIG.  3. — Bacillus  cuniculicida  Ha  vaniensis,  from  peritoneal  cavity  of 
inoculated  rabbit,  showing  leucocytes  containing  bacilli  and  free  bacilli; 
stained  with  fuchsin.  x  1,000.  (Steruberg.) 

FlG.  4. — Bacillus  cadaveris,  smear  preparation  from  yellow-fever  liver  kept 
for  forty-eight  hours  in  an  antiseptic  wrapping  (Havana,  1889) ;  stained  with 
fuchsin.  x  1,000.  (Sternberg.) 

Note. — All  of  the  above  photomicrographs  were  made  with  the  three- 
millimetre  apochromatic  horn.  ol.  im.  objective  and  projection  eye-piece  of 
Zeiss. 

PLATE  II. 

PHOTOGRAPHS  OF  COLONIES  (IN  ESMARCH  ROLL  TUBES)  AND  OF  TEST-TUBE 

CULTURES. 

FIG.  1. — Colonies  of  Bacillus  leporis  lethalis,  in  gelatin  roll  tube,  end  of 
forty-eight  hours  at  room  temperature.  x5.  (Sternberg.) 

FIG.  2. —Colonies  of  Bacillus  coli  similis  in  gelatin  roll  tube,  end  of 
twenty-four  hours  at  22°  C.  xlO.  (Sternberg.) 

FlG.  3. — Stick  culture  of  Bacillus  coli  similis  in  nutrient  gelatin,  end  of 
seven  days  at  20°  C.  (Sternberg.) 

FlG.  4. — Stick  culture  of  Bacillus  intestinus  motilis  in  nutrient  gelatin, 
end  of  four  days  at  22°  C.  (Sternberg.) 

FlG.  5. — Stick  culture  of  Bacillus  leporis  lethalis  in  nutrient  gelatin,  end 
of  eight  days  at  22°  C.  (Sternberg.) 

FlG.  6. — Stick  culture  of  Micrococcus  tetragenus  versatilis  in  nutrient 
gelatin,  end  of  two  weeks  at  22°  C.  (Sternberg.) 

FlG.  7. — Colonies  of  Bacillus  cuniculicida  Ha  vaniensis  in  gelatin  roll 
tube,  end  of  forty-eight  hours  at  21°  C.  x  10.  (Sternberg.) 

FlG.  8. — Colonies  of  Bacillus  coli  commuhis  in  gelatin  roll  tube,  end  of 
forty-eight  hours  at  22°  C.  x  10.  (Sternberg.) 


PART   SECOND. 


GENERAL  BIOLOGICAL  CHARACTERS: 

INCLUDING   AN   ACCOUNT   OF   THE   ACTION   OF   ANTISEPTICS 
AND   GERMICIDES. 

I.  STRUCTURE,   MOTIONS,  REPRODUCTION.     II.    CONDITIONS  OF  GROWTH. 

III.   MODIFICATIONS  OF  BIOLOGICAL  CHARACTERS.     IV.  PRODUCTS  OF 

VITAL  ACTIVITY.  V.  PTOMAINES  AND  TOXALBUMINS.    VI.  INFLUENCE 

OF  PHYSICAL  AGENTS.    VII.  ANTISEPTICS  AND  DISINFECTANTS 

—GENERAL  ACCOUNT  OF  THE  ACTION  OF.    VIII.  ACTION  OF 

GASES  AND  OF  THE  HALOID  ELEMENTS  UPON  BACTERIA. 

IX.  ACTION  OF  ACIDS  AND  ALKALIES.    X.  ACTION  OF 
VARIOUS  SALTS.  XI.  ACTION  OF  COAL-TAR  PRO- 
DUCTS,  ESSENTIAL  OILS,   ETC.      XII.  AC- 
TION OF  BLOOD  SERUM  AND  OTHER  OR- 
GANIC LIQUIDS.    XIII.  PRACTICAL 
DIRECTIONS  FOR  DISINFECTION. 


PART    SECOND. 


I. 
STRUCTURE,   MOTIONS,   REPRODUCTION". 

THE  bacteria  are  unicellular  vegetable  organisms,  and  consist  of 
a  cell  membrane  enclosing  transparent  and  apparently  structureless 
protoplasm.  The  very  varied  biological  characters  which  distin- 
guish different  species  make  it  evident,  however,  that  there  are  es- 
sential differences  in  the  living  cell  contents,  although  these  differ- 
ences are  not  revealed  by  our  optical  appliances.  And  among  the 
bacteria,  as  in  the  cells  of  higher  plants  and  animals,  the  peculiar 
biological  characters  of  a  species  are  transmitted  to  the  cellular  pro- 
geny of  each  individual  cell.  These  characters  are,  however,  sub- 
ject to  various  modifications  as  a  result  of  differing  conditions  of 
environment,  as  is  the  case  with  plants  and  animals  higher  in  the 
scale  of  existence,  and  in  this  way  more  or  less  permanent  varieties 
are  produced.  It  is  probable  that  among  these  lowly  plants  species 
are  evolved  more  quickly,  as  a  result  of  the  laws  of  natural  selec- 
tion, in  the  struggle  for  existence,  than  among  those  of  more  com- 
plex organization.  Still,  this  has  not  been  proved,  and,  on  the  other 
hand,  we  have  ample  evidence  that  widely  distributed  species  exist 
having  very  definite  morphological  and  biological  characters  which 
enable  us  to  recognize  them  wherever  found. 

It  has  generally  been  supposed  that  these  simple  vegetable  cells 
are  destitute  of  a  nucleus,  but  a  recent  author  (Frankel)  suggests 
the  probability  that  a  nucleus  may  exist,  although  it  has  not  been 
demonstrated.  This  suggestion  is  based  upon  the  fact  that  in  stain- 
ing bacteria  very  quickly  it  sometimes  happens  that  a  portion  of  the 
protoplasm  is  sharply  differentiated  by  taking  the  stain  more  deeply 
than  the  remaining  portion. 

Sjobring  has  recently  (1892)  made  an  investigation  for  the  pur- 
pose of  ascertaining  the  structure  of  bacterial  cells.  Various  meth- 
ods were  employed,  but  the  most  satisfactory  results  were  obtained 
by  fixing  with  nitric  acid,  with  or  without  alcohol,  and  without  pre- 


112  STRUCTURE,    MOTIONS,    REPRODUCTION. 

vious  drying  ;  the  preparations  were  then  stained  with  carbol-meth- 
ylene-blue  or  carbol-fuchsin  solution  ;  they  were  decolorized  with 
nitric  acid  and  examined  in  glycerin  or  in  water.  By  this  procedure 
the  author  named  was  able  to  demonstrate  two  kinds  of  corpuscles. 
One  of  these  may  be  seen  just  inside  the  cell  wall ;  it  stains  deeply 
with  the  carbol-fuchsin  solution.  The  other  lies  in  a  position  analo- 
gous to  that  occupied  by  the  nucleus  of  vegetable  cells  higher  in  the 
scale,  and  resembles  this  both  in  its  resting  condition  and  in  the 
process  of  indirect  division. 

In  his  address  before  the  International  Medical  Congress  of  Ber- 
lin (1890)  Koch  says  : 

"  We  had  not  succeeded,  in  spite  of  the  constantly  improving 
methods  of  staining  and  in  spite  of  the  use  o£  objectives  with  con- 
stantly increasing  angles  of  aperture,  in  learning  more  with  reference 
to  the  interior  structure  of  the  bacteria  than  was  shown  by  the  origi- 
nal methods  of  staining.  Only  very  recently  new  methods  of  stain- 
ing appear  to  give  us  further  information  upon  the  structure  of  the 
bacteria,  inasmuch  as  they  serve  to  differentiate  an  interior  portion 
of  the  protoplasm,  which  should  probably  be  regarded  as  a  nucleus, 
from  an  exterior  protoplasmic  envelope  from  which  is  given  off  the 
organ  of  locomotion,  the  flagellum." 

Although  usually  transparent,  the  protoplasm  sometimes  presents 
a  granular  appearance.  The  botanist  Van  Tieghem  claims  to  have 
found  chlorophyll  grains  in  some  water  bacteria  studied  by  him,  and 
in  the  genus  Beggiatoa  grains  of  sulphur  are  found  embedded  in  the 
protoplasm  of  certain  species. 

The  cell  membrane  in  certain  species  appears  to  be  very  flexible, 
as  may  be  seen  in  those  which  have  a  sinuous  motion.  It  is  not 
easily  recognized  under  the  microscope,  but  by  the  use  of  reagents 
which  cause  the  protoplasm  to  contract  may  be  demonstrated — e.g., 
by  iodine  solution.  Outside  of  the  true  cell  membrane  a  gelatinous 
envelope — so-called  capsule — is  sometimes  seen.  This  may  perhaps 
be,  as  claimed  by  some  authors,  nothing  more  than  a  jelly-like  thick- 
ening of  the  outer  layers  of  the  cell  wall.  This  jelly-like  material 
causes  the  cells  to  adhere  to  each  other,  forming  zooglcea  masses. 
In  some  cases  the  growth  upon  the  surface  of  a  culture  medium  is 
extremely  viscid,  and  may  be  drawn  out  into  long  threads  when 
touched  with  a  platinum  needle,  owing  to  the  gelatinous  intercellular 
substance  by  which  the  cells  are  surrounded. 

There  is  but  little  more  to  be  said  of  the  structure  of  these  minute 
organisms,  except  to  mention  the  fact  that  the  motile  species  are 
provided  with  slender,  whip-like  appendages  called  flagella.  The 
micrococci  in  general  are  not  endowed  with  the  power  of  executing 
spontaneous  movements,  and  they  are  not  provided  with  flagella. 


STRUCTURE,    MOTIONS,    REPRODUCTION.  113 

But  recently  two  motile  species  have  been  described,  and  in  one  of 
these — Micrococcus  agilis  of  Ali-Cohen — the  presence  of  flagella  has 
been  demonstrated. 

Many  of  the  bacilli  and  spirilla  are  actively  motile,  and  the  pre- 
sence of  flagella,  which  has  long  been  suspected,  has  recently  been 
demonstrated 'for  a  considerable  number  of  species  by  Loffler  and 
others. 

It  must  be  remembered  that  the  molecular  movement  which  is 
common  to  all  minute  particles  suspended  in  a  fluid  is  a  vibratory 
motion?'?*-  si  hi,  which  does  not  change  the  .relative  position  of  the 
moving  particles.  This  so-called  Brownian  movement  has  frequently 
been  mistaken  for  a  vital  motion,  as  has  also  the  movement  due  to 
currents  in  the  liquid  in  which  non-motile  organisms  are  suspended. 
The  latter  is  to  be  distinguished  by  the  fact  that  the  microorganisms 
are  all  carried  in  one  direction.  This  movement  due  to  a  current,  in 
connection  with  the  vibratory  Brownian  movement,  is  very  deceptive, 
and  it  is  often  hard  for  a  beginner  in  bacteriological  study  to  con- 
vince himself  that  what  'he  sees  is  not  a  vital  movement.  But  in 
true  vital  movements  we  have  progression  in  different  directions,  and 
the  individual  microorganisms  approach  and  pass  each  other,  often 
in  a  most  vigorous  and  active  manner,  passing  entirely  across  the 
field  of  view  or  changing  direction  in  an  abrupt  way.  Sometimes 
the  motion  is  slow  and  deliberate,  the  bacillus  progressing  with  a  to- 
and-fro  motion,  as  if  propelled  by  a  trailing  flagellum  ;  or  it  may  be 
serpentine  when  the  moving  filament  is  flexible  ;  or  again  it  is 
a  darting  forward  motion  which  is  so  rapid  that  the  eye  can  scarcely 
follow  the  moving  body.  The  spirilla  have  a  rotary  movement  as 
well  as  a  progressive  one,  and  this  is  often  extremely  rapid.  Some- 
times bacilli  spin  around  with  a  rotatory  motion,  as  if  they  were  an- 
chored fast  to  a  fixed  point,  as  they  may  be  by  the  flagellum  being 
attached  to  the  slide  or  cover  glass.  Frequently,  in  a  pure  culture, 
the  individual  bacilli  may  be  seen  to  come  to  rest,  and,  after  an  inter- 
val of  repose,  to  dart  forward  again  in  the  most  active  way.  Or  we 
may  find,  on  examining  the  same  culture  at  different  times,  that 
upon  one  occasion  there  is  no  evidence  of  vital  movements,  and  on 
another  all  of  the  bacilli  are  actively  motile.  These  differences  de- 
pend upon  the  age  of  the  culture,  temperature  conditions,  etc. 

Reproduction  by  binary  division  is  common  to  all  of  the  bacte- 
ria, and  in  many  species  this  is  the  only  mode  of  reproduction  known. 
When  circumstances  are  favorable  for  rapid  multiplication  the  indi- 
vidual cells  grow  in  length,  and  a  constriction  occurs  in  the  middle 
transverse  to  the  long  diameter.  This  becomes  deeper,  and  after  a 
time  the  cell  is  completely  divided  into  two  equal  portions,  which 
again  divide  in  the  same  way.  Separation  may  be  complete,  or  the 
8 


114  STRUCTURE,    MOTIONS,    REPRODUCTION. 

cells  may  remain  attached  to  each  other,  forming  chains  (strepto- 
cocci) or  articulated  filaments  (scheinfdden  of  the  Germans). 

The  bacilli  and  spirilla  divide  only  in  a  direction  transverse  to  the 
long  diameter  of  the  cells,  but  among  the  micrococci  division  may 
occur  either  in  one  direction,  forming  chains  ;  or  in  two  directions, 
forming  tetrads  ;  or  in  three  directions,  forming  ' '  packets  "  of  eight 
or  more  elements.  The  staphylococci,  in  which  the  cells  do  not  re- 
main associated,  divide  indifferently  in  any  direction. 

The  rapidity  of  multiplication  by  binary  division  varies  greatly  in 
different  species,  and  in  the  same  species  depends  upon  conditions  re- 
lating to  the  culture  medium,  age  of  the  culture,  temperature,  etc. 
Under  favorable  conditions  bacilli  have  been  observed  to  divide  in 
twenty  minutes,  and  it  is  a  matter  of  common  laboratory  experience 
that  colonies  of  considerable  size  and  containing  millions  of  bacilli 
may  be  developed  from  a  single  cell  in  twenty-four  to  forty-eight 
hours.  A  simple  calculation  will  show  Avhat  an  immense  number  of 
cells  may  be  produced  in  this  time  as  a  result  of  binary  division  oc- 
curring, for  example,  every  hour.  The  progeny  of  a  single  cell 
would  be  at  the  end  of  twenty-four  hours  16,777,220,  and  at  the  end 
of  forty-eight  hours  the  number  would  be  281,500,000,000. 

Some  of  the  earlier  observers  have  noted  the  presence  of  oval  or 
spherical  refractive  bodies  in  cultures  containing  bacilli ;  but  that 
these  were  reproductive  elements,  although  suspected,  was  not  de- 
monstrated until  a  comparatively  recent  date.  Pasteur  was  one  of 
the  first  to  point  out  the  fact  that  certain  bacteria  have  two  modes  of 
reproduction — by  fission  and  by  the  formation  of  endogenous  spores  ; 
but  the  first  careful  study  of  the  last-mentioned  method  was  made  by 
Koch  in  his  classical  study  of  the  anthrax  bacillus  (1878),  and  by 
Cohn,  who  studied  the  formation  of  spores  in  Bacillus  subtilis. 

These  reproductive  bodies  serve  the  same  purpose  in  the  preserva- 
tion of  species  as  the  seeds  of  higher  plants.  They  resist  desiccation 
and  may  retain  their  vitality  for  months  or  years  until  circumstances 
are  favorable  to  their  development,  when,  under  the  influence  of  heat 
and  moisture,  they  reproduce  the  vegetative  form — bacillus  or  spiril- 
lum— with  all  of  its  biological  and  morphological  characters.  They 
are  composed  of  condensed  protoplasm  which  retains  the  vital  char- 
acters of  the  soft  protoplasm  of  the  mother  cell  from  which  it  has 
been  separated  ;  and  it  is  evident  that  whether  reproduction  occurs 
by  fission  or  by  the  formation  of  endogenous  spores,  the  protoplasm 
of  the  cells  in  a  pure  culture  of  any  microorganism  is  simply  a  sepa- 
rated portion  of  the  protoplasm  of  the  progenitors  of  these  cells. 

Some  of  the  bacilli  grow  out  into  long  filaments  before  the  forma- 
tion of  spores  occurs  ;  and  these  filaments  may  be  associated  in  bun- 
dles or  intertwined  in  irregular  masses.  At  first  the  protoplasm  of  the 


STRUCTURE,    MOTIONS,    REPRODUCTION.  115 

filaments  is  homogeneous,  but  after  a  time  it  becomes  segmented, 
and  later  the  protoplasm  of  each  segment  becomes  condensed  into 
a  spherical  or  oval  refractive  body,  which  is  the  spore.  For  a  time 
these  are  retained  in  a  linear  position  by  the  cell  membrane  of  the 
filament  (Fig.  75,  a),  but  this  is  after  a  while  dissolved  or  broken 
up  and  the  spores  are  set  free.  In  liquid  cultures  they  sink  to  the 
bottom  as  a  pulverulent  precipitate,  and  upon  the  surface  of  a  solid 
medium  they  form  a  layer  which  is  usually  of  a  white  or  yellowish- 
white  color,  and  which,  when  examined  under  the  microscope,  in  old 
cultures  is  found  to  consist  almost  entirely  of  shining  spherical  or 
oval  bodies  which  do  not  stain,  by  the  ordinary  methods,  with  the 
aniline  colors.  While  many  of  the  bacilli  during  the  stage  of  spore 
formation  grow  out  into  long  filaments,  others  do  not,  and  one  or 
more  spores  make  their  appearance  in  rods  of  the  ordinary  length 
which  characterizes  the  species.  These  may  be  located  in  the  centre 
of  the  rod  or  at  one  extremity  (Fig.  75,  6).  It  sometimes  occurs 


-a. 


that  when  a  single  central  spore  is  formed  the  rod  becomes  very 
much  enlarged  in  its  central  portion,  assuming  a  spindle  shape  (Fig. 
75,  c);  or  one  extremity  may  be  enlarged,  producing  forms  such  as 
are  shown  in  Fig.  75,  d.  Some  of  the  smaller  spherical  spores  mea- 
sure less  than  0.5  ^  in  diameter,  but  they  are,  for  the  most  part, 
oval  bodies  having  a  short  diameter  of  0. 5  to  1  /«  and  a  long  diame- 
ter of  one  to  two  /<,  or  even  more.  They  are  enveloped  in  a  cellular 
envelope  which,  according  to  some  observers,  consists  of  two  layers 
— an  exosporium  and  an  endosporium. 

The  germination  of  spores  has  been  studied  by  Prazmowski, 
Brefeld,  and  others.  The  process  is  as  follows  :  By  the  absorption 
of  water  they  become  swollen  and  pale,  losing  their  shining,  refrac- 
tive appearance.  Later  a  little  protuberance  is  seen  upon  one  side 
or  at  one  extremity  of  the  spore,  and  this  rapidly  grows  out  to  form 
a  rod  which  consists  of  soft-growing  protoplasm  enveloped  in  a 
membrane  which  is  formed  of  the  endosporium  or  inner  layer  of  the 
cellular  envelope  of  the  spore.  The  outer  envelope,  or  exosporium, 
is  cast  off  and  may  be  seen  in  the  vicinity  of  the  newly  formed  rod 
(Fig.  76).  Sometimes  the  vegetative  cell  emerges  from  one  extrem- 


116  STRUCTURE,    MOTIONS,    REPRODUCTION. 

ity  of  the  oval  spore,  as  shown  at  a,  Fig.  70,  and  in  other  species  the 
exosporium  is  ruptured  and  the  bacillus  emerges  from  the  side,  as 
seen  at  6. 

The  considerable  resistance  of  these  endogenous  spores  to  desic- 
cation, to  heat,  and  to  various  chemical  agents  is  an  important  fact 
both  from  a  biological  and  from  a  hygienic  point  of  view,  and  will 
be  fully  considered  in  a  subsequent  chapter.  The  fact  that  certain 
bacilli  and  spirilla  do  not  withstand  a  temperature  of  80°  to  90°  C., 
which  does  not  destroy  the  vitality  of  known  spores,  leads  to  the  in- 
ference that  they  do  not  form  similar  reproductive  bodies.  But  re- 
productive elements  of  a  different  kind  are  described  by  some  botan- 
ists as  being  produced  during  the  development  of  these  bacteria, 
and  also  of  the  micrococci.  These  are  the  so-called  arthrospores. 
In  the  process  of  binary  division  certain  cells  in  a  chain  may  be  ob- 
served to  be  somewhat  larger  than  others  and  to  refract  light  more 
strongly.  The  same  may  be  true  of  certain  cells  in  a  culture  in 
which  the  elements  are  not  united  in  chains.  These  cells  are  believed 


by  De  Bary  and  others  to  have  greater  resisting  power  to  desiccation 
than  the  remaining  cells  in  the  culture,  and  to  serve  the  purpose  of 
reproductive  elements. 

It  has  generally  been  supposed  that  spore  formation  is  most  likely 
to  occur  when  the  pabulum  for  supporting  the  growth  of  the  vegeta- 
tive form  is  nearly  exhausted.  But,  as  pointed  out  by  Frankel,  facts 
do  not  support  this  view,  as  many  species  form  spores  when  condi- 
tions are  most  favorable  for  a  continued  development.  An  abundant 
supply  of  oxygen  favors  the  formation  of  spores  in  aerobic  species, 
and,  in  some  instances  at  least,  the  temperatiire  has  an  important  in- 
fluence upon  spore  formation.  Thus  the  anthrax  bacillus  does  not 
form  spores  at  temperatures  below  20°  C. 

The  very  interesting  fact  has  been  demonstrated  by  Lehman  and 
by  Behring  that  a  species  which  usually  forms  spores  may  be  so 
modified  by  certain  influences  that  it  is  no  longer  capable  of  spore 
production,  and  that  such  an  asporogenous  variety  may  be  cultivated 
for  an  indefinite  time  without  showing  any  return  to  the  stage  of 
spore  formation.  This  was  effected  in  Behring's  experiments  by 
cultivating  the  anthrax  bacillus  in  a  medium  containing  some  agent 
detrimental  to  the  vitality  of  the  vegetative  cells,  but  not  in  suffi- 
cient quantity  to  restrain  their  development. 


STRUCTURE,    MOTIONS,    REPRODUCTION.  117 

The  chemical  composition  of  the  bacterial  cells  has  been  inves- 
tigated by  Nencki,  Brieger,  and  others.  Putrefactive  bacteria  culti- 
vated in  a  two-per-cent  solution  of  gelatin,  and  which  produced  an 
abundant  intercellular  substance  connecting  the  cells  in  zooglcea 
masses,  were  found  by  Nencki  to  have  the  following  composition  : 
Water,  84.26  per  cent;  solids,  5.74  per  cent,  consisting  of  albumin 
87.46  per  cent,  fat  6.41,  ash  3.04,  undetermined  remnant  3.09. 
The  albuminous  substance,  according  to  Nencki,  is  not  precipitated 
by  alcohol,  and  differs  in  its  chemical  composition  from  other  known 
substances  of  this  class.  He  calls  it  mykoprotein  and  gives  the  fol- 
lowing as  its  chemical  composition  :  C,  52.32  percent;  H,  7.55  per 
cent ;  N,  14.75  per  cent.  It  contains  no  sulphur  and  no  phosphorus. 
The  spores  of  the  anthrax  bacillus,  according  to  Nencki,  do  not  con- 
tain mykoprotein,  but  a  peculiar  albuminous  substance  which  he 
calls  anthrax-protein.  Brieger  analyzed  a  gelatin  culture  of  Fried- 
lander's  bacillus,  with  the  following  result  :  Water,  84.2  per  cent  ; 
solids,  5.8  per  cent,  containing  1.74  per  cent  of  fats.  After  removal 
of  the  fat  the  solids  gave  an  ash  of  30.13  per  cent  ;  this  contains  cal- 
cium phosphate,  magnesium  phosphate,  sodium  sulphate,  and  sodium 
chloride.  The  amount  of  nitrogen  in  the  dried  substance  after  re- 
moval of  the  fat  was  9.75. 


II. 

CONDITIONS  OF  GROWTH. 

BACTERIA  only  grow  in  presence  of  moisture,  under  certain  condi- 
tions of  temperature,  and  when  supplied  with  suitable  pabulum.  As 
they  do  not  contain  chlorophyll,  they  cannot  assimilate  carbon  diox- 
ide, and  light  is  not  favorable  to  their  development. 

The  aerobic  species  obtain  oxygen  from  the  air  and  cannot  grow 
unless  supplied  with  it.  The  anaerobic  species,  on  the  other  hand, 
will  not  grow  in  the  presence  of  oxygen,  and  must  obtain  this  ele- 
ment, as  they  do  carbon  and  nitrogen,  from  the  organic  material 
which  serves  them  as  food. 

As  a  class  the  bacteria  are  supplied  with  nutriment  by  the  higher 
plants  and  animals,  the  dead  tissues  of  which  they  appropriate,  and 
which  it  is  their  function  to  decompose,  releasing  the  organic  ele- 
ments as  simple  compounds  which  may  again  be  assimilated  by  the 
chlorophyll-producing  plants. 

Water  is  essential  for  the  development  of  bacteria,  and  many  spe- 
cies have  their  normal  habitat  in  the  waters  of  the  ocean,  of  lakes, 
and  of  running  streams  ;  others  thrive  upon  damp  surfaces  or  in.  the 
interior  of  moist  masses  of  organic  material.  Many  species  grow  in- 
differently either  in  salt  or  fresh  water,  but  it  is  probable  that  cer- 
tain species  will  be  found  peculiar  to  the  waters  of  the  ocean.  Some 
of  the  water  bacteria  multiply  in  the  presence  of  an  exceedingly 
minute  amount  of  organic  pabulum,  or  even  in  distilled  water.  This 
is  shown  by  the  experiments  of  Bolton  and  others.  The  author 
named  tested  two  species  of  water  bacteria  (Micrococcus  aquatilis 
and  Bacillus  erythrosporus)  in  the  following  manner  :  Ten  cubic 
centimetres  of  distilled  water  in  a  test  tube  were  infected  with  a  small 
quantity  of  a  culture  of  one  of  these  microorganisms.  A  drop  from 
this  tube  was  transferred  to  the  same  quantity  of  distilled  water  in 
a  second  tube,  and  from  this  to  a  third.  The  number  of  bacteria  in 
this  tube  No.  3  was  now  ascertained  by  counting,  and  it  was  put 
aside  for  two  or  three  days,  at  the  end  of  which  time  the  number  was 
again  estimated  by  counting.  In  every  case  there  was  an  enormous 
increase  in  the  number  of  bacteria.  In  order  to  be  sure  that  the  dis- 


CONDITIONS    OF   GROWTH.  119 

tilled  water  was  pure,  it  was  distilled  a  second  time  in  a  clean  glass 
retort,  but  the  result  was  the  same.  Bolton  remarks,  with  reference 
to  these  results:  "If  we  seek  to  explain  this  remarkable  fact  we 
must  remember,  in  the  first  place,  what  an  extremely  small  abso- 
lute mass  is  represented  by  an  enormous  number  of  bacteria,  and 
what  a  minute  amount  of  material  is  required  for  the  formation  of 
this  mass.  In  ten  cubic  centimetres  of  distilled  water,  in  the  experi- 
ment last  referred  to,  there  were  about  twenty  million  bacteria  (two 
million  per  cubic  centimetre).  If  we  estimate  the  diameter  of  each 
at  one  j.i,  with  a  specific  weight  of  1,  the  absolute  weight  would 
be  for  the  entire  number  one-one-hundredth  of  a  milligramme — 
that  is  to  say,  a  quantity  which  cannot  be  determined  by  any  of  our 
methods  of  weighing." 

Bolton  supposes  that  the  small  amount  of  organic  pabulum  re- 
quired fell  into  the  water  in  the  shape  of  dust,  or  was  attached  to  the 
walls  of  the  test  tube  in  spite  of  all  the  precautions  taken. 

Nitrogen  is  chiefly  obtained  from  albuminoid  substances,  but 
Pasteur  has  shown  that  it  may  also  be  obtained  from  ammonia. 
This  is  shown  by  cultivating  bacteria  in  a  medium  containing  an 
ammonia  salt,  as  in  the  following  : 

PASTEUR'S  SOLUTION. 

Distilled  water,               ......  100 

Cane  sugar,               ......  10 

Tartrate  of  ammonia.    .             .             ...            .  1 

Ashes  of  one  gramme  of  yeast,     ....  0.075 

CORN'S  SOLUTION. 

Distilled  water,  .  .  .  .  .  .  100 

Tartrate  of  ammonia,  .....  1 

Ashes  of  yeast,   .......  1 

Many  bacteria  multiply  abundantly  in  these  solutions. 

Carbon  is  obtained  from  the  various  organic  substances  contain- 
ing it  ;  among  others,  from  starch,  sugars,  glycerin,  organic  acids 
and  their  salts,  etc. 

Temperature. — There  are  certain  limits  of  temperature  within 
which  development  may  take  place,  but  these  differ  greatly  with 
different  species.  As  a  rule,  growth  is  arrested  when  the  tempera- 
ture falls  below  10°  C.  (50°  F.),  but  some  species  multiply  at  a  still 
lower  temperature.  Thus  Bolton  observed  a  very  decided  increase 
in  certain  water  bacteria  kept  in  an  ice  chest  at  0°  C.,  and  other  ob- 
servers have  witnessed  development  at  the  freezing  temperature. 

Most  saprophytic  bacteria  grow  within  rather  wide  temperature 
limits,  but  the  rapidity  of  development  is  greatest  at  a  certain  favor- 
able temperature,  which  is  usually  between  25°  and  30°  C.  The 


120  CONDITIONS    OF   GROWTH. 

parasitic  species  have  a  more  restricted  range,  which  approaches  the 
normal  temperature  of  the  animals  in  which  they  habitually  de- 
velop. At  40°  C.  (104°  F.)  growth,  as  a  rule,  ceases,  but  there  are 
some  notable  exceptions  to  this  rule. 

Miquel  some  years  ago  found  a  bacillus  in  the  water  of  the  Seine 
which  grew  at  a  temperature  of  69°  to  70°  C. ;  Van  Tieghem  reports 
having  observed  species  in  thermal  waters  capable  of  growth  at  a 
still  higher  temperature  (74°  C.)  ;  and  Globig  has  more  recently  ob- 
tained from  garden  earth  several  species  which  multiplied  at  65°  C. 
Some  of  the  species  found  by  the  last-named  observer  were  even 
found  to  require  a  temperature  of  about  60°  for  their  development ; 
and  yet  this  temperature  is  quickly  fatal  to  a  large  number  of  the 
best  known  species. 

Low  temperatures,  while  arresting  the  growth  of  bacteria,  do  not 
destroy  their  vitality.  This  has  been  demonstrated  by  numerous  ex- 
periments, in  which  they  have  been  exposed  for  hours  in  a  refrigerat- 
ing mixture  at  —18°  C.  Frisch  has  even  subjected  them  to  a  tempe- 
rature of  —  87°  C.  by  the  evaporation  of  liquid  carbon  dioxide,  and 
found  that  they  still  grew  when  placed  in  favorable  conditions. 

Parasitism. — The  strict  parasites  grow  only  in  the  bodies  of  liv- 
ing animals,  or  in  artificial  media  kept  at  a  suitable  temperature. 
As  examples  we  ma}'  mention  the  bacillus  of  tuberculosis,  the  bacil- 
lus of  leprosy,  the  micrococcus  of  gonorrhoea,  the  spirillum  of  re- 
lapsing fever.  There  is  also  a  large  class  of  facultative  para- 
sites which,  when  introduced  into  the  body  of  a  susceptible  animal, 
multiply  in  it,  and  may  continue  to  live  as  parasites  so  long  as  they 
are  transferred  from  one  animal  to  another,  but  which  are  also  able 
to  live  as  saprophytes  independently  of  a  living  host.  To  this  class 
belong  the  pus  cocci,  the  bacillus  of  typhoid  fever,  the  spirillum  of 
cholera,  and  many  others. 

It  seems  extremely  probable  that  the  strict  parasites  were  at  one 
time  capable  of  living  a  saprophytic  existence,  and  that  their  restric- 
tion to  a  parasitic  mode  of  life  has  been  effected  in  course  of  time  in 
accordance  with  the  laws  of  natural  selection.  This  view  is  sup- 
ported by  the  fact  that  the  tubercle  bacillus,  which  has  been  regarded 
as  a  strict  parasite,  which  can  only  be  cultivated  artificially  under 
very  special  conditions,  has  been  shown  to  be  capable  of  modification  in 
this  regard  to  such  an  extent  that  when  cultivated  for  a  time  in  a  favor- 
able medium — bouillon  with  five  per  cent  of  glycerin — it  will  even  grow 
in  ordinary  bouillon  made  from  the  flesh  of  a  calf  or  a  fowl  (Roux). 

Reaction  of  Medium. — Some  bacteria  grow  readily  in  a  medium 
having  an  acid  reaction,  while  the  slightest  trace  of  acidity  prevents 
the  development  of  others.  As  a  rule,  the  pathogenic  species  require 
a  neutral  or  slightly  alkaline  culture  medium. 


CONDITIONS   OF   GROWTH.  121 

While  many  species  grow  in  various  media  and  under  various 
conditions  of  temperature,  etc.,  others  are  greatly  restricted  in  this 
regard  ;  thus  Bumm  only  succeeded  in  cultivating  the  gonococcus 
upon  human  blood  serum,  and  even  upon  this  was  not  able  to 
carry  it  through  a  series  of  successive  cultures.  It  is  very  probable 
that  certain  species  can  only  grow  in  association  with  others  which 
elaborate  products  necessary  for  their  development. 

Substances  favorable  for  the  growth  of  a  particular  species  may 
restrain  its  development  if  present  in  too  large  an  amount.  Thus 
the  phosphorescent  bacilli  multiply  abundantly  in  a  nutrient  solution 
containing  2. 5  per  cent  of  sodium  chloride  ;  but  this  amount  would 
restrain  the  development  of  some  other  species,  and  a  considerable 
increase  in  the  quantity  of  salt  prevents  the  growth  of  all  microor- 
ganisms. In  the  same  way  the  addition  of  two  per  cent  of  glucose 
to  culture  solutions  is  favorable  for  the  development  of  certain  spe- 
cies, and  especially  for  the  anaerobic  bacteria  ;  but  a  concentrated 
solution  of  the  same  substance  prevents  the  growth  of  all  bacteria. 

The  influence  of  one  species  upon  the  growth  of  another  has 
been  studied  by  various  bacteriologists,  and  especially  by  Sirotinin 
and  by  Freudenreich.  When  several  species  are  associated  in  the 
same  culture  one  may  take  the  precedence  and  the  others  may  de- 
velop later  ;  or  two  or  more  species  may  develop  at  the  same  time  ; 
or  the  growth  of  one  species  may  prevent  the  development  of  an- 
other, either  («)  by  exhausting  the  pabulum  necessary  for  its  growth 
or  (b)  by  producing  substances  which  inhibit  the  development  of  an- 
otlier  species  or  destroy  its  vitality. 

Freudenreich  found,  as  a  result  of  his  numerous  experiments, 
that  the  following  species  cause  a  change  in  bouillon  which  renders 
it  unfit  for  the  growth  of  other  species  :  Bacillus  pyocyanus,  Bacillus 
cyanogenus,  Bacterium  phosphorescens,  Bacillus  prodigiosus,  Spi- 
rillum cholerse  Asiaticse.  The  following  species  do  not  cause  such  a 
change  in  bouillon  as  to  render  it  unfit  for  the  growth  of  other  spe- 
cies :  Bacillus  typhi  abdominalis,  Bacillus  anthracis,  Bacillus  septi- 
caemia? hsemorrhagicEe,  Spirillum  tyrogenum.  The  following  have  a 
decided  antagonism  :  Bacillus  pyogenes  foatidus  prevents  the  growth 
of  Spirillum  choleras  Asiaticae  ;  Micrococcus  roseus  prevents  the 
growth  of  Micrococcus  tetragenus.  The  cholera  spirillum  will  not 
grow  in  sterilized  cultures  of  Bacillus  pyocyanus,  or  in  bouillon 
which  has  served  for  a  previous  culture  of  the  same  microorganism 
(Kitasato).  Other  bacteria  which  fail  to  grow  in  bouillon  which 
has  already  served  for  the  cultivation  of  the  same  species  are  Bacil- 
lus typhi  abdominalis,  Bacillus  cyanogenus,  Bacillus  prodigiosus, 
Micrococcus  roseus,  etc.  (Freudenreich). 


III. 

MODIFICATIONS   OF   BIOLOGICAL   CHARACTERS. 

WE  have  already  referred  to  the  production  of  an  asporogenous 
variety  of  the  anthrax  bacillus.  This  was  effected  by  Behring  by 
cultivation  in  media  containing  small  amounts  of  hydrochloric  acid, 
caustic  soda,  methyl  violet,  malachite  green,  and  various  other 
agents.  This  is  only  one  of  many  instances  of  a  change  in  biologi- 
cal characters  due  to  changed  conditions  of  environment.  We  have 
abundant  experimental  evidence  that  growth  may  occur  under  ad- 
verse conditions  when  the  species  is  gradually  habituated  to  these 
conditions.  Thus  the  temperature  limitations  may  be  passed  by  suc- 
cessive cultivations  at  temperatures  approaching  these  limits,  and 
bacteria  may  grow  in.  the  presence  of  agents  which  in  a  given  pro- 
portion have  a  complete  restraining  influence  upon  their  develop- 
ment. For  example,  in  the  experiments  of  Kossiakoff ,  published  in 
the  Annales  of  the  Pasteur  Institute  (vol.  i.),  it  was  found  that  the 
several  species  tested  all  became  habituated  to  the  presence  of  anti- 
septic agents  in  proportions  which  at  first  completely  restrained 
their  growth. 

This  modification  of  biological  characters  is  well  shown  in  the 
case  of  the  chromogenic  bacteria,  some  of  which  only  form  pig- 
ment under  exceptionally  favorable  conditions  of  growth.  It  has 
been  shown  by  several  observers  that  iion-chromogenic  varieties 
of  some  of  the  best  known  chromogenic  species  may  be  produced 
by  special  methods  of  cultivation.  Thus  Wasserzug  obtained  a 
non-chromogenic  variety  of  the  bacillus  of  green  pus  (Bacillus 
pyocyanus)  by  the  action  of  time  added  to  that  of  antiseptics.  He 
says  :  ' '  These  two  actions  combined  have  permitted  me  to  obtain 
cultures  which  remained  without  color  in  a  durable  way,  and  in 
which,  consequently,  the  chromogenic  function  was  abolished  by 
heredity."  In  the  case  of  a  chromogenic  bacillus  obtained  by  the 
writer  in  Havana  (my  Bacillus  Havaniensis),  a  non-chromogenic  vari- 
ety was  obtained  from  a  culture  on  nutrient  agar  which  had  been  kept 
in  a  hermetically  sealed  glass  tube  for  about  a  year.  The  variety 
preserved  the  morphological  characters  of  the  original  stock,  but,  al- 


MODIFICATIONS   OF   BIOLOGICAL   CHARACTERS.  123 

though  carried  through  successive  cultures  for  a  considerable  period, 
did  not  regain  its  power  to  produce  the  brilliant  carmine  color  which 
is  the  most  striking  character  of  the  species.  Katz,  in  cultivating 
the  phosphorescent  bacilli  isolated  by  him  from  sea  water  at  New 
South  Wales,  found  that,  after  being  propagated  for  some  time  in 
artificial  media,  their  power  to  give  off  a  phosphorescent  light  was 
diminished  or  temporarily  lost.  He  also  found  that  two  species 
which  when  first  cultivated  did  not  liquefy  gelatin,  subsequently, 
after  a  year,  caused  liquefaction  of  the  usual  gelatin  medium. 

Modification  shown  in  Cultures. — When  bacteria  have  been 
subjected  to  the  action  of  heat  or  chemical  agents,  without  having 
their  vitality  completely  destroyed,  they  often  show  diminished  vigor 
of  growth.  Cultures  which  would  ordinarily  show  an  abundant  de- 
velopment within  twenty-four  hours  may  not  commence  to  grow  for 
several  days.  For  this  reason,  in  disinfection  experiments,  it  is  neces- 
sary to  test  the  question  of  destruction  of  vitality  by  leaving  the  cul- 
tures for  a  week  or  more  under  favorable  conditions  as  to  tempera- 
ture. In  plate  cultures  or  Esmarch  roll  tubes  a  few  colonies  may 
develop  in  this  tardy  way,  showing  that  there  was  a  difference  in  the 
vital  resisting  power  of  the  individual  cells,  some  having  survived 
while  the  majority  were  killed.  This  is  well  illustrated  by  Abbott's 
experiments  upon  the  germicidal  action  of  mercuric  chloride  as  tested 
upon  Staphylococcus  p}~ogenes  aureus.  Irregularities  in  the  results  in 
experiments  in  which  the  conditions  were  identical  having  been  no- 
ticed, Abbott  inferred  that  this  was  due  to  a  difference  in  the  resist- 
ing power  of  individual  cocci  (arthrospores  ?).  By  making  cul- 
tures from  colonies  which  developed  from  these  more  resistant  cocci, 
and  again  exposing  the  micrococci  in  these  cultures  to  mercuric  chlo- 
ride in  the  proportion  of  1: 1,000  for  a  longer  time  and  making  new 
cultures  from  the  surviving  cocci,  and  so  on,  Abbott  obtained  cultures 
in  which  a  majority  of  the  cells  survived'  exposure  to  a  solution  of  the 
strength  mentioned  for  ten  to  twenty  minutes,  whereas  in  his  original 
culture  most  of  the  cocci  were  killed  by  this  solution  in  five  minutes. 

These  changes  in.  vital  resisting  power  enable  us  to  comprehend 
other  modifications  which  can  only  be  detected  by  chemical  or  bio- 
logical reactions.  Thus  the  reducing  power  for  various  substances 
may  be  modified  by  changes  in  the  conditions  of  environment.  And 
among  the  pathogenic  bacteria  changes  of  a  more  or  less  permanent 
nature  may  be  induced,  which  are  shown  by  a  modified  degree  of 
virulence  when  injected  into  susceptible  animals. 

Attenuation  of  Virulence  may  be  effected  by  several  methods, 
all  of  which  depend  upon  subjecting  the  cultures  to  prejudicial  in- 
fluences of  one  kind  or  another. 

Pasteur  first  announced,  in  1880,  that  the  microbe  of  fowl  cholera 


124  MODIFICATIONS   OF   BIOLOGICAL   CHARACTERS. 

could  be  modified  by  special  treatment  in  such  a  manner  that  it  no 
longer  produced  a  fatal  form  of  the  disease.  He  found  that  the  viru- 
lence was  greatest  when  cultures  were  made  from  fowls  which  had 
died  from  a  chronic  form  of  the  disease,  and  that  this  virulence  was 
not  lost  by  successive  cultivations  in  chicken  bouillon,  repeated  at 
short  intervals.  But  when  an  interval  of  more  than  two  months 
was  allowed  to  elapse  without  renewing  the  cultures,  the  virulence 
was  diminished  and  fewer  deaths  occurred  in  fowls  inoculated  with 
such  cultures.  This  diminution  of  virulence  became  more  marked 
in  proportion  to  the  length  of  time  during  which  a  culture  solution 
containing  the  microbe  remained  exposed  to  the  action  of  the  atmo- 
sphere, and  at  last  all  virulence  was  lost  as  a  result  of  the  death  of 
the  pathogenic  microorganism.  When  the  virus  was  preserved  in 
hermetically  sealed  tubes  it  did  not  undergo  this  modification,  but  re- 
tained its  full  virulence  for  many  months.  According  to  Pasteur, 
the  various  degrees  of  modification  of  virulence  resulting  from  pro- 
longed exposure  to  the  air  may  be  preserved  in  successive  cultures 
made  at  short  intervals.  Subsequent  experiments  with  cultures  of 
the  anthrax  bacillus  gave  similar  results  and  enabled  him  to  produce 
an  "  attenuated  virus  "  for  his  protective  inoculations. 

In  the  case  of  the  anthrax  bacillus  it  was  found  that  the  spores 
retain  their  full  virulence  for  years,  and  that  the  production  of  an  at- 
tenuated virus  required  the  exclusion  of  these  reproductive  elements. 
Cultivations  were  consequently  made  at  a  temperature  of  43°  to  43° 
C.,  at  which  point  this  bacillus  is  incapable  of  producing  spores. 
Cultivation  at  this  temperature  for  eight  days  gave  an  attenuated 
virus  suitable  for  use  in  protective  inoculations. 

Attenuation  by  Heat. — Toussaint  has  shown  that  a  similar  modi- 
fication of  virulence  may  be  produced  by  exposure  for  a  short  time 
to  a  temperature  a  little  below  that  which  destroys  the  vitality  of  the 
pathogenic  organism.  This  is  best  accomplished,  according  to  Chau- 
veau,  in  the  case  of  the  bacillus  of  anthrax,  by  exposure  for  eighteen 
minutes  to  a  temperature  of  50°  C.  Exposure  to  this  temperature  for 
twenty  minutes  is  said  to  completely  destroy  the  vitality  of  the  bacillus. 

Attenuation  by  Antiseptic  Agents. — The  writer,  in  1880,  ob- 
tained evidence  that  attenuation  of  virulence  may  result  from  ex- 
posure to  the  action  of  antiseptic  agents.  In  a  series  of  experiments 
made  to  determine  the  comparative  value  of  disinfectants,  the  blood 
of  a  rabbit  recently  dead  from  a  form  of  septica3mia  induced  by  the 
subcutaneous  injection  of  my  own  saliva,  and  due  to  the  presence  of 
a  micrococcus  (Micrococcus  pneumoniEB  crouposae),  was  subjected  to 
the  action  of  various  chemical  agents,  and  subsequently  injected 
into  a  rabbit  to  test  the  destruction  of  virulence.  In  the  published 
report  of  these  experiments  the  following  statement  is  made  : 


MODIFICATIONS    OF   BIOLOGICAL   CHARACTERS.  125 

"The  most  important  source  of  error,  however,  and  one  which 
must  be  kept  in  view  in  future  experiments,  is  the  fact  that  a  pro- 
tective influence  has  been  shown  to  result  from  the  injection  of  virus 
the  virulence  of  which  has  been  modified,  without  being  entirely  de- 
stroyed, by  the  agent  used  as  a  disinfectant. " 

"•  Sodium  hyposulphite  and  alcohol  were  the  chemical  reagents 
which  produced  the  result  noted  in  these  experiments  ;  but  it  seems 
probable  that  a  variety  of  antiseptic  substances  will  be  found  to  be 
equally  effective  when  used  in  proper  proportion.  Subsequent  ex- 
periments have  shown  that  neither  of  these  agents  is  capable  of  de- 
stroying the  vitality  of  the  septic  micrococcus  in  the  proportion  used 
(one  per  cent  of  sodium  hyposulphite  or  one  part  of  ninety -five-per- 
cent alcohol  to  three  parts  of  virus),  and  that  both  have  a  restraining 
influence  upon  the  development  of  this  organism  in  culture  fluids." 

Cultivation  in  the  Blood  of  an  Immune  Animal. — It  has 
been  recently  shown  by  the  experiments  of  Ogata  and  Jasuhara  that 
when  the  anthrax  bacillus  is  cultivated  in  the  blood  of  an  immune 
animal,  such  as  the  dog  or  the  white  rat,  its  pathogenic  power  is 
modified  so  that  it  no  longer  kills  susceptible  animals  and  may  be 
used  as  a  vaccine. 

Pasteur  had  previously  shown  (1882)  that  the  virus  of  rouget  can 
be  attenuated  by  passing  it  through  rabbits. 

Recovery  of  Virulence. — Pasteur  has  shown  that  when  the  viru- 
lence of  a  pathogenic  organism  has  been  modified  it  may  be  re- 
stored by  successive  inoculations  into  susceptible  animals.  Thus  in 
the  case  of  the  anthrax  bacillus  a  culture  which  would  not  kill  an 
adult  guinea-pig  may  be  inoculated  into  a  very  young  animal  of  the 
same  species  with  a  fatal  result  ;  and  by  inoculating  the  blood  of 
this  animal  into  another,  and  so  on,  the  original  virulence  may  be 
restored,  so  that  a  culture  is  obtained  which  will  kill  a  sheep.  In 
the  same  way  the  attenuated  virus  of  fowl  cholera  may  be  restored 
to  full  vigor  by  inoculating  a  small  bird: — sparrow  or  canary — to 
which  it  is  fatal.  After  several  successive  inoculations  the  virus 
resumes  its  original  activity. 

In  general,  pathogenic  virulence  is  increased  by  successive  inocu- 
lations into  susceptible  animals,  and  diminished  by  cultivation  in  arti- 
ficial media  under  unfavorable  conditions.  Thus  various  pathogenic 
bacteria  which  have  been  cultivated  in  laboratories  for  a  length  of 
time  are  likely  to  disappoint  the  student  if  he  makes  inoculation  ex- 
periments for  the  purpose  of  demonstrating  their  specific  action  as 
described  in  text  books. 

'Quoted  from  "Bacteria,"  pages  207,  208,  written  in  1883. 


IV. 

PRODUCTS   OF  VITAL  ACTIVITY. 

ALL  living  cells,  animal  or  vegetable,  while  in  active  growth, 
appropriate  certain  elements  for  their  nutrition  from  the  pabulum 
with  which  they  are  supplied,  and  at  the  same  time  excrete  certain 
products  which,  in  some  cases  at  least,  it  is  their  special  function  to 
produce.  In  the  higher  plants  and  animals  specialized  cells  excrete 
substances  which  are  injurious  to  the  economy  of  the  individual, 
and  secrete  substances  which  are  required  to  maintain  its  existence. 
As  an  example  in  animals  we  may  mention  the  excretion  of  urea  by 
the  epithelium  of  the  kidneys,  the  retention  of  which  is  fatal  to  the 
individual,  and  the  gastric  secretion  which  is  essential  for  its  con- 
tinued existence.  Among  the  higher  plants  we  have  an  immense 
variety  of  substances  formed  in  the  cell  laboratories,  some  of  which 
are  evidently  useful  for  the  preservation  of  the  species,  while  others 
are  perhaps  to  be  considered  simply  as  excretory  products.  The 
odorous  volatile  products  given  off  by  flowers  are  supposed  to  be 
useful  to  the  plant  in  attracting  insects  by  which  cross-fertilization 
is  effected.  The  various  poisonous  substances  stored  up  in  leaves 
and  bark  may  serve  to  protect  the  plant  from  enemies,  etc. 

The  minute  plants  with  which  we  are  especially  concerned  also 
produce  a  great  variety  of  substances,  some  of  which  may  be  useful 
to  the  species  in  the  struggle  for  existence.  Thus  the  deadly  pto- 
maines produced  by  some  of  the  pathogenic  bacteria  serve  to  para- 
lyze the  vital  resisting  power  of  living  animals  and  enable  the  para- 
sitic invader  to  thrive  at  the  expense  of  its  host.  In  the  present 
section  we  shall  consider  in  a  general  way  these  various  products  of 
bacterial  growth. 

Pigment  Production. — A  considerable  number  of  species  are 
distinguished  by  the  formation  of  pigment  of  various  colors  and 
shades.  We  have  all  of  the  shades  of  the  spectrum  from  violet  to 
red.  The  color,  as  a  rule,  is  only  produced  in  the  presence  of  oxy- 
gen, and  when  the  pigment-producing  microorganisms  are  massed 
upon  the  surface  of  a  solid  culture  medium  the  pigment  production 
is  often  limited  to  the  superficial  portion  of  the  mass.  In  some 
cases  a  soluble  pigment  is  formed  which  is  absorbed  by  the  transpa- 


EPNBERG'ft  BACTERIOLOGY. 


Plate  III. 


Fig.l. 


Fig.Z. 


Fig3. 


Fig.l .  Sarcinalutea'agar  culture 
Fi^.2.  Bacillus  prodigiosus,  a^ar  culture. 
Fig. 3.  Bacillus  pyocyanus.agar  culture. 
Fig.4-.  Bacillus  Havaniensis,  potato  culture, 


PRODUCTS   OP    VITAL   ACTIVITY.  127 

rent  culture  medium,  coloring  especially  the  upper  portion,  in  stick 
cultures  in  nutrient  gelatin  or  agar.  This  is  the  case  with  Bacillus 
pyocyanus,  which  produces  a  blue  pigment  which  has  been  isolated 
and  carefully  studied  by  Gessard  and  others.  The  pigment,  which  is 
called  pyocyanin,  is  soluble  in  chloroform  and  crystallizes  from  a 
pure  solution  in  long  blue  needles.  Acids  change  the  blue  color  to 
red,  reducing  substances  to  yellow.  It  resembles  the  ptomaines  in 
its  chemical  reactions,  being  precipitated  by  platinum  chloride  and 
phosphomolybdic  acid. 

In  some  media  the  color  produced  by  the  Bacillus  pyocyanus 
(bacillus  of  green  pus)  is  a  fluorescent  green.  The  recent  studies  of 
Gessard  show  that  this  is  a  different  pigment.  According  to  this 
author,  cultures  in  a  two-per-cent  solution  of  peptone  give  a  beautiful 
blue  tint,  the  production  of  which  is  hastened  by  adding  to  the 
liquid  five  per  cent  of  glycerin.  In  nutrient  gelatin  and  agar  cul- 
tures a  fluorescent  green  color  is  developed,  which,  according  to 
Gessard,  is  due  to  the  presence  of  albumin.  Peptone  and  gelatin 
are  said  to  produce  pyocyanin  without  the  fluorescent-green  pig- 
ment, and  cultures  in  bouillon  to  give  both  this  and  pyocyanin.  In 
milk  the  fluorescent-green  color  is  first  seen,  but  subsequently,  when 
the  casein  has  been  peptom'zed  by  a  diastase  produced  in  the  culture, 
pyocyanin  is  also  formed.  Several  other  microorganisms  are  known 
which  produce  a  fluorescent-green  color,  due  probably  to  the  same 
pigment  as  is  produced  by  the  bacillus  of  green  pus  in  albuminous 
media. 

Babes  claims  to  have  obtained  two  pigments  from  cultures  of  the 
Bacillus  pyocyanus  in  addition  to  pyocyanin  :  one,  soluble  in  alco- 
hol, has  by  transmitted  light  a  chlorophyll-green  color,  by  reflected 
light  it  is  blue  ;  the  other,  insoluble  in  alcohol  and  chloroform,  by 
transmitted  light  is  of  a  dark  orange-red,  by  reflected  light  a  green- 
ish-blue. 

In  Gessard's  latest  publication  (1891)  he  shows  that  the  produc- 
tion of  pyocyanin  or  of  the  fluorescent-green  pigment  does  not  de- 
pend alone  upon  the  culture  medium,  but  that  there  are  different 
varieties  of  the  Bacillus  pyocyanus.  He  has  succeeded  in  producing 
four  distinct  varieties — one  which  produces  both  pyocyanin  and 
fluorescence,  one  which  produces  pyocyanin  alone,  one  which  pro- 
duces the  fluorescent-green  pigment  alone,  and  one  which  produces 
no  pigment.  The  last-mentioned  non-chromogenic  variety  was  pro- 
duced by  subjecting  the  second  variety  to  the  action  of  heat.  A 
temperature  of  57°  maintained  for  five  minutes  destroyed  the  power 
to  produce  pigment  without  destroying  the  vitality  of  the  bacillus, 
which  was  propagated  through  successive  cultures  without  regaining 
this  power. 


128  PRODUCTS   OF   VITAL   ACTIVITY. 

The  well-known  Bacillus  prodigiosus  (also  described  as  a  micro- 
coccus)  produces  a  red  pigment  which  is  insoluble  in  water  but  solu- 
ble in  alcohol.  By  the  addition  of  an  acid  the  color  becomes  car- 
mine and  then  violet,  which  is  changed  to  yellow  by  an  alkali.  The 
color  is  said  by  Schottelius  to  be  diffused  in  the  young  cells,  and 
after  the  death  of  the  cells  to  be  present  in  their  vicinity  in  the  form 
of  granules.  The  same  author  has  shown  that  by  subjecting  the 
bacillus  to  special  conditions  a  variety  may  be  obtained  which  no 
longer  produces  pigment. 

The  conditions  which  govern  the  formation  of  pigment  in  the 
chromogenic  bacteria  are  determined  with  comparative  facility  be- 
cause the  results  of  changed  conditions  are  apparent  to  the  eye  ;  in 
the  case  of  products  which  are  not  colored  the  difficulties  attending 
the  study  of  these  conditions  are 'much  greater,  but  the  results  are  in 
many  instances  more  important.  The  following  are  among  the  best 
known  pigment-producing  (chromogenic)  bacteria  : 

Staphylococcus  pyogenes  aureus  (No.  1),  Staphylococcus  pyc- 
genes  citreus  (No.  3),  Sarcina  aurantiaca  (No.  226),  Sarcina  lutea 
(No.  227),  Bacillus  cyanogenus  (No.  257),  Bacillus  janthinus  (No. 
267),  Bacillus  fluorescens  liquefaciens  (No.  277),  Bacillus  indicus  (No. 
283),  Bacillus  pyocyanus  (No.  95),  Bacillus  prodigiosus  (No.  284), 
Spirillum  rubrum  (No.  429). 

Liquefaction  of  Gelatin. — Many  species  of  bacteria,  when 
planted  in  a  medium  containing  gelatin,  cause  a  liquefaction  of  the 
gelatin  in  the  immediate  vicinity  of  the  growing  microorganisms, 
while  many  others  multiply  abundantly  in  the  same  medium  with- 
out liquefying  the  gelatin.  This  character,  as  first  shown  by  Koch, 
is  an  important  one  in  the  differential  diagnosis  of  species  which  re- 
semble each  other  in  form  and  in  other  respects.  It  has  no  relation 
to  pathogenic  power,  as  some  liquefying  organisms  are  harmless  sap- 
rophytes and  some  deadly  disease  germs,  while,  on  the  other  hand, 
non-liquefying  bacteria  may  be  very  pathogenic  or  quite  innocent. 

Liquefaction  is  produced  by  a  soluble  peptonizing  ferment  formed 
during  the  growth  of  the  cells.  This  is  shown  by  the  fact  that  if  a 
liquefying  organism  is  cultivated  in  bouillon  and  the  living  cells  re- 
moved by  filtration  or  killed  by  heat,  the  power  of  liquefying  gelatin 
remains  in  the  culture  fluid.  This  was  first  observed  by  Bitter  (1886) 
and  independently  by  the  writer  in  1887.  In  experiments  made  to 
determine  the  thermal  death-point  of  various  bacteria  the  writer 
found  that  when  cultures  of  liquefying  species  were  subjected  to  a 
temperature  which  killed  the  microorganisms,  a  few  drops  of  the 
culture  added  to  nutrient  gelatin  which  had  been  liquefied  by  heat 
prevented  it  from  subsequently  forming  a  solid  jelly  when  cold. 

In  a  recent  study  of  the  ferments  produced  by  bacteria  which 


PRODUCTS    OF   VITAL   ACTIVITY.  129 

"cause  liquefaction  of  gelatin — "  tryptic  enzymes  " — made  by  Fermir 
in  the  laboratory  of  the  Hygienic  Institute  of  Munich  (1891),  the  fol- 
lowing results  were  obtained  : 

The  enzymes  were  not  obtained  pure,  and  their  isolation  from 
other  proteids  present  in  the  cultures  was  found  to  be  attended  with 
great  difficulties,  but  their  ferment  action  was  studied  and  was  found 
to  be  influenced  by  various  conditions. 

All  were  destroyed  by  a  temperature  of  70°  C.,  but  the  enzymes 
produced  by  various  liquefying  bacteria  differed  considerably  as  to 
the  temperature  which  they  were  able  to  withstand.  Some  were  de- 
stroyed by  a  temperature  of  50°  to  55°  C. — Bacillus  megatherium, 
Bacillus  ramosus,  Staphylococcus  pyogenes  aureus  ;  some  by  a  tem- 
perature of  55°  to  00°  C. — Bacillus  subtilis,  Bacillus  pyocyanus,  Bacil- 
lus fluorescens  liquefaciens,  Sarcina  aurantiaca  ;  some  by  65°  to  70° 
C. — Bacillus  anthracis,  Spirillum  cholerae  Asiaticse,  Spirillum  of 
Finkler  and  Prior,  Spirillum  tyrogenum. 

These  enzymes,  like  the  previously  known  pepsin,  trypsin,  and 
invertin,  do  not  dialyze. 

Only  a  few  of  these  bacteria  enzymes  acted  upon  fibrin,  and  no 
action  was  observed  upon  casein  or  upon  egg  albumen. 

Their  liquefying  action  upon  gelatin  was  prevented  by  the  action 
of  sulphuric  acid,  and  to  a  less  degree  by  nitric  acid,  but  was  not  in- 
terfered with  by  acetic  acid. 

The  liquefying  bacteria,  as  a  rule,  only  produce  enzymes  when 
cultivated  in  a  medium  containing  albumen. 

These  enzymes  are  not  produced  by  a  solution  of  the  protoplasm 
of  dead  bacterial  cells,  but  are  a  product  of  the  vital  activity  of  liv- 
ing cells. 

Among  the  numerous  liquefying  bacteria  known  to  bacteriolo- 
gists we  may  mention  the  following  species  as  deserving  the  student's 
special  attention  :  Staphylococcus  pyogenes  aureus  (No.  1),  Staphylo- 
coccus pyogenes  albus  (No.  2),  Sarcina  lutea  (No.  227),  Sarcina  au- 
rantiaca (No.  226),  Bacillus  anthracis  (No.  45),  Bacillus  pyocyanus 
(No.  95),  Bacillus  subtilis  (No.  379),  Bacillus  indicus  (No.  283),  Ba- 
cillus prodigiosus  (No.  284),  Spirillum  cholerse  Asiaticae  (No.  155), 
Spirillum  of  Finkler  and  Prior  (No.  156),  Proteus  vulgaris  (No.  97). 

Production  of  Acids. — Numerous  bacteria  give  an  acid  reaction 
to  the  media  in  which  they  are  cultivated,  and  the  acids  produced 
are  various — lactic,  acetic,  butyric,  propionic,  succinic,  etc. 

The  power  to  produce  an  acid  is  well  shown  by  adding  to  neu- 
tral or  alkaline  culture  media  a  solution  of  litmus.  The  change  in 
color  due  to  the  formation  of  an  acid  may  be  followed  by  the  eye, 
and  comparative  tests  may  be  made  to  aid  in  the  differentiation  of 
similar  bacteria. 
9 


130  PRODUCTS   OF   VITAL  ACTIVITY. 

A  considerable  number  of  bacteria  are  able  to  produce  lactic 
acid  from  milk  sugar  and  other  carbohydrates.  One  of  these  is 
considered  the  special  lactic-acid  ferment — Bacillus  acidi  lactici — and 
is  the  usual  cause  of  the  acid  fermentation  of  milk.  Pure  cultures 
of  this  bacillus  introduced  into  sterilized  milk  or  solutions  of  milk 
sugar,  cane  sugar,  dextrin,  or  mannite,  give  rise  to  the  lactic-acid 
fermentation,  in  which  carbonic  acid  is  also  set  free.  The  process 
requires  free  access  of  oxygen,  and  progresses  most  favorably  at  a 
temperature  of  35°  to  40°  C.,  ceasing  at  about  45°.  In  milk,  coagu- 
lation of  the  casein  occurs  within  fifteen  to  twenty-four  hours  after 
adding  a  small  quantity  of  a  pure  culture  of  the  lactic-acid  bacillus. 
This  is  not  due,  however,  to  the  acid  fermentation,  but  to  a  ferment 
resembling  that  of  rennet,  which  is  produced  by  many  different 
bacteria,  some  of  which  do  not  produce  an  acid  reaction  of  the  milk. 
Among  the  bacteria  which  produce  lactic  acid  from  milk  sugar  we 
may  mention  the  staphylococci  of  pus,  Bacillus  lactis  aerogenes,  and 
Bacillus  coli  communis. 

The  formula  showing  the  transformation  of  sugar  into  lactic 
acid  is  usually  stated  as  follows  :  CjH^O,,  =  2(HC3H6O3). 

Acetic  acid  is  also  produced  from  dilute  solutions  of  alcohol  by 
the  action  of  a  special  bacterial  ferment,  which  accumulates  upon 
the  surface  of  the  fluid  as  a  mycoderma,  consisting  almost  entirely 
of  the  Bacillus  aceticus  (Mycoderma  aceti).  Free  access  of  oxygen 
is  required,  and  a  temperature  of  about  33°  C.  is  most  favorable  to 
the  process.  According  to  Duclaux,  the  "  Mycoderma  aceti "  oxi- 
dizes the  alcohol,  in  solutions  containing  it,  so  long  as  any  is  present, 
and  when  it  is  exhausted  it  oxidizes  the  acetic  acid  previous^ 
formed  by  oxidation  of  the  alcohol,  producing  from  it  carbon  diox- 
ide and  water. 

The  formation  of  acetic  acid  from  alcohol  is  shown  by  the  follow- 
ing formula  :  Ethyl  alcohol  CHS.CH9.OH  +  O8  =  CH3.COOH  +  H,O. 

Butyric  acid  is  produced  by  a  considerable  number  of  bacteria, 
one  of  which,  named  Bacillus  butyricus,  has  received  the  special  at- 
tention of  Prazmowski.  This  is  strictly  anaerobic.  In  solutions  of 
starch,  dextrin,  sugar,  or  salts  of  lactic  acid,  when  oxygen  is  ex- 
cluded it  produces  butyric  acid  in  considerable  quantity,  and  at  the 
same  time  carbon  dioxide  and  hydrogen  gas  are  set  free.  Duclaux 
gives  the  following  formula  of  a  solution  containing  lactate  of  lime 
in  which  the  action  of  the  butyric-acid  ferment  may  be  well  studied  : 

Water,  .  .  .  .  .  .        8  to  10  litres. 

Lactate  of  lime  (pure),    .  .  .  ..  225  grammes. 

Phosphate  of  ammonia,  .  .  .  .0.75        " 

Phosphate  of  potash, .      .  .  .  ..  0.4 

Sulphate  of  magnesa,  .  .  .  .0.4 

Sulphate  of  ammonia,      .  .  .  .  0.2          " 


PRODUCTS   OF   VITAL  ACTIVITY. 


131 


This  is  introduced  i-nto  a  flask  with  two  necks,  such  as  is  shown 
in  Fig.  77.  Having  filled  the  flask  with  the  culture  liquid,  the  bent 
neck  is  dipped  into  a  porcelain  dish  containing  the  same.  Heat  is 
then  applied  both  to  flask  and  dish,  and  the  liquid  in  each  is  kept  in 
ebullition  for  half  an  hour.  By  this  means  the  air  is  completely 
driven  out  of  the  flask.  This  is  now  allowed  to  cool,  while  the  fluid 
in  the  shallow  dish  is  kept  hot,  so  that  the  liquid  mounting  from  it 
into  the  flask  shall  be  free  from  air.  When  the  flask  is  full  it  is 
transferred  to  an  incubating  oven  heated  to  25°  to  30°  C.,  and  the  bent 
tube  is  immersed  in  a  dish  containing  mercury.  The  little  funnel 
attached  to  the  upright  tube  is  then  filled  with  carbon  dioxide  and  a 
culture  of  the  butyric-acid  bacillus  is  introduced  into  the  funnel. 
By  turning  the  stopcock  in  the  upright  tube  a  little  of  the  culture  is 


FIG.  77. 

admitted  to  the  flask  without  admitting  any  air.  Fermentation  com- 
mences very  soon,  as  is  seen  by  the  bubbles  of  gas  given  off.  The 
liquid  loses  its  transparency  and  the  lactic  acid  is  gradually  con- 
sumed, butyrate  of  lime  taking  the  place  of  the  lactate. 

Aerobic  bacilli  capable  of  producing  butyric  acid  in  culture  solu- 
tions containing  grape  sugar  or  milk  sugar  have  also  been  described 
by  Liborius  and  by  Hueppe. 

Fitz  has  shown  that  in  culture  solutions  containing  glycerin  the 
Bacillus  pyocyanus  produces  butyric  acid  in  addition  to  ethyl  alco- 
hol and  succinic  acid.  Bacillus  Fitzianus  also  produces  some  butyric 
acid  in  solutions  containing  glycerin,  although  the  principal  product 
of  the  fermentation  caused  by  this  microorganism  is,  according  to 
Fitz,  ethyl  alcohol,  twenty-nine  grammes  of  which  may  be  obtained 
from  one  hundred  grammes  of  glycerin. 


132  PRODUCTS   OF   VITAL   ACTIVITY. 

Botkin  has  recently  (1892)  described  a  "Bacillus  butyricus" 
(No.  466)  which  he  has  not  been  able  to  identify  positively  with  the 
butyric-acid  ferment  described  by  Prazmowski  (No.  404).  It  is  a 
widely  distributed  anaerobic  bacillus,  which  he  was  able  to  obtain  from 
milk  or  water  containing  it  by  placing  it  in  the  steam  sterilizer  for 
half  an  hour.  The  spores  resisted  this  temperature  and  subsequently 
grew  in  anaerobic  cultures,  in  a  suitable  medium,  while  all  other  bac- 
teria and  spores  present  were  destroyed. 

The  writer  has  described  a  bacillus  which  causes  active  acid 
fermentation  in  culture  solutions  containing  glycerin.  The  acid 
formed  is  volatile  and  is  probably  propionic  acid — see  Bacillus  acidi- 
formans  (No.  93). 

The  Caucasian  milk  ferment — Bacillus  Kaukasicus — produces 
a  variety  of  products  in  the  fermented  milk  which  is  a  favorite 
drink  among  the  Caucasians.  The  principal  ones  are  ethyl  alcohol, 
lactic  acid,  and  carbon  dioxide,  but  in  addition  to  these  small  quanti- 
ties of  succinic,  butyric,  and  acetic  acids  are  formed.  The  inhabi- 
tants of  the  Caucasian  mountains  prepare  this  fermented  drink  in  a 
very  simple  manner  from  the  milk  of  cows  or  goats,  to  which  they 
add  the  dried  ferment  collected  from  a  receptacle  in  which  the  fermen- 
tation had  previously  taken  place.  Fliigge  gives  the  following  di- 
rections for  the  preparation  of  this  drink  : 

"  Two  methods  may  be  employed.  In  the  first  the  dry  brown  kefir-kdr- 
ner  of  commerce  are  allowed  to  lie  in  water  for  five  to  six  bours  until  they 
swell;  they  are  then  carefully  washed  and  placed  in  fresh  milk,  which 
should  be  changed  once  or  twice  a  day  until  the  korner  become  pure  white 
in  color  and  when  placed  in  fresh  milk  quickly  mount  to  the  surface — in 
twenty  to  thirty  minutes.  One  litre  of  milk  is  then  poured  into  a  flask  and  a 
full  tablespoonful  of  the  prepared  korner  added  to  it.  It  is  allowed  to  stand 
open  for  five  to  eight  hours ;  the  flask  is  then  closed  and  kept  at  18°  C.  It 
should  be  shaken  every  two  hours.  At  the  end  of  twenty- four  hours  the 
milk  is  poured  through  a  fine  sieve  into  another  flask,  which  must  not  be 
more  than  four-fifths  full.  This  is  corked  and  allowed  to  stand,  being 
shaken  from  time  to  time.  At  the  end  of  twenty-four  hours  a  drink  is  ob- 
tained which  contains  but  little  COa  or  alcohol.  Usually  it  is  not  drunk 
until  the  second  day,  when,  upon  standing,  two  layers  are  formed,  the 
lower  milky,  translucent,  and  the  upper  containing  fine  flakes  of  casein. 
When  shaken  it  has  a  cream- like  consistence.  On  the  third  day  it  again 
becomes  thin  and  very  acid. 

"  The  second  method  is  used  when  one  has  a  good  kefir  of  two  or  three 
days  to  start  with.  Three  or  four  parts  of  fresh  cow's  milk  are  added  to  one 
part  of  this  and  poured  into  flasks  which  are  allowed  to  stand  for  forty- 
eight  hours  with  occasional  shaking.  When  the  drink  is  ready  for  use  a 
portion  (one- fifth  to  one- third)  is  left  in  the  flask  as  ferment  for  a  fresh 
quantity  of  milk.  The  temperature  should  be  maintained  at  about  18°  C. ; 
but  at  the  commencement  a  higher  temperature  is  desirable.  The  korner 
should  be  carefully  cleaned  from  time  to  time  and  broken  up  to  the  size  of 
peas.  The  cleaned  korner  may  be  dried  upon  blotting  paper  in  the  sun  or 
in  the  vicinity  of  a  stove :  when  dried  in  the  air  they  retain  their  power  to 
germinate  for  a  long  time." 

Fermentation  of  urea.     The  alkaline  fermentation  of  urine  is 


PRODUCTS   OP   VITAL   ACTIVITY.  133 

effected  by  various  microorganisms,  but  chiefly  by  the  Micrococcus 
urese,  the  ferment  action  of  which  has  been  carefully  studied  by  Pas- 
teur, Duclaux,  and  others.  The  change  which  occurs  under  the 
action  of  the  living  ferment  was  determined  by  the  chemist  Dumas 
as  long  ago  as  1830,  but  it  remained  for  Pasteur  to  show  that  this 
change  depends  upon  the  presence  and  vital  activity  of  a  living 
microorganism. 

The  transformation  of  urea  into  carbonate  of  ammonia  is  shown 
by  the  following  formula  :  COH4N2  +  2H2O  =  CO,  +  2NH9  + 
H,0  =  (NH4),C03. 

According  to  Van  Tieghem,  Micrococcus  urese  continues  to  grow 
in  a  liquid  containing  as  much  as  thirteen  per  cent  of  carbonate  of 
ammonia.  It  may  be  cultivated  in  an  artificial  solution  of  urea,  with 
the  addition  of  some  phosphates,  as  well  as  in  urine. 

The  Bacillus  urese  of  Miquel  has  also  the  power  of  producing  the 
alkaline  fermentation  of  urine,  but  it  does  not  thrive  in  so  strong  a 
solution  of  carbonate  of  ammonia. 

A  different  micrococcus — Micrococcus  urese  liquef aciens — nas  also 
been  studied  in  Flugge's  laboratory  which  possesses  the  same  power. 
According  to  Musculus,  a  soluble  ferment  may  be  isolated  from  urine 
which  has  undergone  alkaline  fermentation,  which  changes  urea  into 
carbonate  of  ammonia.  He  obtained  it  from  urine  containing  con- 
siderable mucus,  in  a  case  of  catarrh  of  the  bladder.  But  Leube  has 
shown  that  cultures  of  Micrococcus  urese  from  which  the  micrococ- 
cus was  removed  by  filtration  through  clay  do  not  induce  alkaline 
fermentation.  The  soluble  ferment  obtained  by  Musculus  must 
therefore  be  from  some  other  source. 

Miquel  has  given  special  attention  to  the  study  of  bacteria  which 
produce  alkaline  fermentation  in  urine,  and  in  addition  to  the  spe- 
cies above  mentioned  has  described  the  following  :  Urobacillus  Pas- 
teuri  (No.  467),  Urobacillus  Duclauxi  (No.  468),  Urobacillus  Freu- 
denreichi  (No.  469),  Urobacillus  Maddoxi  (No.  470),  Urobacillus 
Schutzenbergi  (No.  471). 

Viscous  fermentation.  A  special  fermentation  which  occurs 
sometimes  in  wines,  and  in  the  juices  of  bulbous  roots  containing 
glucose,  and  in  milk,  is  produced  by  various  bacteria.  One  of  these 
is  a  micrococcus  which  has  been  described  by  Conn  under  the  name  of 
Micrococcus  lactis  viscosus  (No.  195).  The  fermented  juices  become 
very  viscous,  owing  to  the  formation  of  a  gum-like  product  resem- 
bling dextrin  ;  at  the  same  time  mannite  and  CO,  are  produced. 
The  gum-like  substance,  called  viscose  by  Bechamp,  is  soluble  in 
cold  water  and  is  precipitated  by  alcohol.  Recently  (1892)  Guille- 
beau  has  described  a  micrococcus  and  a  bacillus  which  produce  vis- 
cous fermentation  in  milk — Micrococcus  Freudenreichi '  (No.  475)  and 


134  PRODUCTS   OF   VITAL   ACTIVITY. 

Bacillus  Hessi  (No.  47G).  A  micrococcus  producing  viscous  fermen- 
tation in  milk  has  also  been  described  by  Schmidt-Miihlheim,  and  a 
bacillus  by  Loffler.  Bacillus  mesentericus  vulgatus  also  produces  a 
similar  change  in  milk. 

Marsh  gas,  CH4,  is  produced  by  the  fermentation  of  cellulose, 
through  the  action  of  microorganisms  the  exact  characters  of  which 
have  not  yet  been  determined.  According  to  Tappeiner,  there  are 
two  different  fermentations  of  cellulose.  The  first  occurs  in  a  neu- 
tral one-per-cent  flesh  extract  solution  to  which  cotton  or  paper  pulp 
has  been  added.  The  gases  given  off  are  CO2  and  CH4  and  small 
quantities  of  H2S.  The  second  fermentation  occurs  when  an  alkaline 
solution  of  flesh  extract  containing  cellulose  in  suspension  is  used. 
The  gases  formed  are  CO3  and  H.  In  both  cases  small  quantities  of 
aldehyde,  isobutyric  acid,  and  acetic  acid  are  produced. 

Hydrosulphuric  acid,  H2S.  This  gas  is  produced  during  the 
growth  of  certain  bacteria.  The  conditions  governing  its  develop- 
ment have  been  studied  by  Holschewnikoff,  who  experimented  with 
two  species,  one  isolated  by  himself  and  one  by  Lindenborn,  named 
respectively  Bacterium  sulfureum  and  Proteus  sulfureus.  The  first- 
mentioned  bacterium,  when  inoculated  into  eggs,  produced  within 
three  or  four  days  an  abundant  quantity  of  H2S  ;  the  other  did  not. 
Upon  raw  albumin  both  species  produced  but  little,  and  on  the  yolk 
of  egg  a  considerable  amount  of  this  gas.  Upon  cooked  egg  the 
action  was  the  reverse.  In  peptone-bouillon  the  evolution  of  H2S 
was  abundant ;  in  the  absence  of  peptone,  very  slight. 

Putrefactive  fermentation.  The  putrefactive  decomposition 
of  albuminous  material  of  animal  and  vegetable  origin  is  effected 
by  a  great  variety  of  microorganisms  and  gives  rise  to  the  forma- 
tion of  a  great  variety  of  products,  some  of  which  are  volatile  and 
are  characterized  by  their  offensive  odors.  According  to  Fliigge,  the 
first  change  which  occurs  consists  in  the  transformation  of  the  albu- 
mins into  peptone,  and  this  may  be  effected  by  a  large  number  of 
different  bacteria.  Among  the  products  of  putrefactive  fermenta- 
tion known  to  chemists  are  the  following  substances  :  Carbon  diox- 
ide, hydrogen,  nitrogen,  hydrosulphuric  acid  (H2S),  phosphoretted 
hydrogen  (PH3),  methane,  formic  acid,  acetic  acid,  butyric  acid, 
valerianic  acid,  palmitic  acid,  crotonic  acid,  glycolic  acid,  oxalic 
acid,  succinic  acid,  propionic  acid,  lactic  acid,  amidostearic  acid, 
leucin,  ammonia,  ammonium  carbonate,  ammonium  sulphide,  tri- 
methylamine,  propylamine,  indol,  skatol,  ty rosin, neuridin,  cadaverin, 
putrescin,  cholin,  neurin,  peptotoxiii,  and  various  other  volatile 
acids,  ptomaines,  etc. 

The  special  products  of  putrefaction  vary  according  to  the  nature 
of  the  material,  the  conditions  in  which  it  is  placed,  and  the  micro- 


PRODUCTS   OP   VITAL   ACTIVITY.  135 

organisms  present.  One  or  the  other  of  the  bacteria  concerned  will 
take  the  precedence  when  circumstances  favor  its  growth.  Thus  the 
aerobic  bacteria  cannot  grow  unless  the  putrefying  material  is  freely 
exposed  to  atmospheric  oxygen  ;  the  anaerobic  species  require  its 
exclusion.  Some  saprophy tic  bacteria  grow  at  a  comparatively  low 
temperature,  others  take  the  precedence  when  the  temperature  is 
high  ;  some,  no  doubt,  thrive  only  in  presence  of  products  evolved 
by  other  species,  and  are  consequently  associated  with  and  depend- 
ent upon  these  species  ;  some  are  restrained  in  their  growth  sooner 
than  others  by  the  products  evolved  as  a  result  of  their  own  vital 
activity  or  that  of  associated  organisms  ;  some  grow  in  the  presence 
of  acids  and  give  rise  to  an  acid  fermentation  which  wholly  prevents 
the  development  of  other  species. 

At  the  outset  putrefaction  is  often  attended  with  the  presence 
of  several  species  of  micrococci  and  certain  large  bacilli,  which  are 
displaced  later  by  short  motile  bacteria  belonging  to  a  group  which 
includes  several  bacilli  formerly  described  under  the  common  name 
of  Bacterium  termo. 

The  malodorous  volatile  products  of  putrefaction  are  to  a  consid- 
erable extent  produced  by  anaerobic  species.  For  this  reason  these 
odors  are  more  pronounced  when  masses  of  albuminous  material 
undergo  putrefaction  in  situations  where  the  oxygen  of  the  air  has 
not  free  access  or  where  it  is  displaced  by  carbon  dioxide.  The 
body  of  a  dead  animal,  although  freely  exposed  to  the  air,  furnishes 
in  its  interior  a  suitable  nidus  for  these  anaerobic  gas-forming  spe- 
cies, and  they  may  give  rise  to  products  of  one  kind,  while  aerobic 
species  upon  the  surface  of  the  mass  induce  different  forms  of  putre- 
factive fermentation.  In  the  bodies  of  living  animals  these  anaero- 
bic microorganisms  are  constantly  present  in  the  intestine,  and  after 
death  they  quickly  invade  the  body  and  multiply  at  its  expense 
under  favorable  conditions  as  to  temperature.  The  surface  decom- 
position due  to  aerobic  bacteria  occurs  later  and  is  not  attended 
with  the  same  putrefactive  odors,  the  products  evolved  being  of  a 
simpler  chemical  composition — COS,  HN3.  No  doubt  these  aerobic 
bacteria,  by  consuming  the  oxygen  and  forming  an  atmosphere  of 
carbon  dioxide,  help  to  make  the  conditions  favorable  for  the  con- 
tinued development  of  the  aiiaerobics  in  the  interior  of  the  organic 
mass  ;  at  the  same  time  they  find  a  suitable  pabulum  in  some  of  the 
more  complex  products  of  decomposition  occurring  in  the  absence 
of  oxygen.  The  gases  produced  in  the  interior  of  a  putrefying  mass 
are  mainly  CH4,  H2S,  and  H. 

Many  of  the  bacteria  of  putrefaction  are  facultative  anaerobics — 
that  is  to  say,  they  are  able  to  multiply  either  in  the  presence  of  oxy- 
gen or  in  its  absence.  The  products  evolved  by  these  differ,  no 


136  PRODUCTS   OF   VITAL   ACTIVITY. 

doubt,  according  to  whether  they  are  or  are  not  supplied  with  atmo- 
spheric oxygen. 

The  anaerobic  bacteria  concerned  in  putrefaction  have  as  yet  re- 
ceived comparatively  little  attention.  Among  the  aerobics  and  fac- 
ultative anaerobics  the  following  are  best  known  :  Micrococcus 
fcetidus  (No.  189),  Bacillus  saprogenes  I.,  II.,  and  III.,  Bacillus 
coprogenes  fcetidus  (No.  116),  Bacillus  putrificus  coli  (No.  324),  Pro- 
teus vulgaris  (No.  97),  Proteus  Zenkeri  (No.  100),  Proteus  mirabilis 
(No.  99),  Bacillus  pyogenes  foetidus  (No.  72),  Bacillus  fluorescens 
liquefaciens  (No.  277),  Bacillus  pyocyanus  (No.  95),  Bacillus  coli 
communis  (No.  89),  Bacillus  janthinus  (No.  267). 

Soluble  Ferments. — Several  species  of  bacteria  produce  soluble 
ferments  capable  of  changing  starch  into  maltose,  dextrin,  etc. 
Hueppe  has  shown  that  the  lactic-acid  bacillus  produces  a  diastase, 
and  Miller  obtained  from  the  human  intestine  a  species  which  dis- 
solves starch.  Marcano,  by  filtering  cultures  of  species  capable  of 
this  ferment  action  through  porcelain,  was  able  to  show  that  the 
effect  is  due  to  a  soluble  ferment,  which  must  have  been  produced 
by  the  vital  activity  of  the  living  microorganisms.  Wortmann  also 
obtained  a  diastase  from  culture  liquids  which  was  precipitated  by 
alcohol  and  again  dissolved  in  water  ;  in  slightly  acid  solutions  it 
promptly  converted  starch  into  glucose.  This  is  said  to  be  produced 
in  culture  liquids  only  when  these  do  not  contain  albumin.  In  the 
presence  of  albumin  a  peptonizing  ferment  was  formed  ;  in  its  ab- 
sence, a  diastase  by  which  starch  was  dissolved  to  serve  as  pabulum 
for  the  bacteria  present.  These  experiments  were  not  made  with 
pure  cultures,  and  more  exact  researches  in  this  direction  are  de- 
sirable. 

A  peptonizing  ferment  for  gelatin  is  produced  by  a  considerable 
number  of  bacteria,  as  stated  under  the  heading  "  Liquefaction  of 
Gelatin."  The  jellified  albumin  in  cultures  in  blood  serum  is  also 
liquefied  by  a  peptonizing  ferment  produced  by  certain  species  of  bac- 
teria. 

Some  authors  also  speak  of  a  soluble  ferment  capable  of  inverting 
cane  sugar  or  milk  sugar.  According  to  Hueppe,  such  a  ferment 
is  produced  by  the  Bacillus  acidi  lactici.  A  soluble  ferment  for  cel- 
lulose is  supposed  by  Fliigge  to  be  produced  by  several  species — 
among  others  by  Bacillus  butyricus  and  by  Vibrio  rugula. 

Several  bacilli  produce  a  soluble  ferment  capable  of  coagulating 
the  casein  of  milk. 

Reduction  of  Nitrates,  and  Nitrification. — The  researches  of 
Gayon,  Dupettit,  and  others  show  that  certain  bacteria  are  able  to 
reduce  nitrates  with  liberation  of  ammonia  and  free  nitrogen.  This 
is  effected  in  the  absence  of  oxygen  by  anaerobic  bacteria,  and, 


PRODUCTS   OF   VITAL   ACTIVITY.  137 

among  others,  by  Bacillus  butyricus.  Certain  aerobic  bacteria  also 
accomplish  the  same  result.  Thus  Herseus  obtained  two  species 
from  water  which  reduced  nitrates  in  a  very  decided  manner.  On 
the  other  hand,  a  number  of  species  are  known  to  oxidize  ammonia, 
producing  nitric  acid.  Schlosing  and  Miinz,  as  a  result  of  numerous 
experiments,  arrived  at  the  conclusion  that  in  the  soil  nitrification  is 
effected  by  a  single  species.  But  it  is  doubtful  whether  they  worked 
with  pure  cultures,  and  more  recent  researches  show  that  several, 
and  probably  many,  different  bacteria  possess  this  power.  Accord- 
ing to  Herseus,  the  following  species,  tested  by  him,  oxidize  am- 
monia :  Bacillus  prodigiosus,  the  cheese  spirillum  of  Deneke,  the 
Finkler-Prior  spirillum,  the  typhoid  bacillus,  the  anthrax  bacillus, 
the  staphylococci  of  pus.  The  oxidation  does  not  always  go  to  the 
point  of  forming  nitrates,  but  nitrites  may  be  formed  in  the  soil 
(Duclaux).  Warrington  states  that  certain  bacteria  which  formed 
nitrates  in  a  suitable  culture  medium  produced  only  nitrites  when, 
after  an  interval  of  four  or  five  months,  some  of  the  culture  was 
transferred  to  a  solution  containing  muriate  of  ammonia.  The  same 
author  states  that  the  process  of  nitrification  occurs  only  in  the 
dark. 

The  recent  researches  of  Winogradsky,  of  the  Franklands,  and  of 
Jordan  show  that  the  failure  of  earlier  investigators  to  obtain  the 
nitrifying  bacteria  from  the  soil  in  pure  cultures  was  due  to  the  fact 
that  these  bacteria  do  not  grow  in  the  usual  culture  media.  By  the 
use  of  certain  saline  solutions  the  authors  named  have  succeeded  in 
isolating  nitrifying  bacteria  in  pure  cultures,  or  nearly  so.  It  is  still 
uncertain  whether  these  investigators  have  obtained  the  same  bac- 
teria, but  the  microorganisms  described  by  them,  and  obtained  from 
widely  distant  sources,  are  similar  in  their  morphological  and  bio- 
logical characters,  and  at  least  belong  to  the  same  group  (see  Nos. 
439,  440,  441).  In  his  latest  communication  (September,  1891)  Win- 
ogradsky arrives  at  the  conclusion  that  the  ferments  which  cause 
the  oxidation  of  ammonia  and  production  of  nitrites  are  not  capable 
of  producing  nitrates,  but  that  other  microorganisms  are  concerned 
in  the  oxidation  of  nitrites.  In  sterilized  soil  to  which  a  pure  culture 
of  his  nitromonas  was  added  nitrites  only  were  produced,  and  the 
presence  of  various  microorganisms  common  in  the  soil  did  not  result 
in  the  formation  of  nitrates  so  long  as  the  specific  ferment  was  ab- 
sent to  which  this  second  oxidation  is  ascribed  (nitrifying  bacillus  of 
Winogradsky,  No.  451). 

Phosphorescence. — Recently  several  different  bacteria  have  been 
studied  which,  in  pure  cultures,  give  rise  to  phosphorescence  in  the 
medium  in  which  they  are  cultivated.  In  gelatin  cultures  the  light 
is  sufficient  in  some  instances  to  enable  one  to  tell  the  time  by  a 


138  PRODUCTS   OP   VITAL   ACTIVITY. 

watch  in  a  perfectly  dark  room,  and  such  cultures  have  even  been 
photographed  by  their  own  light. 

The  phosphorescence  is  influenced  by  changes  in  the  culture 
medium  and  by  conditions  of  temperature,  but  we  have  no  exact 
knowledge  of  the  mode  of  its  production.  The  Bacillus  phosphores- 
cens  from  sea  water  in  the  vicinity  of  the  West  Indies  gives  the 
most  striking  results,  especially  when  planted  upon  the  surface  of 
cooked  fish  and  placed  in  an  incubating  oven  at  30°  C.  Two  other 
species  have  been  studied  by  Fischer — one  obtained  from  the  water 
of  the  harbor  at  Kiel,  and  the  other  a  widely  distributed  species 
called  by  Fischer  Bacterium  phosphorescens.  Katz  (1891)  has  re- 
cently described  several  new  species  obtained  by  him  from  sea  water 
and  from  phosphorescent  fish  in  the  markets  at  Sydney,  New  South 
Wales — Bacillus  smaragdino- phosphorescens,  Bacillus  argenteo-phos- 
phorescens,  Bacillus  cyaneo-phosphorescens,  Bacillus  argenteo-phos- 
phorescens  liquefaciens  (Nos.  337,  338,  341,  and  342). 


V. 
PTOMAINES    AND    TOXALBUMINS. 

VARIOUS  basic  substances  containing  nitrogen,  and  in  chemical 
constitution  resembling  the  vegetable  alkaloids,  have  been  isolated 
by  chemists  from  putrefying  material  and  from  cultures  of  the  bac- 
teria concerned  in  putrefaction,  and  also  from  certain  pathogenic 
species.  Some  of  these  ptomaines  are  non-toxic,  and  others  are 
very  poisonous  in  minute  doses  (toxines).  The  toxic  substances 
sometimes  developed  in  milk,  cheese,  sausage,  etc. ,  are  also  of  this 
nature,  and  are  dotfbtless  produced  by  the  action  of  microorganisms. 
The  pathogenic  power  of  the  bacteria  which  cause  various  infectious 
diseases  in  man  and  the  lower  animals  has  also  been  shown  to  result 
from  the  production  of  toxic  ptomaines  or  of  toxalbumins.  Selmi  first 
gave  the  name  ptomaines  to  cadaveric  alkaloids  isolated  by  him,  and 
Panum  subsequently  called  attention  to  the  fact  that  poisonous  basic 
substances  of  this  class  are  contained  in  putrefying  material.  Ex- 
tended researches  with  reference  to  the  ptomaines  have  since  been 
made  by  numerous  chemists,  the  most  important  being  those  of  Berg- 
mann,  Schmiedeberg,  Zuelzer  and  Sonnenschein,  Hager,  Otto,  Sel- 
mi, Brieger,  Gautier  and  Etard,  and  Vaughan. 

For  a  full  account  of  the  history  and  chemical  composition  of  the 
ptomaines  the  reader  is  referred  to  the  valuable  work  of  Vaughan 
and  Novy  ("  Ptomaines  and  Leucomaines, "  Philadelphia,  1891).  In. 
the  present  volume  we  shall  give  a  brief  account  only  of  some  of  the 
most  important. 

NON-TOXIC  PTOMAINES. 

Neuridin,  C5HMN2. — This  is  one  of  the  most  common  of  the  al- 
kaloids of  putrefaction  and  was  isolated  by  Brieger  in  1884.  It  is 
obtained  most  abundantly  from  tissues  containing  gelatin.  Very 
soluble  in  water,  but  insoluble  in  ether  and  absolute  alcohol.  Has  a 
disagreeable  odor. 

Cadaverin,  C&H,4NS. — Isomeric  with  neuridin  ;  has  a  very  dis- 
agreeable odor  ;  forms  a  thick,  transparent,  syrupy  liquid  ;  is  vola- 
tile, and  can  be  distilled  with  steam  without  undergoing  decomposi- 
tion. When  exposed  to  the  air  the  base  absorbs  carbon  dioxide  and 


140  PTOMAINES   AND   TOXALBUMINS. 

forms  a  crystalline  mass.  Is  produced  in  cultures  of  the  cholera 
spirillum  and  of  the  spirillum  of  Finkler  and  Prior  which  have  been 
kept  for  a  month  or  more  at  37°  C. 

Putrescin,  CjH^N,. — A  base  resembling  cadaverin  and  com- 
monly associated  with  it.  Obtained  by  Brieger  from  various  sources, 
most  abundantly  from  substances  containing  gelatin  and  in  the 
more  advanced  stages  of  putrefaction.  It  is  obtained  in  the  form  of 
a  hydrate,  which  is  a  transparent  liquid  having  a  boiling  point  of 
about  135°.  With  acids  it  forms  crystalline  salts. 

Saprin,  C5AI6N2. — Resembles  cadaverin  and  is  commonly  as- 
sociated with  it  in  putrefying  material.  Isolated  by  Brieger. 

Methylamine,  CH3.NH.,. — Obtained  by  Brieger  from  putrefying 
fish  and  from  old  cultures  of  the  cholera  spirillum. 

Dimethylamine,  (CHJ.^.NH. — Obtained  by  Brieger  from  putre- 
fying gelatin  and  by  Bocklisch  from  decomposing  fish. 

Trimethylamine,  (CH3)3N. — Obtained  from  various  sources,  and 
by  Brieger  from  cultures  of  the  cholera  spirillum  and  of  the  strepto- 
coccus of  pus. 

TOXIC   PTOMAINES. 

Neurin,  C5H13NO. — First  obtained  by  Liebreich  in  1865  as  a 
decomposition  product  of  protagon  from  the  brain.  Obtained  by 
Brieger  from  putrefying  muscular  tissue.  When  crystallized  from 
an  aqueous  solution  it  forms  five-  or  six-sided  plates  ;  from  an  alco- 
holic solution  it  crystallizes  in  the  form  of  needles  (Liebreich).  This 
base  is  toxic  in  small  doses.  In  frogs  the  injection  of  a  few  milli- 
grammes produces  paralysis  of  the  extremities.  Respiration  is  first 
arrested  and  the  heart  stops  in  diastole.  Atropine  appears  to  be  a 
physiological  antidote  to  the  toxic  effects  of  neurin.  In  rabbits  it 
produces  profuse  salivation.  The  pupil  is  contracted  by  the  direct 
application  of  a  concentrated  solution. 

Cholin,  C5H15NOa. — First  obtained  from  hog's  bile  by  Strecker 
in  1862.  Has  been  obtained  by  Brieger  from  various  sources,  in- 
cluding cultures  of  the  cholera  spirillum.  It  is  also  found  widely 
distributed  in  the  vegetable  kingdom.  May  be  prepared  from  the 
yolk  of  eggs  by  the  method  of  Diakonow.  Cholin  is  obtained  in  the 
form  of  a  syrupy,  alkaline  liquid  which  combines  with  acids  to  form 
deliquescent  salts.  At  first  this  base  was  not  supposed  to  have  toxic 
properties,  but  more  recent  researches  have  shown  that  in  compara- 
tively large  doses  it  produces  symptoms  resembling  those  caused  by 
minute  doses  of  neurin. 

Muscarin,  C5H15NO3. — This  toxic  principle  of  poisonous  mush- 
rooms has  also  been  obtained  by  Brieger  from  putrefying  fish.  It  may 
be  produced  artificially  by  the  oxidation  of  cholin.  In  small  doses 
it  kills  rabbits  and  frogs.  In  the  rabbit  it  produces  lacrymation  and 


PTOMAINES   AND   TOXALBUMINS.  141 

salivation,  the  pupil  is  contracted,  and  the  animal  dies  in  convul- 
sions. Frogs  are  completely  paralyzed  by  the  action  of  muscarin 
and  die  with  arrest  of  the  heart's  action  in  diastole. 

Peptotoxin. — The  exact  composition  of  this  ptomaine  has  not 
been  determined.  Brieger  obtained  it  during  the  early  putrefac- 
tion of  proteid  substances  and  also  from  the  artificial  digestion  of 
fibrin.  It  is  very  poisonous  for  frogs,  which  become  paralyzed  and 
die  within  fifteen  or  twenty  minutes  after  the  subcutaneous  injection 
of  a  few  drops  of  a  dilute  solution.  Rabbits  also  are  killed  by  doses 
of  half  a  gramme  to  a  gramme,  the  symptoms  being  paralysis  of  the 
posterior  extremities  and  stupor.  Peptotoxin  is  soluble  in  water, 
but  insoluble  in  ether  or  chloroform.  It  is  not  destroyed  by  boiling. 

Tyrotoxicon. — First  obtained  by  Vaughan  in  poisonous  cheese, 
and  subsequently  by  the  same  chemist  and  others  in  poisonous  milk 
and  ice  cream.  Chemically  tyrotoxicon  is  very  unstable.  It  is  de- 
composed when  heated  with  water  to  90°  C.  It  is  insoluble  in  ether. 
From  sixteen  kilogrammes  of  poisonous  cheese  Vaughan  obtained 
0.  o  gramme  of  the  poison.  The  symptoms  produced  in  man  by  eat- 
ing cheese  or  milk  containing  tyrotoxicon  are  vertigo,  nausea,  vomit- 
ing, and  severe  rigors,  with  pain  in  the  epigastrium,  cramps  in  the 
legs,  griping  pain  in  the  bowels  attended  with  purging,  numbness 
and  a  pricking  sensation  in  the  limbs,  and  great  prostration. 

Methyl-guanidin,  C2H7N3. — Obtained  by  Brieger  from  putrefy- 
ing horseflesh  which  had  been  kept  at  a  low  temperature  for  several 
months.  This  base  was  previously  known  to  chemists,  having  been 
obtained  by  the  oxidation  of  creatin.  By  Bocklisch  it  has  been  ob- 
tained from  impure  cultures  of  the  Finkler-Prior  spirillum  which 
had  been  kept  for  about  a  month.  It  is  obtained  as  a  colorless  mass 
having  an  alkaline  reaction,  and  which  is  quite  deliquescent.  Brie- 
ger gives  the  following  account  of  the  toxic  action  as  tested  on 
guinea-pigs  in  a  dose  of  0.2  gramme  :  The  respiration  increases  in 
rapidity,  the  pupils  dilate  to  the  extreme  limit,  the  animal  has  copi- 
ous discharges  of  urine  and  fseces,  the  extremities  become  paralyzed, 
and  at  the  end  of  about  twenty  minutes  death  occurs  in  convulsions. 

Mytilotoxin. — Obtained  by  Brieger  from  poisonous  mussels. 
The  toxic  action  resembles  that  of  curare. 

Typhotoxin,  C7HnNO2. — Obtained  by  Brieger  from  bouillon 
cultures  of  the  typhoid  bacillus  which  had  been  kept  for  a  week  or 
more  at  a  temperature  of  about  37.5°  C.  In  mice  and  guinea-pigs 
this  base  produces  salivation,  rapid  respiration,  dilatation  of  the 
pupils,  diarrhoea,  and  death  in  from  twenty-four  to  forty-eight  hours. 
It  is  believed  by  Brieger  that  the  specific  action  of  the  typhoid  bacil- 
lus is  due  to  the  production  of  this  ptomaine. 

A  base  which  is  isomeric  with  typhotoxin  has  been  obtained  by 


144  PTOMAINES   AND   TOXALBUMINS. 

anthrax.  In  a  dry  condition  it  has  a  grayish- white  color  and  gives 
the  reactions  of  albumins. 

The  toxalbumin  of  the  tetanus  bacillus  is  also  soluble  in  water. 
It  is  best  obtained  in  bouillon  cultures  containing  glucose. 

Quite  recently  (1891)  G.  and  F.  Klemperer  have  announced  their 
success  in  obtaining  a  toxalbumin  from  cultures  of  Micrococcus 
pneumonisB  crouposse  ("  diplococcus  pneumonise  ");  this  they  propose 
to  call  pneumotoxin. 

Koch's  "  Tuberculin." — This  is  a  glycerin  extract  of  the  toxic 
substances  present  in  cultures  of  the  tubercle  bacillus.  Crude  tu- 
berculin is  obtained  from  liquid  cultures  made  in  veal  broth  to  which 
one  per  cent  of  peptone  and  four  to  five  per  cent  of  glycerin  have 
been  added.  This  culture  liquid  is  placed  in  flasks  and  inoculated 
upon  the  surface  with  small  masses  from  a  pure  culture  of  the  tu- 
bercle bacillus.  A  tolerably  thick  and  dry  white  layer  is  developed, 
which  after  a  time  covers  the  entire  surface.  At  the  end  of  six  to 
eight  weeks  development  ceases  and  the  culture  liquid  is  evaporated 
over  a  water  bath  to  one-tenth  its  volume  ;  this,  after  being  filtered, 
constitutes  the  crude  tuberculin.  By  precipitation  with  sixty-per- 
cent alcohol  Koch  has  obtained  from  this  a  white  precipitate  which 
has  the  active  properties  of  the  glycerin  extract.  This  is  soluble  in 
water  and  in  glycerin,  and  has  the  chemical  reactions  of  an  albumi- 
nous body. 

Zuelzer  has  recently  (1891)  reported  his  success  in  isolating  a 
toxic  substance  from  tubercle  cultures.  The  contents  of  tubes  con- 
taining pure  cultures  of  the  bacillus  are  first  treated  with  hot  water 
acidulated  with  hydrochloric  acid.  This  solution  is  filtered,  evapo- 
rated, and  then  several  times  precipitated  with  platinum  chloride. 
The  double  salt  formed  is  decomposed  by  hydrosulphuric  acid, 
after  which  the  liquid  is  filtered  and  evaporated  to  dryness.  A 
white,  crystalline  salt  is  thus  obtained  which  is  soluble  in  hot  water. 
This  salt  was  toxic  for  rabbits  and  guinea-pigs  in  doses  of  from  one 
to  three  centigrammes.  Death  usually  occurred  in  from  two  to  four 
days.  In  guinea-pigs  one  centigramme  injected  subcutaneously 
caused,  within  a  few  minutes,  a  greatly  increased  frequency  of  respi- 
ration, an  elevation  of  temperature,  and  protrusion  of  the  eyeballs. 

Mullein. — Kalwing,  Preusse,  and  Pearson  have  obtained  from 
cultures  of  the  glanders  bacillus  a  ' '  lymph  "  which  somewhat  re- 
sembles the  crude  tuberculin  of  Koch.  This  was  obtained  by 
Preusse  by  treating  old  potato  cultures  of  the  glanders  bacillus  with 
glycerin  and  water.  The  extract  was  filtered  several  times  and  then 
sterilized  in  a  steam  sterilizer.  This  lymph  injected  into  horses  in- 
fected with  glanders  gives  rise  to  a  very  decided  elevation  of  tempe- 
rature, while  in  horses  free  from  this  disease  no  such  result  follows. 


VI. 
INFLUENCE   OF  PHYSICAL  AGENTS. 

Heat. — We  have  already  seen  (Section  II.,  Part  Second)  that  the 
temperature  favorable  for  the  growth  of  most  bacteria  is  between  20° 
and  40°  C. ;  that  some  species  are  able  to  multiply  at  the  freezing  tem- 
perature, and  others  at  as  high  a  temperature  as  60°  to  70°  C. ;  that, 
as  a  rule,  the  parasitic  species  require  a  temperature  of  35°  to  40°; 
and  that  low  temperatures  do  not  kill  bacteria. 

Frisch  (1877)  exposed  various  cultures  to  a  temperature  of  —87°  C., 
which  he  obtained  by  the  evaporation  of  liquid  CO2,  and  found  that 
micrococci  and  bacilli,  after  exposure  to  such  a  temperature,  multi- 
plied abundantly  when  again  placed  in  favorable  conditions.  Prud- 
den  has  also  made  extended  experiments  upon  the  influence  of 
freezing.  He  found  that  while  certain  species  resisted  the  freezing 
temperature  for  a  long  time,  others  failed  to  grow.  Thus  Bacillus 
prodigiosus  did  not  grow  after  being  frozen  for  fifty-one  days ;  Pro- 
teus vtilgaris  was  killed  in  the  same  time,  and  a  slender,  liquefying 
bacillus  obtained  from  Croton  aqueduct  water  was  killed  in  seven 
days.  Staphylococcus  pyogenes  aureus  withstood  freezing  for  sixty- 
six  days,  a  fluorescent  bacillus  from  Hudson  River  ice  for  seventy- 
seven  days,  and  the  bacillus  of  typhoid  fever  for  one  hundred  and 
three  days.  Cultures  made  at  intervals  showed,  however,  a  dimi- 
nution in  the  number  of  bacteria.  A  similar  diminution  would  per- 
haps have  occurred  in  old  cultures  in  which  the  pabulum  for  growth 
was  exhausted,  independently  of  freezing  ;  for  bacteria,  like  higher 
plants,  die  in  time — which  varies  for  different  species — as  a  result  of 
degenerative  changes  in  the  living  protoplasm  of  the  cells,  and  con- 
tinued vitality  in  a  culture  depends  upon  continued  reproduction. 

Repeated  freezing  and  thawing  was  found  by  Prudden  to  be 
more  fatal  to  the  typhoid  bacillus  than  continuous  freezing.  Cul- 
tures were  sterilized  by  being  thawed  out  at  intervals  of  three  days 
and  again  ref rozen,  after  repeating  the  operation  five  times. 

Cadeac  and  Malet  kept  portions  of  a  tuberculous  lung  in  a  frozen 
condition  for  four  months,  and  found  that  at  the  end  of  this  time 
tuberculosis  was  still  produced  in  guinea-pigs  by  injecting  a  small 
quantity  of  this  material. 
10 


146  INFLUENCE   OF   PHYSICAL   AGENTS. 

In  considering  the  influence  of  high  temperatures  we  must  take 
account  of  the  very  great  difference  in  the  resisting  power  of  the 
vegetative  cells  and  the  reproductive  elements  known  as  spores,  also 
of  the  fact  as  to  whether  dry  or  moist  heat  is  used  and  the  time  of 
exposure. 

Dry  Heat. — When  microorganisms  in  a  desiccated  condition  are 
exposed  to  the  action  of  heated  dry  air,  the  temperature  required  for 
their  destruction  is  much  above  that  required  when  they  are  in  a 
moist  condition  or  when  they  are  exposed  to  the  action  of  hot  water 
or  steam.  This  was  thoroughly  demonstrated  by  the  experiments  of 
Koch  and  Wolff hugel  (1881).  A  large  number  of  pathogenic  and 
non-pathogenic  species  were  tested,  with  the  following  general  result : 
A  temperature  of  78°  to  123°  C.  maintained  for  an  hour  and  a  half 
(over  100°  for  an  hour)  failed  to  kill  various  non-pathogenic  bacteria, 
but  was  fatal  to  the  bacillus  of  mouse  septicaemia  and  that  of  rabbit 
septicaemia.  To  insure  the  destruction  of  all  the  species  tested,  in 
the  absence  of  spores,  a  temperature  of  120°  to  128°  C.,  maintained 
for  an  hour  and  a  half,  was  required. 

The  spores  of  Bacillus  anthracis  and  of  Bacillus  subtilis  resisted 
this  temperature  and  required  to  insure  their  destruction  a  tempera- 
ture of  140°  C.  maintained  for  three  hours.  This  temperature  was 
found  to  injure  most  objects  requiring  disinfection,  such  as  clothing 
and  bedding.  But  the  lower  temperature  which  destroys  micro- 
organisms in  the  absence  of  spores  (120°  C.  =  248°  F.)  can  be  used 
for  disinfecting  articles  soiled  with  the  discharges  of  patients  with 
cholera,  typhoid  fever,  or  diphtheria,  as  the  specific  germs  of  these 
diseases  do  not  form  spores.  It  is  probable  also  that  it  may  be  safely 
used  to  disinfect  the  clothing  of  small-pox  patients,  for  we  have  ex- 
perimental evidence  that  a  lower  temperature  destroys  the  virulence 
of  vaccine  virus  (90°-95°  C. — Baxter). 

In  practical  disinfection  by  means  of  dry  heat  it  will  be  necessary 
to  remember  that  it  has  but  little  penetrating  power.  In  the  experi- 
ments of  Koch  and  Wolffhiigel  it  was  found  that  registering  ther- 
mometers placed  in  the  interior  of  folded  blankets  and  packages  of 
various  kinds  did  not  show  a  temperature  capable  of  killing  bacteria 
after  three  hours'  exposure  in  a  hot-air  oven  at  133°  C.  and  above. 

Moist  Heat. — The  thermal  death-point  of  bacteria,  in  the  ab- 
sence of  spores,  is  comparatively  low  when  they  are  exposed  to  moist 
heat.  The  results  of  the  writer's  experiments  are  given  below: 

"  In  my  temperature  experiments  I  have  taken  great  pains  to  insure  the 
exposure  of  the  test  organisms  to  a  uniform  temperature,  and  have  adopted 
ten  minutes  as  the  standard  time  of  exposure.  The  method  employed 
throughout  has  been  as  follows:  From  glass  tubing  having  a  diameter  of 
about  three-sixteenths  of  an  inch  I  draw  out  in  the  flame  of  a  Burfsen  burner 
a  number  of  capillary  tubes,  with  an  expanded  extremity  which  serves  as 


INFLUENCE    OF   PHYSICAL   AGENTS. 


147 


an  air  chamber.  A  little  material  from  a  pure  culture  of  the  test  organ- 
ism is  drawn  into  each  of  these  capillary  tubes  by  immersing  the  open 
extremity  in  the  culture,  after  having  gently  heated  the  expandea  end.  The 
end  of  the  tube  is  then  hermetically  sealed  by  heat  These  tubes  are  im- 
mersed in  a  water  bath  maintained  at  the  desired  temperature  for  the  stan- 
dard time.  The  bath  is  kept  at  a  uniform  temperature  by  personal  supervi- 
sion. At  the  bottom  of  the  vessel  is  a  thick  glass  plate  which  prevents  the 
thermometer  bulb  and  capillary  tubes,  which  rest  upon  it,  from  being  ex- 
posed to  heat  transmitted  directly  from  the  bottom  of  the  vessel  To  further 
guard  against  thj,s  I  am  in  the  habit  of  applying  the  flame  to  the  sides  of  the 
vessel,  and  a  uniform  temperature  throughout  the  bath  is  maintained  by 
frequent  stirring  with  a  glass  rod.  It  is  impossible  to  avoid  slight  variations, 
but  by  keeping  my  eye  upon  the  thermometer  throughout  the  experiment 
I  have  kept  these  within  very  narrow  limits.  .  .  .  No  attempt  has  been  made 
to  fix  the  thermal  death-point  within  narrower  limits  than  2°  C.,  and  in  the 
table  the  lowest  temperature  is  given  which  has  been  found,  in  the  experi- 
ments made,  to  destroy  all  of  the  microorganisms  in  the  material  subjected 
to  the  test.  No  doubt  more  extended  experiments  would  result,  in  some  in- 
stances, in  a  reduction  of  the  temperature  given  as  the  thermal  death-point 
for  a  degree  or  more.  But  the  results  as  stated  are  sufficiently  accurate  for 
all  practical  purposes." ' 

The  results  obtained  in  these  experiments,  for  non-sporebearing 
bacteria,  are  given  in  the  following  table.  The  time  of  exposure 
was  ten  minutes,  except  for  the  cholera  spirillum  and  the  cheese  spi- 
rillum of  Deneke. 

THERMAL   DEATH-POINT   OF   BACTERIA. 


Spirillum  choler*  Asiatic* 52° 

Spirillum  tyrogenum  (cheese  spirillum) 52 

Spirillum  Finkler- Prior 50 

Bacillus  typhi  abdominalis 56 

Bacillus  of  schweiue-rothlauf  (rouget) 58 

Bacillus  murisepticus 58 

Bacillus  Neapolitanus  (Emmerich's  bacillus) 62 

Bacillus  cavicida 62 

Bacillus  pneumonine  (Friedlander's) 56 

Bacillus  crassus  sputigenus 54 

Bacillus  pyocyanus .     56 

Bacillus  indicus 58 

Bacillus  prodigiosus 58 

Bacillus  cyanogenus 54 

Bacillus  fluorescens . .  54 

Bacillus  acidi  lactici 56 

Staphylococcus  pyogenes  aureus 58 

Staphylococcus  pyogenes  citreus 62 

Staphylococcus  pyogenes  albus 62 

Streptococcus  pyogenes 54 

Micrococcus  tetragenus  ...    .- .  .  58 

Micrococcus  Pasteuri 52 

Sarcina  lutea . .  64 

Sarcina  aurantiaca  . .  62 


Centigrade. 


Fahrenheit. 


125.6° 

125.6 

122. 

138.8 

136.4 

136.4 

143.6 

143.6 

132.8 

129.2 

132.8 

136.4 

136.4 

129.2 

129.2 

132.8 

136.4 

143.6 

143.6 

129.2 

136.4 

125.6 

147.2 

143.6 


(4m.) 
(4m.) 


The  following  determinations  of  the  thermal  death-point  of  path- 

1  Quoted  from  the  Report  of  the  Committee  on  Disinfectants  of  the  American  Pub- 
lic Health  Association,  pages  136  and  152. 


148  INFLUENCE   OF   PHYSICAL   AGENTS. 

ogenic  organisms  have  been  made  by  the  authors  named  :  Bacillus 
anthracis  (Chauveau),  5-4°  C.  ;  Bacillus  mallei — the  bacillus  of  glan- 
ders— (Loffler),  55°  C.,  Bacillus  gallinarum — micrococcus  of  fowl 
cholera— (Salmon),  56°  C.  ;  Bacillus  of  diphtheria  (Loffler),  60°  C. 

In  the  writer's  experiments  the  micrococcus  of  gonorrhosa  was 
apparently  killed  by  exposure  for  ten  minutes  to  a  temperature  of 

60°  C. 

% 

' '  Some  gonorrhceal  pus  from  a  recent  case  which  had  not  undergone 
treatment  was  collected  for  me  by  my  friend  Dr.  Rohe  in  the  capillary 
glass  tubes  heretofore  described.  A  microscopical  examination  of  stained 
cover-glass  preparations  showed  that  this  pus  contained  numerous  '  gono- 
cocci '  in  the  interior  of  the  cells.  Two  of  the  capillary  tubes  were  placed 
in  a  water  bath  maintained  at  60°  C.  for  ten  minutes.  The  pus  was  then 
forced  out  upon  two  pledgets  of  cotton  wet  with  distilled  water.  Two 
healthy  men  had  consented  to  submit  to  the  experiment,  and  one  of  these 
bits  of  cotton  was  introduced  into  the  urethra  of  each  and  left  in  situ  for 
half  an  hour.  As  anticipated,  the  result  was  entirely  negative.  For  obvi- 
ous reasons  no  control  experiment  was  made  to  fix  the  thermal  death-point 
within  narrower  limits. 

"  In  connection  with  these  experiments  upon  the  thermal  death-point  of 
known  pathogenic  organisms,  it  is  of  interest  to  inquire  whether  the  viru- 
lence of  infectious  material,  in  which  it  has  not  been  demonstrated  that  this 
virulence  is  due  to  a  microorganism,  is  destroyed  by  a  correspondingly  low 
temperature.  Evidently,  if  this  proves  to  be  the  case,  it  will  be  a  strong 
argument  in  favor  of  the  view  that  we  have  to  deal  with  a  microorganism 
in  these  diseases  also.  We  have  experimental  proof  that  a  large  number  of 
pathogenic  organisms  are  killed  by  exposure  for  ten  minutes  to  a  tempera- 
ture of  55°  to  t>0°  C.  But,  so  far  as  I  am  aware,  this  low  temperature  would 
not  be  likely  to  destroy  any  of  the  poisonous  chemical  products  which  might 
be  supposed  to  be  the  cause  of  infective  virulence,  leaving  aside  the  fact  that 
such  chemical  products  have  no  power  of  self-multiplication,  and,  there- 
fore, could  not  be  the  independent  cause  of  an  infectious  disease. ' 

"  Vaccine  Virus. — Carstens  and  Coert  have  experimented  upon  the  tem- 
perature required  to  destroy  the  potency  of  vaccine  virus.  In  a  paper  read 
at  the  International  Medical  Congress  in  1879  they  report,  as  a  result  of 
their  experiments,  that  the  maximum  degree  of  heat  to  which  fresh  vaccine 
virus  can  be  exposed  without  losing  its  virulence  probably  varies  between 
52°  and  54°  C.  Fresh  animal  vaccine  heated  to  52°  C.  for  thirty  minutes 
does  not  lose  its  virulence.  Fresh  animal  vaccine  heated  to  54. 5 =  for  thirty 
minutes  loses  its  virulence. 

"Rinderpest. — According  to  Semmer  and  Raupach,  exposure  for  ten 
minutes  to  a  temperature  of  55°  C.  destroys  the  virulence  of  the  infectious 
material  in  this  disease. 

<%  Sheep-pox. — The  authors  last  mentioned  have  also  found  that  the  same 
temperature — 55°  C.  for  ten  minutes — destroys  the  virulence  of  the  blood  of 
an  animal  dead  from  sheep-pox. 

"  Hydrophobia. — Desiring  to  fix  the  thermal  death -point  of  the  virus  of 
hydrophobia,  I  obtained,  through  the  kindness  of  Dr.  H.  C.  Ernst,  a  rabbit 
which  had  been  inoculated,  by  the  method  of  trephining,  with  material 
which  came  originally  from  Pasteur's  laboratory.  The  rabbit  sent  me 
showed  the  first  symptom  of  paralytic  rabies  on  the  eighth  day  after  inocu- 
lation. It  died  on  the  eleventh  day  (March  2d,  1887),  and  I  at  once  pro- 
ceeded to  make  the  following  experiment : 

"A  portion  of  the  medulla  was  removed  and  thoroughly  mixed  with 

1  Since  this  was  written  Brieger  has  isolated  a  toxalbumin  from  cultures  of  the 
diphtheria  bacillus  which  is  destroyed  by  a  temperature  of  60°  C.,  but  resists  50°. 


INFLUENCE   OF   PHYSICAL   AGENTS.  149 

sterilized  water.  The  milky  emulsion  was  introduced  into  four  capillary 
tubes,  such  as  had  been  used  in  my  experiments  heretofore  recorded.  Two 
of  these  tubes  were  then  placed  for  ten  minutes  in  a  water  bath,  the  tem- 
perature of  which  was  maintained  at  60°  C.  Four  rabbits  were  now  inocu- 
lated by  trephining,  two  with  the  material  exposed  to  60°  C.  for  ten  min- 
utes, and  two  with  the  same  material  from  the  capillary  tube  not  so  exposed. 
The  result  was  as  definite  and  satisfactory  as  possible.  The  two  control 
rabbits  were  taken  sick,  one  on  March  10th  and  one  on  the  llth  ;  both  died 
with  the  characteristic  symptoms  of  paralytic  rabies  on  the  third  day.  The 
two  rabbits  inoculated  with  material  exposed  to  60°  C.  remained  in  perfect 
health.  On  the  26th  of  March  one  of  these  rabbits  was  again  inoculated, 
by  trephining,  with  material  from  the  medulla  of  a  rabbit  just  dead  from 
hydrophobia.  This  rabbit  died  from  paralytic  rabies  on  the  8th  of  April. 
Its  companion  remains  in  perfect  health. 

"A  second  experiment  was  made  in  the  same  way  on  the  14th  of  March. 
Two  rabbits  were  inoculated  with  material  exposed  for  ten  minutes  to  a 
temperature  of  50°  C. ;  two  with  material  exposed  to  55°  C. ;  and  two  con- 
trol rabbits  with  material  not  so  exposed.  One  of  the  rabbits  inoculated 
with  material  exposed  to  50°  C.,  and  one  of  the  control  rabbits,  died  on  the 
25th;  the  other  rabbit  inoculated  with  the  material  exposed  to  50°,  the  other 
control,  and  one  inoculated  with  material  exposed  to  55°,  on  the  26th.  The 
second  rabbit  inoculated  with  material  exposed  to  55°  died  five  days  later 
with  the  characteristic  symptoms  of  the  disease.  These  experiments  show, 
then,  that  the  virus  of  hydrophobia  is  destroyed  by  a  temperature  of  60°  C., 
and  that  55°  C.  fails  to  destroy  it,  the  time  of  exposure  being  ten  minutes."1 

The  experimental  data  given  show  that  the  pathogenic  bacteria 
tested  and  different  kinds  of  virus  are  all  killed  by  a  temperature  of 
60°  C.  or  below ;  some,  like  the  cholera  spirillum  and  Micrococcus 
pneumonias  crouposae,  failing  to  grow  after  exposure  to  as  low  a  tem- 
perature as  52°  C.  for  four  minutes.  By  extending  the  time  a  still 
lower  temperature  will  effect  the  same  result.  Thus,  according  to 
Chauveau,  the  anthrax  bacillus  is  killed  by  twenty  minutes'  exposure 
to  a  temperature  of  50°  C.;  and  Brieger  sterilizes  cultures  of  the 
diphtheria  bacillus,  to  obtain  the  soluble  toxalbumin  produced  in 
them,  by  exposure  for  several  hours  to  50°  C.  A  temperature  of  60° 
has  been  found  to  decompose  the  toxalbumin.  The  non-pathogenic 
bacteria  tested  have,  as  a  rule,  a  higher  thermal  death-point — 58°  C. 
for  Bacillus  prodigiosus,  04°  C.  for  Sarcina  lutea,  etc. 

It  is  a  remarkable  fact  that  certain  bacteria  not  only  are  not  de- 
stroyed at  higher  temperatures  than  this,  but  are  able  to  multiply  at 
a  temperature  of  05°  to  70°  C.  Thus  Miquel,  in  1881,  found  in  the 
waters  of  the  Seine  a  motionless  bacillus  which  grew  luxuriantly  in 
bouillon  at  a  temperature  of  69°  to  70°  C.  Van  Tieghem  has  also 
cultivated  several  different  species  at  about  the  same  temperature, 
and  more  recently  Globig  has  obtained  from  the  soil  several  species 
which  grow  at  temperatures  ranging  from  50°  to  70°  C. 

The  resisting  power  of  spores  to  heat  also  varies  in  different  spe- 
cies ;  but  the  spores  of  known  pathogenic  bacteria  are  quickly  de- 
stroyed by  a  temperature  of  100°  C.  (212°  F.).  In  the  writer's  experi- 

1  Report  of  the  Committee  on  Disinfectants  (op.  cit.).  p.  147. 


150  INFLUENCE   OF   PHYSICAL   AGENTS. 

ments  the  spores  of  Bacillus  anthracis  and  of  Bacillus  alvei  failed  to 
grow  after  exposure  to  a  temperature  of  100°  C.  for  four  minutes, 
and  only  a  few  colonies  developed  after  two  minutes'  exposure  to  this 
temperature.  The  thermal  death-point  of  spores  of  the  "  wurtzel  ba- 
cillus "  and  of  Bacillus  butyricus  (of  Hueppe)  was  the  same — 100°  C. 
for  four  minutes. 

Schill  and  Fischer,  in  1884,  made  a  number  of  experiments  to  de- 
termine the  thermal  death-point  of  Bacillus  tuberculosis.  They 
found  that  five  minutes'  exposure  to  a  temperature  of  100°  C.  in 
steam  destroyed  the  vitality  of  the  bacillus  in  sputum  in  five  min- 
utes. When  the  time  was  reduced  to  two  minutes  a  negative  result 
from  inoculation  was  obtained  in  two  guinea-pigs,  but  one  inoculated 
at  the  same  time  became  tuberculous.  My  own  experiments  and 
those  of  Yersin,  made  since,  lead  me  to  think  that  there  may  have 
been  some  cause  of  error  in  this  experiment  of  Schill  and  Fischer, 
and  that  the  thermal  death-point  of  the  spores  of  Bacillus  tuber- 
culosis is  considerably  below  the  boiling  point  of  water.  I  inoculated 
guinea-pigs  with  tuberculous  sputum  subjected  for  ten  minutes  to 
the  following  temperatures  :  50°,  60°,  70°,  80°,  90°  C.  The  animal 
inoculated  with  material  exposed  to  50°  died  from  tuberculosis  at  the 
end  of  seven  weeks.  None  of  the  others  developed  tuberculosis. 

Yersin  exposed  an  old  culture  in  glycerin  bouillon,  in  which  many 
of  the  bacilli  contained  spores — "tres  nettes" — to  the  following  tem- 
peratures :  55°,  60°,  65°,  70°,  75°,  80°,  85°,  90°,  100°  C.  "  At  the  end  of 
ten  days  the  bacilli  heated  to  55°  gave  a  culture  in  glycerin  bouillon ; 
those  exposed  to  60°  grew  after  twenty-two  days  ;  none  of  the 
bacilli  heated  above  70°  gave  any  development.  This  experiment, 
repeated  a  great  number  of  times,  has  always  given  us  the  same  re- 
sult." Voelsh,  who  has  studied  the  same  question,  reports  as  the 
result  of  his  experiments  that  the  tubercle  bacillus  in  sputum  was 
not  destroyed  by  heating  to  100°  C.  Further  experiments  will  be  re- 
quired to  reconcile  these  contradictory  results. 

While  the  spores  of  the  pathogenic  bacteria  mentioned  are  de- 
stroyed by  the  boiling  point  of  water  within  a  few  minutes,  certain 
non-pathogenic  species  resist  this  temperature  for  hours.  Thus 
Globig  obtained  a  bacillus  from  the  soil  the  spores  of  which  required 
five  and  one-half  to  six  hours'  exposure  to  streaming  steam  for  their 
destruction.  These  spores  survived  exposure  for  three-quarters  of  an 
hour  in  steam  under  pressure  at  from  109°  to  113°  C.  They  were  de- 
stroyed, however,  by  exposure  for  twenty-five  minutes  in  steam  at 
113°  to  116°,  and  in  two  minutes  at  127°. 

In  the  practical  application  of  steam  for  disinfecting  purposes  it 
must  be  remembered  that,  while  steam  under  pressure  is  more  effec- 
tive than  streaming  steam,  it  is  scarcely  necessary  to  give  it  the  pre- 


INFLUENCE   OF   PHYSICAL   AGENTS.  151 

ference,  in  view  of  the  fact  that  all  known  pathogenic  bacteria  and 
their  spores  are  quickly  destroyed  by  the  temperature  of  boiling 
water  ;  and  also  that  superheated  steam  is  less  effective  than  moist 
steam.  When  confined  steam  in  pipes  is  "  superheated  "  it  has  about 
the  same  germicidal  power  as  hot  dry  air  at  the  same  temperature. 
This  is  shown  by  the  experiments  of  Esmarch,  who  found  that  an- 
thrax spores  were  killed  in  streaming  steam  in  four  minutes,  but 
were  not  killed  in  the  same  time  by  superheated  steam  at  a  tempera- 
ture of  141°  C. 

Desiccation. — Cultures  of  bacteria  kept  in  a  moist  condition  re- 
tain their  vitality  for  a  considerable  time,  which  varies  greatly  with 
different  species.  The  writer  has  found  that  a  culture  of  the  typhoid 
bacillus  preserved  in  a  hermetically  sealed  glass  tube  retained  its 
vitality  for  eighteen  months,  as  did  also  Bacillus  prodigiosus,  Bacil- 
lus cavicida,  and  some  others.  According  to  Kitasato,  the  cholera 
spirillum  may  be  preserved  in  a  moist  state  for  seven  months  ;  other 
bacteria  die  out  in  a  month  or  two,  but,  as  a  rule,  vitality  is  preserved 
for  several  months  at  least. 

Spores  in  a  desiccated  condition  preserve  their  vitality  for  a 
great  length  of  time.  But  desiccation  is  quickly  fatal  to  some  of  the 
pathogenic  bacteria,  and  especially  so  to  the  cholera  spirillum.  Koch, 
in  his  earlier  experiments,  found  that  his  "comma  bacillus"  did  not 
grow  after  being  dried  upon  a  cover  glass  for  three  hours.  Kitasato, 
in  experiments  made  since,  found  that  a  bouillon  culture  dried  upon 
a  thin  glass  cover  was  incapable  of  development  after  three  hours' 
time,  but  that  cultures  in  nutrient  agar  or  gelatin  survived  for  two 
days,  probably  on  account  of  the  thicker  layer  formed  and  the  longer 
time  required  for  complete  desiccation.  Pfuhl  has  found  that  the 
typhoid  bacillus  dried  upon  a  cover  glass  retains  its  vitality  for 
eight  to  ten  weeks,  and  Loftier  states  that  the  diphtheria  bacillus  re- 
sists desiccation  for  four  or  five  months.  Cadeac  and  Malet  pro- 
duced tuberculosis  in  guinea-pigs  by  injecting  material  from  the 
lung  of  a  tuberculous  cow  which  had  been  kept  in  the  form  of  a  dried 
powder  for  nearly  five  months  ;  at  a  later  date  the  virulence  was 
lost. 

Light. — Downes  and  Blunt,  in  a  communication  made  to  the 
Royal  Society  of  London  in  1877,  first  called  attention  to  the  fact  that 
light  has  an  injurious  effect  upon  bacteria,  and  that  cultures  may  be 
sterilized  by  exposure  to  direct  sunlight. 

Tyndall,  in  experiments  made  in  the  clear  sunlight  of  the  Alps, 
verified  the  fact  that  the  development  of  bacteria  was  restrained  in 
cultures  during  their  exposure,  but  failed  to  obtain  evidence  that 
vitality  was  destroyed. 

In  1885  Duclaux  took  up  the  subject  with  pure  cultures  of  various 


152  INFLUENCE   OF   PHYSICAL   AGENTS. 

bacteria,  and  showed  that  by  prolonged  exposure  to  direct  sunlight  the 
spores  of  various  bacilli  lose  their  capacity  to  germinate.  About  the 
same  time  Arloing  published  his  researches  upon  the  influence  of 
light  upon  the  development  of  anthrax  spores.  He  found  that  the 
anthrax  bacillus  was  not  restrained  in  its  growth  by  diffused  lamp- 
light, but  its  growth  was  retarded  by  an  intense  gaslight.  Spore 
formation  was  more  abundant  in  darkness  than  in  red  light,  and  more 
abundant  in  red  than  in  white  light.  When  a  screen  was  interposed 
between  the  culture  and  the  source  of  light,  consisting  of  an  aqueous 
solution  of  hsematoglobin,  the  growth  of  the  bacilli  and  of  spores  was 
much  more  luxuriant  than  in  white  light.  In  yellow  light  it  was  less 
abundant  than  in  red.  The  blue  and  violet  rays  were  still  less  favor- 
able for  the  growth  of  the  bacillus  and  the  development  of  spores. 
The  pathogenic  power  of  cultures  was  not  especially  influenced  by 
exposure  to  white  gaslight.  In  subsequent  experiments  with  sun- 
light Arloing  found  that  two  hours  of  exposure  to  the  July  sun  suf- 
ficed to  destroy  the  vitality  of  anthrax  spores,  but  that  a  considerably 
longer  exposure  (twenty-six  to  thirty  hours)  was  necessary  when  the 
spores  had  been  allowed  to  germinate  in  a  suitable  culture  medium. 
Cultures  which  were  not  exposed  long  enough  to  destroy  the  vitality 
of  the  bacilli  were  retarded  in  their  growth,  and  subsequent  exposure 
for  a  shorter  time  (nine  to  ten  hours)  completely  sterilized  them. 
Cultures  which  were  weakened  in  their  reproductive  energy  by  ex- 
posure to  sunlight  were  also  "  attenuated  "  as  to  their  pathogenic 
power  and  could  be  used  as  a  vaccine  in  protective  inoculations.  Ac- 
cording to  Arloing,  the  effect  produced  results  from  the  action  of  the 
full  sunlight  and  cannot  be  obtained  by  the  use  of  monochromatic 
light. 

The  experiments  of  Strauss  seemed  to  give  support  to  the  view 
advanced  by  Nocard  that  in  Arloing's  experiments  spores  did  not 
really  exhibit  a  less  degree  of  resisting  power  than  the  vegetating 
bacilli,  but  that  in  fact  they  commenced  to  vegetate  before  they  were 
killed.  Strauss  placed  anthrax  spores  in  sterilized  distilled  water  and 
in  bouillon,  and  found  that,  under  the  same  conditions  of  exposure, 
the  bouillon  cultures  were  sterilized  in  direct  sunlight  in  nine 
hours,  while  the  spores  suspended  in  distilled  water  grew  when  trans- 
ferred to  a  suitable  medium.  This  was  accounted  for  on  the  suppo- 
sition that  the  bouillon  furnishes  the  necessary  pabulum  for  the  de- 
velopment of  the  spores  and  that  distilled  water  does  not. 

Arloing  combats  this  view  and  has  published  additional  experi- 
ments which  seem  to  disprove  it.  He  placed  small  flasks  containing 
anthrax  spores  in  bouillon  in  the  direct  rays  of  the  sun  in  February. 
Some  of  the  flasks  were  placed  upon  a  block  of  ice  which  reduced  the 
temperature  to  4°  C. ;  the  others  were  not  so  placed,  and  the  tempe- 


INFLUENCE   OF   PHYSICAL   AGENTS.  153 

rature,  in  the  open  air  where  all  were  exposed,  was  11°  C.  All  of  the 
spores  failed  to  grow  after  an  exposure  of  four  hours.  When  exposed 
in  water  the  time  of  exposure  was  longer. 

Roux  has  shown  that  the  light  also  has  an  effect  upon  the  culture 
medium,  and  that  sterilized  bouillon  which  has  been  exposed  to  direct 
sunlight  for  some  hours  restrains  the  development  of  anthrax  spores 
subsequently  introduced  into  it,  but  not  of  the  growing  bacilli.  His 
experiments  show  that  access  of  oxygen  is  a  necessary  factor  in  the 
sterilization  of  cultures  by  sunlight, 

In  the  experiments  of  Moment  (1892)  dry  anthrax  spores  were 
found  to  resist  the  action  of  light  for  a  long  time,  but  moist  spores, 
freely  exposed  to  the  air,  failed  to  grow  after  forty-four  hours'  ex- 
posure to  sunlight.  In  the  absence  of  spores,  anthrax  bacilli  in  a 
moist  condition,  when  freely  exposed  to  the  air,  failed  to  grow  after 
exposure  to  sunlight  for  half  an  hour  to  two  hours  ;  but  in  the  ab- 
sence of  air  the  same  bacilli  were  not  destroyed  at  the  end  of  fifty 
hours'  exposure. 

Duclaux,  in  1885,  experimented  upon  several  different  species  of 
micrococci  and  bacilli,  with  the  following  results:  Recent  cultures  of 
micrococci  in  bouillon,  which  preserved  their  vitality  for  more  than  a 
year  in  a  dark  place,  were  sterilized  in  July  by  exposure  in  the  sun 
for  fifteen  days,  and  two  species  even  within  two  or  three  days 
(micrococcus  of  biskra  and  micrococcus  of  pemphigus).  Bacilli 
showed  greater  resisting  power. 

Still  more  recently  Gaillard  has  conducted  a  series  of  experiments, 
under  the  direction  of-  Arloing,  which  confirm  the  results  previously 
obtained  by  observers  heretofore  named  as  to  the  germicidal  power  of 
sunlight  in  the  presence  of  oxygen. 

Geisler  (1892),  in  experiments  made  upon  the  typhoid  bacillus, 
found  that  all  portions  of  the  solar  spectrum  except  the  red  rays  ex- 
ercised a  restraining  influence  upon  the  development  of  this  bacillus. 
The  electric  light  gave  a  similar  result.  The  most  decided  effect  was 
produced  by  rays  from  the  violet  end  of  the  spectrum.  The  restrain- 
ing influence  appears,  from  the  researches  of  Geisler,  not  to  be  due 
solely  to  the  direct  action  of  light  upon  the  development  of  the 
bacilli,  but  also  to  changes  induced  in  the  gelatin  culture  medium 
employed  in  his  experiments. 

In  his  address  before  the  International  Medical  Congress  of  Berlin, 
1890,  Koch  states  that  the  tubercle  bacillus  is  killed  by  the  action  of 
direct  sunlight  in  a  time  varying  from  a  few  minutes  to  several  hours, 
depending  upon  the  thickness  of  the  layer  exposed.  Diffused  day- 
light also  has  the  same  effect,  although  a  considerably  longer  time  of 
exposure  is  required — when  placed  close  to  a  window,  from  five  to 
seven  days. 


154  INFLUENCE   OF  PHYSICAL  AGENTS. 

In  view  of  these  facts  we  may  conclude,  with  Duclaux,  that  sun- 
light is  one  of  the  most  potent  and  one  of  the  cheapest  agents  for  the 
destruction  of  pathogenic  bacteria,  and  that  its  use  for  this  purpose  is 
to  be  remembered  in  making  practical  hygienic  recommendations. 
The  popular  idea  that  the  exposure  of  infected  articles  of  clothing 
and  bedding  in  the  sun  is  a  useful  sanitary  precaution  is  fully  sus- 
tained by  the  experimental  data  relating  to  the  action  of  heat,  desic- 
cation, and  sunlight. 

Electricity. — Cohn  and  Mendelssohn,  in  1879,  attempted  to  de- 
termine the  effect  of  the  galvanic  current  upon  bacteria.  Cultures 
were  placed  in  U  -tubes  through  which  a  constant  current  was  passed. 
A  feeble  current  was  found  to  be  without  effect.  A  strong  current 
from  two  elements,  maintained  for  twenty-four  hours,  restrained  de- 
velopment in  the  vicinity  of  the  positive  pole,  but  this  was  probably 
due  to  the  highly  acid  reaction  which  the  culture  liquid  acquired. 
When  a  current  from  five  elements  was  used  for  twenty -four  hours 
the  liquid  was  sterilized,  but  this  may  have  been  due  to  the  decided 
changes  produced  in  the  chemical  composition  of  the  culture  liquid 
rather  than  to  the  direct  action  of  the  galvanic  current. 

The  same  may  be  said  of  the  similar  results  obtained  in  later  ex- 
periments by  Apostoli  and  Laquerriere,  and  by  Prochownick  and 
Spaeth.  The  last-mentioned  investigators  found  that  the  positive  pole 
had  a  more  decided  effect  than  the  negative,  and  that  the  effect  de- 
pended upon  the  intensity  and  duration  of  the  current.  A  current  of 
fifty  milliamperes  passed  for  a  quarter  of  an  hour  did  not  kill  Staphy- 
lococcus  pyogenes  aureus,  but  a  current  of  sixty  milliamperes  main- 
tained for  the  same  time  did.  The  spores  of  Bacillus  anthracis 
required  a  current  of  two  hundred  to  two  hundred  and  thirty  milli- 
amperes during  an  hour  or  two.  In  these  experiments  the  cultures 
in  gelatin  were  attached  to  the  strips  of  platinum  serving  as  the  two 
poles,  and  these  were  immersed  in  a  solution  of  sodium  chloride.  As 
chlorine  was  disengaged  at  the  positive  pole,  the  germicidal  action  is 
attributed  to  this  gas  rather  than  to  the  direct  action  of  the  current 
upon  the  living  microorganisms. 

The  more  recent  researches  of  Spilker  and  Gottstein,  made  with 
an  induction  current  from  a  dynamo  machine,  are  more  valuable  in 
estimating  the  power  of  this  agent  to  destroy  the  vitality  of  bacteria. 
The  current  was  passed  through  a  spiral  wire  which  was  wrapped 
around  a  test  tube  of  glass,  containing  the  microorganism  to  be  tested, 
suspended  in  distilled  water.  In  a  first  experiment  Bacillus  prodigi- 
osus,  suspended  in  sterilized  distilled  water  and  contained  in  test 
tubes  having  a  capacity  of  two  hundred  and  fifty  cubic  centimetres, 
was  subjected  to  a  current  having  an  energy  of  2.5  amperes  X  1.25 
volts  for  twenty-four  hours.  The  temperature  did  not  go  above 


INFLUENCE   OF   PHYSICAL   AGENTS.  155 

30°  C.  No  development  occurred  when  the  microorganism  tested 
was  subsequently  planted  in  nutrient  gelatin.  Further  experiments 
gave  a  similar  result.  It  was  found  that  stronger  currents  were 
effective  in  shorter  time  ;  but  in  no  case  was  sterilization  effected  in 
less  than  an  hour. 


VII. 
ANTISEPTICS  AND   DISINFECTANTS. 

GENERAL  ACCOUNT  OF  THE  ACTION  OF. 

THE  term  antiseptic  is  used  by  some  authors  to  designate  an 
agent  which  destroys  the  vitality  of  the  microorganisms  which  pro- 
duce septic  decomposition,  and  others  of  the  same  class.  We  prefer 
to  restrict  the  use  of  the  term  to  those  agents  which  restrain  the  de- 
velopment of  such  microorganisms  without  destroying  their  vitality. 
The  complete  destruction  of  vitality  is  effected  by  germicides  or  dis- 
infectants. Material  containing  the  germs  of  infectious  diseases  is 
infectious  material,  and  Ave  disinfect  it  by  the  use  of  agents  which 
destroy  the  living  disease  germs  or  pathogenic  bacteria  which  give 
it  its  infecting  power.  Such  an  agent  is  a  disinfectant.  But  we  ex- 
tend the  use  of  this  term  to  germicides  in  general — that  is,  to  those 
agents  which  kill  non-pathogenic  bacteria  as  well  as  to  those  which 
destroy  disease  germs.  All  disinfectants  are  also  antiseptics,  for 
agents  which  destroy  the  vitality  of  the  bacteria  of  putrefaction  ar- 
rest the  putrefactive  process  ;  and  these  agents,  in  less  amount  than 
is  required  to  completely  destroy  vitality,  arrest  growth  and  thus 
act  as  antiseptics.  But  all  antiseptics  are  not  germicides.  Thus  a 
concentrated  solution  of  salt  or  of  sugar  will  prevent  the  putrefac- 
tive decomposition  of  organic  material,  animal  or  vegetable  ;  but  these 
agents  do  not  destroy  the  vitality  of  the  germs  of  putrefaction.  In 
a  certain  degree  of  concentration  they  are  antiseptics  and  are  .largely 
used  for  the  preservation  of  meats  and  vegetables.  In  the  same  way 
many  mineral  salts  in  solutions  of  various  strengths  act  as  antisep- 
tics, and  some  of  these  in  still  stronger  solutions  are  disinfectants. 
Thus  mercuric  chloride,  when  introduced  into  a  culture  solution  in 
the  proportion  of  1  :  300,000,  will  restrain  the  development  of  anthrax 
spores,  but  to  insure  the  destruction  of  these  spores  a  solution  of 
1  : 1,000  must  be  used.  As  a  rule,  the  difference  between  restraining 
action — antiseptic — and  germicidal  power — disinfectant — is  not  so 
great  as  this.  We  give  below  some  recent  determinations  by  Boer 
which  illustrate  this  point,  the  test  organism  being  the  bacillus  of 
typhoid  fever  in  a  culture  in  bouillon  twenty-four  hours  old  : 


ANTISEPTICS   AND   DISINFECTANTS.  157 


Restrains. 

Kills. 

1  .  2100 

1  -300 

1  .  1550 

1  •  500 

1  :  50000 

1  •  4000 

Sodium  arseniate  

1  :  6000 

1  :  250 

Carbolic  acid  

1  :400 

1  :200 

Method  of  Determining  Antiseptic  Value. — To  determine  the 
restraining  or  antiseptic  power  of  an  agent  for  a  particular  micro- 
organism, the  agent  is  dissolved  in  a  definite  proportion  in  a  suitable 
culture  medium,  which  is  then  inoculated  with  a  pure  culture  of  the 
test  organism  and  placed  in  favorable  circumstances — as  to  tempera- 
ture— for  its  growth.  At  the  same  time  a  control  experiment  is 
made  by  placing  another  portion  of  the  same  culture  medium,  inocu- 
lated with  the  same  microorganism,  in  the  same  conditions,  but  with- 
out the  addition  of  the  antiseptic  agent.  If  development  occurs  in 
the  control  experiment  and  not  in  the  culture  medium  containing 
the  antiseptic,  the  failure  to  grow  must  be  attributed  to  the  presence 
of  this  agent.  Having  made  a  preliminary  experiment,  we  are 
guided  by  the  result  in  further  experiments  to  determine  the  exact 
amount  required  to  restrain  development  under  the  same  conditions. 
Or  we  may  make  a  series  of  experiments  in  the  first  instance.  The 
problem  being,  for  example,  to  determine  the  antiseptic  value  of 
carbolic  acid  for  the  typhoid  bacillus,  we  may  add  this  agent  to  a 
definite  amount  of  bouillon  in  test  tubes  in  the  proportion  of  1  : 100, 
1  :  200,  1  : 300,  1  : 400,  1  :  500.  In  experiments  with  volatile  agents 
the  bouillon,  in  test  tubes  or  small  flasks,  must  be  sterilized  in  ad- 
vance, and  the  antiseptic  agent  introduced  by  means  of  a  sterilized 
pipette  with  great  care  to  prevent  the  accidental  contamination  of 
the  nutrient  medium.  In  experiments  with  non- volatile  agents  it  will 
be  best  to  sterilize  the  culture  medium  after  the  antiseptic  has  been 
added.  Next  we  inoculate  the  liquid  in  each  flask  with  a  pure  cul- 
ture of  the  test  organism.  The  flasks  are  then  placed  in  an  incubat- 
ing oven  at  35°  to  37°  C.  At  the  same  time  a  control,  not  containing 
any  carbolic  acid,  is  placed  in  the  oven.  At  the  end  of  twenty-four 
hours  the  control  will  be  found  to  be  clouded,  showing  an  abundant 
multiplication  of  the  bacillus.  Taking  the  result  of  Boer  above  given, 
we  would  expect  to  find  all  of  the  solutions  clear  except  that  contain- 
ing 1  :  500.  This  too  might  remain  clear  for  some  days  and  finally 
"  break  down,"  for  experience  shows  that  when  we  pass  the  point  at 
which  a  permanent  restraining  influence  is  exerted  there  may  be  a 
temporary  restraint  or  retardation  of  development.  For  this  reason 
we  must  continue  the  experiment  for  a  considerable  time — not  less 


158  ANTISEPTICS   AND   DISINFECTANTS. 

than  two  weeks.  Having  found  that  1  :400  and  below  prevents 
development,  and  1  : 500  does  not,  we  may  make  further  experiments 
to  determine  the  antiseptic  power  within  narrower  limits  ;  but  this 
is  hardly  necessary  from  a  practical  point  of  view. 

In  these  experiments  the  result  will  be  influenced  by  several  cir- 
cumstances, as  follows  : 

(a)  By  the  composition  of  the  nutrient  medium.     This  is  a 
very  important  factor,  especially  in  determining  the  antiseptic  value 
of  certain  metallic  salts.     The  presence  of  a  considerable  quantity 
of  albumin,  for  example,  reduces  greatly  the   antiseptic  power  of 
mercuric  chloride,  silver  nitrate,  creolin,  etc.    The  presence  of  a  sub- 
stance chemically  incompatible,  as,  for  example,  sodium  chloride  in 
testing  nitrate  of  silver,  will  of  course  neutralize  antiseptic  action. 

(b)  The  nature  of  the  test  organism.     Within  certain  limits  an 
antiseptic  for  one  microorganism  of  this  class  restrains  the  devel- 
opment of  all,  but  there  are  wide  differences  in  the  ability  of  differ- 
ent species  to  grow  in  the  presence  of  different  chemical  agents. 
Some  grow  readily  in  the  presence  of  a  considerable  amount  of  free 
acid,  others  are  restrained  by  a  slightly  acid  reaction  of  the  medium 
in  which  they  are  placed.     The  Bacillus  acidi  lactici,  for  example, 
can  thrive  in  the  presence  of  a  considerable  amount  of  the  acid 
which  is  a  product  of  its  growth,  but  there  is  a  limit  to  its  power  of 
developing  in  the  presence  of  this  and  other  acids.     So,  too,   Mi- 
crococcus  urea3,  which  causes  the  alkaline  fermentation  of  urine, 
grows  in  the  presence  of  a  considerable  amount  of  carbonate  of  am- 
monia, but  is  finally  restrained  in  its  growth  by  this  alkaline  salt. 
The  following  determinations  by  Boer  show  the  difference  in  the 
antiseptic  power  of  hydrochloric  acid  for  certain  pathogenic  bacte- 
ria :  Bacillus  of  anthrax  (without  spores),  1  : 3,400  ;  diphtheria  bacil- 
lus, I  :  3,400  ;  glanders  bacillus,   1  :  700  ;  typhoid  bacillus,   1  :  2,100  ; 
cholera  spirillum,  1  :5,500.     It  will  be  noted  that  the  cholera  spiril- 
lum is  restrained  in  its  growth  by  about  one-eighth  the  amount  of 
hydrochloric  acid  which  is  required  to  prevent  the  development  of 
the  bacillus  of  glanders.     The  typhoid  bacillus  has  a  special  tole- 
rance for  carbolic  acid,  etc. 

(c)  The  temperature  at  which  the  experiment  is  made.     At 
the  temperature  most  favorable  for  growth  a  greater  proportion  of 
the  antiseptic  agent  is  required  than  at  unfavorable  temperatures — 
lower  or  higher. 

(d)  The  restraining  influence  for  spores  is  much  greater  than 
for  the  vegetative  form  of  bacteria. 

Methods  of  Determining  Germicide  Value. — The  disinfecting 
power  of  a  chemical  agent  is  determined  by  allowing  it  to  act  for  a 
given  time,  in  a  definite  proportion,  on  a  pure  culture  of  a  given 


ANTISEPTICS   AND    DISINFECTANTS.  159 

microorganism,  and  then  testing  the  question  of  loss  of  vitality  by 
culture  experiments  or  by  inoculations  of  infectious  disease  germs 
into  susceptible  animals. 

The  test  by  cultivation  is  the  most  reliable,  but  in  making  it 
several  points  must  be  kept  in  view.  Naturally  the  conditions  must 
be  such  as  are  favorable  for  the  growth  of  the  particular  microor- 
ganism which  serves  as  the  test ;  and  we  must  allow  a  considerable 
time  for  the  development  of  the  test  organism,  for  it  often  happens 
that  its  vital  activity  has  been  weakened  without  being  completely 
destroyed,  and  that  growth  will  occur  after  an  interval  of  several 
days,  while  in  the  control  experiment  it  has  perhaps  been  seen  at 
the  end  of  twenty-four  hours.  Another  most  important  point  is  the 
fact  that  some  of  the  disinfecting  agent  is  necessarily  carried  over 
with  the  test  organisms  when  these  are  transferred  to  a  nutrient 
medium  to  ascertain  whether  they  will  grow,  and  this  may  be  in 
sufficient  amount  to  restrain  their  development  and  lead  to  the  mis- 
taken inference  that  they  have  been  killed.  This  is  especially  true 
of  mercuric  chloride,  which  restrains  the  development  of  spores  in 
very  minute  amounts.  Spores  which  have  been  subjected  to  its  ac- 
tion in  comparatively  strong  solutions,  when  transferred  to  a  culture 
medium  may  fail  to  grow  because  of  the  restraining  influence  of 
the  mercuric  chloride  carried  over  at  the  same  time.  For  this  rea- 
son liquid  cultures  are  to  be  preferred  in  experiments  of  this  kind. 
When  the  test  organisms  are  planted  in  a  solid  culture  medium  the 
chemical  agent  is  left  associated  with  them  ;  in  a  liquid  culture,  on 
the  other  hand,  it  is  diluted,  and  the  microorganisms,  being  distri- 
buted through  the  nutrient  medium,  have  the  disinfecting  agent 
washed  from  their  surface.  In  the  case  of  mercuric  chloride,  how- 
ever, the  experiments  of  Geppert  show  that  the  agent  is  so  attached 
to  spores  which  have  been  subjected  to  its  action  that  ordinary 
washing  does  not  suffice.  Moreover,  spores  which  have  been  ex- 
posed to  the  action  of  mercuric  chloride  without  being  killed  are  re- 
strained in  their  growth  by  a  much  smaller  proportion  of  the  corro- 
sive sublimate  than  is  required  for  spores  not  so  exposed — according 
to  Geppert,  by  1  part  in  2,000,000.  Geppert  therefore  proposes,  in 
experiments  with  this  agent,  to  neutralize  the  mercuric  chloride 
which  remains  attached  to  the  test  organisms  by  washing  these  in 
a  solution  of  ammonium  sulphide,  by  which  the  sublimate  is  preci- 
pitated as  an  inert  sulphide. 

With  most  agents  simple  dilution  will  serve  the  purpose  of  pre- 
venting an  erroneous  inference  from  the  restraining  influence  of  the 
chemical  agent  being  tested.  If  we  carry,  by  means  of  a  platinum 
loop,  one  or  two  ose  into  five  to  ten  cubic  centimetres  of  bouillon, 
the  dilution  will  usually  be  beyond  the  restraining  influence  of  the 


160  ANTISEPTICS   AND   DISINFECTANTS. 

germicidal  agent  ;  but  we  may  carry  the  dilution  still  further,  to  be 
on  the  side  of  safety,  by  inoculating  a  second  tube  containing  the 
same  amount  of  sterile  bouillon  from  the  first,  carrying  over  in  the 
same  way  one  or  two  ose.  We  will  still  be  very  sure  to  have  a 
considerable  number  of  the  microorganisms  to  test  the  question  of 
the  destruction  of  vitality.  Instead  of  bouillon  we  may  use  liquefied 
flesh-peptoiie-gelatin,  which  gives  us  the  same  advantage  as  to  dilu- 
tion of  the  disinfecting  agent ;  and  after  inoculating  two  tubes  as 
above  indicated,  we  may  make  Esmarch  roll  tubes  by  turning  them 
upon  a  block  of  ice.  The  development  of  colonies  will  show  that 
there  was  a  failure  to  disinfect ;  their  absence,  after  a  proper  inter- 
val, will  be  evidence  of  the  germicidal  action  of  the  agent  employed. 

Koch's  Method. — In  1881  Koch  published  his  extended  experi- 
ments made  to  determine  the  germicidal  power  of  various  chemical 
agents  as  tested  upon  anthrax  spores.  His  method  consisted  in  ex- 
posing silk  threads,  to  which  the  dried  spores  were  attached,  in  a 
solution  of  the  disinfecting  agent,  and  at  intervals  transferring  one 
of  these  threads  to  a  solid  culture  medium.  The  precaution  was 
taken  to  wash  the  thread  in  distilled  water  when  the  agent  tested  was 
supposed  to  be  likely  to  restrain  development.  In  these  experiments 
a  standard  solution  of  the  disinfecting  agent  was  used,  and  the  time 
of  exposure  was  varied  from  a  few  hours  to  many  days. 

The  Writer's  Method. — In  the  writer's  experiments,  made  in 
1880  and  subsequently,  a  different  method  has  been  adopted.  The 
time  has  been  constant — usually  two  hours — and  the  object  has  been 
to  find  the  minimum  amount  of  various  chemical  agents  which 
would  destroy  the  test  organisms  in  this  time  ;  and  instead  of  sub- 
jecting a  few  of  the  test  organisms  attached  to  a  silk  thread  to  the 
action  of  the  disinfecting  agent,  a  certain  quantity  of  a  recent  cul- 
ture— usually  five  cubic  centimetres — has  been  mixed  with  an  equal 
quantity  of  a  standard,  solution  of  the  germicidal  agent.  Thus  five 
cubic  centimetres  of  a  1  : 200  solution  of  carbolic  acid  would  be 
added  to  five  cubic  centimetres  of  a  recent  culture  of  the  typhoid 
bacillus,  for  example,  and  after  two  hours'  contact  one  or  two  ose 
would  be  introduced  into  a  suitable  nutrient  medium  to  test  the 
question  of  disinfection.  In  the  case  given  the  result  obtained 
would  be  set  down  as  the  action  of  a  solution  of  carbolic  acid  in  the 
proportion  of  1  :  400,  for  the  1  :  200  solution  was  diluted  by  the  addi- 
tion of  an  equal  quantity  of  the  culture. 

Other  experimenters  have  adopted  still  a  different  method.  In- 
stead of  using  a  considerable  and  definite  quantity  of  a  culture  con- 
taining the  test  organism,  they  introduce  one  or  two  ose  from  such 
a  culture  into  a  solution  containing  a  given  proportion  of  the  disin- 
fectant ;  then  after  exposure  for  a  given  time  the  nutrient  medium  is 
inoculated. 


ANTISEPTICS   AND    DISINFECTANTS. 


101 


These  different  methods  give  results  which  cannot  be  directly 
compared  one  with  another,  for  to  obtain  corresponding  results  we 
must  have  identical  conditions. 

Test  by  Inoculation  into  Susceptible  Animals. — In  testing  the 
action  of  disinfectants  upon  anthrax  spores  and  other  infectious  dis- 
ease germs,  we  may  inoculate  the  microorganisms,  after  exposure  to 
the  disinfectant,  into  a  susceptible  animal.  This  method  was  adopted 
by  the  writer  in  a  series  of  experiments  in  1881,  but  he  has  not  since 
employed  it,  for  reasons  set  forth  in  his  paper  giving  an  account  of 
these  experiments. 

"First.  The  test  organism  maybe  modified  as  regards  repro- 
ductive activity  without  being  killed;  and  in  this  case  a  modified  form 
of  disease  may  result  from  the  inoculation,  of  so  mild  a  character  as 
to  escape  observation.  Second.  An  animal  which  has  suffered  this 
modified  form  of  the  disease  enjoys  protection,  more  or  less  perfect, 
from  future  attacks,  and  if  used  for  a  subsequent  experiment  may, 
by  its  immunity  from  the  effects  of  the  pathogenic  test  organism, 
give  rise  to  the  mistaken  assumption  that  this  had  been  destroyed 
by  the  action  of  the  germicidal  agent  to  which  it  had  been  sub- 
jected.''1 

In  experiments  to  determine  the  value  of  an  agent  as  a  disinfec- 
tant, no  matter  by  what  method,  the  following  conditions,  which  in- 
fluence the  result,  should  be  kept  in  view  : 

(a)  The  difference  in  vital  resisting  power  of  different  species 
of  bacteria.  As  a  rule,  the  pathogenic  species  have  rather  less  re- 
sisting power  than  the  common  saprophytes,  and  the  micrococci 
have  greater  resisting  power  than  many  of  the  bacilli.  The  differ- 
ence in  the  vital  resisting  power  of  some  of  the  best  known  patho- 
genic species  is  shown  in  the  following  table,  which  we  have  made 
up  from  determinations  made  by  Boer — cultures  in  bouillon  twenty- 
four  hours  old  ;  time  of  exposure,  two  hours. 


Hydrochloric 
Acid. 

Caustic 
Soda. 

Chloride  of 
Gold  and 
Sodium. 

Nitrate 
of 
Silver. 

Carbolic 
Acid. 

Anthrax  bacillus  

1  •  1100 

1  :  450 

1  :8000 

1  •  20000 

1  -300 

Diphtheria  bacillus  
Glanders  bacillus  
Typhoid  bacillus  

1  :700 
1  :200 
1  :300 

1  :300 
1  :150 
1  :190 

1  :1000 
1  :400 
1  :500 

1  :  2500 
1  :  4000 
1  :4000 

1:300 
1  :300 
1  -200 

Cholera  spirillum  

1  -.1850 

1  :150 

1  :  1000 

1  :4000 

1  :400 

(b)  The  presence  or  absence  of  spores.  The  reproductive  ele- 
ments known  as  spores  have  a  far  greater  resisting  power  to  chemi- 
cal agents,  as  well  as  to  heat,  than  have  the  vegetative  cells.  In 

1  Quoted  from  article  on  "  Germicides  and  Disinfectants,"  in  "  Bacteria,"  p.  212. 
11 


162  ANTISEPTICS   AND   DISINFECTANTS. 

practical  disinfection,  therefore,  it  is  important  to  know  what  disease 
germs  form  spores  and  what  do  not.  The  following  are  known  to 
form  spores  :  The  bacillus  of  anthrax,  the  bacillus  of  tetanus,  the 
bacillus  of  malignant  oedema,  the  bacillus  of  symptomatic  anthrax, 
the  bacillus  of  foul  brood  (infectious  disease  of  bees).  The  following, 
so  far  as  is  known,  do  not  form  spores  :  The  pus  cocci  (Staphylo- 
coccus  pyogenes  albus,  aureus,  and  citreus,  and  Streptococcus  pyo- 
genes),  the  micrococcus  of  pneumonia,  the  bacillus  of  typhoid  fever, 
the  bacillus  of  glanders,  the  bacillus  of  diphtheria,  the  spirillum  of 
cholera,  the  spirillum  of  relapsing  fever. 

Many  agents  which  kill  the  growing  bacteria  are  incapable  of 
destroying  the  vitality  of  spores,  and  others  only  do  so  in  much 
stronger  solutions  or  after  a  long  exposure  to  their  action. 

(c)  The  number  of  bacteria  to  be  destroyed.     This  is  an  essen- 
tial factor  which  has  often  been  overlooked  by  those  making  experi- 
ments.   To  destroy  the  bacteria  carried  over  to  five  cubic  centimetres 
of  distilled  water  by  means  of  a  platinum  loop,  is  a  very  different 
matter  from  destroying  the  immensely  greater  number  in  five  cubic 
centimetres  of  a  recent  bouillon  culture. 

(d)  The  nature  and  quantity  of  associated  material.     The 
oxidizing  disinfectants,  like  permanganate  of  potash  and  chloride  of 
lime,  not  only  act  upon  the  bacteria,  destroying  them  by  oxidation, 
but  upon  all  organic  matter  with  which  they  come  in  contact,  and  at 
the  same  time  the  disinfecting  agent  is  destroyed  in  the  chemical 
reaction,  which  is  a  quantitative  one.     The  presence,  therefore,  of 
organic  material  in  association  with  the  bacteria  is  an  important 
factor,  and  if  this  is  in  excess  the  disinfectant  may  be  neutralized 
before  the  living  bacteria  are  destroyed.     Other  substances  which 
precipitate  the  disinfecting  agent  in  an  insoluble  form,  or  decompose 
it,  must  of  course  have  the  same  effect.    Thus  the  presence  of  sodium 
chloride  in  a  culture  medium  would  be  an  important  circumstance  if 
nitrate  of  silver  was  the  agent  being  tested,  as  the  insoluble  chloride 
would  be  precipitated.     And  in  the  case  of  mercuric  chloride  and 
certain  other  metallic  salts  the  presence  of  albumin  very  materially 
influences  the  result.     Van  Ermengem  states  that  the  cholera  spiril- 
lum in  bouillon  is  destroyed  in  half  an  hour  by  mercuric  chloride  in 
the  proportion  of  1:  GO,  000,  while  in  blood  serum  1:  800  was  required 
to  destroy  it  in  the  same  time. 

(e)  The  time  of  exposure  is  also  an  important  factor.     Some 
agents  act  very  promptly,  while  others  require  a  considerable  time  to 
effect  the  destruction  of  bacteria  exposed  to  their  action.     Thus  a 
solution  of  chloride  of  lime  containing  0.12  per  cent  destroys  the 
typhoid  bacillus  and  the  cholera  spirillum  in   five  minutes,    and 
the  anthrax  bacillus  in  one  minute  (Nissen).     On  the  other  hand, 


ANTISEPTICS   AND   DISINFECTANTS.  163 

quicklime  (milk  of  lime)  requires  a  contact  of  several  hours  to  in- 
sure the  destruction  of  pathogenic  bacteria. 

(/)  The  temperature  at  ivhich  the  exposure  is  made  has  a 
material  influence  upon  the  result.  This  is  shown  by  the  experi- 
ments of  Henle  and  of  Nocht. 

(g)  The  degree  of  dilution  of  the  disinfecting  agent  is  also  a 
matter  of  importance.  This  is  especially  true  of  solutions  of  acids 
and  alkalies.  When  a  silk  thread  to  which  bacteria  are  attached  is 
suspended  in  an  acid  solution  the  essential  point  is  the  degree  of 
acidity,  and  not  the  quantity  of  acid  in  the  entire  solution.  But  if  a 
solution  of  permanganate  of  potash,  or  any  other  active  oxidizing 
agent,  is  used,  the  principal  question  is  not  the  degree  of  dilution,  but 
the  amount  of  the  disinfecting  agent  present  in  the  solution  used.  A 
grain  of  potassium  permanganate  dissolved  in  two  fluidounces  of 
distilled  water  would  probably  kill  just  as  many  bacteria  as  if  it 
were  dissolved  in  half  a  fluidounce,  although  the  time  required  for 
disinfection  might  be  longer. 

From  what  has  been  said  it  is  evident  that  the  simple  statement 
that  a  certain  agent  is  a  germicide  in  a  certain  proportion  has  but 
little  scientific  value,  unless  we  are  made  acquainted  with  the  condi- 
tions under  which  its  germicidal  action  has  been  tested. 


VIII. 

ACTION  OF  GASES  AND   OF   THE   HALOID  ELEMENTS 
UPON   BACTERIA. 

Oxygen. — Free  oxygen  is  essential  for  the  development  of  a  large 
number  of  species  of  bacteria — aerobics  ;  and  it  completely  prevents 
the  growth  of  others — anaerobics.  Many  bacteria,  even  when  freely 
exposed  in  a  desiccated  condition  to  the  action  of  atmospheric  oxygen, 
retain  their  vitality  for  a  long  time.  The  gradual  loss  of  pathogenic 
power  which  Pasteur  has  shown  occurs  in  cultures  of  the  anthrax 
bacillus  and  the  micrococcus  of  fowl  cholera,  is  ascribed  by  him  to 
exposure  to  oxygen,  and  as  proof  of  this  he  states  that  cultures  kept 
in  hermetically  sealed  tubes  do  not  lose  their  virulence  in  the  same 
degree.  But  other  circumstances  may  influence  the  result.  Thus 
some  of  the  products  of  growth  which  accumulate  in  culture  fluids 
have  an  injurious  effect  upon  the  vitality  of  the  bacteria  which  pro- 
duced them,  and  in  time  may  cause  a  complete  destruction  of  vitality. 
In  cultures  exposed  to  the  air  these  products  would  be  in  a  more 
concentrated  solution  from  the  gradual  evaporation  of  the  culture 
liquid.  It  must  also  be  remembered  that  light  in  the  presence  of 
oxygen  is  a  germicidal  agent. 

The  experiments  of  Frankel  show  that  the  aerobic  bacteria  grow 
abundantly  in  the  presence  of  pure  oxygen,  and  some  species  even 
more  so  than  in  ordinary  air.  Micrococcus  prodigiosus,  however, 
appeared  to  be  unfavorably  affected  by  pure  oxygen,  inasmuch  as  it 
did  not  produce  pigment  so  readily  as  when  cultivated  in  ordinary  air. 

Nascent  oxygen  is  a  very  potent  germicidal  agent,  as  will  be  seen 
in  our  account  of  such  oxidizing  disinfectants  as  potassium  perman- 
ganate and  the  hypochlorite  of  lime. 

Ozone. — It  was  formerly  supposed  that  ozone  would  prove  to  be 
a  most  valuable  agent  for  disinfecting  purposes  ;  but  recent  experi- 
ments show  that  it  is  not  so  active  a  germicide  as  was  anticipated, 
and  that  from  a  practical  point  of  view  it  has  comparatively  little 
value. 

Lukaschewitsch  found  that  one  gramme  in  the  space  of  a  cubic 
metre  failed  to  kill  anthrax  spores  in  twenty-four  hours.  The  cholera 
spirillum  in  a  moist  state  was  killed  in  this  time  by  the  same  amount, 
but  fifteen  hours'  exposure  failed  to  destroy  it.  Ozone  for  these  ex- 
periments was  developed  by  means  of  electricity. 


ACTION   OF   GASES   AND   HALOID    ELEMENTS   UPON  BACTERIA.      165 

Wyssokowicz  found  that  the  presence  of  ozone  in  a  culture  me- 
dium restrained  the  development  of  the  anthrax  bacillus,  the  bacillus 
of  typhoid  fever,  and  others  tested,  but  concludes  that  this  is  rather 
due  to  the  oxidation  of  bases  contained  in  the  nutrient  medium  than 
to  a  direct  action  upon  the  pathogenic  bacteria. 

Sonntag,  in  his  carefully  conducted  experiments,  in  which  a  cur- 
rent of  ozonized  air  was  made  to  pass  over  silk  threads  to  which  were 
attached  anthrax  spores,  had  an  entirely  negative  result.  The  an- 
thrax bacillus  from  the  spleen  of  a  mouse,  and  free  from  spores,  was 
then  tested,  also  with  a  negative  result,  even  after  exposure  to  the 
ozonized  air  for  twenty  minutes  at  a  time  on  four  successive  days.  In 
another  experiment  several  test  organisms  (Bacillus  anthracis,  Bacil- 
lus pneumonise  of  Friedlander,  Staphylococcus  pyogenes  aureus, 
Staphylococcus  pyogenes  albus,  Bacillus  murisepticus,  Bacillus 
crassus  sputigenus)  were  exposed  on  silk  threads  for  twenty-four 
hours  in  an  atmosphere  containing  4. 1  milligrammes  of  ozone  to  the 
litre  of  air  (0. 19  volumes  per  cent).  The  result  was  entirely  negative. 
When  the  amount  was  increased  to  13.53  milligrammes  per  litre  the 
anthrax  bacillus  and  Staphylococcus  pyogenes  albus  failed  to  grow 
after  twenty-four  hours'  exposure.  The  conclusion  reached  by  Nis- 
sen,  from  his  own  experiments  and  a  careful  consideration  of  those 
previously  made  by  others,  is  that  ozone  is  of  no  practical  value  as  a 
germicide  in  therapeutics  or  disinfection. 

Hydrogen. — This  gas  has  no  injurious  effect  upon  bacteria,  as  is 
shown  by  the  fact  that  the  anaerobic  and  facultative  anaerobic  species 
grow  readily  in  an  atmosphere  of  pure  hydrogen. 

Hydrogen  peroxide  in  solution  in  water  is  a  valuable  antiseptic 
and  deodorant,  but  its  value  as  a  germicide  has  been  very  much 
overestimated.  Miquel,  in  his  experiments  to  determine  the  anti- 
septic value  of  various  agents,  places  H2O.,  third  in  the  list  of  "  sub- 
stances eminently  antiseptic,"  and  states  that  it  prevents  the  develop- 
ment of  the  bacteria  of  putrefaction  in  the  proportion  of  1:20,000. 

In  the  writer's  experiments  (1885)  a  solution  was  used  which 
contained  at  first  4. 8  per  cent  of  H2O2,  and  five  per  cent  of  sulphuric 
acid  which  was  added  by  the  chemist  who  prepared  the  solution,  to 
prevent  loss  of  the  hydrogen  peroxide.  At  the  end  of  a  month  the 
amount  of  H.,Oa  was  again  estimated,  and  found  to  be  3. 98  per  cent. 
Five  weeks  later  the  proportion  was  2.4  per  cent.  Tested  upon 
' "  broken-down  "  beef  tea,  this  solution  was  found  to  destroy  the 
vitality  of  the  bacteria  of  putrefaction  contained  in  it,  in  two  hours' 
time,  in  the  proportion  of  thirty  per  cent  (about  1.2  per  cent  of  H2O.,). 
Anthrax  spores  were  killed  in  the  same  time  by  a  twenty-per-cent 
solution  (0.8  per  cent  HaO,).  Tested  upon  a  pure  culture  of  pus 
cocci,  it  was  active  in  the  proportion  of  ten  per  cent  (0.4  per  cent  of 


166  ACTION   OF   GASES   AND   OF  THE 

H2O2);  a  solution  containing  0.24  per  cent  of  H3O.,  failed  to  kill  pus 
cocci.  But  the  solution  used  in  these  experiments  contained  also  five 
per  cent  of  sulphuric  acid,  which  by  itself  kills  micrococci  in  the  pro- 
portion of  1 :  200.  My  conclusion  was  that,  unless  the  chemists  can 
furnish  more  concentrated  solutions  which  will  keep  better  than  that 
with  which  I  experimented,  we  are  not  likely  to  derive  any  practical 
benefit  from  the  use  of  hydrogen  peroxide  as  a  disinfectant. 

Altehof  er  more  recently  has  experimented  with  a  solution  contain- 
ing 9.7  per  cent  of  H2O2,  and  reports  the  following  results:  He  added 
to  ninety-eight  cubic  centimetres  of  hydrant  water  two  cubic  centi- 
metres of  a  bouillon  culture  of  the  typhoid  bacillus,  and  to  this  was 
added  sufficient  of  his  aqueous  solution  of  H2O2  to  make  the  propor- 
tion present  1:1,000.  At  the  end  of  twenty-four  hours  the  bacillus 
was  proved  by  culture  experiments  to  be  killed.  Water  containing 
the  cholera  spirillum,  treated  in  the  same  way,  was  not  entirely  steril- 
ized, as  a  few  colonies  developed  in  Esmarch  roll  tubes  ;  but  the  gen- 
eral result  of  his  experiments  was  that  the  ordinary  water  bacteria, 
and  the  pathogenic  bacteria  named  (cholera,  typhoid)  when  sus- 
pended in  water,  required  for  their  destruction  exposure  for  twenty- 
four  hours  in  a  solution  containing  one  part  of  H.2O2  in  one  thousand 
of  water. 

Carbon  Dioxide. — The  experiments  of  Frankel  show  that  certain 
bacteria  grow  in  an  atmosphere  of  C0a  as  well  as  in  the  air  ;  among 
these  are  the  bacillus  of  typhoid  fever  and  the  pneumonia  bacillus 
of  Friedlander.  Other  species  are  slightly  restricted  in  their  growth, 
e.  g.  Bacillus  prodigiosus,  Proteus  vulgaris.  Still  others  grow  only 
when  the  temperature  is  elevated,  including  the  pus  cocci  and  the 
bacillus  of  swine  pest.  Most  of  the  saprophytic  bacteria  failed  to 
grow  in  an  atmosphere  of  CO2,  although  their  vitality  was  not  de- 
stroyed by  it.  Certain  pathogenic  species  were,  however,  killed  by 
the  action  of  this  gas,  among  others  the  cholera  spirillum,  Bacillus 
anthracis,  and  Staphylococcus  pyogenes  aureus. 

Leone  and  Hochstetter  had  previously  reported  that  certain  bac- 
teria are  injuriously  affected  by  C02.  Frankel  also  found  that  the 
growth  of  strictly  anaerobic  species  was  restricted  in  an  atmosphere 
of  carbon  dioxide.  The  aerobic  species  which  failed  to  grow  in  pure 
CO,  grew  abundantly  when  a  little  atmospheric  oxygen  was  ad- 
mitted. In  the  experiments  of  Frankland  the  cholera  spirillum  and 
the  Finkler-Prior  spirillum  failed  to  develop  in  an  atmosphere  of 
CO2,  and  at  the  end  of  eight  days  were  no  longer  capable  of  growth 
when  the  carbon  dioxide  was  replaced  with  atmospheric  air. 

Carbonic  Oxide. — Frankland's  experiments  show  that  an  atmo- 
sphere of  this  gas  is  not  favorable  to  the  growth  of  the  cholera  spiril- 
lum or  of  the  Finkler-Prior  spirillum,  although  it  did  not  entirely 


HALOID    ELEMENTS   UPON   BACTERIA.  167 

prevent  development,  and  after  seven  days'  exposure  the  spirilla  were 
not  all  killed,  although  a  comparatively  small  number  of  colonies 
developed.  Bacillus  pyocyaiius  failed  to  grow  in  an  atmosphere  of 
CO,  but  when  air  was  admitted,  at  the  end  of  seven  or  eight  days, 
abundant  development  occurred. 

Methane,  CH4. — We  have  no  exact  experiments  to  determine 
the  action  of  marsh  gas  in  a  pure  state  on  bacteria,  but  the  experi- 
ments of  Kladakis  upon  illuminating  gas  may  be  taken  as  repre- 
senting approximately  what  might  be  expected  from  exposure  in 
pure  CH4.  An  analysis  of  the  gas  used  in  his  experiments  showed 
it  to  contain  37.97  per  cent  of  hydrogen,  39.37  per  cent  of  methane 
(CH4),  9.99  per  cent  of  nitrogen,  4.29  per  cent  of  ethene  (CaH4),  3.97 
per  cent  of  carbonic  oxide  (CO),  O.G1  per  cent  of  oxygen,  and  0.41  per 
cent  of  carbon  dioxide.  As  hydrogen  and  nitrogen  are  neutral,  and 
carbonic  oxide  is  shown  by  the  experiments  of  Frankland  not  to  act 
as  a  germicide  after  several  days'  exposure  to  its  action,  the  positive 
results  obtained  in  the  experiments  of  Kladakis  may  be  ascribed  to 
the  presence  of  CH4  (39.37  per  cent)  or  of  C2H4  (4.29  per  cent),  or  of 
both  together. 

A  large  number  of  microorganisms  were  tested,  and  among  these 
Proteus  vulgaris  alone  grew  in  an  atmosphere  of  illuminating  gas. 
The  others  not  only  failed  to  grow  in  such  an  atmosphere,  but  were 
destroyed  by  it.  Cultures  of  Bacillus  anthracis,  Staphylococcus  pyo- 
genes  aureus,  and  Spirillum  cholerse  Asiaticse  were  sterilized  in  half 
an  hour  by  the  action  of  this  gas.  The  gas  was  also  found  to  be  un- 
suitable for  anaerobic  cultures. 

Nitrous  Oxide,  N2O. — The  experiments  of  Frankland,  made 
upon  the  cholera  spirillum,  the  spirillum  of  Finkler-Prior,  and  the 
bacillus  of  green  pus,  gave  results  similar  to  those  obtained  with  CO, 
viz. ,  seven  days'  exposure  in  an  atmosphere  of  this  gas  failed  to  de- 
stroy the  test  organisms,  but  completely  restrained  the  growth  of 
Bacillus  pyocyanus  and  interfered  materially  with  the  development 
of  the  two  species  of  spirillum  without  entirely  preventing  it. 

Nitrogen  Dioxide,  NO. — Frankland  found  that  his  test  organ- 
isms were  quickly  killed  by  this  gas  (Bacillus  pyocyanus,  Spirillum 
cholerse  Asiaticse,  Spirillum  Finkler-Prior). 

Hydrosulphuric  Acid,  H2S. — In  the  experiments  of  Frankland 
this  gas  proved  to  be  quickly  fatal  to  the  bacteria  tested  (Bacillus 
pyocyanus,  Spirillum  cholerse  Asiaticse,  Spirillum  Finkler-Prior).  On 
the  other  hand,  Grauer  found  that  this  gas  did  not  exercise  any  in- 
jurious influence  upon  the  tubercle  bacillus,  the  bacillus  of  anthrax, 
the  typhoid  bacillus,  or  the  cholera  spirillum,  after  the  exposure  of 
these  microorganisms  in  a  current  of  the  gas  for  an  hour. 

It  has  been   shown   by  the  experiments  of  Holschewnikoff  and 


1G8  ACTION   OF   GASES   AND   OF   THE 

others  that  certain  species  of  bacteria  cause  an  abundant  evolution 
of  H2S  as  a  result  of  their  development  in  an  albuminous  medium 
(Bacillus  sulfureus  and  Proteus  sulfureus). 

Sulphur  Dioxide,  S02. — Very  numerous  experiments  have  been 
made  with  this  gas,  owing  to  the  fact  that  it  has  been  extensively 
used  in  various  parts  of  the  world  for  the  disinfection  of  hospitals, 
ships,  apartments,  clothing,  etc. 

In  the  writer's  experiments,  made  in  1880,  dry  vaccine  virus  on 
ivory  points  was  disinfected  by  exposure  for  twelve  hours  in  an  at- 
mosphere containing  one  volume  per  cent  of  this  gas,  and  liquid 
virus,  exposed  in  a  watch  glass,  by  one-third  of  this  amount.  Sub- 
sequent experiments  (1885)  showed  that  pus  micrococci  were  killed 
by  exposure  for  eighteen  hours  in  a  dry  atmosphere  containing  twenty 
volumes  per  cent  of  SO2,  but  that  four  volumes  per  cent  failed.  In 
the  presence  of  moisture  this  gas  has  considerably  greater  germicidal 
power  than  this,  owing,  no  doubt,  to  the  formation  of  the  more  ac- 
tive agent,  sulphurous  acid  (H2S03).  But  in  a  pure  state  anhydrous 
sulphur  dioxide  does  not  destroy  spores.  The  writer  has  shown  that 
the  spores  of  Bacillus  anthracis  and  Bacillus  subtilis  are  not  killed  by 
contact  for  some  time  with  liquid  SO2  (liquefied  by  pressure).  Koch 
exposed  various  species  of  spore-bearing  bacilli  in  a  disinfection  cham- 
ber for  ninety-six  hours,  the  amount  of  SO2  at  the  outset  of  the  ex- 
periment being  6.13  volumes  per  cent,  and  at  the  end  3.3  per  cent. 
The  result  was  entirely  negative. 

But  in  the  absence  of  spores  the  anthrax  bacillus,  in  a  moist  con- 
dition, attached  to  silk  threads,  was  destroyed  in  thirty  minutes  in 
an  atmosphere  containing  one  volume  per  cent. 

In  another  of  Koch's  experiments  the  amount  of  S02  in  the  disin- 
fection chamber  was  at  the  outset  0. 84  per  cent,  and  at  the  end  of 
twenty-four  hours  0.55  per  cent.  An  exposure  of  one  hour  in  this  at- 
mosphere killed  anthrax  bacilli  attached  to  silk  threads,  in  a  moist 
condition;  but  four  hours'  exposure  failed  to  kill  Bacillus  prodigiosus 
growing  on  potato,  while  twenty-four  hours'  exposure  was  successful. 
A  similar  result  was  obtained  with  Bacillus  pyocyanus. 

Thinot,  as  a  result  of  experiments  made  in  1890,  arrives  at  the 
conclusion  that  the  specific  germs  of  tuberculosis,  glanders,  farcy  of 
cattle,  typhoid  fever,  cholera,  and  diphtheria  are  destroyed  by  twenty- 
four  hours'  exposure  in  an  atmosphere  containing  SO2  developed  by 
the  combustion  of  sixty  grains  of  sulphur  per  cubic  metre.  This 
amount  corresponds  closely  with  that  fixed  by  the  Committee  on  Dis- 
infectants of  the  American  Public  Health  Association  on  the  experi- 
mental evidence  obtained  by  the  writer  in  1885.  But  the  committee 
insisted  upon  the  presence  of  moisture  and  made  the  time  of  exposure 
twelve  hours — "exposure  for  twelve  hours  to  an  atmosphere  con- 


HALOID   ELEMENTS    UPON  BACTERIA.  169 

taining  at  least  four  volumes  per  cent  of  this  gas  in  the  presence  of 
moisture." 

Chlorine. — The  haloid  elements  are  active  germicidal  agents, 
especially  chlorine  on  account  of  its  affinity  for  hydrogen,  and  the 
consequent  release  of  nascent  oxygen  when  it  comes  in  contact  with 
microorganisms  in  a  moist  condition.  And  for  the  same  reason  this 
agent  is  a  much  more  active  germicide  in  the  presence  of  moisture 
than  in  a  dry  condition.  The  experiments  of  Fischer  and  Proskauer 
showed  that  when  dried  anthrax  spores  were  exposed  for  an  hour  in 
an  atmosphere  containing  44. 7  per  cent  of  dry  chlorine  they  were  not 
destroyed  ;  but  if  the  spores  were  previously  moistened  and  were  ex- 
posed in  a  moist  atmosphere  for  the  same  time,  four  per  cent  was 
effective,  and  when  the  time  was  extended  to  three  hours  one  per 
cent  destroyed  their  vitality.  The  anthrax  bacillus,  in  the  absence  of 
spores,  was  killed  by  exposure  in  a  moist  atmosphere  containing  1 
part  to  2,500,  the  time  of  exposure  being  twenty-four  hours,  and  the 
same  amount  was  effective  for  Micrococcus  tetragenus  ;  the  strepto- 
coccus of  erysipelas  and  the  micrococcus  of  fowl  cholera  were  killed  in 
three  hours  by  1  :  2,500,  and  in  twenty-four  hours  by  1:  25,000.  The 
bacillus  of  mouse  septicaemia  and  the  tubercle  bacillus  were  killed  in 
one  hour  by  1  : 200. 

In  the  writer's  experiments  (1880)  four  children  were  vaccinated 
with  virus  from  ivory  points  which  had  been  exposed  for  six  hours  in 
an  atmosphere  containing  one-half  per  cent  of  chlorine  ;  also  with 
four  points,  from  the  same  lot,  not  disinfected.  Vaccination  was  un- 
successful in  every  case  with  the  disinfected  points,  and  successful 
with  those  not  disinfected.  Koch  found  that  anthrax  spores  failed 
to  grow  after  twenty-four  hours'  exposure  in  chlorine  water.  In 
the  experiments  of  De  la  Croix  to  determine  the  antiseptic  power  of 
this  agent,  it  was  found  that  when  present  in  unboiled  beef  infusion 
in  the  proportion  of  1  : 15,000  no  development  of  bacteria  occurred. 
Miquel  gives  the  antiseptic  value  of  chlorine  as  1  :  4,000. 

Chloroform. — Immersion  for  one  hundred  days  in  chloroform 
does  not  destroy  the  vitality  of  anthrax  spores  (Koch).  This  agent 
is  without  effect  on  the  virus  of  symptomatic  anthrax  (Arloing, 
Cornevin,  and  Thomas).  Salkowski  found  that  the  anthrax  bacillus 
in  the  absence  of  spores,  and  the  cholera  spirillum,  were  killed  by 
being  immersed  in  chloroform  water  for  half  an  hour.  Kirchner 
reports  still  more  favorable  results.  In  his  experiments  a  one-per- 
cent solution  killed  the  cholera  spirillum  in  less  than  a  minute,  and 
a  one-quarter-per-cent  solution  in  an  hour.  But  the  typhoid  bacillus 
required  at  least  one-half  per  cent  acting  for  an  hour. 

Iodine. — In  the  writer's  experiments  (1880)  iodine  in  aqueous 
solution  with  potassium  iodide  was  found  to  be  fatal  to  Micrococcus 


170  ACTION   OF   ACIDS   AND    OF   THE 

pneumonias  croupossc  in  the  proportion  of  1  :  1,000,  and  to  the  staphy- 
lococci  of  pus  in  1  :  500 — time  of  exposure  two  hours.  Iodine  water 
was  found  by  Koch  to  destroy  the  vitality  of  anthrax  spores  in 
twenty-four  hours,  but  a  two-per-ceiit  solution  in  alcohol  failed  to 
destroy  anthrax  spores  in  forty -eight  hours.  In  the  experiments  of 
Schill  and  Fischer  twenty  hours'  contact  with  a  solution  of  the 
strength  of  1  :  500  failed  to  destroy  the  virulence  of  tuberculous  spu- 
tum, as  tested  by  inoculation  experiments.  The  antiseptic  value  of 
iodine  is  given  by  Miquel  as  1  : 4,000. 

Bromine. — Fischer  and  Proskauer  have  studied  the  action  of 
bromine  vapor  upon  various  microorganisms.  They  found  that  ex- 
posure for  three  hours  in  a  dry  atmosphere  to  three  per  cent  does, 
not  destroy  the  tubercle  bacillus  in  sputum  or  the  spores  of  an- 
thrax. But  when  the  atmosphere  is  saturated  with  moisture  1  :  500 
is  effective  ;  and  when  the  time  of  exposure  was  extended  to  twenty- 
four  hours,  1  :  3,500.  A  two-per-cent  solution  destroys  the  vitality 
of  anthrax  spores  in  twenty-four  hours  (Koch).  Bromine  vapor  is 
an  active  agent  for  the  destruction  of  the  virus  of  symptomatic  an- 
thrax (Arloing,  Cornevin,  and  Thomas).  Miquel  gives  the  antisep- 
tic value  of  bromine  as  1  : 1,666,  which  is  considerably  below  that  of 
chlorine  and  iodine. 

Iodine  Trichloride. — According  to  Behririg,  we  possess  in  this 
agent  a  disinfectant  which  possesses  the  potency  of  free  chlorine  and 
iodine  without  having  their  disadvantages.  As  prepared  by  O.  Rie- 
del  it  is  a  yellowish-red  powder  of  penetrating  odor.  It  remains  un- 
changed for  weeks  in  concentrated  aqueous  solution  (five  per  cent). 
A  one-per-cent  solution  destroys  anthrax  spores  suspended  in  water 
almost  instantly,  and  a  0.2-per- cent  solution  within  a  few  minutes. 
Anthrax  spores  in  blood  serum  are  killed  by  a  one-per-cent  solution 
in  forty  minutes  (Behring).  Langenbuch  found  that  a  solution  of 
1  : 1,000  kills  spores  in  a  short  time,  and  that  when  added  to  nutri- 
ent gelatin  in  the  proportion  of  1  : 1,200  it  restrains  the  develop- 
ment of  bacteria. 

Iodoform. — Numerous  experiments  have  been  made  with  this 
agent,  which  show  that  it  has  little,  if  any,  germicidal  power  ;  but 
it  acts  to  some  extent  as  an  antiseptic.  Tilanus  reports  that  the  tu- 
bercle bacillus  will  not  grow  in  glycerin-agar  cultures  to  which  a 
small  quantity  of  iodoform  has  been  added,  and  that  a  pure  culture 
of  the  tubercle  bacillus  was  not  killed  in  six  days  by  exposure  to 
iodoform  vapor,  but  that  after  six  weeks'  exposure  it  failed  to  grow. 
The  experiments  of  Neisser  and  of  Buchner  show  that  while  most 
bacteria  are  not  injuriously  affected  by  exposure  to  iodoform  vapor, 
the  cholera  spirillum  and  the  Finkler-Prior  spirillum  are  restrained  in 
their  growth  by  such  exposure.  When  plate  cultures  of  the  cholera 


HALOID   ELEMENTS   UPON   BACTERIA.  171 

spirillum  were  placed  under  a  bell  jar  beside  iodoform  powder 
no  development  occurred,  but  when  they  were  removed  colonies  de- 
veloped, showing  that  the  spirilla  were  not  killed. 

Iodoform  Ether,  according  to  Yersin,  is  fatal  to  the  tubercle  ba- 
cillus in  one-per-cent  solution  in  five  minutes.  Cadeac  and  Meunier 
found  that  a  saturated  solution  required  thirty-six  hours  to  kill  the 
bacillus  of  typhoid  fever. 

lodol. — In  experiments  made  by  the  writer  (1885)  this  agent  was 
found  to  be  without  germicidal  power.  Riedliii  found  it  without  any 
action,  even  upon  the  cholera  spirillum. 

Hydrofluoric  Acid,  HFL — From  a  series  of  experiments  made 
with  this  gas,  Grancher  and  Chautard  arrive  at  the  conclusion  that 
"  the  direct  and  prolonged  action  of  hydrofluoric  acid  upon  the  tuber- 
cle bacillus  diminishes  its  virulence  but  does  not  kill  it." 


IX. 


ACTION   OF   ACIDS   AND   ALKALIES. 

Sulphuric  Acid,  H2SO4. — The  experiments  of  Koch  (1881) 
showed  that  anthrax  spores  were  still  capable  of  growing  after  ex- 
posure in  a  one-per-cent  solution  of  sulphuric  acid  for  twenty  days. 
In  the  writer's  experiments  (1885)  a  four-per-cent  solution  failed  to 
destroy  the  spores  of  Bacillus  subtilis  in  four  hours,  and  an  eight- 
per-cent  solution  was  found  to  be  required  for  the  sterilization  of 
culture  fluids  containing  spores  ;  but  the  multiplication  of  the  bacte- 
ria of  putrefaction  was  prevented  by  the  presence  of  this  acid  in  a 
culture  solution  in  the  proportion  of  1  :  800.  Pus  micrococci  were 
destroyed  by  exposure  for  two  hours  in  a  solution  containing  1  :  200. 

The  experiments  of  Boer  show  that  there  is  a  considerable  differ- 
ence in  the  resisting  power  of  different  pathogenic  bacteria.  The 
time  of  exposure  being  two  hours,  cultures  in  bouillon  twenty-four 
hours  old  gave  the  following  results  : 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus  

1  •  2550 

1  •  1300 

Diphtheria  bacillus  ...   

1  :  2050 

1  -500 

Glanders  bacillus  

1  :750 

1  •  200 

Typhoid  bacillus  

1  :  1550 

1  -500 

Cholera  spirillum  

1  :  7000 

1  :  1300 

Leitz,  in  his  studies  relating  to  the  bacillus  of  typhoid  fever, 
reports  the  following,  results  :  The  dejections  of  typhoid  patients, 
mixed  with  an  equal  proportion  of  the  disinfecting  solution,  were 
sterilized  by  a  five-per-cent  solution  of  sulphuric  acid  in  three  days. 
A  pure  culture  was  sterilized  in  fifteen  minutes  by  two  per  cent,  and 
in  five  minutes  by  five  per  cent. 

Sulphurous  Acid,  H,SO3. — In  the  writers  experiments  (1885) 
micrococci  were  destroyed  in  two  hours  by  1  :  2,000  by  weight  of  SOa 
added  to  water.  Kitasato  found  that  solutions  of  sulphurous  acid 
in  the  proportion  of  0. 28  per  cent  killed  the  typhoid  bacillus,  and 
0.148  per  cent  the  cholera  spirillum.  De  la  Croix  found  that  one 


ACTION   OF   ACIDS  AND   ALKALIES.  173 

gramme  of  SO2  added  to  two  thousand  of  bouillon  prevents  the  de- 
velopment of  putrefactive  bacteria  and  after  a  time  destroys  the 
vitality  of  these  bacteria.  The  writer  found  that  pus  cocci  failed  to 
grow  in  a  culture  solution  containing  one  part  of  SO,2  in  five  thousand 
of  water. 

Nitric  Acid,  HNO3. — In  the  writer's  experiments  an  eight-per- 
cent solution  which  contained  0.819  gramme  of  HNO3  in  each  cubic 
centimetre  sterilized  broken-down  beef  tea  containing  spores,  and 
five  per  cent  failed  to  do  so.  Kitasato,  in  experiments  upon  the  chol- 
era spirillum  and  typhoid  bacillus,  obtained  results  corresponding 
with  those  obtained  with  hydrochloric  acid — 0. 2  per  cent  destroyed 
vitality  at  the  end  of  four  or  five  hours.  In  these  experiments  the 
acid  used  contained  0.35  gramme  HNO3  in  one  cubic  centimetre. 

Xitrous  Acid. — In  the  writer's  experiments  on  vaccine  virus  (1880) 
exposure  for  six  hours  in  an  atmosphere  containing  one  per  cent  of 
nitrous  acid  destroyed  the  virulence  of  dried  virus  upon  ivory  points. 

Hydrochloric  Acid,  HC1. — Anthrax  spores  are  destroyed  in  ten 
days  by  a  two-per-cent  solution,  but  not  in  five  days  (Koch).  Tested 
upon  broken-down  beef  tea  containing  spores  of  Bacillus  subtilis,  it 
was  effective  in  two  hours  in  the  proportion  of  fifteen  per  cent,  but 
failed  in  ten  per  cent  (Sternberg).  In  the  experiments  of  Kitasato  this 
acid  destroyed  the  typhoid  bacillus  in  five  hours  in  the  proportion  of 
0.3  per  cent,  and  the  cholera  spirillum  in  0.132  per  cent — the  acid 
used  contained  0.26  gramme  HC1  in  one  cubic  centimetre.  We  give 
the  more  recent  determinations  of  Boer  in  tabular  form.  Its  germi- 
cidal  power  was  tested  upon  bouillon  cultures  which  had  been  kept 
for  twenty-four  hours  in  an  incubating  oven ;  time  of  exposure  to 
the  action  of  the  acid  solution,  two  hours. 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus  

1  :  3400 

1  :1100 

Diphtheria  bacillus.  ...         

1  :  3400 

1  :700 

Glanders  bacillus  .  .             

1  :700 

1  -200 

Typhoid  bacillus            .               

1  :  2100 

1  :300 

Cholera  spirillum              .           

1  :  5500 

1  •  1350 

Chromic  Acid. — In  Koch's  experiments  a  one-per-cent  solution 
destroyed  anthrax  spores  in  from  one  to  two  days.  In  the  propor- 
tion of  1  :  5,000  it  prevents  the  development  of  putrefactive  bacteria 
(Miquel). 

Osmic  Acid. — A  solution  of  one  per  cent  kills  anthrax  spores -in 
twenty-four  hours  (Koch).  It  is  an  antiseptic  in  the  proportion  of 
1  :6,6G6  (Miquel). 

Phosphoric  Acid. — Exposure  for  four  or  five  hours  to  a  solution 


174  ACTION   OF   ACIDS  AND   ALKALIES. 

containing  0.3  per  cent  destroys  the  typhoid  bacillus,  and  0.183  per 
€ent  the  cholera  spirillum  (Kitasato).  The  acid  used  contained  0.152 
gramme  H3P04  in  one  cubic  centimetre. 

Acetic  Acid. — A  five-per-cent  solution  failed  to  kill  anthrax 
spores  after  five  days'  exposure  (Koch).  In  Abbott's  experiments 
glacial  acetic  acid  in  fifty-per-cent  solution  failed  in  two  hours  to  kill 
anthrax  spores,  but  micrococci  were  killed  by  two  hours'  exposure  to 
a  one-per-cent  solution.  A  solution  of  1  : 300  of  glacial  acetic  acid 
destroys  the  cholera  spirillum  in  half  an  hour  (Van  Ermengem).  In 
the  proportion  of  0.25  per  cent  it  restrains  the  growth  of  the  typhoid 
bacillus,  and  0.3  per  cent  destroys  its  vitality  after  five  hours'  expo- 
sure ;  the  cholera  spirillum  fails  to  grow  in  presence  of  0.132  per  cent 
and  is  destroyed  by  0.2  per  cent  (Kitasato). 

Lactic  Acid. — The  bacillus  of  typhoid  fever  is  killed  in  five  hours 
"by  a  solution  containing  0. 4  per  cent,  the  cholera  spirillum  by  0. 3  per 
cent  (Kitasato). 

Citric  Acid. — The  bacillus  of  typhoid  fever  is  killed  in  five  hours 
"by  0.43  per  cent,  the  cholera  spirillum  by  0.3  percent  (Kitasato). 
The  cholera  spirillum  is  killed  in  half  an  hour  by  1  : 200  (Van  Er- 
mengem). 

Oxalic  Acid. — The  typhoid  bacillus  requires  a  solution  of  0.30 
per  cent,  the  cholera  spirillum  one  of  0. 28  per  cent,  to  destroy  vitality 
in  five  hours  (Kitasato). 

Boracic  Acid. — In  the  writer's  experiments  (1883)  a  saturated 
solution  failed  to  kill  pus  cocci  in  two  hours.  A  five-per-cent  solu- 
tion failed  to  destroy  anthrax  spores  in  five  days  (Koch).  The 
typhoid  bacillus  is  killed  in  five  hours  by  2. 7  per  cent,  the  cholera 
spirillum  by  1.5  per  cent  (Kitasato).  According  to  Arloing,  Corne- 
vin,  and  Thomas,  the  fresh  virus  of  symptomatic  anthrax  requires 
exposure  to  a  twenty-per-cent  solution  for  forty -eight  hours  for  the 
destruction  of  vitality.  Boracic  acid  acts  as  an  antiseptic  in  the  pro- 
'  portion  of  1  : 143  (Miquel). 

Salicylic  Acid. — In  the  writer's  experiments  this  agent  was  dis- 
solved by  the  addition  of  sodium  biborate,  which  by  itself  has  no 
germicidal  power.  A  two-per-cent  solution  was  found  to  destroy  pus 
cocci  in  two  hours.  Dissolved  in  oil  or  in  alcohol  a  five-per-cent  so- 
lution does  not  destroy  anthrax  spores  (Koch).  Micrococci  are  de- 
stroyed by  solutions  containing  1  : 400  (Abbott).  The  typhoid  bacillus 
is  killed  in  five  hours  by  1.6  per  cent,  the  cholera  spirillum  by  1.3  per 
cent  (Kitasato).  A  one-per-cent  solution  destroys  Micrococcus  Pas- 
teuri  in  half  an  hour  (Sternberg).  It  is  an  antiseptic  in  the  propor- 
tion of  1  : 1,000  (Miquel).  A  solution  of  2.5  percent  kills  the  tubercle 
bacillus  in  six  hours  ( Yersin).  In  the  proportion  of  1  : 300  it  destroys 
the  cholera  spirillum  in  half  an  hour  (Van  Ermengem). 


ACTION  OF  ACIDS   AND   ALKALIES.  175 

Benzoic  Acid. — According  to  Miquel,  this  acid  restrains  the  de- 
velopment of  putrefactive  bacteria  when  present  in  bouillon  in  the 
proportion  of  1:909.  In  the  proportion  of  1  :  2, 000  it  retards  the  de- 
velopment of  anthrax  spores  (Koch). 

Formic  Acid. — The  typhoid  bacillus  is  restrained  in  its  growth  by 
0.25  per  cent,  and  is  killed  in  five  hours  by  0.35  per  cent,  the  cholera 
spirillum  by  0.22  per  cent  (Kitasato). 

Tannic  Acid. — A  solution  of  one  per  cent  kills  Micrococcus  Pas- 
teuri  in  the  blood  of  a  rabbit  in  half  an  hour  (Sternberg).  A  five- 
per-cent  solution  failed  in  ten  days  to  destroy  anthrax  spores  (Koch). 
A  twenty-per-cent  solution  failed  in  two  hours  to  destroy  the  vitality 
of  spores  of  the  anthrax  bacillus  or  of  Bacillus  subtilis  (Abbott). 
Micrococci  are  destroyed  by  1  : 400,  and  1  : 800  failed  (Abbott).  A 
tweiity-per-cent  solution  has  no  effect  upon  the  virus  of  symptomatic 
anthrax  (Arloing,  Cornevin,  and  Thomas).  A  solution  of  1.66  per 
cent  kills  the  typhoid  bacillus  in  five  hours,  and  1.5  per  cent  the 
cholera  bacillus  in  the  same  time  (Kitasato).  It  restrains  the  devel- 
opment of  putrefactive  bacteria  in  the  proportion  of  1  :  207  (Miquel). 

Tartaric  Acid. — A  twenty-per-cent  solution  of  this  acid  fails, 
after  two  hours'  exposure,  to  destroy  the  spores  of  Bacillus  anthracis 
or  Bacillus  subtilis.  Micrococci  are  killed  by  two  hours'  exposure  in 
a  solution  containing  1  :  400  (Abbott). 

Malic  Acid. — This  was  found  by  Kitasato  to  correspond  with 
citric  acid  in  its  germicidal  power. 

Valerianic  Acid. — A  five-per-cent  solution  in  ether  failed  in  five 
days  to  destroy  anthrax  spores  (Koch). 

Oleic  Acid. — A  solution  of  five  percent  in  ether  does  not  destroy 
anthrax  spores  in  five  days  (Koch). 

Thyinic  Acid. — In  the  proportion  of  1  :  500  this  acid  prevents  the 
putrefactive  decomposition  of  beef  tea  (Miquel). 

Butyric  Acid. — Five  days'  immersion  in  this  acid  failed  to  de- 
stroy anthrax  spores  (Koch). 

Arsenious  Acid. — A  one-per-cent  solution  destroys  the  vitality 
of  anthrax  spores  in  ten  days,  but  failed  to  do  so  in  six  days  (Koch). 
In  the  proportion  of  1  : 166  it  prevents  putrefactive  changes  in  bouillon 
(Miquel). 

Gallic  Acid. — Abbott  found  this  acid  to  destroy  the  bacteria  in 
broken-down  beef  tea  in  the  proportion  of  2.37  per  cent,  but  it  failed 
to  destroy  anthrax  spores  in  two  hours  in  the  same  proportion.  Mi- 
crococci were  killed  in  two  hours  by  1  : 142,  while  1  :  250  failed. 

ALKALIES. 

Potassium  Hydroxide,  KHO. — In  the  writer's  experiments  aten- 
per-cent  solution  of  caustic  potash  was  fatal  to  pus  cocci,  and  an 


176  ACTION   OF   ACIDS   AND   ALKALIES. 

eight-per-cent  solution  failed — two  hours'  exposure.  Exposure  for 
twenty-four  hours  to  a  ten-per-cent  solution  failed  to  kill  the  tubercle 
bacillus  (Schill  and  Fischer).  A  solution  of  one  per  cent  kills  the 
anthrax  bacillus,  the  bacillus  of  rothlauf,  and  several  others  (Jager). 
The  addition  of  0. 14  per  cent  restrains  the  development  of  the  typhoid 
bacillus,  and  0.18  per  cent  kills  this  bacillus  in  four  or  five  hours;  the 
cholera  spirillum  failed  to  grow  in  cultures  containing  0.18  per  cent 
and  was  killed  by  0.237  per  cent  in  the  same  time  (Kitasato). 

Sodium  Hydroxide,  NaHO. — The  experiments  of  Jager  and  of 
Kitasato  show  that  soda  has  about  the  same  germicidal  power  as 
caustic  potash.  Boer  obtained  the  following  results  with  bouillon 
cultures  after  two  hours' exposure:  Anthrax  bacillus,  1:450;  diph- 
theria bacillus,  1  : 300  ;  glanders  bacillus,  1  :  150  ;  typhoid  bacillus, 
1  : 190  ;  cholera  spirillum,  1  : 150.  In  about  one-half  the  amount 
required  to  destroy  vitality  the  development  of  the  above-named  bac- 
teria was  prevented.  In  the  proportion  of  1  :  56  it  acts  as  an  anti- 
septic (Miquel). 

Ammonia,  ]STH3. — In  Kitasato's  experiments  the  typhoid  bacillus 
was  destroyed  in  five  hours  by  0.3  per  cent  of  NH3,  and  the  cholera 
spirillum  by  about  the  same  amount.  Boer  obtained  the  following 
results,  the  time  of  exposure  being  two  hours  :  Anthrax  bacillus, 
1 : 300  ;  diphtheria  bacillus,  1  :  250  ;  glanders  bacillus,  1  : 250  ;  typhoid 
bacillus,  1  : 200 ;  cholera  spirillum,  1  :  350.  The  growth  of  the  an- 
thrax bacillus  and  of  the  diphtheria  bacillus  in  culture  solutions  was 
prevented  by  1  :  650. 

Calcium  Hydroxide,  Ca2HO. — According  to  Kitasato,  the  ty- 
phoid bacillus  and  the  cholera  spirillum,  in  bouillon  cultures,  are 
killed  in  four  or  five  hours  by  the  addition  of  0. 1  per  cent  of  calcium 
oxide.  Liborius  had  previously  reported  still  more  favorable  results, 
but  his  bouillon  cultures  were  largely  diluted  with  distilled  water. 
From  a  practical  point  of  view  the  experiments  of  Pfuhl  are  more 
valuable.  Calcium  hydrate  was  added  to  the  dejections  of  typhoid 
patients.  When  added  in  the  proportion  of  three  per  cent  steriliza- 
tion was  effected  in  six  hours,  and  by  six  per  cent  in  two  hours. 
When  milk  of  lime  containing  twenty  per  cent  of  calcium  hydrate 
was  used  the  results  were  still  more  favorable,  the  typhoid  bacillus 
and  cholera  spirillum  being  killed  in  one  hour  by  the  addition  of 
two  per  cent  of  the  disinfectant.  The  practical  value  of  lime-wash 
applied  to  walls  has  been  determined  by  Jager.  Silk  threads  soaked 
in  cultures  of  various  pathogenic  bacteria  were  attached  to  boards 
and  the  lime-wash  applied  with  a  camel's-hair  brush.  Anthrax  ba- 
cilli (without  spores),  the  glanders  bacillus,  Staphylococcus  pyogene? 
aureus,  and  several  other  pathogenic  bacteria  were  killed  by  a  single 
application  after  twenty-four  hours,  but  the  tubercle  bacillus  was  not 


ACTION   OF   ACIDS   AND    ALKALIES.  177 

killed  by  three  successive  applications.  In  the  writer's  experiments 
(1885)  the  typhoid  bacillus  and  Staphylococcus  pyogenes  aureus  were 
killed  in  two  hours  by  a  solution  containing  1 : 40  of  calcium  oxide, 
and  1 : 80  failed.  Spores  of  the  anthrax  bacillus  and  of  several  other 
spore-forming  species  were  not  killed  by  two  hours'  exposure  to  a 
milk  of  lime  containing  twenty  per  cent  of  calcium  oxide. 

12 


X. 
ACTION   OF   SALTS. 

WHILE  some  of  the  metallic  salts,  and  especially  those  of  mer- 
cury, silver,  and  gold,  have  remarkable  germicidal  power,  others, 
even  in  concentrated  solutions,  do  not  destroy  the  vitality  of  bacteria 
exposed  to  their  action.  For  convenience  of  reference  we  shall  con- 
sider the  agents  in  this  group  in  alphabetical  order,  but  first  we  give 
Miquel's  tables  of  antiseptic  value.  This  author  recognizes  the  im- 
portance of  experiments  to  determine  the  restraining  power  of  chem- 
ical agents  for  various  species  of  pathogenic  bacteria,  but  says  :  ' '  As 
to  me,  faithful  to  a  plan  I  adopted  at  the  outset,  I  will  treat  the  sub- 
ject in  a  more  general  manner  by  making  known  simply  the  mini- 
mum weight  of  the  substances  capable  of  preventing  the  evolution  of 
any  bacteria  or  germs.  The  method  adopted  is  very  simple.  To  a 
liquid  always  comparable  to  itself  it  is  sufficient  at  first  to  add  a 
known  weight  of  the  antiseptic  and  some  atmospheric  germs  or  adult 
bacteria,  and  to  vary  the  quantity  of  the  antiseptic  until  the  amount 
is  ascertained  which  will  preserve  indefinitely  the  liquid  from  putre- 
faction. In  order  to  obtain  germs  of  all  kinds  in  a  dry  state  it  suf- 
fices to  take  them,  where  they  are  most  abundant,  in  the  dust  col- 
lected in  the  interior  of  houses  or  of  hospitals;  and  to  procure  a 
variety  of  adult  bacteria  we  may  take  the  water  of  sewers. " 

SUBSTANCES  EMINENTLY  ANTISEPTIC. 

Efficient  in  the 
proportion  of— 

Mercuric  iodide,          .            .            .            .            .  .        1 : 40000 

Silver  iodide,         ......  1:33000 

Hydrogen  peroxide,  .             .             .             .             .  1 : 20000 

Mercuric  chloride,            .             .             .             .             .  1 : 14300 

Silver  nitrate,                                                              .  .        1 : 12500 

SUBSTANCES   VERY   STRONGLY   ANTISEPTIC. 

Osmic  acid,            .             .             .             .             .            .  1 : 6666 

Chromic  acid,              .             .             .            .            .    .  .        1 : 5000 

Chlorine,                ......  1:4000 

Iodine,  .......        1:4000 

Chloride  of  gold,  .            .....  1:4000 

Bichloride  of  platinum,         .            .            „         •   .  .        1 : 3333 

Hydrocyanic  acid,            .            .            .            .            .  1 : 2500 


ACTION   OP   SALTS.  179 

Bromine,          .  .  .  .  .  .  1 : 1666 

Cupric  chloride,    .  .  •.  .  .  .  1:1428 

Thymol,  .  .  .  .  .  .       1:1340 

Cupric  sulphate,  ......  1:1111 

Salicylic  acid,  .  .  .  .  .  1 : 1000 


SUBSTANCES   STRONGLY   ANTISEPTIC. 

Benzoic  acid,         .            .             .             .            .             .  1 : 909 

Potassium  bichromate,           .             .             .             .  .       1 : 909 

Potassium  cyanide,           .             .             .             .             .  1 : 909 

Aluminum  chloride,  .....       1:714 

Ammonia,              .             .             .             .             .             .  1 : 714 

Zinc  chloride,              .             .             .             .            .  .1:526 

Mineral  acids,        .  .  .  .          1 : 500  to  1 : 333 

Thymicacid,  .             .             .            .             .             .  .1:500 

Lead  chloride,       .            .            .            .            .            .  1 : 500 

Nitrate  of  cobalt,         .            .            .            .            .  .1:476 

Sulphate  of  nickel,            .....  1:400 

Nitrate  of  uranium,    .             .            .             .            .  .       1 : 356 

Carbolic  acid,        .            .             .             .             .             .  1:333 

Potassium  permanganate,     .             .             .             .  .       1 : 285 

Lead  nitrate,          .             .             .             .             .            .  1 : 277 

Alum,.            .            .            .            .            .            .  ;      1:222 

Tannin, 1:207 


SUBSTANCES   MODERATELY   ANTISEPTIC. 

Bromhydrate  of  quinine,       .....  1:182 

Arsenious  acid,     .  .  .  .  .  .  1 : 166 

Boracic  acid,   .  .  .  .  .  .  1 : 143 

Sulphate  of  strychnia,     .  .  .  .  .  1 : 143 

Arsenite  of  soda,         ......  1:111 

Hydrate  of  chloral,  .  .  .  .  .  1:107 

Salicylate  of  soda,      .  .  .  .  .  1 : 100 

Ferrous  sulphate,  .  .  .  .  .  1 : 90 

Caustic  soda,   .  .  .  .  .  .  1 : 56 


SUBSTANCES   FREELY  ANTISEPTIC. 

Perchloride  of  manganese,          .             .             .  .             1 : 40 

Calcium  chloride,       .             .             .             .             .  .       1 : 25 

Sodium  borate,      .             .             .             .             .  .             1 : 14 

Muriate  of  morphia,  .             .             .             .             .  .       1 : 13 

Strontium  chloride,          .             .             .             .  .             1 : 12 

Lithium  chloride,        .             .             .             .             .  .1:11 

Barium  chloride,  .             .             .             .             .  .             1 : 10 

Alcohol 1:10 


SUBSTANCES    VERY   FEEBLY   ANTISEPTIC. 

Ammonium  chloride,  .             .             .             .             .             1:9 

Potassium  arsenite,    .  .            .            .            .            .1:8 

Potassium  iodide,  .            .             .             .             .             1:7 

Sodium  chloride,         .  .             .            .             .             .1:6 

Glycerin  (sp.  gr.  1.25),  . 

Ammonium  sulphate,  .             .            .             .             .1:4 

Sodium  hyposulphite,  .             .             .             .             .             1:3 


180  ACTION   OF   SALTS. 

ANTISEPTIC   AND    GERMICIDAL   VALUE   OF   VARIOUS   SALTS, 
ARRANGED   ALPHABETICALLY. 

Alum. — Antiseptic  in  the  proportion  of  1  :  222  (Miquel). 

Aluminum  Acetate. — According  to  De  la  Croix,  this  salt  is  an 
antiseptic  in  the  proportion  of  i  :  6,310.  Kuhn  found  it  to  be  anti- 
septic in  1  : 5,250. 

Aluminum  Chloride. — Antiseptic  in  the  proportion  of  1  :  714 
(Miquel). 

Ammonium  Carbonate. — When  present  in  the  proportion  of 
1  : 125  it  restrains  the  development  of  typhoid  bacilli,  and  in  five 
hours'  time  it  kills  these  bacilli  in  the  proportion  of  1  : 100 ;  the 
cholera  spirillum  is  killed  in  the  same  time  by  1  :  77  (Kitasato). 

Ammonium  Chloride. — Antiseptic  in  the  proportion  of  1:9 
(Miquel).  A  five-per-cent  solution  does  not  kill  anthrax  spores  in 
twenty-five  days  (Koch). 

Ammonium  Fluosilicate. — The  bacillus  of  anthrax  and  of  ty- 
phoid fever  fail  to  grow  in  nutrient  gelatin  containing  1  : 1,000,  and 
a  two-per-cent  solution  kills  anthrax  spores  in  one-quarter  to  three- 
quarters  of  an  hour  (Faktor). 

Ammonium  Sulphate. — Antiseptic  in  the  proportion  of  1:4 
(Miquel).  A  five-per-cent  solution  failed  in  two  days  to  kill  an- 
thrax spores,  but  was  effective  in  five  days  (Koch). 

Barium  Chloride  is  an  antiseptic  in  the  proportion  of  1  :  10 
(Miquel). 

Calcium  Chloride  is  an  antiseptic  in  the  proportion  of  1  :  25 
(Miquel).  A  saturated  solution  does  not  destroy  anthrax  spores 
(Koch). 

Calcium  Hypochlorite. — This  is  a  powerful  germicidal  agent 
and  has  great  value  as  a  practical  disinfectant.  Good  chloride  of 
lime  contains  from  twenty-five  to  thirty  per  cent  of  available  chlo- 
rine as  hypochlorite.  The  experiments  made  by  the  Committee  on 
Disinfectants  of  the  American  Public  Health  Association  in  1885 
showed  that  a  solution  containing  0. 25  per  cent  of  chlorine  as  hypo- 
chlorite is  an  effective  germicide,  even  when  allowed  to  act  only 
for  one  or  two  minutes.  In  Bolton's  experiments  a  solution  of  chlo- 
ride of  lime  of  1  : 2,000  (available  chlorine  0.015)  destroyed  the  ty- 
phoid bacillus  and  the  cholera  spirillum  in  two  hours.  For  the  de- 
struction of  anthrax  spores  a  one-per-cent  solution  was  required 
(available  chlorine  0.3  per  cent).  Nissen  found  that  the  typhoid 
bacillus  and  the  cholera  spirillum  are  destroyed  with  certainty  in 
five  minutes  by  a  solution  containing  0.12  percent,  anthrax  bacilli 
in  one  minute  by  0. 1  per  cent,  Staphylococcus  pyogenes  aureus  in 
one  minute  by  0. 2  per  cent,  anthrax  spores  in  thirty  minutes  by  a 


ACTION   OF   SALTS.  181 

five-per-cent  solution  and  in  seventy  minutes  by  a  one-per-cent  solu- 
tion. Experiments  made  by  the  same  author  upon  the  sterilization 
of  faeces  showed  that  0. 5  per  cent  to  one  per  cent  could  be  relied  upon 
to  destroy  the  typhoid  bacillus  or  the  cholera  spirillum  in  faeces  in 
ten  minutes. 

Chloral  Hydrate; — Antiseptic  in  the  proportion  of  1  : 107  (Mi- 
quel).  A  twenty-per-cent  solution  destroys  pus  cocci  in  two  hours 
(Sternberg). 

Cupric  Chloride. — Antiseptic  in  the  proportion  of  1  •  1,428 
(Miquel). 

Cupric  Sulphate. — Antiseptic  in  the  proportion  of  1  :  111  (Mi- 
quel). Kills  the  cholera  spirillum  in  the  proportion  of  1  : 3,000  in 
ten  minutes  (Nicati  and  Bietsch).  Destroys  the  cholera  spirillum  in 
bouillon  cultures  in  less  than  half  an  hour  in  1  :  600,  and  in  four 
hours  in  1  : 1,000  ;  cultures  in  blood  serum  require  1  : 200  (Van  Er- 
mengem).  A  solution  of  1  :  20  kills  the  typhoid  bacillus  in  ten  min- 
utes (Leitz).  This  salt  failed,  in  the  writer's  experiments,  to  kill  the 
spores  of  Bacillus  anthracis  and  Bacillus  subtilis  in  two  hours'  time 
in  a  twenty-per-cent  solution.  In  Koch's  experiments  a  five-per-cent 
solution  failed  to  kill  anthrax  spores  in  ten  days.  Kills  pus  micro- 
cocci  in  two  hours  in  the  proportion  of  1  :  200  (Sternberg).  In  Bol- 
ton's  experiments  made  for  the  Committee  on  Disinfectants  of  the 
American  Public  Health  Association  the  following  results  were  ob- 
tained: Recent  cultures  in  bouillon,  time  of  exposure  two  hours  :  Ba- 
cillus of  typhoid  fever,  1  :  200;  cholera  spirillum,  1  :  500;  Bacillus  pyo- 
cyanus,  1  :200;  Brieger's  bacillus,  1  :200;  Emmerich's  bacillus,  1  :  200; 
Staphylococcus  pyogenes  aureus,  1  : 100  ;  Staphylococcus  pyogenes 
citreus,  1  : 100;  Staphylococcus  pyogenes  albus,  1  :  200;  Streptococcus 
pyogenes,  1  : 500.  When  ten  per  cent  of  dried  egg  albumin  was 
added  to  a  recent  culture  in  bouillon  of  the  typhoid  bacillus  the 
amount  required  to  insure  sterilization  was  1  :  10. 

In  the  report  of  the  Committee  on  Disinfectants  of  the  American 
Public  Health  Association  this  agent  is  recommended  in  "  a  solu- 
tion of  two  to  five  per  cent  for  the  destruction  of  infectious  material 
not  containing  spores."  The  experimental  data  above  given  show 
that  this  is  a  liberal  allowance  for  material  which  does  not  contain 
an  excessive  amount  of  albumin.  In  the  experiments  of  Leitz  the 
typhoid  bacillus  in  cultures  was  destroyed  in  ten  minutes  by  a  five- 
per-cent  solution. 

Ferric  Chloride. — A  five-per-cent  solution  failed  in  two  days  to 
destroy  anthrax  spores,  but  was  effective  in  five  days  (Koch). 

Ferrous  Sulphate. — In  the  writer's  experiments  (1883)  a  solution 
of  twenty  per  cent  failed  to  destroy  micrococci  and  putrefactive  bac- 
teria. In  a  more  recent  experiment  ten  per  cent  failed  to  kill  pus 


182  ACTION  OF  SALTS. 

cocci,  but  was  fatal  to  Micrococcus  tetragenus — two  hours'  exposure. 
Koch  found  that  a  five-per-cent  solution  failed  to  destroy  anthrax 
spores  in  six  days.  Exposure  to  a  twenty-per-cent  solution  for  forty- 
eight  hours  does  not  destroy  the  virus  of  symptomatic  anthrax  (Ar- 
loing,  Cornevin,  and  Thomas).  In  the  experiments  of  Jager  immer- 
sion in  a  solution  of  1  :  3  destroyed  the  infective  virulence  of  certain 
pathogenic  bacteria  (fowl  cholera,  rothlauf,  glanders),  as  tested  by 
injection  into  mice,  but  failed  to  kill  anthrax  spores  and  tubercle  ba- 
cilli. The  antiseptic  power  of  ferrous  sulphate  is  placed  by  Miquel 
at  1  :  90.  In  the  writer's  experiments  1  :  200  prevented  the  develop- 
ment of  micrococci  and  of  putrefactive  bacteria  in  bouillon  placed 
in  the  incubating  oven  for  forty-eight  hours.  Leitz  found  that  a 
five-per-cent  solution  required  three  days'  exposure  for  the  destruc- 
tion of  the  typhoid  bacillus. 

Grold  Chloride. — Antiseptic  in  the  proportion  of  1  :  4, 000  (Miquel). 
Boer  has  made  extended  experiments  with  the  chloride  of  gold  and 
sodium.  We  give  his  results  below.  In  his  disinfection  experi- 
ments a  bouillon  culture  which  had  been  in  the  incubating  oven  for 
twenty-four  hours  was  used,  and  the  time  of  exposure  was  two  hours. 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus     ,  ,  

1  :  40000 

1  :  8000 

Diphtheria  bacillus  

1  :  40000 

1  :1000 

Glanders  bacillus     

1  :  15000 

1  :400 

Typhoid  bacillus  

1:20000 

1  :500 

Cholera  spirillum         

1  :  25000 

1  :  1000 

Lead  Chloride. — Antiseptic  in  the  proportion  of  1  :  500  (Miquel). 

Lead  Nitrate. — Antiseptic  in  the  proportion  of  1  :  277  (Miquel). 

Lithium  Chloride. — Antiseptic  in  the  proportion  of  1  : 11  (Mi- 
quel). 

Manganese  Protochloride. — Antiseptic  in  the  proportion  of  1:40 
(Miquel). 

Mercuric  Chloride. — Koch's  experiments  (1881)  gave  the  follow- 
ing results  :  A  solution  of  1  : 1,000  destroys  anthrax  spores  in  a  few 
minutes,  and  1  : 10,000  is  effective  after  a  more  prolonged  exposure. 
The  writer  (1884)  obtained  similar  results — 1  : 10,000  destroyed  the 
spores  of  Bacillus  anthracis  and  of  Bacillus  subtilis  in  two  hours. 
More  recent  experiments  indicate  that  failure  to  grow  in  culture  so- 
lutions cannot  be  accepted  as  evidence  of  the  destruction  of  vitality 
in  the  case  of  spores  'exposed  to  the  action  of  this  agent,  unless  due 
precautions  are  taken  to  exclude  the  restraining  influence  of  the  small 
amount  of  mercuric  chloride  which  remains  attached  to  the  spores. 
Koch  had  ascertained  that  the  development  of  spores  is  restrained  by 


ACTION   OP   SALTS.  183 

the  presence  of  1  : 300,000  in  a  culture  medium,  and  Geppert  has  re- 
cently shown  that  even  so  small  an  amount  as  1  :  2,000,000  will  pre- 
vent the  development  of  spores  the  vitality  of  which  has  been  reduced 
by  the  action  of  a  strong  solution  (1  : 1,000).  When  this  restraining 
action  is  entirely  neutralized  by  washing  the  spores  in  a  solution  con- 
taining ammonium  sulphide  it  requires,  according  to  Geppert,  a  solu- 
tion of  1:1,000  acting  for  one  hour  to  completely  destroy  the  vitality 
of  anthrax  spores.  Frankel  found  that  a  solution  of  1  : 1,000  was 
effective  in  half  an  hour.  The  typhoid  bacillus,  the  bacillus  of  mouse 
septicaemia,  and  the  cholera  spirillum,  in  bouillon  cultures  and  in 
cultures  in  flesh-peptone-gelatin,  are  destroyed  in  two  hours  by 
1  : 10,000  ;  but  in  a  bouillon  culture  to  which  ten  per  cent  of  dried 
egg  albumin  was  added  a  oiie-per-cent  solution  was  required  to  de- 
stroy the  typhoid  bacillus  in  the  same  time  (Bolton).  According  to 
Van  Ermengem,  cultures  of  the  cholera  spirillum  in  bouillon  are  steril- 
ized in  half  an  hour  by  1  :  GO,  000,  but  cultures  in  blood  serum  require 
1  :  800  to  1  : 1,000.  In  experiments  upon  tuberculous  sputum  Schill 
and  Fischer  found  that  exposure  of  fresh  sputum  to  an  equal  amount 
of  a  1  :  2,000  solution  for  twenty-four  hours  failed  to  disinfect  it,  as 
shown  by  inoculation  experiments  in  guinea-pigs.  The  antiseptic 
power  of  mercuric  chloride  is  given  by  Miquel  as  1  : 14,300.  In  the 
writer's"  experiments  1  : 33,000  was  found  to  prevent  the  development 
of  putrefactive  bacteria  in  bouillon,  but  a  minute  bacillus  contained  in 
broken-down  beef  infusion  multiplied,  after  several  days,  in  1  : 20,000. 
The  pus  cocci  were  restrained  in  their  development  by  1  : 30,000. 

In  Behring's  experiments  the  anthrax  bacillus  and  cholera  spiril- 
lum were  killed  in  one  hour  by  1  : 100,000  when  the  temperature 
was  36°  C.,  but  at  a  temperature  of  3°  C.  the  proportion  required 
was  1  : 25,000.  The  same  author  states  that  at  22°  C.  Staphylo- 
coccus  aureus  in  bouillon  is  not  always  killed  in  twenty-five  minutes 
by  1  : 1,000. 

In  a  recent  series  (1891)  of  experiments  Abbott  has  shown  that  a 
1  : 1,000  solution  does  not  always  destroy  Staphylococcus  pyogenes 
aureus  in  five  minutes.  He  says:  "Frequently  all  the  organisms 
would  be  destroyed  after  five  minutes'  exposure,  but  almost  as  often 
a  certain  few  would  resist  for  that  length  of  time,  and  even  longer, 
going  in  some  cases  to  ten,  twenty,  and  even  thirty  minutes." 

According  to  Yersin,  a  solution  of  1  : 1,000  kills  the  tubercle  bacil- 
lus in  one  minute. 

We  might  add  considerably  to  the  experimental  data  given,  but 
the  results  already  recorded  are  sufficient  to  show  the  value  of  this 
agent  as  an  antiseptic  and  germicide,  and  justify  its  use  for  general 
purposes  of  disinfection  in  the  proportion  of  1  : 500  or  1  :  1,000  for 
material  containing  spores,  and  in  the  proportion  of  1  : 2,000  to 


184  ACTION   OF   SALTS. 

1  :  5,000  for  pathogenic  bacteria  in  the  absence  of  spores;  due  regard 
being  had  to  the  fact  that  the  presence  of  albumin  very  materially 
reduces  its  germicidal  potency,  and  that  it  may  be  decomposed  and 
neutralized  by  alkalies  and  their  carbonates,  by  hydrosulphuric  acid, 
and  by  many  other  substances. 

The  albuminate  of  mercury,  as  has  been  shown  by  Lister,  is  solu- 
ble in  an  excess  of  albumin,  and,  according  to  Behring,  is  just  as 
effective  as  an  aqueous  solution  containing  the  same  amount  of  sub- 
limate when  dissolved  in  an  albuminous  liquid  like  blood  serum  (?). 

In  practice  the  addition  of  a  mineral  acid  to  sublimate  solutions, 
or  of  sodium,  potassium,  or  ammonium  chloride,  is  to  be  recom- 
mended, to  prevent  the  precipitation  of  the  mercuric  chloride  by  al- 
bumin in  fluids  containing  it.  Behring  recommends  the  addition 
of  five  parts  of  sodium  or  potassium  chloride  to  one  of  the  subli- 
mate. Such  a  solution  is  more  stable  than  a  simple  solution  of  sub- 
limate, and  no  precipitate  is  formed  by  the  addition  of  alkalies  or  by 
albumin. 

The  same  result  is  obtained,  according  to  La  Place,  by  the  addi- 
tion of  five  parts  of  hydrochloric  or  tartaric  acid  to  one  part  of  sub- 
limate in  aqueous  solution, 

Mercuric  Cyanide,  Hg(CN)2,  and  the  Oxycyanide  of  mercury 
have  been  tested,  with  the  following  results  :  Staphylococcus  aureus 
is  destroyed  in  five  minutes  by  1  : 100,  in  one  hour  by  1  : 1,000,  in 
two  hours  by  1  : 1,500  (Chibret).  The  development  of  Bacillus  an- 
thracis  in  culture  solutions  is  prevented  by  the  presence  of  cyanide 
of  mercury  in  the  proportion  of  1  :  25,000,  and  by  the  oxycyanide  by 
1  : 16,000  (Behring). 

Boer  obtained  the  following  results  with  the  oxycyanide — cul- 
tures in  bouillon,  twenty-four  hours  in  incubating  oven,  time  of 
exposure  two  hours  : 


Restrained 
development. 

Destroyed 
vitality. 

Anthrax  bacillus  

1  :  80000 

1  :  40000 

Diphtheria  bacillus  

1  :  80000 

1  •  40000 

Glanders  bacillus.  .  .   

1  :  60000 

1  :  30000 

Typhoid  bacillus  .  .   .  .     ,  

1  :  60000 

1  :  30000 

Cholera  spirillum  ....             

1  :  90000 

1  •  60000 

Mercuric  Iodide. — The  antiseptic  value  of  this  salt  is  placed  by 
Miquel  at  1  : 40,000,  which  is  more  than  double  that  given  by  the 
same  author  to  the  bichloride.  In  the  writer's  experiments  upon  the 
antiseptic  value  of  salts  and  oxides  of  mercury  the  following  results 
were  obtained  : 


ACTION   OF   SALTS.  185 


Active. 

Failed. 

Biniodide  of  mercury  

1  .  20000 

1  •  40000 

Bichloride    

1  :  15000 

1  :  20000 

Protiodide  

1  ;  10000 

1  :  20000 

Yellow  oxide  

1  :  1000 

1  :  2000 

Black  oxide  

1  :500 

1    1000 

Morphia  Hydroclilorate. — Antiseptic  in  the  proportion  of  1  : 13 
(Miquel). 

Nickel  Sulphate. — Antiseptic  in  the  proportion  of  1  : 400  (Mi- 
quel). 

Platinum  Bichloride. — Antiseptic  in  the  proportion  of  1  :  3,333 
(Miquel). 

Potassium  Acetate. — A  saturated  solution  of  this  salt  failed  to 
kill  anthrax  spores  in  ten  days  (Koch). 

Potassium  Arsenite. — In  the  writer's  experiments  Fowler's  solu- 
tion failed  to  kill  ruicrococci  in  two  hours  in  the  proportion  of  four 
per  cent.  Miquel  places  the  antiseptic  value  of  potassium  arsenite 
at  1  :  8. 

Potassium  Bichromate. — A  five-per-cent  solution  failed  in  two 
days  to  destroy  anthrax  spores  (Koch).  Efficient  as  an  antiseptic  in 
the  proportion  of  1  :  909  (Miquel). 

Potassium  Bromide. — The  bacillus  of  typhoid  fever  and  the 
cholera  spirillum  fail  to  grow  in  culture  solutions  containing  9  to 
10.0  per  cent,  and  are  killed  in  four  or  five  hours  by  ten  to  twelve 
per  cent  (Kitasato). 

Potassium  Carbonate. — The  development  of  the  typhoid  bacil- 
lus and  of  the  cholera  spirillum  is  prevented  by  0.74  to  0.81  per 
cent,  and  these  bacteria  are  killed  in  five  hours  by  1  per  cent  (Kita- 
sato). 

Potassium  Chlorate. — In  the  writer's  experiments  a  four-per- 
cent solution  failed  in  two  hours  to  kill  Micrococcus  Pasteuri.  A 
five-per-cent  solution  failed  in  six  days  to  destroy  anthrax  spores 
(Koch). 

Potassium  Chr ornate. — A  five-per-cent  solution  failed  to  kill 
anthrax  spores  in  five  days  (Koch). 

Potassium  Cyanide. — Antiseptic  in  the  proportion  of  1  :  909 
(Miquel). 

Potassium  Iodide. — A  solution  of  five  per  cent  does  not  destroy 
anthrax  spores  in  eighty  days  (Koch).  Putrefactive  bacteria  in 
broken-down  beef  infusion  are  not  destroyed  by  two  hours'  exposure 
in  a  twenty-per-cent  solution  (Sternberg).  The  typhoid  bacillus  and 
the  cholera  spirillum  do  not  grow  in  culture  solutions  containing 


186  ACTION    OF   SALTS. 

eight  per  cent,  and  are  destroyed  by  five  hours'  exposure  to  9.23  per 
cent  (Kitasato).  Antiseptic  in  the  proportion  of  1  :  7  (Miquel). 

Potassium  Permanganate. — In  the  writer's  experiments  (1881) 
a  two-per-cent  solution  was  required  to  destroy  Micrococcus  Pasteuri 
in  the  blood  of  a  rabbit.  In  later  experiments  pus  cocci  in  bouillon 
were  killed  by  1  :  833 — time  of  exposure  two  hours.  One  per  cent 
was  found  by  Koch  not  to  destroy  anthrax  spores  in  two  days,  but 
five  per  cent  was  effective  in  one  day.  The  glanders  bacillus  is  de- 
stroyed in  two  minutes  by  a  one-per-cent  solution  ( Loftier).  The 
experiments  of  Jager  show  that  a  one-per-cent  solution  is  not  reli- 
able for  the  destruction  of  anthrax  bacilli  and  other  pathogenic  bac- 
teria tested,  but  a  five-per-cent  solution  was  effective.  The  tubercle 
bacillus  was  not,  however,  killed  by  exposure  in  a  five-per-cent  solu- 
tion. According  to  Miquel,  permanganate  of  potash  is  an  antiseptic 
in  the  proportion  of  1  :  285. 

Quinine  Hydrobromate. — Antiseptic  in  the  proportion  of  1  : 182 
(Miquel). 

Quinine  Hydrochlorate. — Antiseptic  in  the  proportion  of  1  : 900 
(Ceri).  Quinine  dissolved  with  hydrochloric  acid  destroys  anthrax 
spores  in  ten  days  in  one-per-cent  solution  (Koch). 

Quinine  Sulphate. — The  writer  found  that  in  the  proportion  of 
1  : 800  quinine  prevents  the  development  of  various  micrococci  and 
bacilli.  A  ten-per-cent  solution  does  not  destroy  the  bacilli  of  symp- 
tomatic anthrax  (Arloing,  Cornevin,  and  Thomas). 

Silver  Nitrate. — Miquel  places  nitrate  of  silver  next  to  mercuric 
chloride  as  an  antiseptic,  effective  in  the  proportion  of  1  : 12, 500. 
Behring  also  places  it  next  to  bichloride  as  an  antiseptic  and  germi- 
cide, and  says  that  it  is  even  superior  to  this  salt  in  albuminous 
fluids.  He  reports  that  it  prevents  the  development  of  anthrax 
spores  when  present  in  a  culture  liquid  in  the  proportion  of  1 : 80,000, 
and  in  the  proportion  of  1  : 10,000  destroys  these  spores  in  forty- 
eight  hours.  We  give  below  the  result  of  recent  experiments  by 
Boer,  in  which  the  time  of  exposure  was  two  hours  : 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus       

1    60000 

1  •  20000 

Diphtheria  bacillus  

1  •  60000 

1  •  2500 

Glanders  bacillus     ....            .  .       

1  :  75000 

1  :  4000 

Typhoid  bacillus  

1  :  50000 

1  :  4000 

Cholera  spirillum.  

1  :  50000 

1  :  4000 

Silver  Chloride. — A  solution  of  chloride  of  silver  in  hyposulphite 
of  soda  is  much  less  effective  as  an  antiseptic  than  nitrate  of  silver. 


ACTION   OF   SALTS.  187 

Behring  found  that  to  prevent  the  development  of  anthrax  spores  a 
solution  of  1  :  8,000  was  required. 

Sodium  Borate. — In  the  writer's  experiments  a  saturated  solu- 
tion of  borax  was  found  to  be  without  germicidal  power.  A  twenty- 
per-cent  solution  does  not  destroy  the  virus  of  symptomatic  anthrax 
(Arloing,  Cornevin,  and  Thomas).  A  five-per-cent  solution  failed 
to  destroy  anthrax  spores  in  fifteen  days  (Koch).  Antiseptic  in  the 
proportion  of  1  : 14  (Miquel). 

Sodium  Carbonate. — A  solution  of  2.2  per  cent  restrains  the 
growth  of  the  typhoid  bacillus,  and  of  2.47  per  cent  of  the  cholera 
spirillum.  The  first-named  bacillus  is  killed  by  four  or  five  hours' 
exposure  in  a  2.47-per-cent  solution,  and  the  cholera  spirillum  by 
3.45  per  cent  (Kitasato). 

Sodium  Chloride. — A  saturated  solution  failed  in  forty-eight 
hours  to  destroy  the  virus  of  symptomatic  anthrax  (Arloing,  Corne- 
vin, and  Thomas).  A  saturated  solution  failed  in  forty  days  to  de- 
stroy anthrax  spores  (Koch).  A  saturated  solution  failed  in  twenty 
hours  to  destroy  the  tubercle  bacillus  in  fresh  sputum  (Schill  and 
Fischer).  In  the  writer's  experiments  a  five-per-cent  solution  failed 
to  kill  Micrococcus  Pasteuri  in  blood.  Antiseptic  in  the  proportion 
of  1  : 6  (Miquel).  According  to  Forster,  the  bacillus  of  typhoid 
fever,  the  bacillus  of  rouget,  and  the  streptococcus  of  pus  are  not 
killed  by  several  weeks'  exposure  in  strong  solutions  of  sodium  chlo- 
ride, but  the  cholera  spirillum  is  destroyed  in  a  few  hours.  Cultures 
of  the  tubercle  bacillus  are  not  sterilized  in  two  months  by  a  satu- 
rated solution ;  and  tuberculous  organs  from  an  ox,  preserved  in  a 
solution  of  salt,  did  not  lose  their  power  of  infecting  susceptible  ani- 
mals inoculated  with  material  from  the  diseased  tissue.  The  flesh 
of  swine  which  died  of  rothlauf  was  found  by  Petri  to  still  contain 
the  bacillus  in  a  living  condition  after  having  been  preserved  in 
brine  for  a  month. 

Sodium  Hyposulphite. — In  the  writer's  experiments  a  saturated 
solution  failed  in  two  hours  to  kill  micrococci  and  bacilli.  Exposure 
for  forty-eight  hours  to  a  fifty-per-csnt  solution  does  not  destroy  the 
virus  of  symptomatic  anthrax  (Arloing,  Cornevin,  and  Thomas). 
Antiseptic  in  the  proportion  of  1  :  3  (Miquel). 

Sodium  Sulphite. — The  results  with  a  saturated  solution  of  this 
salt  were,  in  the  writer's  experiments,  entirely  negative. 

Tin  Chloride. — A  one-per-cent  solution  acting  for  two  hours  de- 
stroyed the  bacteria  in  putrefying  bouillon,  while  0. 8  per  cent  failed 
(Abbott). 

Zinc  Chloride. — In  the  writer's  experiments  1:200  destroyed 
Micrococcus  Pasteuri  in  two  hours,  but  a  two-per-cent  solution  was  re- 
quired to  kill  pus  cocci  in  the  same  time  ;  spores  of  Bacillus  anthracis 


188  ACTION   OF   SALTS. 

were  not  destroyed  by  two  hours'  exposure  in  a  ten-per-cent  solution, 
but  a  solution  of  five  per  cent  killed  the  spores  of  Bacillus  subtilis  in 
the  same  time.  Koch  found  that  anthrax  spores  germinated  after 
being  immersed  in  a  five-per-cent  solution  for  thirty  days.  The  de- 
velopment of  Bacillus  prodigiosus  is  only  slightly  retarded  by  expo- 
sure for  sixteen  hours  in  a  one-per-cent  solution.  Antiseptic  in  the 
proportion  of  1  :  526  (Miquel). 

Zinc  Sulphate. — In  the  writer's  first  experiments  a  twenty-per- 
cent solution  failed  to  destroy  in  two  hours  micrococci  obtained  from 
the  pus  of  an  acute  abscess.  In  later  experiments  a  micrococcus  from 
the  same  source  resisted  two  hours'  exposure  to  a  ten-per-cent  solu- 
tion, but  Micrococcus  tetragenus  was  destroyed  by  this  amount. 
Broken-down  beef  infusion  mixed  with  an  equal  quantity  of  a  forty  - 
per-cent  solution  was  not  sterilized  after  two  hours'  contact.  In 
Koch's  experiments  anthrax  spores  were  found  to  germinate  after 
having  been  immersed  for  ten  days  in  a  five-per-cent  solution. 


XI. 

ACTION  OF  COAL-TAR  PRODUCTS,   ESSENTIAL 
OILS,   ETC. 

IN  the  present  section  we  shall  consider  the  action  upon  bacteria 
of  a  variety  of  organic  products,  and  for  convenience  will  arrange 
them  alphabetically. 

Acetone. — Anthrax  spores  grow  freely  after  two  days'  exposure 
to  the  action  of  this  agent;  at  the  end  of  five  days  their  development 
is  feeble  (Koch). 

Alcohol. — In  the  writer's  experiments  ninety-five-per-cent  alco- 
hol did  not  destroy  the  bacteria  (spores)  in  broken-down  beef  tea  in 
forty-eight  hours.  Micrococcus  Pasteuri  was  destroyed  by  two  hours' 
exposure  in  a  twenty -four-per-cent  solution  ;  pus  cocci  required  a 
forty-per-cent  solution.  Koch  found  that  absolute  alcohol  had  no 
effect  upon  anthrax  spores  exposed  to  its  action  for  one  hundred  and 
ten  days.  Schill  and  Fischer  found  that  when  tuberculous  sputum 
was  mixed  with  an  equal  amount  of  absolute  alcohol  its  infecting 
power  was  not  destroyed  in  twenty-four  hours,  but  that  in  the  pro- 
portion of  five  parts  to  one  of  sputum  it  was  effective  in  destroying 
the  tubercle  bacillus,  as  proved  by  inoculation  experiments.  Yersin 
found  that  in  pure  cultures  the  tubercle  bacillus  is  killed  by  five 
minutes'  exposure  to  the  action  of  absolute  alcohol. 

Aniline  Dyes. — Recent  researches  have  shown  that  some  of  the 
aniline  colors  possess  very  decided  germicidal  power.  Stilling  found 
that  solutions  of  methyl  violet  containing  1  : 30,000  exercise  a  re- 
straining influence  upon  the  development  of  putrefactive  bacteria 
and  pus  cocci,  and  that  these  microorganisms  are  destroyed  by  solu- 
tions containing  1  :  2,000  to  1  : 1,000.  Methyl  violet  has  been  placed 
in  the  market  by  Merck  under  the  name  of  pyoktanin.  Janicke  re- 
ports the  following  results  with  pyoktanin  :  Staphylococcus  pyogenes 
aureus  was  restrained  in  its  development  by  solutions  containing 
1  :  2,000,000,  Bacillus  anthracis  by  1  : 1,000,000,  Staphylococcus  pyo- 
genes by  1  :  333,300,  Spirillum  cholerae  Asiaticse  by  1  :  62,500,  Bacil- 
lus typhi  abdominalis  by  1  : 5,000.  In  blood  serum  stronger  solutions 
were  required  (1  : 500,000  for  Staphylococcus  pyogenes  aureus).  Sta- 
phylococcus pyogenes  aureus,  Streptococcus  pyogenes,  and  Bacillus 


190 


ACTION   OF   COAL-TAR   PRODUCTS, 


anthracis  were  killed  in  thirty  seconds  by  1  : 1,000,  the  typhoid  bacil- 
lus by  the  same  amount  in  thirty  minutes.  Boer  found  malachite 
green  to  be  still  more  effective  than  methyl  violet.  In  his  experi- 
ments upon  bouillon  cultures  twenty-four  hours  old,  with  two  hours' 
exposure  to  the  action  of  the  disinfectant,  he  obtained  the  following 
results : 

MALACHITE    GREEN. 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus     

1  :  120000 

1  •  40000 

Diphtheria  bacillus            

I  •  40000 

1  '8000 

Glanders  bacillus  

1  :  5000 

1  :300 

Typhoid  bacillus     

1  :  5000 

1  :300 

Cholera  spirillum       .  .       

1  •  1  00000 

1  •  5000 

METHYL   VIOLET    (PYOKTANIN). 

Anthrax  bacillus  

Restrains 
development. 

Destroys 
vitality. 

1  :  70000 
1  :  10000 
1  :  2500 
1:2500 
1  :  30000 

1  :  5000 
1  :  2000 
1  :150 
1  :150 
1  :  1000 

Diphtheria  bacillus  

Typhoid  bacillus  

Cholera  spirillum  

line  water  prevents  the  development  of  all  bacteria  in  nutrient  gelatin. 

Aromatic  Products  of  Decomposition. — Klein  has  tested  the 
germicidal  power  of  phenylpropionic  and  phenylacetic  acids.  He 
finds  that  anthrax  spores  resist  both  of  these  acids,  in  the  proportion 
of  1  : 400,  for  two  days,  but  in  the  absence  of  spores  anthrax  bacilli 
are  quickly  killed  by  a  solution  of  this  strength.  Certain  non-patho- 
genic micrococci  were  not  killed  by  exposure  for  twenty-five  minutes 
to  1  : 200.  The  caseous  matter  of  pulmonary  tuberculosis  infected 
guinea-pigs  after  exposure  for  ninety-six  hours  to  1  :  200. 

Aseptol. — A  ten-per-cent  aqueous  solution  kills  anthrax  spores  in 
ten  minutes,  and  a  three-  to  five-per-cent  solution  is  a  reliable  disin- 
fectant in  the  absence  of  spores  (Hueppe). 

Benzene,  C6H6. — Exposure  in  benzol  for  twenty  days  failed  to 
destroy  the  vitality  of  anthrax  spores  (Koch). 

Camphor. — Alcohol  saturated  with  camphor  has  no  effect  upon 
the  virus  of  symptomatic  anthrax  (Arloing,  Cornevin,  and  Thomas) 

The  experiments  of  Cadeac  and  Meunier  show  that  camphor  (oil 
of,  or  tincture  ?)  has  but  little  germicidal  power.  The  typhoid  ba- 


ESSENTIAL   OILS,    ETC.  191 

cillus  and  cholera  spirillum  were  only  destroyed  after  eight  to  ten 
days'  exposure  to  the  action  of  camphor  ("essence"). 

Carbolic  Acid. — Tested  upon  anthrax  spores,  Koch  found  a  one- 
per-cent  solution  to  be  without  effect  after  fifteen  days'  exposure  ;  a 
two-per-cent  solution  retarded  development  but  did  not  completely 
destroy  vitality  in  seven  days  ;  a  three-per-cent  solution  was  effec- 
tive in  two  days.  In  the  absence  of  spores  Koch  found  that  a  one- 
per-cent  solution  quickly  destroys  the  vitality  of  anthrax  bacilli. 
He  recommends  a  five-per-cent  solution  for  the  destruction  of  the 
"comma  bacillus"  in  the  discharges  of  cholera  patients,  and  a  two- 
per-cent  solution  for  the  disinfection  of  surfaces  soiled  with  such  dis- 
charges. In  the  writer's  experiments  1  :  200  destroyed  Micrococcus 
Pasteuri  in  two  hours  ;  and  pus  cocci  were  destroyed  by  1  : 125,  while 
1  : 200  failed.  Davaine  showed  by  inoculation  experiments  that  an- 
thrax bacilli  in  fresh  blood  are  destroyed  by  being  exposed  to  the 
action  of  a  one-per-cent  solution  for  one  hour.  A  two-per-cent  solu- 
tion destroys  the  dried  virus  of  symptomatic  anthrax  in  forty-eight 
hours  (Arloing,  Cornevin,  and  Thomas).  Solutions  in  oil  or  in  alco- 
hol have  been  shown  by  Koch  to  be  less  effective  than  aqueous  solu- 
tions. Thus  a  five-per-cent  solution  in  oil  failed  to  destroy  anthrax 
spores  in  one  hundred  and  ten  days,  and  the  same  solution  failed  to 
kill  the  bacilli,  in  the  absence  of  spores,  in  less  than  six  days.  A 
five-per-cent  solution  in  alcohol  did  not  destroy  anthrax  spores  in 
seventy  days.  Schill  and  Fischer  found  that  a  three-per-cent  solu- 
tion destroyed  the  infecting  power  of  tuberculous  sputum,  as  shown 
by  inoculation  into  guinea-pigs,  in  twenty-four  hours,  while  solutions 
of  one  and  two  per  cent  failed.  Bolton's  experiments  gave  the  fol- 
lowing results,  the  test  organisms  being  in  fresh  bouillon  cultures 
and  the  time  of  exposure  two  hours  :  The  cholera  spirillum,  the 
bacillus  of  typhoid  fever,  the  bacillus  of  schweinerothlauf,  Brieger's 
bacillus,  the  bacillus  of  green  pus,  and  the  pus  cocci  (Staphylococcus 
pyogenes  aureus,  albus,  and  citreus,  and  Streptococcus  pyogenes) 
were  all  killed  by  a  solution  of  one  per  cent,  while  in  a  majority  of 
the  experiments  a  one-half -per-cent  (1  : 200)  solution  failed.  Cul- 
tures of  the  typhoid  bacillus  in  flesh-peptone-gelatin  gave  the  same 
result  (1  : 100  with  two  hours'  exposure),  and  the  addition  of  ten  per 
cent  of  dried  egg  albumin  to  bouillon  cultures  did  not  influence  the 
result. 

The  experiments  of  La  Place  show  that  the  addition  of  hydro- 
chloric acid  to  a  disinfecting  solution  containing  carbolic  acid  greatly 
increases  its  germicidal  power  for  spores.  Thus  it  is  stated  that 
"  two  per  cent  of  crude  carbolic  acid  with  one  per  cent  of  pure  hydro- 
chloric acid  destroyed  anthrax  spores  in  seven  days,  while  two  per 
cent  of  carbolic  acid  or  one  per  cent  of  hydrochloric  acid  alone  did 


192 


ACTION   OF   COAL-TAR   PRODUCTS, 


not  destroy  these  spores  in  thirty  clays.  A  f  our-per-cent  solution  of 
crude  carbolic  acid  with  two  per  cent  of  hydrochloric  acid  destroyed 
spores  in  less  than  an  hour  ;  four  per  cent  of  carbolic  acid  alone  did 
not  destroy  them  in  twelve  days.  Van  Ermengem  reports  that  in 
his  experiments  the  cholera  spirillum  in  chicken  bouillon  was  killed 
in  less  than  half  an  hour  by  1  :  600,  and  that  in  blood  serum  1  :  400 
was  effective.  ISTicati  and  Rietsch  fix  the  germicidal  power  for  the 
cholera  spirillum  as  1  : 200,  the  time  of  exposure  being  ten  minutes  ; 
Ramon  and  Cajal,  1  :  50.  Boer  gives  the  following  results,  the  time 
of  exposure  being  two  hours,  cultures  in  bouillon  twenty-four  hours 
old: 


Restrains 
development. 

Destroys 
vitality. 

Anthrax  bacillus  

1  •  750 

1  •  300 

Diphtheria  bacillus  

1  -500 

1  •  300 

Glanders  bacillus  

1  -500 

1  '300 

Typhoid  bacillus  

1  -400 

1  •  200 

Cholera  spirillum  

1  :600 

1  -400 

Leitz  reports  the  following  results  :     The  dejections  of  patient 
suffering  from  typhoid  fever,  mixed  in  equal  quantity  with  the  disin- 
fecting solution,  were  sterilized  by  a  five-per-cent  solution  of  car 
bolic  acid  in  three  days.     Pure  cultures  of  the  typhoid  bacillus  wei 
sterilized  in  fifteen  minutes  by  a  five-per-cent  solution. 

In  the  experiments  of  Nocht  upon  anthrax  spores  it  was  founc 
that  while  at  the  room  temperature  these  spores  were  not  destroys 
by  several  days'  exposure  in  a  five-per-cent  solution,  they  were  dc 
stroyed  in  three  hours  by  the  same  solution  at  a  temperature  of  37.5°. 

Carbolic  acid  prevents  putrefactive  changes  in  bouillon  when  prt 
sent  in  the  proportion  of  1  :  333   (Miquel).     The  tubercle  bacillus  is 
killed  in  thirty  seconds  by  a  five-per-cent  solution,  and  in  one  minute 
by  a  one-per-cent  solution  (Yersin). 

Coffee  Infusion. — Experiments  have  been  made  by  Heim  and  by 
Liideritz  on  the  antiseptic  power  of  an  infusion  of  coffee.  The  first- 
named  author  found  that  anthrax  bacilli  no  longer  developed  after 
three  hours'  exposure  in  a  ten-per-cent  solution,  but  spores  were  not 
killed  at  the  end  of  a  week.  Streptococci  in  a  bouillon  culture  re- 
quired twenty-four  hours'  exposure,  and  the  staphylococci  of  pus  were 
not  destroyed  in  this  time.  Liideritz  found  that  a  three-per-cent  in- 
fusion restrained  the  growth  in  nutrient  gelatin  of  the  typhoid  ba- 
cillus, and  a  five-per-cent  infusion  killed  the  bacillus  in  two  days  ; 
the  cholera  spirillum  failed  to  grow  in  presence  of  one  per  cent,  and 
a  solution  of  this  strength  killed  it  in  seven  hours  ;  Staphylococcus 


ESSENTIAL   OILS,    ETC.  193 

pyogenes  aureus  was  prevented  from  developing  by  two  per  cent, 
and  was  killed  in  six  days  by  a  five-per-cent  solution  ;  Streptococcus 
pyogenes  was  prevented  from  growing  by  one  per  cent,  and  killed  by 
a  ten-per-cent  solution  in  one  day  ;  Proteus  vulgaris  did  not  grow  in 
presence  of  2.5  per  cent,  and  was  killed  in* two  days  by  ten  per  cent. 
The  question  as  to  what  constituent  of  the  infusion  of  roasted  coffee 
was  the  active  germicidal  agent  was  not  determined,  but  the  authors 
referred  to  agree  that  it  was  not  caffeine. 

Creolin. — This  is  a  coal-tar  product  which  resembles  crude  carbolic 
acid  in  appearance,  but  smells  rather  like  tar  than  like  phenol.  It 
makes  a  milky  emulsion  with  water,  which  has  been  proved  by  nu- 
merous experiments  to  possess  very  decided  germicidal  power,  being 
superior  to  carbolic  acid.  The  first  careful  test  of  the  germicidal 
power  of  this  agent  was  made  by  Esmarch,  who  found  that  a  solu- 
tion of  1 :  200  killed  the  cholera  spirillum  in  a  minute,  the  typhoid 
bacillus  at  the  end  of  several  days.  Anthrax  spores  were  not  de- 
stroyed in  twenty  days  by  a  five-per-cent  solution,  but  this  solution 
killed  the  tubercle,  bacillus  attached  to  silk  threads  which  were  im- 
mersed in  it  for  a  short  time,  and  also  disinfected  tuberculous  sputum. 
Behring  has  shown  that  in  albuminous  liquids  creolin  is  less  effective 
than  carbolic  acid.  In  blood  serum  1  : 175  was  required  to  restrain 
the  development  of  staphylococci,  and  I  :  100  to  destroy  the  same  in 
ten  minutes.  Van  Ermengem,  as  a  result  of  numerous  experiments, 
arrived  at  the  conclusion  that  creolin  is  a  cheap  and  useful  disinfect- 
ing agent,  in  a  five-per-cent  solution,  for  various  pathogenic  organ- 
isms. Kaupe  reports  that  in  his  experiments  a  ten-per-cent  solution 
killed  anthrax  spores  in  twenty-four  hours.  According  to  Boer,  a 
solution  of  1  : 5,000  destroys  anthrax  bacilli  in  bouillon  cultures  in 
two  hours,  1  : 2,000  diphtheria  bacilli,  1  :  300  the  glanders  bacillus, 
1 : 250  the  typhoid  bacillus,  and  1 : 3,000  the  cholera  spirillum. 

Creosote. — This  agent  was  found  by  the  writer  to  be  fatal  to 
micrococci  in  the  proportion  of  1  :  200.  In  the  proportion  of  one  per 
cent  it  failed,  after  twenty  hours'  exposure,  to  destroy  tubercle  ba- 
cilli in  sputum  (Schill  and  Fischer).  A  saturated  aqueous  solution 
does  not  destroy  the  tubercle  bacillus  in  cultures  in  twelve  hours 
(Yersin).  Guttman,  in  extended  experiments  upon  various  patho- 
genic organisms,  found  that  development  was  prevented  by  1  :  3,000 
to  1 : 4,000.  A  solution  containing  1  : 300  killed  Bacillus  pyocyanus 
and  Bacillus  anthracis  in  one  minute,  Bacillus  prodigiosus  in  two 
minutes,  and  the  Finkler-Prior  spirillum  in  one  minute  in  the  pro- 
portion of  1  : 600. 

Cresol. — This  is  a  dark,  reddish-brown,  transparent  fluid,  some- 
what thinner  than  creolin,  and,  like  it,  having  an  odor  of  tar.  It 

forms  an  emulsion  with  water,  which  is  not  so  stable  as  that  formed 

13 


194  ACTION   OP  COAL-TAR   PRODUCTS, 

by  creolin.  Of  the  three  cresols,  ortho,  meta-,  and  paracresol,  the 
second  was  found  by  Frankel  to  be  most  active.  This  author  states 
that  the  addition  of  sulphuric  acid  adds  greatly  to  its  germicidal 
power.  A  four-per-cent  solution,  containing  equal  parts  of  cresol 
and  H2SO4,  killed  anthrax  spores  in  less  than  twenty-four  hours.  In 
Behring's  experiments  a  solution  containing  ten  per  cent  of  each  killed 
anthrax  spores  in  eighty  minutes,  and  five  per  cent  of  each  in  one 
hundred  minutes,  while  an  eighteen-per-cent  solution  of  sulphuric 
acid  alone  did  not  kill  them  in  twenty -four  hours.  In  the  experi- 
ments of  Jager  a  two-per-cent  solution  destroyed  the  tubercle  bacillus 
in  cultures  and  in  sputum.  As  a  result  of  his  experiments  Bearing 
concludes  that  cresol  has  no  advantage  over  carbolic  acid  as  a  ger- 
micide for  the  destruction  of  spores.  Tested  upon  Staphylococcus 
aureus,  Streptococcus  erysipelatos,  and  Bacillus  pyocyanus,  Frankel 
found  that  a  solution- of  0.3  per  cent  destroyed  these  microorganisms 
in  five  minutes,  while  a  two-per-cent  solution  of  carbolic  acid  re- 
quired fifteen  minutes'  contact  to  accomplish  the  same  result. 

Disinfektol. — This  is  a  coal-tar  product  similar  to  creolin  which 
has  been  recommended  in  Germany  for  disinfecting  purposes.  It  is 
an  oily,  dark-brown  fluid  having  a  specific  gravity  of  1.086.  It  forms 
an  emulsion  with  water,  which  has  a  slightly  alkaline  reaction.  It 
has  been  tested  upon  typhoid  stools  by  Uffelmann  and  by  Beselin. 
The  last-named  author  gives  the  following  summary  of  the  results 
obtained  :  An  emulsion  of  five  per  cent  of  disinf  ektol  equals  in  value, 
for  the  disinfection  of  the  liquid  discharges  of  typhoid  patients,  12.5 
per  cent  of  creolin,  thirty-three  per  Cent  of  hydrochloric  acid,  five  per 
cent  of  carbolic  acid,  1  :  500  of  mercuric  chloride. 

Ether. — Anthrax  spores  may  germinate  after  being  immersed  in 
sulphuric  ether  for  eight  days  (Koch).  The  tubercle  bacillus  is  de- 
stroyed by  ten  minutes'  exposure  to  the  action  of  ether  (Yersin). 

Essential  Oils. — Chamberlain  has  made  an  extended  series  of 
experiments  to  determine  the  antiseptic  power  of  the  vapor  of  vola- 
tile oils.  A  large  number  of  essential  oils  tested  were  found  to  pre- 
vent the  development  of  the  anthrax  bacillus,  while  a  few  did  not. 
At  the  end  of  six  days  the  tubes  were  opened  and  the  oil  absorbed  by 
the  culture  liquid  allowed  to  evaporate.  Cultures  were  now  obtained 
from  all  except  the  following,  which,  it  was  inferred,  had  destroyed 
the  vitality  of  the  spores  :  Angelica,  cinnamon  of  China,  cinnamon 
of  Ceylon,  geranium  of  France,  geranium  of  Algeria,  origanum. 

Cadeac  and  Meunier  have  also  made  extended  experiments  upon 
the  typhoid  bacillus  and  the  bacillus  of  glanders,  for  the  purpose  of 
determining  the  germicidal  power  of  agents  of  this  class.  Their 
method  consisted  in  the  introduction  of  a  sterilized  platinum  needle 
into  a  pure  culture  of  the  test  organism,  in  immersing  it  in  the 


ESSENTIAL   OILS,    ETC.  195 

essential  oil  for  a  certain  time,  and  then  making  with  it  a  puncture 
in  a  suitable  solid  culture  medium.  Their  results  are  given  below 
for  the  typhoid  bacillus. 

Essences  which  kill  the  bacillus  after  a  contact  of  less  than 
twenty-four  hours: 

At  the  end  of — 

Cinnamon  of  Ceylon,       .  .  .  .  .12  minutes. 

Cloves,  ......  25 

Eugenol,    .......      30 

Thyme,  ......  35 

Wild  thyme,          .  .  .  .  .  ."35 

Verbena  of  India,       .....  45 

Geranium  of  France,        .  .  .  .  .50 

Origanum,       .  .  •»  .  .75 

Patchouly,  .  .  .  .  .80 

Zedoary,  .  .  .  .  .  2  hours. 

Absinthe,   .  .  .  .  .  .        4      " 

Sandal  wood,    .  .  .  .  .  12 

The  following  were  effective  in  from  twenty-four  to  forty-eight 
hours:  Cumin,  caraway,  juniper,  matico,  galbanum,  valerian,  citron, 
angelica,  celery,  savin,  copaiba,  pepper,  turpentine,  opoponax,  rose, 
chamomile  ;  the  following  required  from  two  to  four  days:  Illicium, 
sassafras,  tuberose,  coriander;  the  following  from  four  to  eight  days: 
Calamus,  sage,  fennel,  mace,  cascarilla,  orange  of  Portugal;  the  fol- 
lowing in  eight  to  ten  days  :  Mint,  nutmeg,  rosemary,  carrot,  mus- 
tard, anise,  onion,  marjoram,  bitter  almonds,  cherry  laurel,  myrtle, 
lavender,  eucalyptus,  cedar,  cajuput,  wintergreen,  camphor. 

Kiedlin  reports  as  the  result  of  his  experiments  that  the  essential 
oils  which  have  the  greatest  antiseptic  value  are  oil  of  lavender,  eu- 
calyptus, rosemary,  and  cloves. 

Eucalyptol. — Chabaunes  and  Ferret  found  that  a  five-per-cent 
solution  of  eucalyptol  is  without  effect  upon  tubercle  bacilli  in  spu- 
tum. According  to  Behring,  eucalyptol  is  about  four  times  less  ac- 
tive as  a  disinfectant  than  carbolic  acid. 

Glycerin  has  no  action  upon  the  virus  of  symptomatic  anthrax 
(Arloing,  Cornevin,  and  Thomas),  and  is  inert  as  regards  the  spores 
of  anthrax  (Koch).  Glycerin  prevents  putrefactive  decomposition  in 
bouillon  when  present  in  the  proportion  of  1: 4  (Miquel).  Roux  has 
shown  that  the  addition  of  five  per  cent  of  glycerin  to  a  culture 
medium  is  favorable  to  the  growth  of  the  tubercle  bacillus  ;  it  is  also 
appropriated  as  pabulum  by  various  other  species. 

Hydroxylamin. — Heinisch  found  that  the  development  of  the 
anthrax  bacillus  is  prevented  by  1:77  of  hydroxylamin  hydro- 
chlorate,  and  of  the  diphtheria  bacillus  by  1 : 75.  In  these  experi- 
ments a  solution  of  soda  was  added  to  release  the  hydroxylamin. 
Marpmann  found  that  1 : 100  preserved  milk  without  change  for  four 


196  ACTION   OF   COAL-TAR   PRODUCTS, 

to  six  weeks,  and  that  alkaline  fermentation  of  urine  was  prevented 
by  1:1,000. 

Indol. — When  added  in  excess  to  water  this  agent  failed  to  de- 
stroy anthrax  spores  in  eighty  days  (Koch). 

Lanolin. — According  to  Gottstein,  various  microorganisms  tested 
by  him  failed  to  grow  in  cultures  after  having  been  in  contact  with 
pure  lanolin  for  five  to  seven  days. 

Naphthol. — In  the  proportion  of  1: 10,000  naphthol  prevents  the 
development  of  the  glanders  bacillus,  the  anthrax  bacillus,  the  ty- 
phoid bacillus,  the  micrococcus  of  fowl  cholera,  of  Staphylococcus. 
aureus  and  albus,  and  of  several  other  microorganisms  tested  by 
Maximovitch.  The  same  author  states  that  although  insoluble  in 
cold  water,  water  at  70°  C.  dissolves  0.44  in  one  thousand  parts. 
When  urine  is  shaken  up  with  naphthol  in  powder  it  does  not  undergo 
fermentation. 

In  the  experiments  of  Foote  hydronaphthol  was  found  to  show 
some  germicidal  power  in  the  proportion  of  1 : 2,300,  but  the  conclusion 
is  reached  that  a  saturated  aqueous  solution  (1: 1,150)  does  not  equal 
a  one-per-cent  solution  of  carbolic  acid  or  of  creolin. 

Olive  Oil. — Anthrax  spores  germinate  after  having  been  im- 
mersed for  ninety  days  in  pure  olive  oil  (Koch). 

Oil  of  Mustard. — Koch  found  that  the  development  of  anthrax 
spores  is  prevented  by  1: 33,000. 

Oil  of  Peppermint. — A  five-per-cent  solution  in  alcohol  failed  in 
twelve  days  to  destroy  anthrax  spores,  but  the  development  of  these 
spores  is  restrained  by  1: 33,000  (Koch). 

Oil  of  Turpentine  destroys  anthrax  spores  in  five  days,  but  failed 
to  do  so  in  one  day  (Koch).  The  development  of  anthrax  spores  i& 
prevented  by  1:75,000  (Koch).  The  addition  of  1:200  to  nutrient 
gelatin  prevents  the  development  of  bacteria  (Riedlin).  An  excess 
of  oil  of  turpentine  added  to  a  liquefied  gelatin  culture  of  Staphylo- 
coccus aureus  does  not  destroy  this  micrococcus  in  five  hours  (v. 
Christmas-  Dirckinck-  Holmf  eld) . 

Skatol  in  excess  in  water  has  no  germicidal  power,  as  tested  upon 
anthrax  spores  (Koch). 

Smoke. — The  researches  of  Beu  show  that  meats  which  have 
been  preserved  by  smoking  commonly  contain  living  bacteria  cap- 
able of  growing  in  culture'  media ;  and  Petri  has  shown  that  pork 
which  has  been  salted  for  a  month  and  then  smoked  for  fourteen 
days  may  still  contain  the  bacillus  of  rothlauf  in  a  living  condition, 
as  shown  by  inoculation  experiments.  It  was  not  until  about 
six  months  after  smoking  that  the  bacillus  failed  to  give  evidence 
of  vitality. 

Thymol. — A  five-per-cent  solution  in  alcohol  does  not  destroy 


ESSENTIAL  OILS,    ETC.  197 

anthrax  spores  in  fifteen  days,  but  the  development  of  these  spores 
is  retarded  by  a  solution  of  1  : 80,000  (Koch).  The  anthrax  bacillus 
and  staphylococci  fail  to  grow  in  culture  media  containing  1  :  3,000 
(Samter).  The  tubercle  bacillus  is  destroyed  by  contact  with  thy- 
mol for  three  hours  (Yersin).  Thymol  has  about  four  times  less 
germicidal  power  than  carbolic  acid  (Behring).  Antiseptic  in  the 
proportion  of  1  : 1,340  (Miquel). 

Tobacco  Smoke. — Tassinari  found  that  tobacco  smoke  restrains 
the  development  of  bacteria,  and  that  certain  species  failed  to  de- 
velop after  exposure  for  half  an  hour  in  an  atmosphere  of  tobacco 
smoke — spirillum  of  cholera  and  Friedlander's  bacillus. 


XII. 

ACTION  OF  BLOOD   SERUM  AND   OTHER  ORGANIC 

LIQUIDS. 

Blood  Serum. — Bacteriologists  have  long  been  aware  of  the  fact 
that  many  species  of  bacteria,  when  injected  into  the  circulation  of  a 
living  animal,  soon  disappear  from  the  blood,  and  that  the  blood  of 
such  an  animal  a  few  hours  after  an  injection  of  putrefactive  bacte- 
ria, for  example,  does  not  contain  living  bacteria  capable  of  develop- 
ing in  a  suitable  nutrient  medium.  Wyssokowitsch,  in  an  extended 
series  of  experiments,  has  shown  that  non-pathogenic  bacteria  in- 
jected into  the  circulation  may  be  obtained  in  cultures  from  the  liver, 
spleen,  kidneys,  and  bone  marrow  after  they  have  disappeared  from 
the  blood,  but  that,  as  a  rule,  those  present  in  these  organs  have  lost 
their  vitality,  as  shown  by  culture  experiments,  in  a  period  varying 
from  a  few  hours  to  two  or  three  days.  According  to  the  theory  of 
Metschnikoff,  this  destruction  of  bacteria  in  the  blood  and  tissues  of  a 
living  animal  is  effected  by  the  cellular  elements,  and  especially  by 
the  leucocytes,  which  pick  up  and  digest  these  vegetable  cells  very 
much  as  an  amoeba  disposes  of  similar  microorganisms  which  serve 
it  as  food.  Some  such  theory  seemed  necessary  to  account  for  the 
disappearance  of  bacteria  from  the  blood  before  the  demonstration 
was  made  that  the  serum  of  the  circulating  fluid,  quite  indepen- 
dently of  its  cellular  elements,  possesses  very  decided  germicidal 
power. 

Von  Fodor  first  (1887)  called  attention  to  the  fact  that  anthrax  ba- 
cilli may  be  destroyed  by  freshly  drawn  blood  ;  and  Nuttall  (1888), 
in  an  extended  series  of  experiments,  showed  that  various  bacteria 
are  destroyed  within  a  short  time  by  the  fresh  blood  of  warm- 
blooded animals.  Thus  the  anthrax  bacillus  in  rabbit's  blood  was 
usually  killed  in  from  two  to  four  hours  when  the  temperature  was 
maintained  at  37°-38°  C.,  and  the  same  result  was  obtained  with 
pigeon's  blood  at  41°  C.  But  when  the  blood  was  allowed  to  stand 
for  a  considerable  time,  or  was  heated  for  forty-five  minutes  to 
45°  C. ,  it  served  as  a  culture  fluid,  and  an  abundant  development  of 
anthrax  bacilli  occurred  in  it.  Bacillus  subtilis  and  Bacillus  mega- 


ACTION   OF   BLOOD    SERUM    AND    OTHER   ORGANIC   LIQUIDS.     199 

therium  were  also  destroyed  in  two  hours  by  fresh  rabbit's  blood, 
but  it  was  without  action  on  Staphylococcus  pyogenes  aureus,  which 
at  a  temperature  of  37.5°  C.  was  found  to  have  increased  in  num- 
bers at  the  end  of  two  hours.  Further  researches  by  Nissen  and 
Behring  show  that  there  is  a  wide  difference  in  the  blood  of  dif- 
ferent animals  as  to  germicidal  power,  and  that  certain  bacteria 
are  promptly  destroyed,  while  other  species  are  simply  restrained  for 
a  time  in  their  development  or  are  not  affected.  Thus  Nissen  found 
that  the  cholera  spirillum,  the  bacillus  of  anthrax,  the  bacillus  of 
typhoid  fever,  and  Friedlander's  pneumococcus  were  killed,  while 
Staphylococcus  pyogenes  aureus  and  albus,  the  streptococcus  of  ery- 
sipelas, the  bacillus  of  fowl  cholera,  the  bacillus  of  rothlauf,  and 
Proteus  hominis  were  able  to  multiply  in  rabbit's  blood  after  having 
been  restrained  for  a  short  time  in  their  development.  In  the  case 
of  the  cholera  spirillum  a  period  of  ten  to  forty  minutes  sufficed  for 
the  complete  destruction  of  a  limited  number,  but  when  the  number 
exceeded  1,200,000  per  cubic  centimetre  they  were  no  longer  de- 
stroyed with  certainty,  and  after  five  hours  an  increase  occurred. 
The  anthrax  bacillus  was  commonly  destroyed  within  twenty  minutes 
and  the  typhoid  bacillus  at  the  end  of  two  hours.  In  the  experi- 
ments of  Behring  and  Mssen  it  was  found  that  the  most  pronounced 
germicidal  effect  upon  the  anthrax  bacillus  was  obtained  from  the 
blood  of  the  rat,  an  animal  which  has  a  natural  immunity  against 
anthrax ;  while  the  blood  of  the  guinea-pig,  a  very  susceptible  ani- 
mal, had  no  restraining  effect  and  served  as  a  favorable  culture 
medium  for  the  anthrax  bacillus.  And  the  remarkable  fact  was  de- 
monstrated that  when  the  blood  cf  a  rat  was  added  to  the  blood  of 
the  guinea-pig  in  the  proportion  of  1:8,  it  exercised  a  decided  re- 
straining influence  upon  the  growth  of  the  anthrax  bacillus.  Later 
researches  have  shown  that  cultivation  in  the  blood  of  an  immune 
animal  causes  an  attenuation  of  the  virulence  of  an  anthrax  cul- 
ture (Ogata  and  Jasuhara)  ;  and  also  that  the  injection  of  the  blood 
of  a  frog  or  rat — naturally  immune — into  a  susceptible  animal  which 
has  been  inoculated  with  a  virulent  culture  of  the  anthrax  bacillus, 
will  prevent  the  death  of  the  inoculated  animal. 

Buchner  has  shown  that  the  germicidal  power  of  the  blood  of 
dogs  and  rabbits  does  not  depend  upon  the  presence  of  the  cellular 
elements,  but  is  present  in  clear  serum  which  has  been  allowed  to 
separate  from  the  clot  in  a  cool  place.  Exposure  for  an  hour  to  a 
temperature  of  55°  C.  destroys  the  germicidal  action  of  serum  as 
well  as  of  blood  ;  the  same  effect  is  produced  by  heating  to  52°  C.  for 
six  hours  or  to  45.6°  C.  for  twenty  hours.  The  germicidal  power 
of  blood  serum  is  not  destroyed  by  freezing  and  thawing,  but  is 
lost  after  it  has  been  kept  for  some  time.  Buchner's  experiments  led 


200    ACTION   OF   BLOOD    SERUM   AND    OTHER   ORGANIC   LIQUIDS. 

him  to  the  conclusion  that  the  germicidal  power  of  fresh  blood 
serum  depends  upon  the  presence  of  some  albuminous  body  present 
in  it.  This  view  is  sustained  by  the  researches  of  Ogata,  who  has 
obtained  from  the  blood  of  dogs  and  other  animals  a  glycerin  ex- 
tract of  a  "  ferment "  which  is  insoluble  in  alcohol  or  in  ether  and 
which  has  germicidal  properties. 

It  has  been  demonstrated  by  several  experimenters  that  other 
albuminous  fluids  possess  a  similar  germicidal  power.  Thus  Nuttall 
found  that  a  pleuritic  exudation  from  man  destroyed  the  anthrax 
bacillus  in  an  hour,  the  aqueous  humor  of  a  rabbit  in  two  hours 
Wurz  has  experimented  with  fresh  egg  albumin,  and  found  that  the 
anthrax  bacillus  failed  to  grow  after  having  been  exposed  for  an  hour 
to  the  action  of  albumin  from  a  hen's  egg ;  other  bacteria  tested 
were  not  killed  so  promptly,  but  a  decided  germicidal  action  was 
manifested.  Prudden  has  shown  that  the  albuminous  fluid  obtained 
from  a  hydrocele,  or  from  the  abdominal  cavity  in  ascites,  possesses 
similar  germicidal  power  ;  and  Fokker  has  demonstrated  that  fresh 
milk  destroys  the  vitality  of  certain  bacteria  which  induce  an  acid 
fermentation  of  this  fluid. 

The  results  heretofore  referred  to  induced  Hankin  to  experiment 
with  cell  globulin  obtained  from  the  spleen  or  lymphatic  glands  of  a 
dog  or  cat.  This  is  extracted  by  means  of  a  solution  of  chloride  of 
sodium,  the  solution  is  filtered,  and  the  globulin  precipitated  by  the 
addition  of  alcohol.  The  precipitate  is  washed  and  again  dissolved 
in  salt  solution.  The  result  showed  that  this  cell  globulin  possesses 
germicidal  power  similar  to  that  of  blood  serum. 

Urine. — The  experiments  of  Lehmann  show  that  fresh  urine  has 
a  decided  germicidal  power  for  the  cholera  spirillum  and  the  anthrax 
bacillus,  and  no  doubt  for  other  bacteria  as  well.  To  what  constitu- 
ent of  the  urine  this  is  due  has  not  been  determined. 


XIII. 
PRACTICAL  DIRECTIONS  FOR  DISINFECTION. 

THE  Committee  on  Disinfectants  of  the  American  Public  Health 
Association  (appointed  in  1884),  after  an  extended  investigation  with 
reference  to  the  germicidal  value  of  various  agents,  in  a  final  report 
submitted  in  1887  submits  the  following  "  Conclusions": 

The  experimental  evidence  recorded  in  this  report  seems  to  justify  the 
following  conclusions: 

The  most  useful  agents  for  the  destruction  of  spore-containing  infectious 
material  are — 

1.  Fire.     Complete  destruction  by  burning. 

2.  Steam  underpressure.     105°  C.  (221°  F.)  for  ten  minutes. 

3.  Boiling  in  water  for  half  an  hour. 

4.  Chloride  of  lime.1    A  four-per-cent  solution. 

5.  Mercuric  chloride.     A  solution  of  1 :  500. 

For  the  destruction  of  infectious  material  which  owes  its  infecting  power 
to  the  presence  of  microorganisms  not  containing  spores,  the  committee  rec- 
ommends— 

1.  Fire.     Complete  destruction  by  burning. 

2.  Boiling  in  water  for  ten  minutes. 

3.  Dry  heat.     110'  C.  (230°  F  )  for  two  hours. 

4.  Chloride  of  lime.     A  two-per-cent  solution. 

5.  Solution  of  chlorinated  soda.*    A  ten-per-cent  solution. 

6.  Mercuric  chloride.     A  solution  of  1 :  2,000. 

7.  Carbolic  acid.     A  five  per-cent  solution. 

8.  Sulphate  of  copper.     A  five-per-cent  solution. 

9.  Chloride  of  zinc.    A  ten-per-cent  solution. 

10.  Sulphur  dioxide*  Exposure  for  twelve  hours  to  an  atmosphere  con- 
taining at  least  four  volumes  per  cent  of  this  gas  in  presence  of 
moisture. 

The  committee  would  make  the  following  recommendations  with  refe- 
rence to  the  practical  application  of  these  agents  for  disinfecting  purposes : 

FOR  EXCRETA. 

(a)  In  the  sick-room : 

1.  Chloride  of  lime  in  solution,  four  per  cent. 
In  the  absence  of  spores : 

2.  Carbolic  acid  in  solution,  five  per  cent. 

3.  Sulphate  of  copper  in  solution,  five  per  cent. 

1  Should  contain  at  least  twenty-five  per  cent  of  availab'e  chlorine. 
a  Should  contain  at  least  three  per  cent  of  available  chlorine. 

3  This  will  require  the  combustion  of  between  three  and  four  pounds  of  sulphur 
for  every  thousand  cubic  feet  of  air  space. 


202  PRACTICAL   DIRECTIONS   FOR   DISINFECTION. 

(6)  In  privy  vaults : 

1.  Mercuric  chloride  in  solution,  1:  500. 1 

2.  Carbolic  acid  in  solution,  five  per  cent. 

(c)  For  the  disinfection  and  deodorization  of  the  surface  of  masses  of  or- 
ganic material  in  privy  vaults,  etc. : 

Chloride  of  lime  in  powder. 

FOR  CLOTHING,    BEDDING,   ETC. 

(a)  Soiled  underclothing,  bed  linen,  etc. : 

1.  Destruction  by  fire,  if  of  little  value. 

2.  Boiling  for  at  least  half  an  hour. 

3.  Immersion  in  a  solution  of  mercuric  chloride  of  the  strength  of 

1 : 2,000  for  four  hours. 

4.  Immersion  in  a  two-per-cent  solution  of  carbolic  acid  for  four  hours. 
(6)  Outer  garments  of  wool  or  silk,  and  similar  articles,  which  would  be 

injured  by  immersion  in  boiling  water  or  in  a  disinfecting  solution: 

1.  Exposure  in  a  suitable  apparatus  to  a  current  of  steam  for  ten  min- 

utes. 

2.  Exposure  to  dry  heat  at  a  temperature  of  110°  C.  (230°  F.)  for  two- 

hours. 

(d)  Mattresses  and  blankets  soiled  by  the  discharges  of  the  sick: 

1.  Destruction  by  fire. 

2.  Exposure  to  superheated  steam,  105°  C.  (221°  F.),  for  ten  minutes. 

(Mattresses  to  have  the  cover  removed  or  freely  opened.) 

3.  Immersion  in  boiling  water  for  half  an  hour. 

FURNITURE  AND  ARTICLES  OF  WOOD,    LEATHER,    AND  PORCELAIN. 

Washing,  several  times  repeated,  with — 
1.  Solution  of  carbolic  acid,  two  per  cent. 

FOR  THE    PERSON. 

The  hands  and  general  surface  of  the  body  of  attendants  of  the  sick,  and 
of  convalescents,  should  be  washed  with — 

1.  Solution  of  chlorinated  soda  diluted  with  nine  parts  of  water,  1 : 10. 

2.  Carbolic  acid,  two-per-cent  solution. 

3.  Mercuric  chloride,  1 : 1,000. 

FOR  THE  DEAD. 

Envelop  the  body  in  a  sheet  thoroughly  saturated  with — 

1.  Chloride  of  lime  in  solution,  four  per  cent. 

2.  Mercuric  chloride  in  solution,  1 :  500. 

3.  Carbolic  acid  in  solution,  five  per  cent. 

FOR  THE  SICK-ROOM  AND  HOSPITAL  WARDS. 

(a)  While  occupied,  wa«h  all  surfaces  with — 

1.  Mercuric  chloride  in  solution,  1: 1,000. 

2.  Carbolic  acid  in  solution,  two  per  cent. 

(6)  When  vacated,  fumigate  with  sulphur  dioxide  for  twelve  hours,  burn- 
ing at  least  three  pounds  of  sulphur  for  every  thousand  cubic  feet  of  air 
space  in  the  room;  then  wash  all  surfaces  with  one  of  the  above-mentioned 
disinfecting  solutions,  and  afterward  with  soap  and  hot  water;  finally  throw 
open  doors  and  windows,  and  ventilate  freely. 

1  The  addition  of  an  equal  quantity  of  potassium  permanganate  as  a  deodorant, 
and  to  give  color  to  the  solution,  is  to  be  recommended.  [The  writer  no  longer  in- 
dorses this  recommendation.  See  his  paper  on  "  The  Disinfection  of  Excreta,"  ap- 
pended.] 


PRACTICAL   DIRECTIONS    FOR    DISINFECTION. 
FOR  MERCHANDISE  AND  THE  MAILS. 

The  disinfection  of  merchandise  and  of  the  mails  will  only  be  required 
under  exceptional  circumstances;  free  aeration  will  usually  be  sufficient.  If 
disinfection  seems  necessary,  fumigation  with  sulphur  dioxide  will  be  the 
only  practicable  method  of  accomplishing  it  without  injury. 

RAGS. 

(a)  Rags  which  have  been  usea  for  wiping  away  infectious  discharges 
should  at  once  be  burned. 

(b)  Rags  collected  for  the  paper-makers  during  the  prevalence  of  an  epi- 
demic should  be  disinfected,  before  they  are  compressed  in  bales,  by — 

1.  Exposure  to  superheated  steam  of  105°  C.  (221°  F.)  for  ten  minutes. 

2.  Immersion  in  boiling  water  for  half  an  hour. 

SHIPS. 

(a)  Infected  ships  at  sea  should  be  washed  in  every  accessible  place,  and 
especially  the  localities  occupied  by  the  sick,  with — 

1.  Solution  of  mercuric  chloride,  1 : 1,000. 

2.  Solution  of  carbolic  acid,  two  per  cent. 

The  bilge  should  be  disinfected  by  the  liberal  use  of  a  strong  solution  of 
mercuric  chloride. 

(&)  Upon  arrival  at  a  quarantine  station,  an  infected  ship  should  at 
once  be  fumigated  with  sulphurous  acid  gas,  using  three  pounds  of  sulphur 
for  every  thousand  cubic  feet  of  air  space;  the  cargo  should  then  be  dis- 
charged on  lighters ;  a  liberal  supply  of  the  concentrated  solution  of  mercuric 
chloride  (four  ounces  to  the  gallon)  should  be  thrown  into  the  bilge,  and  at 
the  end  of  twenty-four  hours  the  bilge  watei  should  be  pumped  out  and  re- 
placed with  pure  sea  water ;  this  should  be  repeated.  A  second  fumigation, 
after  the  removal  of  the  cargo,  is  recommended;  all  accessible  surfaces  should 
be  washed  with  one  of  the  disinfecting  solutions  heretofore  recommended, 
and  subsequently  with  soap  and  hot  water. 

FOR  RAILWAY  CARS. 

The  directions  given  for  the  disinfection  of  dwellings,  hospital  wards,  and 
ships  apply  as  well  to  infected  railway  cars.  The  treatment  of  excreta  with 
a  disinfectant,  before  they  are  scattered  along  the  tracks,  seems  desirable  at 
all  times  in  view  of  the  fact  that  they  may  contain  infectious  germs.  Dur- 
ing the  prevalence  of  an  epidemic  of  cholera  this  is  imperative.  For  this 
purpose  the  standard  solution  of  chloride  of  lime  is  recommended. 

DISINFECTION  BY   STEAM. 

The  Committee  on  Disinfectants,  in  tne  above-quoted  "  Conclu- 
sions/' recommends  the  use  of  "  steam  under  pressure,  105°  C.  (221° 
F.),  for  ten  minutes"  for  the  destruction  of  spore-containing  infec- 
tious material.  The  spores  of  all  known  pathogenic  bacteria  are  de- 
stroj'-ed  by  a  temperature  of  100°  C.  maintained  for  five  minutes,  and 
in  view  of  this  fact  the  temperature  fixed  by  the  committee  is  ample, 
and  to  exact  a  higher  temperature  or  longer  exposure  would  be  un- 
reasonable. But  in  practical  disinfection  the  temperature  required 
to  destroy  infectious  material  is  not  the  only  question  to  be  considered. 
Economy  in  the  construction  and  operation  of  the  steam  disinfecting 
apparatus  must  have  due  attention,  and  an  important  point  relates. 


204  PRACTICAL   DIRECTIONS   FOR   DISINFECTION. 

to  the  penetration  of  porous,  non-conducting  articles,  such  as  rolls  of 
blankets,  clothing,  etc.  These  points  have  been  the  subject  of  nu- 
merous experimental  investigations,  and  the  principles  involved 
have  been  elucidated,  especially  by  the  investigations  of  Esmarch 
(1887),  of  Budde  (1889),  and  of  Teuschner  (1890). 

It  has  been  shown  that  streaming  steam  is  more  effective  than 
confined  steam  at  the  same  temperature,  because  it  penetrates  porous 
objects  more  quickly.  Also  that  superheated,  "  dry  "  steam  is  not  as 
effective  as  flowing  steam  at  100°  C. ;  on  the  other  hand,  it  corre- 
sponds in  effectiveness  with  dry  air,  and  the  temperature  must  be 
raised  to  140°  to  150°  C.  in  order  to  quickly  destroy  the  spores  of 
bacilli. 

Esmarch's  investigations  show  that  streaming  steam  penetrates 
porous  objects,  like  rolled  blankets,  more  readily  than  confined 
steam ;  but  the  later  researches  of  Budde  and  of  Teuschner  show 
that  a  temperature  of  100°  C.  is  more  rapidly  reached  in  the  interior 
of  such  rolls  when  the  flowing  steam  is  under  pressure.  With  the 
same  pressure  (fifteen  pounds)  a  temperature  of  100°  C.  was  reached 
in  two  and  one-half  minutes  when  the  steam  was  flowing,  and  in 
eleven  minutes  by  steam  at  rest  (Budde).  Intermittent  pressure 
was  not  found  by  Budde  to  present  any  advantages  over  continuously 
flowing  steam  ;  on  the  contrary,  the  time  of  penetration  was  longer. 

Teuschner,  whose  investigations  are  the  most  recent,  arrives  at 
the  following  conclusions  : 

1.  Strongly  superheated  steam  is  not  to  be  recommended  for  practical 
disinfection.     On  the  contrary,  a  slight  supei-heating  of  the  steam,  such  as 
occurs  in  the  apparatus  of  Schimmel,  is  not  objectionable. 

2.  Those  forms  of  apparatus  in  which  the  steam  enters  from  above  are 
much  safer  and  quicker  in  their  disinfecting  action  than  those  in  which  this 
is  not  the  case.     In  the  construction  of  such  apparatus  care  must  be  taken, 
in  order  to  secure  penetration  of  the  objects,  that  the  air  and  steam  have  a 
free  escape  below. 

3.  Disinfection  is  hastened  by  previously  warming  the  apparatus. 

4.  The  most  rapid  disinfecting  action  is  secured  by  the  use  of  streaming 
steam  in  a  state  of  tension  (under  pressure). 

5.  Objects  which  have  been  in  contact  with  fatty  or    oily  substances 
require  a  longer  time  for  disinfection  than  those  which  have  not. 

6.  To  accomplish  disinfection  it  is  necessary  to  expel,  as  completely  as 
possible,  all  air  from  the  objects  to  be  disinfected,  and  also  to  secure  a  suffi- 
cient condensation  of  the  steam. 

7.  The  condensation  of  the  steam  advances  in  a  sharply  denned  line 
from  the  periphery  to  the  centre  of  porous  objects. 

8.  The  temperature  necessary  for  disinfection  is  only  found  in  the  zone 
-where  condensation  has  already  taken  place. 

9.  Only  a  few  centimetres  from  the  zone  in  which  the  temperature  is 
100°  C. — when  disinfection  is  incomplete— there  may  be  places  in  which 
the  temperature  is  40°  C.  or  more  below  the  boiling  point. 


PRACTICAL   DIRECTIONS    FOR    DISINFECTION.  205 

DISINFECTION   OF   THE   HANDS. 

The  importance  of  a  reliable  method  of  disinfecting  the  hands  of 
surgeons,  obstetricians,  and  nurses  after  they  have  been  in  contact 
with  infectious  material  from  wounds,  puerperal  discharges,  etc. ,  is 
now  fully  recognized,  and  some  surgeons  consider  it  necessary  to 
completely  sterilize  the  hands  before  undertaking  any  surgical  opera- 
tion which  will  bring  them  in  contact  with  the  freshly-cut  tissues. 
The  numerous  experiments  which  have  been  made  with  a  view  to 
ascertaining  the  best  method  of  accomplishing  such  sterilization  of 
the  hands  show  that  it  is  by  no  means  a  simple  matter  to  effect  it,  • 
and  especially  to  insure  the  destruction  of  microorganisms  con- 
cealed beneath  the  finger  nails.  Fiirbringer,  in  an  extended  series 
of  experiments  (1888),  found  that  a  preliminary  cleansing  with  soap 
and  a  brush  was  even  more  important  than  the  degree  of  potency  of 
the  disinfecting  wash  subsequently  applied.  He  recommends  the 
following  procedure  : 

1.  Remove  all  visible  dirt  from  beneath  and  around  the  nails. 

2.  Brush  the  spaces  beneath  the  nails  with  soap  and  hot  water 
for  a  minute. 

3.  Wash  for  a  minute  in  alcohol  (not  below  eighty  per  cent),  and, 
before  this  evaporates,  in  the  following  solution  : 

4.  Wash  thoroughly  for  a  minute  in  a  solution  containing  1  :  500 
of  mercuric  chloride  or  three  per  cent  of  carbolic  acid. 

Roux  and  Reynes  tested  the  above  method  of  Fiirbringer,  and 
found  that  it  gave  better  results  than  others  previously  proposed,  al- 
though not  always  entirely  successful  in  securing  complete  steriliza- 
tion. 

Boll  has  recently  (1890)  reported  favorable  results  from  the  fol- 
lowing method  : 

1.  Cleanse  the  finger  nails  from  visible  dirt  with  knife  or  nail  scissors. 

2.  Brush  the  hands  for  three  minutes  with  hot  water  and  potash  soap. 

3.  Wash  for  half  a  minute  in  a  three-per-cent  solution  of  carbolic  acid, 
and  subsequently  in  a  1  :  2,000  solution  of  mercuric  chloride. 

4.  Rub  the  spaces  beneath  the  nails  and  around  their  margins  with  iodo- 
form  gauze  wet  in  a  five-per-ceut  solution  of  carbolic  acid. 

Welch,  as  a  result  of  extended  experiments  made  at  the  Johns 
Hopkins  Hospital,  recommends  the  following  procedure  : 

1.  The  nails  are  kept  short  and  clean. 

2.  The  hands  are  washed  thoroughly  for  several  minutes  with  soap  and 
water,  the  water  being  as  warm  as  can  be  comfortably  borne,  and  being  fre- 
quently changed.     A  brush  sterilized  by  steam  is  used.     The  excess  of  soap 
is  washed  off  with  water. 

3.  The  hands  are  immersed  for  one  or  two  minutes  in  a  warm  saturated 
solution  of  permanganate  of  ootash  and  are  rubbed  over  thoroughly  with  a 
sterilized  swab. 


306  PRACTICAL,   DIRECTIONS   FOR   DISINFECTION. 

4.  They  are   then  placed  in  a  warm  saturated  solution  of  oxalic  acid, 
where  they  remain  until  complete  decolorization  of  the    permanganate 
occurs. 

5.  They  are  then  washed  off  with  sterilized  salt  solution  or  water. 

6.  They  are  immersed  for  two  minutes  in  sublimate  solution,  1  :  500. 
The  bacteriological  examination  of  the  skin  thus  treated  yields  almost 

uniformly  negative  results,  the  material  for  the  cultures  being  taken  from 
underneath  and  around  the  nails.  This  is  the  procedure  now  employed  in 
the  gynecological  and  surgical  wards  of  the  hospital. 

THE   DISINFECTION   OF   EXCRETA. 

The  following  paper  by  the  present  writer  was  read  before  the 
'Section  on  State  Medicine  at  the  last  (1891)  meeting  of  the  American 
Medical  Association  : 

The  Committee  on  Disinfectants  appointed  by  the  American  Public 
Health  Association  in  1884,  in  its  final  report  submitted  in  1887,  gives  the 
following  general  directions : 

1 'Disinfection  of  Excreta,  etc. — The  infectious  character  of  the  dejections 
•of  patients  suffering  from  cholera  and  from  typhoid  fever  is  well  established, 
and  this  is  true  of  mild  cases  and  of  the  earliest  stages  of  these  diseases  as 
well  as  of  severe  and  fatal  cases.  It  is  probable  that  epidemic  dysentery, 
tuberculosis,  and  perhaps  diphtheria,  yellow  fever,  scarlet  fever,  and  typhus 
fever,  may  also  be  transmitted  by  means  of  the  alvine  discharges  of  the 
sick.  It  is,  therefore,  of  the  first  importance  that  these  should  be  disin- 
fected. In  cholera,  diphtheria,  yellow  fever,  and  scarlet  fever  all  vomited 
material  should  also  be  looked  upon  as  infectious.  And  in  tuberculosis, 
diphtheria,  scarlet  fever,  and  infectious  pneumonia  the  sputa  of  the  sick 
should  be  disinfected  or  destroyed  by  fire.  It  seems  advisable  also  to  treat 
the  urine  of  patients  eick  with  an  infectious  disease  with  one  of  the  disinfect- 
ing solutions  below  recommended. 

"Chloride  of  lime,  or  bleaching  powder,  is  perhaps  entitled  to  the  first 
place  for  disinfecting  excreta,  on  account  of  the  rapidity  of  its  action. 

"  The  following  standard  solution  is  recommended: 

"  Dissolve  chloride  of  lime  of  the  best  quality, l  in  pure  water,  in  the  pro- 
portion of  six  ounces  to  one  gallon.  Use  one  quart  of  this  solution  for  the 
disinfection  of  each  discharge  in  cholera,  typhoid  fever,  etc."  Mix  well  and 
leave  in  the  vessel  for  at  least  one  hour  before  throwing  into  the  privy  vault 
or  water  closet. 

"  The  same  directions  apply  to  the  disinfection  of  vomited  matters.  In- 
fected sputum  should  be  discharged  directly  into  a  cup  half-full  of  the  solu- 
tion. A  five-per-cent  solution  of  carbolic  acid  may  be  used  instead  of  the 
chloride  of  lime  solution,  the  time  of  exposure  to  the  action  of  the  disinfect- 
ant being  four  hours"  (op.  cit.,  pp.  237,  238). 

The  object  of  this  paper  is  to  inquire  whether  these  recommendations, 
which  were  based  upon  the  experimental  data  available  at  the  time  they 
were  made,  are  sustained  by  subsequent  investigations ;  and  whether  any 
other  agents  have  been  shown  to  possess  superior  advantages  for  the  pur- 
pose in  view. 

But  first  we  desire  to  call  attention  to  another  portion  of  the  report  of  the 

1  Gfood  chloride  of  lime  should  contain  at  least  twenty-five  per  cent  of  available 
chlorine  (page  92).  It  may  be  purchased  by  the  quantity  at  three  and  one-half  cents 
per  pound.  The  cost  of  the  standard  solution  recommended  i.«  therefore  but  little 
more  than  one  cent  a  gallon.  A  clear  solution  may  be  obtained  by  filtration  or  by 
decantation,  but  the  insoluble  sediment  does  no  harm  and  this  is  an  unnecessary  re- 
finement. 

8  For  a  very  copious  discharge  use  a  larger  quantity. 


PRACTICAL   DIRECTIONS   FOR   DISINFECTION.  207 

•Committee  on  Disinfectants.  On  page  236  the  following  definition  of  disin 
fection  and  disinfectants  is  given : 

"  The  object  of  disinfection  is  to  prevent  the  extension  of  infectious  dis- 
eases by  destroying  the  specific  infectious  material  which  gives  rise  to  them. 
This  is  accomplished  by  the  use  of  disinfectants.  There  can  be  no  partial 
disinfection  of  such  material;  either  its  infecting  power  is  destroyed  or  it  is 
not.  In  the  latter  case  there  is  a  failure  to  disinfect.  Nor  can  there  be  any 
disinfection  in  the  absence  of  infectious  material. " 

I  have  italicized  the  last  sentence  because  I  wish  to  call  especial  attention 
to  it.  I  am  frequently  asked,  "  What  is  the  best  disinfectant  to  put  into  a 
water  closet? "  Now,  if  a  closet  or  privy  vault  is  resorted  to  only  by  healthy 
pers  ons  and  no  infectious  material  has  been  thrown  into  it,  there  is  nothing 
in  it  to  disinfect,  and  the  recommendation  of  the  Committee  on  Disinfect- 
ants does  not  apply  to  it  at  all.  It  may  smell  badly,  and  in  this  case  the 
bad  odor  may  be  neutralized  by  the  use  of  deodorants ;  or  we  may  prevent 
the  putrefactive  decomposition  of  its  contents,  and  thus  prevent  the  forma- 
tion of  the  offensive  gases  given  off  as  a  result  of  such  decomposition,  by 
the  use  of  antiseptics.  But  to  accomplish  this  it  is  not  necessary  to  sterilize 
the  entire  contents  by  the  use  of  active  germicidal  agents. 

A  solution  of  sulphate  of  iron  or  of  chloride  of  zinc  is  a  useful  antiseptic 
and  deodorizing  agent,  and  the  Committee  on  Disinfectants,  in  making  its 
recommendations,  did  not  intend  to  discourage  the  use  of  such  agents.  But 
exact  experimental  data  showed  that  these  agents  could  not  be  depended 
upon  for  the  destruction  of  infectious  disease  germs,  and  the  recommenda- 
tions made  related  to  disinfection  in  the  strict  and  proper  use  of  the  term  as 
above  denned.  This  definition  is  now  accepted  by  sanitarians  in  all  parts 
of  the  world,  but  many  practising  physicians  still  use  the  term  disinfectant 
as  synonymous  with  deodorant.  For  example,  I  find  in  a  recent  sanitary 
periodical,  under  the  heading  "  Medical  Excerpt,"  an  item  copied  from  the 
American  Journal  of  Obstetrics,  to  which  the  name  of  a  distinguished  gy- 
necologist is  attached,  in  which  the  following  statement  is  made  with  reference 
to  a  much-advertised  so-called  "disinfectant":  "Asa  disinfectant  I  have 
used  it  in  my  house  for  over  a  year  with  great  satisfaction."  Now,  the  agent 
referred  to  has  been  proved  by  exact  experiments  to  have  comparatively 
little  disinfecting  power,  although  it  is  a  very  good  deodorant.  According 
to  our  definition,  "the  object  of  disinfection  is  to  prevent  the  extension  of 
infectious  diseases  by  destroying  the  specific  infectious  material  which  gives 
rise  to  them."  Are  we  to  suppose  that  the  distinguished  gynecologist  above 
quoted  had  such  infectious  material  in  his  house  "  for  over  a  year  "  at  the 
time  he  was  employing  "  with  great  satisfaction  "  the  agent  he  recommends? 
If  not,  the  term  was  improperly  employed,  for  ' '  there  can  be  no  disinfec- 
tion in  the  absence  of  infectious  material. "  I  wish  to  emphasize  this  point, 
because  I  have  reason  to  believe  that,  in  the  army  at  least,  the  recommen- 
dation of  the  Committee  on  Disinfectants  has  led  to  the  substitution  of  chlo- 
ride of  lime  for  cheaper  deodorants  and  antiseptic  agents — and  especially  for 
sulphate  of  iron — in  latrines  which  are  frequented  only  by  healthy  persons 
and  consequently  need  no  disinfection.  The  amount  of  chloride  of  lime 
issued  from  the  Medical  Purveying  Depot  at  San  Francisco  during  the  past 
six  months  for  use  at  military  posts  on  the  Pacific  coast  is  more  than 
double  the  amount  of  sulphate  of  iron;  but  there  has  been  no  epidemic  of 
an  infectious  disease,  and  probably  comparatively  little  call  for  the  use  of  a 
disinfecting  agent  in  the  •sick-room.  We  quote  again  from  the  report  of  the 
Committee  on  Disinfectants : 

!'  In  the  sick-room  we  have  disease  germs  at  an  advantage,  for  we  know 
where  to  find  them  as  well  as  how  to  kill  them.  Having  this  knowledge, 
not  to  apply  it  would  be  criminal  negligence,  for  our  efforts  to  restrict  the 
extension  of  infectious  diseases  must  depend  largely  upon  the  proper  use  of 
disinfectants  in  the  sick-room"  (op.  cit.,  p.  237). 

"  The  injurious  consequences  which  are  likely  to  result  from  such  mis- 
apprehension and  misuse  of  the  word  disinfectant  will  be  appreciated  when 


208  PRACTICAL   DIRECTIONS   FOR   DISINFECTION. 

it  is  known  that  recent  researches  have  demonstrated  that  many  of  the 
agents  which  have  been  found  useful  as  deodorizers  or  as  antiseptics  are  en- 
tirely without  value  for  the  destruction  of  disease  germs. 

"  This  is  true,  for  example,  as  regards  the  sulphate  of  iron,  or  copperas,  a 
salt  which  has  been  extensively  used  with  the  idea  that  it  is  a  valuable  dis- 
infectant. As  a  matter  of  fact,  sulphate  of  iron  in  saturated  solution  does 
not  destroy  the  vitality  of  disease  germs,  or  the  infecting  power  of  material 
containing  them.  This  salt  is,  nevertheless,  a  very  valuable  antiseptic,  and 
its  low  price  makes  it  one  of  the  most  available  agents  for  the  arrest  of  putre- 
factive decomposition  "  (op.  cit.,  p.  237). 

Chloride  of  lime  is  also  a  valuable  antiseptic  and  deodorant,  and  I  know 
of  no  objection  to  substituting  it  for  sulphate  of  iron  other  than  the  question 
of  cost.  The  first  cost  of  chloride  of  lirne,  by  the  quantity,  is  about  double 
that  of  sulphate  of  iron,  but  practically  the  difference  is  much  greater,  be- 
cause it  is  necessary  to  preserve  the  chloride  of  lime  in  air-tight  packages. 
When  exposed  to  the  air  it  deteriorates  in  value  very  rapidly.  It  is,  there- 
fore, necessary  to  pack  it  in  air-tight  receptacles  which  will  not  be  injured 
by  the  corrosive  action  of  free  chlorine,  and  in  comparatively  small  quanti- 
ties so  that  the  contents  of  a  package  may  be  used  soon  after  it  is  opened. 

We  now  proceed  to  consider  the  experimental  data  relating  to  the  germi- 
cidal  value  of  chloride  of  lime. 

The  Committee  on  Disinfectants  gave  it  "  the  first  place  for  disinfecting 
excreta,  on  account  of  the  rapidity  of  its  action.''  This  recommendation  was 
upon  experimental  data  obtained  in  the  pathological  laboratory  of  the  Johns 
Hopkins  University,  under  the  writer's  direction,  and  is  sustained  by  more 
recent  experiments  made  in  Germany. 

The  experiments  of  Bolton,  made  for  the  Committee  on  Disinfectants  in 
1886,  gave  the  following  results  :  The  time  of  exposure  being  two  hours,  the 
typhoid  bacillus  and  cholera  spirillum  in  bouillon  cultures  were  killed  by  a 
solution  containing  one  part  to  one  thousand  parts  of  water  (containing  0  03 
per  cent  of  available  chlorine).  Anthrax  spores  were  killed  in  the  same  time 
by  a  solution  containing  0.3  per  cent  of  available  chlorine.  Typhoid  faeces 
were  sterilized  by  a  two-per-cent  solution,  and  in  several  instances  by  a  one- 
half-per-cent  solution ;  but  some  resistant  spores  of  non-pathogenic  bacilli  sur- 
vived in  two  experiments  in  which  a  solution  of  1 : 100  was  used.  In  bouillon 
cultures  to  which  ten  per  cent  of  dried  egg  albumin  had  been  added  the 
typhoid  bacillus  was  destroyed  by  one-half  per  cent  (1: 200). 

Nissen,  whose  experiments  were  made  in  Koch's  laboratory  in  1890,  found 
that  anthrax  spores  were  destroyed  in  thirty  minutes  by  a  five-per-cent 
solution,  and  in  seventy  minutes  by  a  one-per-cent  solution.  In  his  experi- 
ments the  typhoid  bacillus  and  the  cholera  spirillum  were  destroyed  with 
certainty  in  five  minutes  by  a  solution  containing  0.12  per  cent  (1 :  833) ;  the 
anthrax  bacillus  in  one  minute  by  1 : 1,000 ;  Staphylococcus  pyogenes  aureus  in 
one  minute  by  1 :  500.  Experiments  made  by  the  same  author  on  the  sterili- 
zation of  fieces  showed  that  one  per  cent  could  be  relied  upon  to  destroy  the 
bacillus  of  typhoid  fever  and  the  spirillum  of  cholera  in  faeces  in  ten  min- 
utes. 

Carbolic  Acid. — The  Committee  on  Disinfectants  says:  "  A  five-per-cent 
solution  of  carbolic  acid  may  be  used  instead  of  the  chloride  of  lime  solution, 
the  time  of  exposure  to  the  action  of  the  disinfectant  being  four  hours." 
This  recommendation  is  made  in  view  of  the  fact  that  in  those  diseases  in 
which  it  is  most  important  to  disinfect  the  excret*  the  specific  germ  does  not 
form  spores.  This  is  now  believed  to  be  true  of  the  typhoid  bacillus,  the 
spirillum  of  cholera,  the  bacillus  of  diphtheria,  the  bacillus  of  glanders,  and 
the  streptococcus  of  erysipelas ;  and  it  has  been  shown  by  exact  experiments 
that  all  of  these  pathogenic  bacteria  are  destroyed  in  two  hours  by  a  one-per- 
cent solution,  or  less,  of  this  agent. 

Spores  require  for  their  destruction  a  stronger  solution  and  a  longer  time. 
Koch  found  a  one-per-cent  solution  to  be  without  effect  on  anthrax  spores 
after  fifteen  days'  exposure;  a  two-per-cent  solution  retarded  their  develop- 


PRACTICAL  DIRECTIONS   FOR  DISINFECTION.  209 

meiit,  but  did  not  destroy  their  vitality  in  seven  days;  a  three-per  cent  olu- 
tion  was  effective  in  two  days.  According  to  Nocht,  at  a  temperature  of 
37.50°  C.  anthrax  spores  are  killed  by  a  five-per-cent  solution  in  three  hours. 

Carbolic  acid  possesses  the  advantage  of  not  being  neutralized  by  the  sub- 
stances found  in  excreta,  or  by  the  presence  of  albumin.  ThusBolton  found 
that  the  addition  of  ten  per  cent  of  dried  albumin  to  a  bouillon  culture  of 
the  typhoid  bacillus  did  not  materially  influence  the  result,  the  bacillus  be- 
ing destroyed  in  two  hours  by  a  one-per-cent  solution. 

This  agent,  then,  is  firmly  established  as  a  valuable  disinfectant  for  ex- 
creta, but  we  still  give  the  preference  to  the  standard  solution  of  chloride 
of  lime  of  the  Committee  on  Disinfectants  for  use  in  the  sick-room,  "on 
account  of  the  rapidity  of  its  action,  ''  and  also  on  account  of  its  compara- 
tive cheapness. 

At  the  International  Sanitary  Conference  at  Rome  (1885)  the  writer,  who 
was  associated  with  Dr.  Koch  on  the  Committee  on  Disinfectants,  presented 
the  claims  of  chloride  of  lime,  and  in.  the  recommendations  of  the  commit- 
tee it  was  placed  beside  carbolic  acid  with  the  following  directions : 

"  Carbolic  acid  and  chloride  of  lime  are  to  be  used  in  aqueous  solution. 

"Weak  solutions,  carbolic  acid,  two  per  cent;  chloride  of  lime,  one  per 
cent.  , 

"Strong  solutions,  carbolic  acid,  five  per  cent;  <  hloride  of  lime,  four  per 
cent/' 

The  strong  solutions  were  to  be  used  for  the  disinfection  of  excreta. 

Creolin,  a  coal-tar  product,  which  is  a  syrupy,  dark-brown  fluid  with  the 
odor  of  tar,  has  during  the  past  three  years  received  much  attention  from 
the  German  bacteriologists.  It  is  probably  the  same  product  which  was 
tested  under  the  writer's  direction  for  the  Committee  on  Disinfectants,  in 
1885,  under  the  name  of  "Little's  soluble  phenyle."  It  stood  at  the  head 
of  the  "  Commercial  Disinfectants  "  tested.  The  experiments  made  in  Ger- 
many show  that  it  is  not  so  active  for  spores  as  carbolic  acid,  but  that  it 
very  promptly  kills  known  pathogenic  bacteria,  in  the  absence  of  spores,  in 
solutions  of  two  per  cent  or  less.  Eisenberg  found  that  a  solution  of  two 
per  cent  killed  all  test  organisms  within  fifteen  minutes.  Esmarch  found 
it  especially  fatal  to  the  cholera  spirillum,  which  was  killed  by  solutions  of 
1  : 1,000  in  ten  minutes.  The  typhoid  bacillus  showed  much  greater  resist- 
ing power — a  one-half-per-cent  solution  failed  after  ten  minutes'  exposure. 
The  pus  cocci  was  still  more  resistant.  Behring  has  shown  that  the  pre- 
sence of  albumin  greatly  diminishes  its  germicidal  power.  As  a  deodorant 
it  is  superior  to  carbolic  acid,  and  on  this  account  is  to  be  preferred  in  the 
sick-room.  A  recently  prepared  emulsion  may  be  used  to  disinfect  the  liquid 
excreta  of  cholera  or  typhoid  patients,  in  the  proportion  of  four  per  cent, 
two  hours'  time  being  allowed  for  the  action  of  the  disinfectant.  The  ex- 
periments of  Jiiger  upon  pure  cultures  of  the  tubercle  bacillus  attached  to 
silk  threads  were  successful  in  destroying  the  infecting  power  of  these  cul- 
tures, as  tested  by  inoculation  into  the  anterior  chamber  of  the  eye  of  a 
rabbit,  when  solutions  of  two  per  cent  were  used. 

The  value  of  this  agent  as  a  disinfectant  is  then  fully  established;  as  to 
its  cost  in  comparison  with  the  agents  heretofore  mentioned  I  am  not  in- 
formed. 

Quicklime. — Experiments  made  in  Koch's  laboratory  in  1887  by  Libo- 
vius  led  him  to  place  a  high  value  upon  recently  burned  quicklime  as  a  dis- 
infectant. More  recent  experiments  by  Jager,  Kitasato,  Pfuhl,  and  others 
have  shown  that  this  agent  has  considerable  germicidal  power  in  the  ab- 
sence of  spores,  and  that  the  value  which  has  long  been  placed  upon  it  for 
the  treatment  of  excrementitious  material  in  latrines,  etc.,  and  as  a  wash  for 
exposed  surfaces,  is  justified  by  the  results  of  exact  experiments  made  upon 
known  pathogenic  bacteria.  The  germicidal  power  of  lime  is  not  interfered 
with  by  the  presence  of  albuminous  material,  but  is  neutralized  by  phos- 
phates, carbonates,  and  other  bases,  and  by  carbonic  acid. 

In  the  writer's  experiments  a  saturated  aqueous  solution  of  calcium  oxide 

14 


210  PRACTICAL   DIRECTIONS   FOR   DISINFECTION. 

failed  to  kill  typhoid  bacilli  ;  but  when  suspended  in  water  in  the  proportion 
of  1  : 40  by  weight  this  bacillus  was  killed  at  the  end  of  two  hours.  Anthrax 
spores  were  not  killed  in  the  same  time  by  a  lime  wash  containing  twenty 
per  cent  by  weight  of  pure  calcium  oxide.  According  to  Kitasato,  the 
typhoid  bacillus  and  the  cholera  spirillum  in  bouillon  cultures  are  destroyed 
by  the  addition  of  one-tenth  per  cent  of  calcium  oxide.  Pf  uhl  experimented 
upon  sterilized  faeces  to  which  pure  cultures  of  the  typhoid  bacillus  or 
cholera  spirillum  were  added.  The  liquid  discharges  of  patients  with  typhoid 
fever  or  diarrhoea  were  used  for  the  purpose.  He  found  that  sterilization 
was  effected  at  the  end  of  two  hours  by  adding  fragments  of  calcium  hydrate 
in  the  proportion  of  six  per  cent,  and  that  three  per  cent  was  effective  in  six 
hours.  When  a  milk  of  lime  was  used  which  could  be  thoroughly  mixed 
with  the  dejecta  the  result  was  still  more  favorable.  A  standard  preparation 
of  milk  of  lime  containing  twenty  per  cent  of  calcium  hydrate  killed  the 
typhoid  bacillus  and  the  cholera  spirillum  in  one  hour  when  added  to  liquid 
faeces  in  the  proportion  of  two  per  cent. 

The  experiments  with  this  agent  show  that  time  is  an  important  factor, 
and  that  much  longer  exposures,  as  well  as  stronger  solutions,  are  required 
to  destroy  pathogenic  bacteria  than  is  the  case  with  chloride  of  lime.  For 
this  reason  we  still  give  the  last-named  agent  the  preference  for  the  disinfec- 
tion of  excreta  in  the  sick-room.  But  in  latrines  the  time  required  to  accom- 
plish disinfection  is  of  less  importance,  and  we  are  disposed  to  give  recently 
burned  quicklime  the  first  place  for  the  disinfection  of  excreta  in  privy 
vaults  or  on  the  surface  of  the  ground.  It  may  be  applied  in  the  form  of 
milk  of  lime,  prepared  by  adding  gradually  eight  parts,  by  weight,  of  water 
to  one  part  of  calcium  hydrate.  This  must  be  freshly  prepared,  or  protected 
from  the  air  to  prevent  the  formation  of  the  inactive  carbonate  of  lime. 

According  to  Behring,  lime  has  about  the  same  germicidal  value  as  the 
other  caustic  alkalies,  and  destroys  the  cholera  spirillum  and  the  bacillus  of 
typhoid  fever,  of  diphtheria,  and  of  glanders  after  several  hours'  exposure, 
in  the  proportion  of  fifty  cubic  centimetres  normal-lauge  per  litre.  Wood 
ashes  or  lye  of  the  same  alkaline  strength  may  therefore  be  substituted  for 
quicklime. 

Finally,  it  must  not  be  forgotten  that  we  have  a  ready  means  of  disinfect- 
ing excreta  in  the  sick-room  or  its  vicinity  by  the  application  of  heat. 
Exact  experiments,  made  by  the  writer  and  others,  show  that  the  thermal 
death-point  of  the  following  pathogenic  bacteria,  and  of  the  kinds  of  virus 
mentioned  is  below  60°  C.  (140°  F.):  Spirillum  of  cholera,  bacillus  of  an- 
thrax, bacillus  of  typhoid  fever,  bacillus  of  diphtheria,  bacillus  of  glanders, 
diplococcus  of  pneumonia  (Micrococcus  Pasteuri),  streptococcus  of  erysipelas, 
staphylococci  of  pus,  micrococcus  of  gonorrhoea,  vaccine  virus,  sheep  pox 
virus,  hydrophobia  virus.  Ten  minutes'  exposure  to  the  temperature  men- 
tioned may  be  relied  upon  for  the  disinfection  of  material  containing  any  of 
these  pathogenic  organisms,  except  the  anthrax  bacillus  when  in  the  stage 
of  spore  formation.  The  use,  therefore,  of  boiling  water  in  the  proportion 
of  three  or  four  parts  to  one  part  of  the  material  to  be  disinfected  may  be 
safely  recommended  for  such  material.  Or,  better  still,  a  ten-per-cent  solu- 
tion of  sulphate  of  iron  or  of  chloride  of  zinc  at  the  boiling  point  may  be 
used  in  the  same  way  (three  parts  to  one).  This  will  have  a  higher  boiling 
point  than  water,  and  will  serve  at  the  same  time  as  a  deodorant.  During 
an  epidemic  of  cholera  or  typhoid  fever  such  a  solution  might  be  kept  boil- 
ing in  a  proper  receptacle  in  the  vicinity  of  hospital  wards  containing 
patients,  and  would  serve  to  conveniently,  promptly,  and  cheaply  disinfect 
all  excreta. 

DISINFECTION   IN  DIPHTHERIA. 

At  the  meeting  of  the  Tenth  International  Medial  Congress 
Berlin  (1890)  Loffler  made  an  important  communication    upon  the 


PRACTICAL,   DIRECTIONS   FOR   DISINFECTION.  211 

measures  to  be  taken  to  prevent  the  spread  of  diphtheria.     His  con- 
clusions are  summarized  as  follows  : 

1.  The  cause  of  diphtheria  is  the  diphtheria  bacillus,  which  is  found  in  the 
secretions  of  the  affected  mucous  membrane. 

2.  With  this  secretion  it  is  distributed  outside  of  the  body  and  may  be 
deposited  upon  anything  in  the  vicinity  of  the  sick. 

3.  Those  sick  with  diphtheria  carry  about  bacilli  capable  of  infecting 
others  so  long  as  there  is  the  slightest  trace  of  diphtheritic  deposit,  and  even 
for  several  days  after  such  deposit  has  disappeared. 

4.  Those  sick  with  diphtheria  are  to  be  rigidly  isolated  so  long  as  tbe 
diphtheria  bacilli  are  present  in  their  secretions.     Children  who  have  been 
sick  with  diphtheria  should  be  kept  from  school  for  at  least  four  weeks. 

5.  The  diphtheria  bacilli  may  preserve  their  vitality  in  dried  fragments 
of  diphtheritic  membrane  for  four  or  five  months.     Therefore  all  objects 
which  may  have  been  exposed  to  contact  with  the  excretions  of  .those  sick 
with  diphtheria,  such  as  linen,  bedclothing,  utensils,  clothing  of  nurses,  etc., 
should  be  disinfected  by  boiling  in  water  or  treated  with  steam  at  100°  C. 
In  the  same  way  the  rooms  occupied  by  diphtheria  patients  are  to  be  care- 
fully disinfected.     The  floors  should  be  repeatedly  scrubbed   with  hot  sub- 
limate solution  (1: 1,000)  and  the  walls  rubbed  down  with  bread. 

The  recommendation  made  by  Loftier  with  reference  to  rubbing 
down  the  walls  of  an  infected  apartment  with  bread  is  based  upon 
the  experiments  of  Esmarch  (1887),  as  a  result  of  which  he  arrived 
at  the  conclusion  that  this  is  the  most  reliable  method  of  removing 
bacteria  attached  fo  the  walls  of  an  apartment.  Fresh  bread  is  used, 
and,  after  having  been  used,  is  destroyed  by  burning.  We  judge 
that  this  method  would  be  especially  applicable  to  painted  surfaces 
or  to  walls  covered  with  paper.  For  plastered  walls  the  liberal  ap- 
plication of  lime  wash  is  probably  the  safest  method  of  disinfection. 


PART  THIRD. 


PATHOGENIC   BACTERIA. 

I.  MODES  OF  ACTION.  II.  CHANNELS  OF  INFECTION.    III.  SUSCEPTIBILITY  AND 
IMMUNITY     IV.  PYOGENIC  BACTERIA.    V.  BACTERIA  IN  CROUPOUS  PNEU- 
MONIA.   VI.  PATHOGENIC  MICROCOCCI  NOT  DESCRIBED  IN  SECTIONS  IV. 
AND  V.    VII.  THE  BACILLUS  OF  ANTHRAX.    VIII.  THE  BACILLUS 
OF  TYPHOID  FEVER.    IX.  BACTERIA  IN  DIPHTHERIA.    X.  BAC- 
TERIA IN  INFLUENZA.    XI.  BACILLI  IN  CHRONIC  INFECTIOUS 
DISEASES.    XII.  BACILLI  WHICH  PRODUCE  SEPTICAE- 
MIA IN  SUSCEPTIBLE  ANIMALS.  XIII.  PATHOGENIC 
AEROBIC  BACILLI  NOT  DESCRIBED  IN  PREVIOUS 
SECTIONS.  XIV.  PATHOGENIC  ANAEROBIC 
BACILLI.  XV.  PATHOGENIC  SPIRILLA. 
XVI.  BACTERIA   IN   INFECTIOUS 
DISEASES    NOT    PROVED    TO 
BE  OF  PARASITIC  ORIGIN. 
XVII.    CLASSIFICA- 
TION OF  PATHO- 
GENIC BAC- 
TERIA. 


PART    THIRD. 


PATHOGENIC    BACTERIA. 


I. 


MODES  OF  ACTION. 

MANY  of  the  saprophytic  bacteria  are  pathogenic  for  man,  or  for 
one  or  more  species  of  the  lower  animals,  when  by  accident  or  ex- 
perimental inoculation  they  obtain  access  to  the  body  ;  these  may  be 
designated  facultative  parasites.  Other  species  which,  for  a  time 
at  least,  are  able  to  lead  a  saprophytic  mode  of  life  have  their  nor- 
mal habitat  in  the  bodies  of  infected  animals,  in  which  they  produce 
specific  infectious  diseases.  To  this  class  belong  the  cholera  spirillum, 
the  anthrax  bacillus,  the  bacillus  of  typhoid  fever,  and  various  other 
microorganisms  which  are  the  cause  of  specific  infectious  diseases  in 
some  of  the  lower  animals.  These  we  may  speak  of  as  parasites 
and  facultative  saprophytes.  Still  others  are  strict  parasites  and 
do  not  find  the  conditions  for  their  development  outside  of  the  bodies 
of  the  animals  which  they  infest,  except  under  the  special  conditions 
in  which  bacteriologists  have  succeeded  in  cultivating  some  of  them. 
The  best  known  strict  parasites  are  the  tubercle  bacillus,  the  bacillus 
of  leprosy,  the  spirillum  of  relapsing  fever,  and  the  micrococcus  of 
gonorrhosa. 

There  can  be  but  little  doubt  that  even  the  strict  parasites,  at  some 
time  in  the  past,  were  also  saprophytes,  and  that  the  adaptation  to  a 
parasitic  mode  of  life  was  gradually  effected  under  the  laws  of  natural 
selection.  In  a  previous  chapter  (Section  III.,  Part  Second)  we  have 
referred  to  the  modifications  in  biological  characters  which  may 
occur  as  a  result  of  special  conditions  of  environment.  Thus  we  may 
obtain  non-chromogenic  varieties  of  species  which  usually  produce 
pigment,  or  non-pathogenic  varieties  of  bacteria  which  are  usually 
pathogenic.  There  is  also  evidence  that  the  tubercle  bacillus,  a  strict 


216  MODES   OF  ACTION. 

parasite,  may  be  so  modified,  by  cultivation  for  successive  genera- 
tions in  a  culture  medium  containing  glycerin,  that  it  will  finally 
grow  in  ordinary  beef  infusion,  thus  showing  a  tendency  to  adapt 
itself  to  a  saprophytic  mode  of  life. 

Some  of  the  saprophytic  bacteria  are  indirectly  pathogenic  bj 
reason  of  their  power  to  multiply  in  articles  of  food,  such  as  mill 
cheese,  fish,  sausage,  etc.,  and  there  produce  poisonous  ptomaine 
which,  when  these  articles  are  ingested,  give  rise  to  various  morbk 
symptoms,  such  as  vomiting,  gastric  and  intestinal  irritation,  fever, 
etc.     Or  similar  symptoms  may  result  from  the  multiplication  of 
bacteria  producing  toxic  ptomaines  in  the  alimentary  canal.    Nc 
doubt  gastric  and  intestinal  disorders  are  largely  due-  to  this  cause 
and  may  be  induced  by  a  variety  of  saprophytic  bacteria  when  thes 
establish  themselves  in  undue  numbers  in  any  portion  of  the  ali- 
mentary tract.     In  Asiatic  cholera  the  same  thing  occurs,  but  wit 
more  fatal  results  from  the  introduction  of  the  East  Indian  cholei 
germ  discovered  by  Koch.     This  is  pathogenic  for  man,  because  it  is 
able  to  multiply  rapidly  in  the  human  intestine,  and  there  produces 
toxic  substance  which,  being  absorbed,  gives  rise  to  the  morbid  phenc 
mena  of  the  disease.     The  spirillum  itself  does  not  enter  the  blood 
invade  the  tissues,  except  to  a  limited  extent  in  the  mucous  coat  of 
the  intestine,  and  the  true  explanation  of  its  pathogenic  power  is  nc 
doubt  that  which  has  been  given. 

Other  microorganisms  invade  the  tissues  and  multiply  in  cei 
tain  favorable  localities,  but  have  not  the  power  of  developing  in  the 
blood,  in  which  they  are  only  found  occasionally  and  in  very  small 
numbers  or  not  at  all.  Thus  the  typhoid  bacillus  locates  itself  in  the 
intestinal  glands,  in  the  spleen,  and  in  the  liver,  forming  colonies  of 
limited  extent,  and  evidently  not  finding  the  conditions  extremely 
favorable  for  its  growth,  inasmuch  as  it  does  not  take  complete  pos- 
session of  these  organs.  The  symptoms  which  result  from  its  pre- 
sence are  doubtless  partly  due  to  local  irritation,  disturbance  of  func- 
tion, and,  in  the  case  of  the  intestinal  glands,  necrotic  changes 
induced  by  it.  But  in  addition  to  this  its  pathogenic  action  depends 
upon  the  production  of  a  poisonous  ptomaine  which  has  been  isolated 
and  studied  by  the  German  chemist  Brieger  (typhotoxine). 

Certain  saprophytic  bacteria,  when  injected  beneath  the  skin  of  a 
susceptible  animal,  multiply  at  the  point  of  inoculation  and  invade 
the  surrounding  tissues,  giving  rise  in  some  instances  to  the  forma- 
tion of  a  local  abscess,  in  others  to  an  infiltration  of  the  tissues  with 
bloody  serum,  and  in  others  to  extensive  necrotic  changes.  These 
local  changes  are  due  not  simply  to  the  mechanical  presence  of  the 
microorganisms  which  induce  them,  but  to  chemical  products  evolved 
during  the  growth  of  these  pathogenic  bacteria.  Indeed,  their  patho- 


MODES   OF   ACTION.  217 

genie  power  evidently  depends,  in  some  instances  at  least,  upon  these 
toxic  products  of  their  growth,  by  which  the  vital  resisting  power  of 
the  tissues  is  overcome. 

Among  the  bacteria  which  in  this  way  produce  extensive  local 
inflammatory  and  necrotic  changes  are  certain  anaerobic  species 
found  in  the  soil  and  in  putrefying  material,  such  as  the  bacillus  of 
malignant  oedema  and  the  writer's  Bacillus  cadaveris.  The  bacillus 
of  symptomatic  anthrax,  an  infectious  disease  of  cattle,  acts  in  the' 
same  way.  All  of  these  produce  toxic  substances  which  have  a  very 
pronounced  local  action  upon  the  tissues  invaded  by  them.  Other 
bacteria,  while  they  develop  chiefly  in  the  vicinity  of  the  point  of 
entrance — by  accident  or  by  inoculation — produce  a  potent  toxic  sub- 
stance which  gives  rise  to  general  symptoms  of  a  serious  character, 
such  as  tetanic  convulsions  (bacillus  of  tetanus)  or  intense  fever  and 
nervous  phenomena  (micrococcus  of  erysipelas).  Again,  the  local 
irritation  resulting  from  the  presence  of  parasitic  bacteria  may  pri- 
marily give  rise  to  the  formation  of  new  growths  having  alow  grade 
of  vitality,  which  later  may  undergo  necrotic  changes,  as  in  tubercu- 
losis, glanders,  and  leprosy.  In  this  case  constitutional  symptoms 
are  not  present,  or  are  of  a  mild  character  during  the  development 
of  these  new  formations,  which  apparently  result  from  the  local  ac- 
tion of  substances  eliminated  during  the  growth  of  the  parasite, 
rather  than  from  its  simple  presence.  This  is  an  inference  based 
upon  the  fact  that  non-living  particles,  or  even  living  parasites,  as  in 
trichinosis,  do  not  produce  similar  new  growths  composed  of  cells/ 
but  become  encysted  in  a  fibrous  capsule. 

In  pneumonia  we  have  a  local  process  in  which  one  or  more  lobes 
of  the  lung  are  invaded  by  a  pathogenic  micrococcus  (Micrococcus 
pneumonise  crouposse)  which  induces  a  fibrinous  exudation  that  com- 
pletely fills  the  air  cells.  How  far  the  symptoms  of  the  disease  are 
due  to  the  local  inflammation  and  disturbance  of  function,  and  to 
what  extent  they  may  be  due  to  the  absorption  of  a  soluble  toxic 
substance  evolved  as  a  result  of  the  growth  of  the  micrococcus,  has 
not  been  determined.  But  the  mild  character  of  the  general  symp- 
toms when  a  limited  area  of  lung  tissue  is  involved  leads  to  the  in- 
ference that  the  pathogenic  power  of  this  particular  pathogenic 
microorganism  is  chiefly  exercised  locally. 

The  pus  cocci  and  various  other  saprophytic  bacteria,  when  intro- 
duced beneath  the  skin,  give  rise  to  the  formation  of  abscesses,  un- 
attended by  any  very  considerable  general  disturbance  ;  and  also  to 
secondary  purulent  accumulations — metastatic  abscesses. 

That  this  is  not  due  simply  to  their  mechanical  presence  is  shown 
by  the  fact  that  powdered  glass  and  other  inert  substances,  when 
thoroughly  sterilized,  do  not  give  rise  to  pus  formation  when  intro- 


218  MODES   OF   ACTION. 

duced  beneath  the  skin  or  injected  into  the  cavity  of  the  abdomen. 
On  the  other  hand,  it  has  been  demonstrated  by  the  experiments  of 
Grawitz,  De  Bary,  and  others  that  certain  chemical  substances 
which  act  as  local  irritants  when  brought  in  contact  with  the  tissues 
may  induce  pus  formation  quite  independently  of  microorganisms  : 
nitrate  of  silver,  oil  of  turpentine,  and  strong  liquor  ammonise  have 
been  shown  to  possess  this  power.  And  it  has  been  demonstrated  by 
the  recent  experiments  of  Buchner  that  sterilized  cultures  of  a  long 
list  of  different  bacteria — seventeen  species  tested — give  rise  to  sup- 
puration when  introduced  into  the  subcutaneous  tissues. 

Buchner  has  further  shown  that  this  property  of  inducing  pus  for- 
mation resides  in  the  dead  bacterial  cells  and  not  in  soluble  products- 
present  in  the  cultures.  For  the  clear  fluid  obtained  by  passing 
these  sterilized  cultures  through  a  porcelain  filter  gave  a  negative  re- 
sult, while  the  bacteria  retained  by  the  filter,  although  no  longer 
capable  of  development,  having  been  killed  by  heat,  invariably 
caused  suppuration. 

Individuals  suffering  from  malnutrition  are  more  susceptible  to 
invasion  by  specific  disease  germs  or  by  the  common  pus  cocci 
than  are  those  in  vigorous  health.  Thus  the  sufferers  from  starva- 
tion, from  crowd  poisoning,  sewer-gas  poisoning,  etc.,  are  not  only 
liable  to  be  early  victims  during  the  prevalence  of  an  epidemic  dis- 
ease, but  are  very  subject  to  abscesses,  boils,  ulcers,  etc.  A  slight 
abrasion  in  such  an  individual,  inoculated  by  the  ever-present  pus 
cocci,  may  give  rise  to  an  obstinate  ulcer  or  a  phlegmonous  inflam- 
mation. 

In  the  same  way  some  of  the  ordinary  saprophytes,  which  usually 
have  no  pathogenic  power,  may  be  pathogenic  for  an  animal  whose 
strength  is  reduced  by  disease  or  injury.  Thus  necrotic  changes 
may  occur  in  injured  tissues,  or  in  those  which  have  a  deficient  blood 
supply — from  occlusion  of  an  artery,  for  example — due  to  the  presence 
of  putrefactive  bacteria  which  are  incapable  of  development  in  the 
circulation  of  a  healthy  animal  or  in  healthy  tissues.  We  may  also 
have  a,  progressive  gangrene,  due  to  infection  of  wounds  by  bacteria 
which  are  able  to  invade  healthy  tissues.  This  is  seen  in  the  so- 
called  hospital  gangrene,  which  is  undoubtedly  due  to  microorgan- 
isms, although  the  species  concerned  in.  its  production  has  not  been 
determined,  owing  to  the  fact  that  modern  bacteriologists  have  had 
few,  if  any,  opportunities  for  studying  it.  The  history  of  the  disease, 
its  rapid  extension  in  infected  surgical  wards,  the  extensive  slough- 
ing which  occurs  within  a  few  hours  in  previously  healthy  wounds. 
and  the  effect  of  deep  cauterization  by  the  hot  iron,  nitric  acid,  or 
bromine  in  arresting  the  progress  of  the  disease,  all  support  this  vi<nv 
of  its  etiology.  Whether  it  is  due  to  a  specific  pathogenic  micro- 


MODES   OF   ACTION.  219 

organism,  or  to  exceptional  pathogenic  power  acquired  by  some  one 
of  the  common  bacteria  which  infest  suppurating  wounds,  cannot  be 
determined  in  the  absence  of  exact  experiments  by  modern  methods. 
But  the  latter  view  has  seemed  to  the  writer  the  most  probably  cor- 
rect. There  are  many  facts  which  go  to  show  that  pathogenic  viru- 
lence may  be  increased  by  cultivation  in  animal  fluids,  and  where 
wounded  men  are  brought  together  under  unfavorable  sanitary  con- 
ditions, as  has  been  the  case  where  hospital  gangrene  has  made  its 
appearance,  it  may  be  that  some  common  saprophyte  acquires  the 
power  of  invading  the  exposed  tissues  instead  of  simply  feeding  upon 
the  secretions  which  bathe  its  surface. 

Koch  has  described  a  progressive  tissue  necrosis  in  mice,  due  to  a 
streptococcus,  which  he  first  obtained  by  inoculating  a  mouse  in  the 
ear  with  putrid  material.  The  morbid  process  is  entirely  local  and 
rapidly  progressive,  causing  a  fatal  termination  in  about  three  days, 
without  invasion  of  the  blood. 

In  diphtheritic  inflammations  of  mucous  membranes  we  have 
a  local  invasion  of  the  tissues  and  a  characteristic  plastic  exudation. 
In  true  diphtheria  the  local  inflammation  and  necrotic  changes  in 
the  invaded  tissues  are  not  sufficient  to  account  for  the  serious  gen- 
eral symptoms,  and  we  now  have  experimental  evidence  that  the 
diphtheria  bacillus  produces  a  very  potent  toxic  substance  to  which 
these  symptoms  are  no  doubt  largely  due.  The  diphtheria  bacillus 
of  Lofner  appears  to  be  the  cause  of  the  fatal  malady  which  goes 
by  this  name,  but  undoubtedly  other  microorganisms  may  be  con- 
cerned in  the  formation  of  diphtheritic  false  membranes.  In  cer- 
tain forms  of  diphtheria,  and  especially  when  it  occurs  as  a  com- 
plication of  scarlet  fever,  measles,  and  other  diseases,  the  Klebs- 
Loffler  bacillus  is  absent,  and  a  streptococcus,  which  appears  to  be 
identical  with  Streptococcus  pyogenes,  is  found  in  considerable  num- 
bers and  is  probably  the  cause  of  the  diphtheritic  inflammation. 
An  epidemic  of  diphtheria  occurring  among  calves  was  studied  by 
Loffler,  and  is  ascribed  by  him  to  his  Bacillus  diphtherise  vitulo- 
rum.  The  same  bacteriologist  has  shown  that  the  diphtheria  of 
chickens  and  of  pigeons  is  due  to  a  specific  bacillus  which  differs 
from  that  found  in  human  diphtheria,  and  which  he  calls  Bacillus 
diphtherise  columbrarum. 

Recently  Prof.  Welch  has  studied  the  histological  lesions  pro- 
duced by  filtered  cultures  of  the  diphtheria  bacillus.  Cultures  in 
glycerin-bouillon,  several  weeks  old,  were  filtered  through  porce- 
lain, and  the  sterile  filtrate  was  injected  beneath  the  skin  of  guinea- 
pigs.  One  cubic  centimetre  of  this  filtrate  was  injected  into  a  gui- 
nea-pig on  the  10th  of  December,  and  two  cubic  centimetres  more  on 
the  14th  of  the  same  month.  The  animal  succumbed  at  the  end  of 


220  MODES   OP   ACTION. 

three  weeks  and  five  days  after  the  first  inoculation.  At  the  autopsy 
"  the  lymphatic  glands  of  the  inguinal  and  axillary  regions  were 
found  to  be  enlarged  and  reddened;  the  cervical  glands  were  swollen 
and  the  thyroid  gland  was  greatly  congested.  There  was  a  consider- 
able excess  of  clear  fluid  in  the  peritoneal  cavity.  Both  layers  of  the 
peritoneum  were  reddened,  the  vessels  of  the  visceral  layer  being  es- 
pecially injected.  The  spleen  was  enlarged  to  double  the  average 
size;  it  was  mottled,  and  the  white  follicles  were  distinctly  outlined 
against  the  red  ground.  The  liver  was  dark  in  color  and  contained 
much  blood.  .  .  .  The  kidneys  were  congested  and  the  cut  surface 
was  cloudy.  .  .  .  The  pericardial  sac  was  distended  with  clear  se- 
rum. Under  the  epicardium  were  many  ecchymotic  spots.  The 
lungs  exhibited  areas  of  intense  congestion  or  actual  hsemorrhage 
into  the  tissues.  .  .  .  The  histological  lesions  in  this  case  are  identi- 
cal with  those  observed  by  us  in  connection  with  the  inoculation  of 
the  living  organisms. " 

To  what  extent  non-specific  catarrhal  inflammations  of  mucous 
membranes  are  caused  by  the  local  action  of  microorganisms  has 
not  been  determined,  but  in  gonorrhoea  the  proof  is  now  considered 
satisfactory  that  the  "  gonococcus  "  of  Neisser  is  the  cause  of  the 
intense  local  inflammation  and  purulent  discharge.  In  this  disease 
the  action  of  the  pathogenic  microorganism  seems  to  be  limited  to 
the  tissues  invaded  by  it,  as  there  is  no  general  systemic  disturbance 
indicating  the  absorption  of  a  toxic  ptomaine. 

Chronic  catarrhal  inflammations  appear,  in  some  cases  at  least, 
to  be  kept  up  by  the  presence  of  microorganisms,  which  are  always 
found  in  the  discharges  from  inflamed  mucous  surfaces. 

The  influence  of  microorganisms,  and  especially  of  the  pus  cocci, 
in  preventing  the  prompt  healing  of  wounds,  is  now  well  established. 
An  extensive  suppurating  wound  or  collection  of  pus,  especially  if 
putrefactive  bacteria  are  present,  causes  fever  and  nervous  symp 
toms,  due  to  the  absorption  of  toxic  products.  More  intense  general 
symptoms  result  from  the  presence  of  the  streptococcus  of  pus  than 
from  the  less  pathogenic  staphylococci ;  this  is  seen  in  erysipelatous 
inflammations  and  in  puerperal  metritis  due  to  the  presence  of  this 
micrococcus.  Like  the  other  pus  cocci,  the  Streptococcus  pyogenes 
does  not  invade  the  blood,  but  when  introduced  into  the  subcuta- 
neous tissues  it  induces  a  local  inflammatory  process,  with  a  ten- 
dency to  pus  formation,  and  it  invades  the  neighboring  lymph  chan- 
nels, in  which  the  conditions  appear  to  be  especially  favorable  for  its 
multiplication. 

Finally,  certain  pathogenic  bacteria,  when  introduced  into  the 
bodies  of  susceptible  animals,  quickly  invade  the  blood  and  multiply 
in  it.  In  so  doing  they  necessarily  interfere  with  its  physiological 


MODES   OF   ACTION.  221 

functions  by  appropriating  for  their  own  use  material  required  for 
the  nutrition  of  the  tissues ;  and  at  the  same  time  toxic  substances 
are  formed  which  play  an  important  part  in  the  production  of  the 
morbid  phenomena,  which  in  this  class  of  diseases  very  commonly 
lead  to  a  fatal  result.  The  pathogenic  bacteria  which  invade  the 
blood  may  also,  in  certain  cases,  give  rise  to  local  necrosis  and  dis- 
turbance of  function  in  various  organs  in  a  mechanical  way  by 
blocking  up  the  capillaries. 

The  invasion  of  the  blood  which  occurs  in  anthrax  and  in  vari- 
ous forms  of  septicaemia  in  the  lower  animals,  induced  by  subcuta- 
neous inoculation  with  pure  cultures  of  certain  pathogenic  bacteria, 
does  not  generally  immediately  follow  the  inoculation.  Usualh-  a 
considerable  local  development  first  occurs,  which  gives  rise  to  more 
or  less  inflammation  of  the  invaded  tissues,  and  very  commonly  to 
an  effusion  of  bloody  serum  in  which  the  pathogenic  microorganism 
is  found  in  great  numbers.  Even  in  susceptible  animals  the  blood 
seems  to  offer  a  certain  resistance  to  invasion,  which  is  overcome 
after  a  time  by  the  vast  number  of  the  parasitic  host  located  in  the 
vicinity  of  the  point  of  inoculation,  aided  probably  by  the  toxic  sub- 
stances developed  as  a  result  of  their  vital  activity. 

The  experiments  of  Cheyne  (1886)  seem  to  show  that  in  the  case 
of  very  pathogenic  species,  like  the  anthrax  bacillus  or  Koch's  bacil- 
lus of  mouse  septicaemia,  a  single  bacillus  introduced  subcutaneously 
may  produce  a  fatal  result  in  the  most  susceptible  animals,  while 
greater  numbers  are  required  in  those  which  are  less  susceptible. 
Thus  a  guinea-pig  succumbed  to  general  infection  after  being  inocu- 
lated subcutaneously  with  anthrax  blood  diluted  to  such  an  extent 
that,  by  estimation,  only  one  bacillus  was  present  in  the  fluid  in- 
jected ;  and  a  similar  result  in  mice  was  obtained  with  Bacillus 
murisepticus.  In  the  case  of  the  microbe  of  fowl  cholera  (Bacillus 
septicsBmise  haemorrhagicae)  Cheyne  found  that  for  rabbits  the  fatal 
dose  is  300,000  or  more,  that  from  10,000  to  300,000  cause  a  local 
abscess,  and  that  less  than  10,000  produce  no  appreciable  effect. 
The  common  saprophyte  Proteus  vulgaris  was  found  to  be  patho- 
genic for  rabbits  when  injected  into  the  dorsal  muscles  in  sufficient 
numbers.  But,  according"  to  the  estimates  made,  225,000,000  were 
required  to  cause  death,  while  with  doses  of  from  9,000,000  to  112,- 
000,000  a  local  abscess  was  produced,  and  less  than  9,000,000  gave 
an  entirely  negative  result. 

Secondary  infections  occurring  in  the  course  of  specific  infec- 
tious diseases  are  of  common  occurrence.  Thus  a  pneumonia  may 
be  developed  in  the  course  of  an  attack  of  measles  or  of  typhoid 
fever  ;  or  infection  by  the  common  pus  cocci  in  the  course  of  scarlet 
fever,  typhoid  fever,  mumps,  etc.,  may  give  rise  to  local  abscesses, 


222  MODES   OF   ACTION. 

to  endocarditis,  etc.  Again,  mixed  infection  may  be  induced  by 
injecting  simultaneously  into  susceptible  animals  two  species  of  path- 
ogenic bacteria. 

Bumm,  Bockhart,  and  others  have  reported  cases  of  mixed  gonor- 
rhoeal  infection  in  which  the  pyogenic  micrococci  gave  rise  to  ab- 
scesses in  the  glands  of  Bartholin,  to  cystitis,  parametritis,  or  to 
"  gonorrhoeal  inflammation  "  of  the  knee  joint.  Babes  gives  numer- 
ous examples  of  mixed  infection  in  scarlet  fever  and  in  other  diseases 
of  childhood.  Anton  and  Fiitterer  have  studied  the  question  of 
secondary  infection  in  typhoid  fever.  Karlinski  has  reported  a  case 
of  secondary  infection  with  anthrax  in  a  case  of  typhoid  fever,  infec- 
tion occurring  by  way  of  the  intestine.  Many  other  examples  of 
secondary  or  mixed  infection  are  recorded  in  the  recent  literature  of 
bacteriology  and  clinical  medicine,  but  enough  has  been  said  to  call 
attention  to  the  importance  of  the  subject. 


II. 

CHANNELS   OF  INFECTION. 

WE  have  abundant  evidence  that  susceptible  animals  may  be  in- 
fected by  the  injection  of  various  pathogenic  bacteria  beneath  the 
skin,  and  accidental  infection  through  an  open  ivound  or  abrasion 
of  the  skin  is  the  common  mode  of  infection  in  tetanus,  erysipelas, 
hospital  gangrene,  and  the  "traumatic  infectious  diseases"  generally. 
Other  infectious  diseases,  like  anthrax  and  glanders,  are  frequently 
transmitted  in  the  same  way.  We  have  also  satisfactory  evidence 
that  tuberculosis  may  be  transmitted  to  man  by  the  accidental  inocu- 
lation of  an  open  wound  ;  and  in  view  of  the  fact  that  susceptible 
animals  are  readily  infected  in  this  way,  it  would  be  strange  if  it 
were  otherwise. 

The  question  whether  infection  may  occur  through  the  unbroken 
skin  has  been  studied  by  several  bacteriologists  and  an  affirmative 
result  obtained.  Thus  Schimmelbusch  produced  pustules  upon  the 
thigh  in  two  young  persons  suffering  from  pyaemia  by  rubbing  upon 
the  surface  a  pure  culture  of  Staphylococcus  pyogenes  aureus  which 
he  had  obtained  from  the  pus  of  a  furuncle.  The  same  author  also 
succeeded  in  infecting  rabbits  and  guinea-pigs  with  anthrax,  and 
rabbits  with  rabbit  septicaemia,  by  rubbing  pure  cultures  upon 
the  uninjured  skin.  Similar  results  had  previously  been  reported 
by  Roth,  who  also  showed  that  infection  might  occur  through 
the  uninjured  mucous  membrane  of  the  nose.  Machnoff  also  suc- 
ceeded in  infecting  guinea-pigs  with  anthrax  through  the  unin- 
jured skin  of  the  back,  and,  as  a  result  of  subsequent  microscop- 
ical examination  of  stained  sections,  arrived  at  the  conclusion  that 
the  principal  channel  through  which  infection  was  accomplished  was 
the  hair  follicles.  Braunschweig,  in  a  series  of  experiments  in  which 
he  introduced  various  pathogenic  bacteria  into  the  conjunctival  sac 
of  mice,  rabbits,  and  guinea-pigs,  obtained  a  negative  result  with  the 
anthrax  bacillus,  the  bacillus  of  mouse  septicaBmia,  the  bacillus  of 
chicken  cholera,  and  Micrococcus  tetragenus;  but  the  bacillus  ob- 
tained by  Ribbert  from  the  intestinal  diphtheria  of  rabbits  gave  a 
positive  result  in  five  mice,  two  guinea-pigs,  and  a  rabbit. 


224  CHANNELS   OF   INFECTION. 

Infection  through  the  mucous  membrane  of  the  intestine  no 
doubt  occurs  in  certain  diseases.  This  is  believed  to  be  a  common 
mode  of  the  infection  of  sheep  and  cattle  with  anthrax,  and  probably 
also  in  the  infectious  disease  of  swine  known  as  hog  cholera.  The 
anthrax  bacillus  would  be  destroyed  by  the  acid  secretions  of  the 
stomach,  but  if  spores  are  present  in  food  ingested  they  will  reach 
the  intestine.  The  experiments  of  Korkunoff  do  not,  however,  sup- 
port the  view  that  infection  is  likely  to  occur  in  this  way.  In  a  series 
of  experiments  upon  white  mice  fed  with  bread  containing  a  quantity 
of  anthrax  spores  the  result  was  uniformly  negative,  but  exception- 
ally infection  occurred  in  rabbits.  The  same  author  obtained  posi- 
tive results  in  rabbits  fed  with  food  to  which  a  pure  culture  of  the 
bacillus  of  chicken  cholera  had  been  added. 

Buchner,  in  experiments  upon  mice  and  guinea-pigs  fed  with 
material  containing  anthrax  spores,  obtained  a  positive  result  in  four 
out  of  thirty-three  animals.  This  is  no  doubt  the  usual  mode  of  in- 
fection in  typhoid  fever  in  man. 

Infection  may  also  occur  through  the  mucous  membrane  of  the 
respiratory  organs.  This  has  been  demonstrated  by  several  bac- 
teriologists, and  especially  by  the  experiments  of  Buchner,  who 
mixed  dried  anthrax  spores  with  ly  cop  odium  powder  or  pulverized 
charcoal,  and  caused  mice  and  guinea-pigs  to  respire  an  atmosphere 
containing  this  powder  in  suspension.  In  a  series  of  sixty-six  experi- 
ments fifty  animals  died  of  anthrax,  nine  of  pneumonia,  and  seven 
survived.  That  infection  did  not  occur  through  the  mucous  mem- 
brane of  the  alimentary  canal  was  proved  by  comparative  experi- 
ments in  which  animals  were  fed  with  double  the  quantity  of  spores 
used  in  the  inhalation  experiments.  Out  of  thirty-three  animals  fed 
in  this  way  but  four  contracted  anthrax.  That  infection  occurred 
through  the  lungs  was  also  demonstrated  by  the  microscopical  ex- 
amination of  sections  and  by  culture  experiments,  which  showed  that 
the  lungs  were  extensively  invaded,  while  in  many  cases  the  spleen 
contained  no  bacilli.  Positive  results  were  also  obtained  with  cul- 
tures of  the  anthrax  bacillus  not  containing  spores,  which  the  ani- 
mals were  made  to  inhale  in  the  form  of  spray.  But  in  this  case  a 
considerable  quantity  was  required,  and  a  sero-fibrinous  pneumonia 
was  usually  produced  as  well  as  general  infection ;  the  inhalation  of 
small  quantities  gave  no  result.  Positive  results  in  rabbits  were  also 
obtained  by  causing  them  to  inhale  considerable  quantities  of  a  spray 
containing  the  bacillus  of  chicken  cholera. 

The  fact  that  large  quantities  of  a  liquid  culture  of  these  virulent 
bacilli  were  required  to  infect  very  susceptible  animals  by  way  of 
the  pulmonary  mucous  membrane,  and  that  Buchner  failed  to  cause 
the  infection  of  these  animals  with  small  quantities  of  a  pure  culture 


CHANNELS   OF   INFECTION.  225 

inhaled  in  the  form  of  spray,  indicates  that  this  is  not  a  common 
mode  of  infection  in  the  absence  of  spores.  This  view  receives 
further  support  from  the  experiments  of  Hildebrandt,  who  made 
tracheal  fistulae  in  three  rabbits,  and,  after  the  wound  had  entirely 
healed,  injected  into  the  trachea  of  each  a  pure  culture  of  the  anthrax 
bacillus,  which  was  proved  to  be  virulent  by  inoculation  in  mice  or 
guinea-pigs.  All  of  the  animals  remained  in  good  health.  On  the 
other  hand,  three  rabbits  which  received  in  the  same  way  a  pure  cul- 
ture of  the  bacillus  of  rabbit  septicaemia  died  as  a  result  of  general 
infection. 

That  man  may  be  infected  with  anthrax  by  way  of  the  respira- 
tory organs  seems  to  be  well  established.  In  England  the  disease 
known  as  "wool-sorter's  disease"  results  from  infection  in  this  way 
among  workmen  engaged  in  sorting  wool,  which  is  liable  to  contain 
the  spores  of  the  anthrax  bacillus  when  obtained  from  the  skin  of  an 
animal  which  has  fallen  a  victim  to  this  disease.  That  infection 
occurs  through  the  lungs  is  shown  by  the  fact  that  these  organs  are 
first  involved,  the  disease  being,  in  fact,  a  pulmonic  anthrax. 

While  these  experiments  prove  the  possibility  of  infection  through 
the  respiratory  mucous  membrane,  other  experiments  made  by  Hil- 
debrandt show  that  under  ordinary  circumstances  bacteria  suspended 
in  the  air  do  not  reach  the  trachea  in  rabbits,  but  are  deposited  upon 
the  mucous  membrane  of  the  mouth,  nares,  and  fauces.  In  healthy 
rabbits  the  tracheal  mucus  was,  as  a  rule,  found  to  be  free  from  bac- 
teria, while  they  were  very  numerous  in  mucus  obtained  from  the 
mouth  or  nares.  But  when  a  rabbit  was  made  to  inhale  for  half  an 
hour  an  atmosphere  charged  with  the  spores  of  Aspergillus  f  umigatus 
their  presence  in  the  lungs  was  demonstrated  by  cultivation,  the  ani- 
.mal  being  killed  for  the  purpose  half  an  hour  after  the  inhalation 
experiment. 
15 


III. 

SUSCEPTIBILITY  AND   IMMUNITY. 

No  questions  in  general  biology  are  more  interesting,  or  more 
important  from  a  practical  point  of  view,  than  those  which  relate  to 
the  susceptibility  of  certain  animals  to  the  pathogenic  action  of  cer- 
tain species  of  bacteria,  and  the  immunity,  natural  or  acquired,  from 
such  pathogenic  action  which  is  possessed  by  other  animals.  It  has 
long  been  known  that  certain  infectious  diseases,  now  demonstrated 
to  be  of  bacterial  origin,  prevail  only  or  principally  among  animals 
of  a  single  species.  Thus  typhoid  fever,  cholera,  and  relapsing 
fever  are  diseases  of  man,  and  the  lower  animals  do  not  suffer  from 
them  when  they  are  prevailing  as  an  epidemic.  On  the  other  hand, 
man  has  a  natural  immunity  from  many  of  the  infectious  diseases  of 
the  lower  animals,  and  diseases  of  this  class  which  prevail  among 
animals  are  frequently  limited  to  a  single  species.  Again,  several 
species,  including  man,  may  be  susceptible  to  a  disease,  while  other 
animals  have  a  natural  immunity  from  it.  Thus  tuberculosis  is 
common  to  man,  to  cattle,  to  apes,  and  to  the  small  herbivorous  ani- 
mals, while  the  carnivora  are,  as  a  rule,  immune  ;  anthrax  may  be 
communicated  by  inoculation  to  man,  to  cattle,  to  sheep,  to  guinea- 
pigs,  rabbits,  and  mice,  but  the  rat,  the  dog,  carnivorous  animals,  and 
birds  are  generally  immune  ;  glanders,  which  is  essentially  a  disease 
of  the  equine  genus,  may  be  communicated  to  man,  to  the  guinea- 
pig,  and  to  field  mice,  while  house  mice,  rabbits,  cattle,  and  swine 
are  to  a  great  extent  immune. 

In  addition  to  this  general  race  immunity  or  susceptibility  we 
have  individual  differences  in  susceptibility  or  resistance  to  the  ac- 
tion of  pathogenic  bacteria,  which  may  be  either  natural  or  acquired. 
As  a  rule,  young  animals  are  more  susceptible  than  older  ones. 
Thus  in  man  the  young  are  especially  susceptible  to  scarlet  fever, 
whooping  cough,  and  other  "children's  diseases,"  and  after  forty 
years  of  age  the  susceptibility  to  tubercular  infection  is  very  much 
diminished.  Among  the  lower  animals  it  is  a  matter  of  common 
laboratory  experience  that  the  very  young  of  a  susceptible  species 
may  be  infected  when  inoculated  with  an  "attenuated  culture" 
which  older  animals  of  the  same  species  are  able  to  resist. 


SUSCEPTIBILITY   AMD    IMMUNITY.  227 

Considerable  differences  as  to  susceptibility  may  also  exist  among 
adults  of  the  same  species.  In  man  these  differences  in  individual 
susceptibility  to  infectious  diseases  are  frequently  manifested.  Of  a 
number  of  persons  exposed  to  infection  in  the  same  way,  some  may 
escape  entirely  while  others  have  attacks  differing  in  severity  and 
duration.  In  our  experiments  upon  the  lower  animals  we  constantly 
meet  with  similar  results,  some  individuals  proving  to  be  exception- 
ally resistant.  Exceptional  susceptibility  or  immunity  may  be  to 
some  extent  a  family  characteristic  or  one  of  race.  Thus  the  negro 
race  is  decidedly  less  subject  to  yellow  fever  than  the  white  race, 
and  this  disease  is  more  fatal  among  the  fair-skinned  races  of  the 
north  of  Europe  than  among  the  Latin  races  living  in  tropical  or  sub- 
tropical regions.  On  the  other  hand,  small-pox  appears  to  be  excep- 
tionally fatal  among  negroes  and  dark-skinned  races  generally. 

A  very  remarkable  instance  of  race  immunity  is  that  of  Algerian 
sheep  against  anthrax,  a  disease  which  is  very  fatal  to  other  sheep. 

In  the  instances  mentioned  race  immunity  is  probably  an  ac- 
quired tolerance  due  to  natural  selection  and  inheritance.  If,  for 
example,  a  susceptible  population  is  exposed  to  the  ravages  of  small- 
pox, the  least  susceptible  individuals  will  survive  and  may  be  the  pa- 
rents of  children  who  will  be  likely  to  inherit  the  special  bodily  char- 
acters upon  which  this  comparative  immunity  depends.  The  ten- 
dency of  continuous  or  repeated  exposure  to  the  same  pathogenic 
agent  will  evidently  be  to  establish  a  race  tolerance ;  and  there  is 
reason  to  believe  that  such  has  been  the  effect  in  the  case  of  some 
of  the  more  common  infectious  diseases  of  man,  which  have  been 
noticed  to  prevail  with  especial  severity  when  first  introduced  among 
a  virgin  population,  as  in  the  islands  of  the  Pacific,  etc. 

In  the  same  way  we  may  explain  the  immunity  which  carnivor- 
ous animals  have  for  anthrax  and  various  forms  of  septicaemia  to 
which  the  herbivora  are  very  susceptible  when  the  pathogenic  germ 
is  introduced  into  their  bodies  by  inoculation.  Prom  time  immemo- 
rial the  carnivora  have  been  in  the  habit  of  fighting  over  the  dead 
bodies  of  herbivorous  animals,  some  of  which  may  have  fallen  a  prey 
to  these  infectious  germ  diseases,  and  in  their  fighting  they  receive 
wounds,  inoculated  with  the  infectious  material  from  these  bodies, 
which  would  be  fatal  to  a  susceptible  animal.  If  at  any  time  in  the 
past  a  similar  susceptibility  existed  among  the  carnivora,  with  indi- 
vidual differences  as  to  resisting  power,  it  is  evident  that  there  would 
be  a  constant  tendency  for  the  most  susceptible  individuals  to  perish 
and  for  the  least  susceptible  to  survive. 

But  if  we  admit  this  to  be  a  probable  explanation  of  the  immu- 
nity of  carnivorous  animals  from  septic  infection,  we  have  not  yet 
explained  the  precise  reason  for  the  immunity  enjoyed  by  the 


228  SUSCEPTIBILITY   AND   IMMUNITY. 

selected  individuals  and  their  progeny.  The  essential  difference  be- 
tween a  susceptible  and  immune  animal  depends  upon  the  fact  that 
in  one  the  pathogenic  germ,  when  introduced  by  accident  or  ex- 
perimental inoculation,  multiplies  and  invades  the  tissues  or  the 
blood,  where,  by  reason  of  its  nutritive  requirements  and  toxic  pro- 
ducts, it  produces  changes  in  the  tissues  and  fluids  of  the  body  incon- 
sistent with  the  vital  requirements  of  the  infected  animal ;  while  in 
the  immune  animal  multiplication  does  not  occur  or  is  restricted  to  a- 
local  invasion  of  limited  extent,  and  in  which  after  a  time  the  re- 
sources of  nature  suffice  to  destroy  the  parasitic  invader. 

Now  the  question  is,  upon  what  does  this  essential  difference  de- 
pend ?  Evidently  upon  conditions  favorable  or  unfavorable  to  the 
development  of  the  pathogenic  germ ;  or  upon  its  destruction  by 
some  active  agent  present  in  the  tissues  or  fluids  of  the  body  of  the 
immune  animal;  or  upon  a  neutralization  of  its  toxic  products  by  some 
substance  present  in  the  body  of  the  animal  which  survives  infec- 
tion. 

What,  then,  are  the  unfavorable  conditions  which  may  be  supposed 
to  prevent  development  in  immune  animals  ?  In  the  first  place,  the 
temperature  of  the  body  may  not  be  favorable.  Certain  pathogenic 
bacteria  are  only  able  to  develop  within  very  narrow  temperature  lim- 
its, and,  if  all  other  conditions  were  favorable,  could  not  be  expected 
to  multiply  in  the  bodies  of  cold-blooded  animals.  Or  the  temperature 
of  warm-blooded  animals,  and  especially  of  fowls,  may  be  above  the 
point  favorable  for  their  development.  This  is  the  explanation 
offered  by  Pasteur  of  the  immunity  of  fowls,  which  are  usually  re- 
fractory against  anthrax  ;  and  in  support  of  this  view  he  showed  by 
experiment  that  when  chickens  are  refrigerated  after  inoculation,  by 
being  partly  immersed  in  cold  water,  they  are  liable  to  become  in- 
fected and  to  perish.  But,  as  pointed  out  by  Koch,  the  sparrow, 
which  has  a  temperature  as  high  as  that  of  the  chicken,  may  con- 
tract anthrax  without  being  refrigerated.  We  must  not,  therefore, 
too  hastily  conclude  that  the  success  in  Pasteur's  experiment  de- 
pended alone  upon  a  reduction  of  the  body  heat.  Gibier  has  shown 
that  the  anthrax  bacillus  may  multiply  in  the  bodies  of  frogs  or 
fish,  if  these  are  kept  in  water  having  a  temperature  of  35°  C. 
But  the  anthrax  bacillus  grows  within  comparatively  wide  tempera- 
ture limits,  while  other  pathogenic  bacteria  are  known  to  have  a 
more  restricted  temperature  range  and  would  be  more  decidedly 
influenced  by  this  factor — e.g.,  the  tubercle  bacillus. 

The  composition  of  the  body  fluids,  and  especially  their  reaction, 
is  probably  a  determining  factor  in  some  instances.  Thus  Behring 
has  ascribed  the  failure  of  the  anthrax  bacillus  to  develop  in  the 
white  rat,  which  possesses  a  remarkable  immunity  against  anthrax, 


SUSCEPTIBILITY   AND   IMMUNITY.  229 

to  the  highly  alkaline  reaction  of  the  blood  and  tissue  juices  of  this 
animal.  Behring  claims  to  have  obtained  experimental  proof  of  the 
truth  of  this  explanation  by  feeding  white  rats  on  an  exclusively 
vegetable  diet  or  by  adding  acid  phosphate  of  lime  to  their  food,  by 
which  means  this  excessive  alkalinity  of  the  blood  is  diminished. 
Rats  so  treated  are  said  to  lose  their  natural  immunity,  and  to  die  as 
a  result  of  inoculation  with  virulent  cultures  of  the  anthrax  bacillus. 

The  recent  experiments  of  Nuttall,  Behring,  Buchner,  and  others 
have  established  the  fact  that  recently  drawn  blood  of  various  ani- 
mals possesses  decided  germicidal  power,  and  Buchner  has  shown 
that  this  property  belongs  to  the  fluid  part  of  the  blood  and  not  to 
its  cellular  elements.  It  has  also  been  shown  that  aqueous  humor, 
the  fluid  of  ascites,  and  lymph  from  the  dorsal  lymph  sac  of  a  frog 
possess  the  same  power.  This  power  to  kill  bacteria  is  destroyed  by 
heat,  and  is  lost  when  the  blood  has  been  kept  for  a  considerable 
time,  but  it  is  not  neutralized  by  freezing.  Further,  this  power  to 
destroy  bacteria  differs  greatly  for  different  species,  being  very  de- 
cided in  the  case  of  certain  pathogenic  bacteria,  less  so  for  others, 
and  absent  in  the  case  of  certain  common  saprophytes.  Behring 
has  also  shown  that  the  blood  of  different  animals  differs  consider- 
ably in  this  regard,  and  that  the  blood  of  the  rat  and  of  the  frog, 
which  animals  have  a  natural  immunity  against  anthrax,  is  espe- 
cially fatal  to  the  anthrax  bacillus.  The  experiments  made  show 
that  this  germicidal  power  is  very  prompt  in  its  action,  but  that  it  is 
limited  as  to  the  number  of  bacteria  which  can  be  destroyed  by  a 
given  quantity  of  blood  serum.  When  the  number  is  excessive,  de- 
velopment occurs  after  an  interval  during  which  a  limited  destruc- 
tion has  taken  place.  It  would  appear  that  the  element  in  the  blood 
to  which  this  germicidal  action  is  due  is  neutralized  in  exercising 
this  power  ;  and  as,  independently  of  this,  blood  serum  is  an  excel- 
lent culture  medium  for  bacteria,  an  abundant  development  takes 
place  when  the  destruction  has  been  incomplete. 

Buchner  has  ascribed  this  remarkable  property  of  blood  serum  to 
the  presence  of  some  albuminoid  substance,  the  exact  nature  of 
which  he  was  not  able  to  determine  ;  and  quite  recently  Hankin 
(1891)  has  published  the  results  of  his  interesting  researches  con- 
firming this  view.  From  the  spleen  and  blood  serum  of  rats  he  has 
isolated  a  globulin  possessing  germicidal  properties,  to  which  he 
ascribes  the  power  of  rat's  blood  to  destroy  anthrax  bacilli,  without, 
however,  rejecting  the  view  that  the  excessive  alkalinity  of  the 
blood  of  this  animal  may  be  a  factor  in  producing  this  result.  The 
globulin  obtained  by  him  is  insoluble  in  water  or  in  alcohol  and  does 
not  dialyze. 

In  a  recent  communication  (1892)  Brieger,  Kitasato,  and  Wasser. 


230  SUSCEPTIBILITY   AND   IMMUNITY. 

mann  have  published  the  results  of  their  interesting  experiments 
with  a  bouillon  made  from  the  thymus  gland  of  the  calf.  It  was 
found  that  the  tetanus  bacillus  cultivated  in  this  bouillon  did  not 
form  spores  and  had  comparatively  little  virulence.  Mice  or  rabbits 
inoculated  with  it  in  small  doses — 0.001  to  0.2  cubic  centimetre  for 
a  mouse — proved  to  be  subsequently  immune.  And  the  blood  serum 
of  an  immune  rabbit  injected  into  the  peritoneal  cavity  of  a  mouse 
— 0. 1  to  0. 5  cubic  centimetre — was  found  to  give  it  immunity  from 
the  pathogenic  action  of  a  virulent  culture  of  the  tetanus  bacillus. 
Similar  results  were  obtained  with  several  other  pathogenic  bacteria 
cultivated  in  the  thymus  bouillon — spirillum  of  cholera,  bacillus  of 
diphtheria,  typhoid  bacillus.  We  give  here  the  directions  for  pre- 
paring the  thymus  bouillon  as  used  by  the  authors  named  : 

Two  or  three  thymus  glands  are  chopped  into  small  pieces  immediately 
after  they  are  taken  from  the  animal.  An  equal  part  of  distilled  water  is 
added  to  the  mass  and  stirred  for  some  time  ;  it  is  then  placed  in  an  ice  chest 
for  twelve  hours.  The  juices  are  now  expressed  through  gauze  by  means  of 
a  flesh  press.  A  clouded,  slimy  fluid  is  obtained,  which  constitutes  a  stock 
solution.  This  is  diluted  with  water,  and  a  certain  quantity  of  carbonate  of 
soda  is  added  to  the  solution  before  sterilization.  By  this  means  coagulation 
and  precipitation  of  the  active  substance  from  the  thymus  gland  are  avoided. 
The  exact  amount  of  water  and  of  sodium  carbonate  required  to  prevent  pre- 
cipitation must  be  determined  by  experiment,  as  it  differs  for  different  glands. 
Usually  an  equal  portion  of  water  and  sufficient  soda  solution  to  turn  litmus 
paper  feebly  blue  will  give  the  desired  result.  The  liquid  is  now  heated  in 
a  large  flask,  which  is  left  for  fifteen  minutes  in  the  steam  sterilizer.  The 
liquid  is  allowed  to  cool  and  then  filtered  through  fine  linen  to  remove  any 
suspended  coagula  ;  the  filtrate  has  a  milky  opalescence.  It  is  now  placed 
in  test  tubes  and  again  sterilized.  The  active  principle  is  precipitated  by  the 
addition  of  a  few  drops  of  acetic  acid . 

Additional  facts  bearing  upon  this  important  question  have  been 
developed  by  the  experiments  of  Ogata  and  Jasuhara,  which  show 
that  the  anthrax  bacillus,  when  cultivated  in  the  blood  of  an  immune 
animal  (rat,  dog,  or  frog),  becomes  attenuated  as  to  its  pathogenic 
power,  and  that  such  cultures  injected  into  a  susceptible  animal 
give  rise  to  a  mild  attack  followed  by  immunity.  Moreover,  the  in- 
jection of  a  small  amount — one  drop — of  blood  from  a  frog  or  a  dog 
into  a  mouse,  made  before  or  after  inoculating  it  with  a  virulent  cul- 
ture of  the  anthrax  bacillus,  was  found  to  protect  the  animal  from  a 
fatal  attack,  and,  after  its  recovery  from  the  mild  attack  resulting 
from  the  injection,  it  proved  to  be  immune.  The  protective  influence 
was  exercised  when  the  blood  was  injected  as  long  as  seventy-two 
hours  before  the  inoculation,  or  five  hours  after  ;  and  it  was  not  lost 
when  the  blood  was  kept  for  weeks  in  a  cool  place.  But  subjecting 
it  to  a  temperature  of  45°  C.  for  an  hour  completely  destroyed  its 
power  to  protect  inoculated  mice  from  a  fatal  attack  of  anthrax. 

Similar  results  have  been  reported  by  Behring  and  Kitasato  in 


SUSCEPTIBILITY   AND   IMMUNITY.  231 

experiments  made  by  them  relating  to  acquired  immunity  from  the 
pathogenic  action  of  the  bacillus  of  tetanus.  The  blood  of  animals 
which  had  been  made  immune  was  injected  into  a  susceptible  animal, 
and  at  the  end  of  twenty-four  hours  it  was  inoculated  with  a  virulent 
culture.  The  result  was  negative,  while  control  experiments  made 
with  the  same  culture  gave  a  uniformly  fatal  result.  So  small  a 
quantity  as  0.2  cubic  centimetre  of  blood  from  an  immune  rabbit,  in- 
jected into  the  cavity  of  the  abdomen  of  a  mouse,  was  sufficient  to 
protect  it  from  the  fatal  effects  of  a  virulent  culture  of  the  tetanus 
bacillus  injected  twenty-four  hours  later.  Further,  these  bacteriolo- 
gists have  shown  that  the  toxic  substances  present  in  a-  filtered  cul- 
ture of  the  tetanus  bacillus  are  neutralized  by  admixture  with  the 
blood  of  an  immune  rabbit.  A  culture  ten  days  old  was  sterilized 
by  filtration  ;  0.0001  cubic  centimetre  of  the  filtrate  was  found  to  kill 
a  mouse  with  certainty  in  less  than  two  days.  Of  this  filtered  cul- 
ture one  cubic  centimetre  was  added  to  five  cubic  centimetres  of  blood 
serum  from  an  immune  rabbit.  At  the  end  of  twenty-four  hours 
four  mice  received  each  0. 2  cubic  centimetre  of  the  mixture,  contain- 
ing more  than  three  hundred  times  the  fatal  dose  of  the  filtered  cul- 
ture. All  of  these  mice  survived  the  injection  and  proved  subse- 
quently to  be  immune  for  virulent  tetanus  bacilli,  while  four  control 
mice,  each  of  which  was  inoculated  with  0.0001  cubic  centimetre  of 
the  same  filtrate  unmixed  with  blood,  perished  within  thirty-six 
hours.  The  blood  of  rabbits  not  immune  was  without  effect  in  neu- 
tralizing the  toxic  substances  in  a  filtered  culture  of  the  tetanus  ba- 
cillus, as  was  also  the  blood  of  children,  calves,  sheep,  and  horses. 

The  same  bacteriologists  have  obtained  similar  results  by  mixing 
the  blood  of  an  animal  which  had  an  acquired  immunity  against  the 
poison  of  the  diphtheria  bacillus  with  filtered  cultures  of  this  bacillus. 
The  toxic  substances  present  are  neutralized  by  such  admixture,  but, 
according  to  Behring,  the  bacilli  themselves  are  not  destroyed  by  the 
blood  of  an  immune  animal. 

It  has  also  been  shown  by  experiment  that  naturally  Immune  ani- 
mals may  be  infected  by  the  addition  of  certain  substances  to  cultures 
of  pathogenic  bacteria.  Thus  Arloing  was  able  to  induce  symptomatic 
anthrax  in  animals  naturally  immune  by  mixing  with  his  cultures 
various  chemical  substances,  such  as  carbolic  acid,  pyrogallic  acid, 
and  especially  lactic  acid  (twenty  per  cent).  Leo  has  shown  that 
white  mice,  which  are  not  subject  to  the  pathogenic  action  of  the 
glanders  bacillus,  may  be  rendered  susceptible  by  feeding  them  for 
some  time  upon  phloridzin,  which  gives  rise  to  an  artificial  diabetes 
and  causes  the  tissues  to  be  impregnated  with  sugar. 

Before  discussing  the  rationale  of  acquired  immunity  a  state- 
ment of  certain  established  facts  will  ba  desirable. 


232  SUSCEPTIBILITY   AND   IMMUNITY. 

In  the  infectious  diseases  of  man  involving  the  system  generally, 
a  single  attack  commonly  confers  immunity  from  subsequent  attacks. 
This  is  true  of  the  eruptive  fevers,  of  typhoid  fever,  of  yellow  fever, 
of  mumps,  of  whooping  cough,  and,  to  some  extent  at  least,  of  syphi- 
lis. But  it  seems  not  to  be  the  case  in  epidemic  influenza  (la  grippe), 
in  croupous  pneumonia,  or  in  Asiatic  cholera,  in  which  diseases 
second  attacks  not  infrequently  occur.  In  localized  infectious  dis- 
eases such  as  diphtheria,  erysipelas,  and  gonorrhoea  one  attack  is  not 
protective.  Croupous  pneumonia  and  Asiatic  cholera  should  per- 
haps be  grouped  with  diphtheria  and  erysipelas  as  local  infections 
with  constitutional  symptoms  resulting  from  the  absorption  of  toxic 
products.  But  typhoid  fever,  mum^s,  and  whooping  cough,  in 
which  one  attack  gives  immunity,  are  also  localized  infectious  dis- 
eases. 

We  are  therefore  not  able  to  group  infectious  diseases  into  two 
classes,  in  one  of  which  there  is  a  general  infection  followed  by  im- 
munity, and  in  the  other  a  local  infection  without  subsequent  immu- 
nity. Indeed,  in  the  eruptive  fevers  and  specific  febrile  infectious 
diseases  generally  the  immunity  following  an  attack  is  not  abso- 
lute. Second  attacks  of  small-pox,  of  scarlet  fever,  and  of  yellow 
fever  occur  occasionally,  although  a  large  majority  of  those  who  suf- 
fer an  attack  of  one  of  these  diseases  have  an  immunity  for  life.  On 
the  other  hand,  in  the  diseases  mentioned  in  which  one  attack  is  not 
generally  recognized  as  protecting  from  future  attacks,  it  is  probable 
that  a  certain  degree  of  immunity,  of  limited  duration  perhaps,  is 
acquired.  In  localized  infection,  as  in  gonorrhoea  or  erysipelas,  the 
invaded  tissues  appear  after  a  time  to  acquire  a  certain  tolerance  to 
the  pathogenic  action  of  the  invading  parasite,  and  no  doubt  recovery 
from  these  diseases  would  in  many  cases  occur,  after  a  time,  without 
medical  interference.  In  diphtheria,  cholera,  and  epidemic  influenza 
second  attacks  do  not  often  occur  during  the  same  epidemic,  and 
there  is  reason  to  believe  that  a  recent  attack  affords  a  certain  degree 
of  immunity. 

That  immunity  may  result  from  a  comparatively  mild  attack  as 
well  as  from  a  severe  one  is  a  matter  of  common  observation  in  the 
case  of  small-pox,  scarlet  fever,  yellow  fever,  etc. ;  and  since  the  dis- 
covery of  Jenner  we  have  in  vaccination  a  simple  method  of  produc- 
ing immunity  in  the  first-mentioned  disease.  The  acquired  immunity 
resulting  from  vaccination  is  not,  however,  as  complete  or  as  per- 
manent as  that  which  results  from  an  attack  of  the  disease. 

These  general  facts  relating  to  acquired  immunity  from  infectious 
diseases  constituted  the  principal  portion  of  our  knowledge  with  re- 
ference to  this  important  matter  up  to  the  time  that  Pasteur  (1880) 
demonstrated  that  in  the  disease  of  fowls  known  as  chicken  cholera, 


SUSCEPTIBILITY   AND   IMMUNITY.  233 

which  he  had  proved  to  be  due  to  a  specific  microorganism,  a  mild 
attack  followed  by  immunity  may  be  induced  by  inoculation  with  an 
"  attenuated  virus  " — i.e.,  by  inoculation  with  a  culture  of  the  patho- 
genic microorganism  the  virulence  of  which  had  been  so  modified 
that  it  gave  rise  to  a  comparatively  mild  attack  of  the  disease  in 
question.  Pasteur's  original  method  of  obtaining  an  attenuated  virus 
consisted  in  exposing  his  cultures  for  a  considerable  time  to  the  ac- 
tion of  atmospheric  oxygen.  It  has  since  been  ascertained  that  the 
same  result  is  obtained  with  greater  certainty  by  exposing  cultures 
for  a  given  time  to  a  temperature  slightly  below  that  which  would 
destroy  the  vitality  of  the  pathogenic  microorganism,  and  also  by  ex- 
posure to  the  action  of  certain  chemical  agents  (see  Part  Second,  p. 
124). 

Pasteur  at  once  comprehended  the  importance  of  his  discovery, 
and  inferred  that  what  was  true,  of  one  infectious  germ  disease  was 
likely  to  be  true  of  others.  Subsequent  researches,  by  this  savant 
and  by  other  bacteriologists,  have  justified  this  anticipation,  and  the 
demonstration  has  already  been  made  for  a  considerable  number  of 
similar  diseases — anthrax,  symptomatic  anthrax,  rouget. 

A  virus  which  has  been  attenuated  artificially — by  heat,  for  ex- 
ample— may  be  cultivated  through  successive  generations  without  re- 
gaining its  original  virulence.  As  this  virulence  depends,  to  a  con- 
siderable extent  at  least,  upon  the  formation  of  toxic  products  during 
the  development  of  the  pathogenic  microorganism,  we  naturally  infer 
that  diminished  virulence  is  due  to  a  diminished  production  of  these 
toxic  substances. 

There  is  reason  to  believe  that  a  natural  attenuation  of  virulence 
may  occur  in  pathogenic  bacteria  which  are  able  to  lead  a  sapro- 
phytic  existence  during  their  multiplication  external  to  the  bodies  of 
living  animals,  and  the  comparatively  mild  character  of  some  epi- 
demics is  probably  due  to  this  fact. 

Again,  cultivation  within  the  body  of  a  living  animal  may,  in 
certain  cases,  cause  a  diminution  in  the  virulence  of  a  pathogenic 
microorganism.  Thus  Pasteur  and  Thuiller  have  shown  that  the 
microbe  of  rouget  when  inoculated  into  a  rabbit  kills  the  animal,  but 
that  its  pathogenic  virulence  is  nevertheless  so  modified  that  a  cul- 
ture made  from  the  blood  of  a  rabbit  killed  by  it  is  a  suitable  ' '  vac- 
cine "  for  the  pig. 

On  the  other  hand,  we  have  experimental  evidence  that  the  viru- 
lence of  attenuated  cultures  may  be  reestablished  by  passing  them 
through  the  bodies  of  susceptible  animals.  Thus  a  culture  of  the 
bacillus  of  rouget,  attenuated  by  having  been  passed  through  the 
body  of  a  rabbit,  is  restored  to  its  original  virulence  by  passing  it 
through  the  bodies  of  pigeons.  And  a  culture  of  the  anthrax  bacillus 


234  SUSCEPTIBILITY   AND    IMMUNITY. 

which  will  not  kill  an  adult  guinea-pig  may  be  fatal  to  a  very  young 
animal  of  the  same  species  or  to  a  mouse,  and  the  bacillus  cultivated 
from  the  blood  of  such  an  animal  will  be  found  to  have  greatly  in- 
creased virulence. 

In  Pasteur's  inoculations  against  anthrax  "attenuated"  cultures 
are  employed  which  contain  the  living  pathogenic  germ  as  well  as 
the  toxic  products  developed  during  its  growth.  Usually  two  inocu- 
lations are  made  with  cultures  of  different  degrees  of  attenuation — 
that  is  to  say,  with  cultures  in  which  the  toxic  products  are  formed 
in  less  amount  than  in  virus  of  full  power.  The  most  attenuated 
virus  is  first  injected,  and  after  some  time  the  second  vaccine,  which 
if  injected  first  might  have  caused  a  considerable  mortality.  The 
animal  is  thus  protected  from  the  pathogenic  action  of  the  most 
virulent  cultures. 

Now,  it  has  been  shown  by  recent  experiments  that  a  similar  im- 
munity may  result  from  the  injection  into  a  susceptible  animal  of  the 
toxic  products  contained  in  a  virulent  culture,  independently  of  the 
living  bacteria  to  which  they  owe  their  origin.  Chauveau,  in  1880, 
ascertained  that  if  pregnant  ewes  are  protected  against  anthrax  by 
inoculation  with  an  attenuated  virus,  their  lambs,  when  born,  also 
give  evidence  of  having  acquired  an  immunity  from  the  disease.  As 
the  investigations  of  Davaine  seemed  to  show  that  the  anthrax 
bacillus  cannot  pass  through  the  placenta  from  the  mother  to  the 
foatus,  the  inference  seemed  justified  that  the  acquired  immunity  of 
the  latter  was  due  to  some  soluble  substance  which  could  pass  the 
placental  barrier.  More  recent  researches  by  Strauss  and  Chamber- 
lain, Malvoz  and  Jacquet,  and  others,  show  that  the  placenta  is  not 
such  an  impassable  barrier  for  bacteria  as  was  generally  believed  at 
the  time  of  Chauveau's  experiments,  so  that  these  cannot  be  accepted 
as  establishing  the  inference  referred  to.  But  we  have  more  recent 
experimental  evidence  which  shows  that  immunity  may  result  from 
the  introduction  into  the  bodies  of  susceptible  animals  of  the  toxic 
substances  produced  by  certain  pathogenic  bacteria.  The  first  satis- 
factory experimental  evidence  of  this  important  fact  was  obtained  by 
Salmon  and  Smith  in  1886,  who  succeeded  in  making  pigeons  im- 
mune from  the  pathogenic  effects  of  cultures  of  the  bacillus  of  hog 
cholera  by  inoculating  them  with  sterilized  cultures  of  this  bacillus. 
In  1888  Roux  reported  similar  results  obtained  by  injecting  into  sus- 
ceptible animals  sterilized  cultures  of  the  anthrax  bacillus.  As 
already  stated,  Behring  and  Kitasato  have  quite  recently  reported 
their  success  in  establishing  immunity  against  virulent  cultures  of 
the  bacillus  of  tetanus  and  the  diphtheria  bacillus  by  inoculating 
susceptible  animals  with  filtered,  germ-free  cultures  of  these  patho- 
genic bacteria. 


SUSCEPTIBILITY   AND    IMMUNITY.  235 

In  Pasteur's  inoculations  against  hydrophobia,  made  subsequently 
to  infection  by  the  bite  of  a  rabid  animal,  an  attenuated  virus  is  in- 
troduced subcutaneously  in  considerable  quantity  by  daily  injections, 
and  immunity  is  established  during  the  interval — so-called  period  of 
incubation — which  usually  occurs  between  the  date  of  infection  and 
the  development  of  the  disease.  That  the  immunity  in  this  case  also 
depends  upon  the  introduction  of  a  chemical  substance  present  in  the 
desiccated  spinal  cord  of  rabbits  which  have  succumbed  to  rabies, 
which  is  used  in  these  inoculations,  is  extremely  probable.  But,  as 
the  germ  of  rabies  has  not  been  isolated  or  cultivated  artificially,  this 
has  not  yet  been  demonstrated.  Wooldridge  claims  to  have  made 
susceptible  animals  immune  against  anthrax  by  inoculating  them 
with  an  aqueous  extract  of  the  testicle  or  of  the  thymus  gland  of 
healthy  animals. 

We  may  mention  also  the  interesting  results  obtained  by  Em- 
merich, Freudenreich,  and  others,  who  have  shown  that  an  anthrax 
infection  in  a  susceptible  animal  inoculated  with  a  virulent  culture 
may  be  made  to  take  a  modified  and  non-fatal  course  by  the  simul- 
taneous or  subsequent  inoculation  of  certain  other  non-pathogenic 
bacteria — streptococcus  of  erysipelas,  Bacillus  pyocyanus. 

In  a  series  of  experiments  made  by  the  writer  about  two  years  ago 
evidence  was  obtained  that,  under  certain  circumstances,  immunity 
from  the  effects  of  one  pathogenic  bacillus  may  be  obtained  by  the 
previous  injection  of  a  pure  culture  of  a  different  species.  In  the 
experiments  referred  to  injections  into  the  cavity  of  the  abdomen 
of  a  culture  of  Bacillus  pyocyanus  protected  rabbits  from  the  lethal 
effects  of  Bacillus  cuniculicida  Havaniensis,  when  subsequently  in- 
jected into  the  cavity  of  the  abdomen  in  such  amount  (cne  cubic  centi- 
metre of  a  bouillon  culture)  as  invariably  proved  fatal  in  rabbits  not 
protected  by  such  injections. 

Before  considering  the  theories  which  have  been  offered  in  expla- 
nation of  acquired  immunity  it  is  desirable  to  call  attention  to  certain 
observations  which  have  been  made  during  the  past  few  years  relat- 
ing to  "chemiotaxis." 

The  term  chemiotaxis  was  first  used  by  Pfeffer  to  designate  the 
property,  observed  by  himself  and  others,  which  certain  living  cells 
exhibit  with  reference  to  non-living  organic  material,  and  by  virtue 
of  which  they  approach  or  recede  from  certain  substances.  The 
chemiotaxis  is  said  to  be  positive  when  the  living  cell  approaches,  and 
negative  when  it  recedes  from,  a  chemical  substance.  As  examples 
of  this  we  may  mention  the  approach  of  motile  bacteria  to  nutrient 
material  or  to  the  surface  of  a  liquid  medium  where  they  find  the 
oxygen  required  for  their  vital  activities  ;  and  of  leucocytes  to  cer- 
tain substances  when  these  are  introduced  beneath  the  skin  of  warm- 


236  SUSCEPTIBILITY   AND   IMMUNITY. 

or  cold-blooded  animals.  This  subject  has  Recently  received  much 
attention  and  has  been  studied  especially  by  Ali-Cohen,  Massart  and 
Bordet,  Gabritchevski,  and  others. 

According  to  Gabritchevski,  the  following  substances  have  a  neg- 
ative chemiotaxis  for  the  leucocytes  :  Sodium  chloride  in  ten-per-cent 
solution,  alcohol  in  ten-per-cent  solution,  quinine,  lactic  acid,  gly- 
cerin, chloroform,  bile.  On  the  other  hand,  a  positive  chemiotaxis 
is  excited  by  sterilized  or  non-sterilized  cultures  of  various  bacteria. 
This  is  shown  by  the  fact  that  when  a  small  capillary  tube,  closed  at 
one  end,  which  contains  the  substance  to  be  tested,  is  introduced  be- 
neath the  skin  of  an  animal,  the  leucocytes  are  repelled  from  the  tube 
by  certain  substances,  while  those  which  incite  positive  chemiotaxis 
cause  them  to  enter  the  tube  in  great  numbers.  The  experiments  of 
Buchner  seem  to  show  that  the  positive  chemiotaxis  induced  by 
sterilized  cultures  of  bacteria  introduced  beneath  the  skin  of  an 
animal,  is  due  to  the  proteid  contents  of  the  cells  rather  than  to  the 
chemical  products  elaborated  as  a  result  of  their  vital  activity.  But 
that  such  chemical  products  may,  in  some  instances  at  least,  produce 
a  positive  chemiotaxis  independently  of  the  bacteria  is  shown  by 
the  experiments  of  Gabritchevski  with  filtered  cultures  of  Bacillus 
pyocyanus — confirmed  by  Massart  and  Bordet. 

An  important  observation  made  by  Bouchard,  and  confirmed  by 
Massart  and  Bordet,  is  the  following:  When  a  tube  containing  a  cul- 
ture of  Bacillus  pyocyanus  is  introduced  beneath  the  skin  of  a  rabbit 
it  is  found,  at  the  end  of  a  few  hours,  to  contain  a  great  number  of 
leucocytes.  But  if  immediately  after  its  introduction  ten  cubic  centi- 
metres of  a  sterilized  culture  of  the  same  bacillus  are  injected  into  the 
circulation  through  a  vein,  very  few  leucocytes  enter  the  tube  intro- 
duced beneath  the  skin — that  is,  the  chemiotaxis  of  the  leucocytes 
for  the  bacilli  contained  in  the  tube  has  been  neutralized  by  injecting 
a  considerable  quantity  of  the  soluble  products  of  the  same  bacillus 
into  the  circulation. 

Buchner,  having  shown  that  the  bacterial  cells  contain  a  proteid 
substance  which  attracts  the  leucocytes,  experimented  with  various 
other  proteids  and  found  that  gluten,  casein  from  wheat,  and  legumin 
from  peas  had  a  similar  effect.  Starch  has  no  effect,  but  a  mass  of 
flour,  made  from  wheat  or  from  peas,  introduced  beneath  the  skin  of 
a  rabbit  or  of  a  guinea-pig,  with  antiseptic  precautions,  in  the  course 
of  a  day  or  two  is  enveloped  and  penetrated  by  immense  numbers  of 
leucocytes.  If,  instead  of  introducing  these  substances  which  induce 
positive  chemiotaxis  beneath  the  skin,  they  are  injected  into  the  cir- 
culation, Buchner  has  shown  that  a  great  increase  in  the  number  of 
leucocytes  occurs. 


SUSCEPTIBILITY   AND    IMMUNITY.  237 

THEORIES    OF   IMMUNITY. 

Exhaustion  Theory. — For  a  time  Pasteur  supported  the  view 
that  during  an  attack  of  an  infectious  disease  the  pathogenic  micro- 
organism, in  its  multiplication  in  the  body  of  a  susceptible  animal, 
exhausts  the  supply  of  some  substance  necessary  for  its  development, 
that  this  substance  is  not  subsequently  reproduced,  and  that  conse- 
quently the  same  pathogenic  germ  cannot  again  multiply  in  the  body 
of  the  protected  animal.  This  view  is  sustained  in  a  memoir  pub- 
lished in  the  Comptes  Bendus  of  the  French  Academy  in  1880,  in 
which  Pasteur  says  : 

"  It  is  the  life  of  a  parasite  in  the  anterior  of  the  body  which  produces  the 
malady  commonly  called  '  cholera  des  ponies,1  and  which  causes  death. 
From  the  moment  when  this  culture  (i.e.,  the  multiplication  of  the  parasite) 
is  no  longer  possible  in  the  fowl  the  sickness  cannot  appear.  The  fowls  are 
then  in  the  constitutional  state  of  fowls  not  subject  to  be  attacked  by  the 
disease.  These  last  are  as  if  vaccinated  from  birth  for  this  malady,  because 
the  foetal  evolution  has  not  introduced  into  their  bodies  the  material  neces- 
sary to  support  the  life  of  the  microbe,  or  these  nutritive  materials  have 
disappeared  at  an  early  age. 

"Certainly  one  should  not  be  surprised  that  there  may  be  constitutions 
sometimes  susceptible  and  sometimes  rebellious  to  inoculation — that  is  to 
say,  to  the  cultivation  of  a  certain  virus — when,  as  I  have  announced  in  my 
first  note,  one  sees  a  preparation  of  beer  yeast  made,  exactly  like  one  from 
the  muscles  of  fowls  (bouillon),  to  show  itself  absolutely  unsuited  for  the  cul- 
tivation of  the  parasite  of  fowl  cholera,  while  it  is  admirably  adapted  to  the 
cultivation  of  a  multitude  of  microscopic  species,  notably  to  the  bacteride 
charbonneuse  (Bacillus  aiithracis). 

' '  The  explanation  to  which  these  facts  conduct  us,  as  well  of  the  consti- 
tutional resistance  of  some  individuals  as  of  the  immunity  produced  by 
protective  inoculations,  is  only  natural  when  we  consider  that  every  culture, 
in  general,  modifies  the  medium  in  which  it  is  effected — a  modification  of 
the  soil  when  it  relates  to  ordinary  plants;  a  modification  of  plants  and  ani- 
mals when  it  relates  to  their  parasites  ;  a  modification  of  our  culture  liquids 
when  it  relates  to  mucedines,  vibrionie'/is,  or  ferments. 

"  These  modifications  are  manifested  and  characterized  by  the  circum- 
stance that  new  cultivations  of  the  same  species  in  these  media  become 
promptly  difficult  or  impossible.  If  we  sow  chicken  bouillon  with  the  mi- 
crobe of  fowl  cholera,  and,  after  three  or  four  days,  filter  the  liquid  in  order 
to  remove  all  trace  of  the  microbe,  and  subsequently  sow  anew  in  the  fil- 
tered liquid  this  pai'asite,  it  will  be  found  quite  powerless  to  resume  the  most 
feeble  development.  The  liquid,  which  is  perfectly  limpid  after  being  fil- 
tered, retains  its  limpidity  indefinitely. 

"How  can  we  fail  to  believe  that  by  cultivation  in  the  fowl  of  the  atten- 
uated virus  we  place  its  body  in  the  state  of  this  filtered  liquid  which  can 
no  longer  cultivate  the  microbe  ?  The  comparison  can  be  pushed  still 
further;  for  if  we  filter  the  bouillon  containing  the  microbe  in  full  develop- 
ment, not  on  the  fourth  day  of  culture,  but  on  the  second,  the  filtered  liquid 
will  still  be  able  to  support  the  development  of  the  microbe,  although  with 
less  energy  than  at  the  outset.  We  comprehend,  then,  that  after  a  cultiva- 
tion of  the  modified  (attenue)  microbe  in  the  body  of  the  fowl  we  may  not 
have  removed  from  all  parts  of  its  body  the  aliment  of  the  microbe.  That 
which  remains  will  permit,  then,  a  new  culture,  but  in  a  more  restricted 
measure. 

' '  This  is  the  effect  of  a  first  inoculation  ;  subsequent  inoculations  will 


"338  SUSCEPTIBILITY   AND   IMMUNITY. 

remove  progressively  all  the  material  necessary  for  the  development  of  the 
parasite. " 

In  discussing  this  theory,  in  a  paper  published  in  the  American 
Journal  of  the  Medical  Sciences  (April,  1881),  the  writer  says: 

"Let  us  see  where  this  hypothesis  leads  us.  In  the  first  place,  we  must 
have  a  material  of  small-pox,  and  a  material  of  measles,  and  a  material  of 
scarlet  fever,  etc.,  etc.  Then  we  must  admit  that  each  of  these  different 
materials  has  been  formed  in  the  system  and  stored  up  for  these  emergencies 
— attacks  of  the  diseases  in  question — for  we  can  scarcely  conceive  that  they 
were  all  packed  away  in  the  germ  cell  of  the  mother  and  the  sperm  cell  of 
the  father  of  each  susceptible  individual.  If,  then,  these  peculiar  materials 
have  been  formed  and  stored  up  during  the  development  of  the  individual, 
how  are  we  to  account  for  the  fact  that  no  new  production  takes  place  after 
an  attack  of  any  one  of  the  diseases  in  question  ? 

"Again,  how  shall  we  account  for  the  fact  that  the  amount  of  material 
which  would  nourish  the  small-pox  germ,  to  the  extent  of  producing  a  case 
of  confluent  small-pox,  may  be  exhausted  by  the  action  of  the  attenuated 
virus  (germ)  introduced  by  vaccination  ?  Pasteur's  comparison  of  a  fowl 
protected  by  inoculation  with  the  microbe  of  fowl  cholera,  with  a  culture 
fluid  in  which  the  growth  of  a  particular  organism  has  exhausted  the  pabu- 
lum necessary  for  the  development  of  additional  organisms  of  the  same  kind, 
does  not  seem  to  me  to  be  a  just  one,  as  in  the  latter  case  we  have  a  limited 
supply  of  nutriment,  while  in  the  former  we  have  new  supplies  constantly 
provided  of  the  material— food — from  which  the  whole  body,  including  the 
hypothetical  substance  essential  to  the  development  of  the  disease  germ,  was 
built  up  prior  to  the  attack.  Besides  this  we  have  a  constant  provision  for 
the  elimination  of  effete  and  useless  products. 

"  This  hypothesis,  then,  requires  the  formation  in  the  human  body,  and 
the  retention  up  to  a  certain  time,  of  a  variety  of  materials  which,  so  far  as 
we  can  see,  serve  no  purpose  except  to  nourish  the  germs  of  various  specific 
diseases,  and  which,  having  served  this  purpose,  are  not  again  formed  in  the 
same  system,  subjected  to  similar  external  conditions,  and  supplied  with  the 
same  kind  of  nutriment." 

It  is  unnecessary  to  discuss  this  hypothesis  any  further,  inasmuch 
as  it  is  no  longer  sustained  by  Pasteur  or  his  pupils,  and  is  evidently 
untenable. 

The  Retention  Theory,  proposed  by  Chauveau  (1880),  is  subject  to 
similar  objections.  According  to  this  view,  certain  products  formed 
;  during  the  development  of  a  pathogenic  microorganism  in  the  body 
of  a  susceptible  animal  accumulate  during  the  attack  and  are  subse- 
quently retained,  and,  being  prejudicial  to  the  growth  of  the  particu- 
lar microorganism  which  produced  them,  a  second  infection  cannot 
occur.  Support  for  this  theory  has  been  found  by  its  advocates  in 
the  fact  that  various  processes  of  fermentation  are  arrested  after  a 
time  by  the  formation  of  substances  which  restrain  the  development 
of  the  microorganisms  to  which  they  are  due.  But  in  the  case  of  a 
living  animal  the  conditions  are  very  different,  and  it  is  hard  to  con- 
ceive that  adventitious  products  of  this  kind  could  be  retained  for 
years,  when  in  the  normal  processes  of  nutrition  and  excretion  the 
tissues  and  fluids  of  the  body  are  constantly  undergoing  change. 
Certainly  the  substances  which  arrest  ordinary  processes  of  fermen- 


SUSCEPTIBILITY   AND   IMMUNITY.  239 

tation  by  their  accumulation  in  the  fermenting  liquid,  such  as  alco- 
hol, lactic  acid,  phenol,  etc. ,  would  not  be  so  retained.  But  we  can- 
not speak  so  positively  with  reference  to  the  toxic  albuminous 
substances  which  recent  researches  have  demonstrated  to  be  present 
in  cultures  of  some  of  the  best  known  pathogenic  bacteria.  It  is 
difficult,  however,  to  believe  that  an  individual  who  has  passed 
through  attacks  of  half  a  dozen  different  infectious  diseases  carries 
about  with  him  a  store  of  as  many  different  chemical  substances  pro- 
duced during  these  attacks,  and  sufficient  in  quantity  to  prevent  the 
development  of  the  several  germs  of  these  diseases.  Nor  does  the 
experimental  evidence  relating  to  the  action  of  germicide  and  germ- 
restraining  agents  justify  the  view  that  a  substance  capable  of 
preventing  the  development  of  one  microorganism  should  be  with- 
out effect  upon  others  of  the  same  class ;  but  if  we  accept  the  re- 
tention hypothesis  we  must  admit  that  the  inhibiting  substance 
produced  by  each  particular  pathogenic  germ  is  effective  only  in 
restraining  the  development  of  the  microbe  which  produced  it  in  the 
first  instance. 

Pasteur  discusses  this  hypothesis  in  his  paper  from  which  we 
have  already  quoted,  as  follows  : 

"We  may  admit  the  possibility  that  the  development  of  the  microbe,  in 
place  of  removing  or  destroying  certain  matters  in  the  bodies  of  the  fowls, 
adds,  on  the  contrary,  something  which  is  an  obstacle  to  the  future  develop- 
ment of  this  microbe.  The  history  of  the  life  of  inferior  beings  authorizes 
such  a  supposition.  The  excretions  resulting  from  vital  processes  may  arrest 
vital  processes  of  the  same  nature.  In  certain  fermentations  we  see  anti- 
septic products  make  their  appearance  during,  and  as  a  result  of,  the  fer- 
mentation, which  put  an  end  to  the  active  life  of  the  ferments  and  arrest 
the  fermentations  long  before  they  are  completed.  In  the  cultivation  of  our 
microbe,  products  may  have  been  formed  the  presence  of  which,  possibly, 
may  explain  the  protection  following  inoculation. 

"Our  artificial  cultures  permit  us  to  test  the  truth  of  this  hypothesis. 
Let  us  prepare  an  artificial  culture  of  the  microbe,  and  after  having  evapo- 
rated it,  in  vacuo,  without  heat,  let  us  bring  it  back  to  its  original  volume 
by  means  of  fresh  chicken  bouillon.  If  the  extract  contains  a  poison  for 
the  life  of  the  microbe,  and  if  this  is  the  cause  of  its  failure  to  multiply  in  the 
filtered  liquid,  the  new  liquid  should  remain  sterile.  Now,  this  is  not  the  case. 
We  cannot,  then,  believe  that  during  the  life  of  the  parasite  certain  substances 
are  produced  which  are  capable  of  arresting  its  ulterior  development." 

This  experiment  of  Pasteur  appears  to  be  conclusive  so  far  as  the 
particular  pathogenic  microorganism  referred  to  is  concerned ;  and 
we  may  say,  in  brief,  that  more  recent  investigations  do  not  sustain 
the  view  that  acquired  immunity  is  due  to  the  retention  of  products 
such  as  are  formed  by  pathogenic  bacteria  in  artificial  culture  media, 
and  which  act  by  destroying  these  bacteria  or  restraining  their  devel- 
opment when  they  are  introduced  into  the  bodies  of  immune  animals. 

Moreover,  if  we  suppose  that  the  toxic  substances  which  give 
pathogenic  power  to  a  particular  microorganism  are  retained  in  the 


240  SUSCEPTIBILITY  AND    IMMUNITY. 

body  of  an  immune  animal,  we  must  admit  that  the  animal  has  ac- 
quired a  tolerance  to  the  pathogenic  action  of  these  toxic  substances, 
for  their  presence  no  longer  gives  rise  to  any  morbid  phenomena. 
And  this  being  the  case,  we  are  not  restricted  to  the  explanation 
that  immunity  depends  upon  a  restraining  influence  exercised  upon 
the  microbe  when  subsequently  introduced. 

Another  explanation  offers  itself,  viz.,  that  immunity  depends 
upon  an  acquired  tolerance  to  the  toxic  products  of  pathogenic 
bacteria.  This  is  a  view  which  the  writer  has  advocated  in  various 
published  papers  since  1881.  In  a  paper  contributed  to  the  Ameri- 
can Journal  of  the  Medical  Sciences  in  April,  1881,  it  is  presented 
in  the  following  language  : 

"The  view  that  I  am  endeavoring-  to  elucidate  is  that,  during1  a  non- 
fatal  attack  of  one  of  the  specific  diseases,  the  cellular  elements  implicated 
which  do  not  succumb  to  the  destructive  influence  of  the  poison  acquire  a 
tolerance  to  this  poison  which  is  transmissible  to  their  progeny,  and  which 
is  the  reason  of  the  exemption  which  the  individual  enjoys  from  future 
attacks  of  the  same  disease. "  l 

In  my  chapter  on  "Bacteria  in  Infectious  Diseases,"  in  "Bac- 
teria," published  in  the  spring  of  1884,  but  placed  in  the  hands  of  the 
publishers  .in  1883,  I  say: 

"  It  may  be  that  the  true  explanation  of  the  immunity  afforded  by  a  mild 
attack  of  an  infectious  germ  disease  is  to  be  found  in  an  acquired  tolerance  to 
the  action  of  a  chemical  poison  produced  by  the  microorganism,  and  conse- 
quent ability  to  bring  the  resources  of  nature  to  bear  to  restrict  invasion  by 
the  parasite." 

The  "resources  of  nature"  are  referred  to  in  the  same  chapter  as 
follows  : 

"The  hypothesis  of  Pasteur  would  account  for  the  fact  that  one  individual 
suffers  a  severe  attack  and  another  a  mild  attack  of  an  infectious  disease, 
after  being  subjected  to  the  influence  of  the  poison  under  identical  circum- 
stances, by  the  supposition  that  the  pabulum  required  for  the  development 
of  this  particular  poison  is  more  abundant  in  the  body  of  one  individual 
than  in  the  other.  The  explanation  which  seems  to  us  more  satisfactory  is 
that  the  vital  resistance  offered  by  the  cellular  elements  in  the  bodies  of 
these  two  individuals  was  not  the  same  for  this  poison.  It  is  well  known 
that  in  conditions  of  lowered  vitality  resulting  from  starvation,  profuse 
discharges,  or  any  other  cause,  the  power  to  resist  disease  poisons  is  greatly 
diminished,  and,  consequently,  that  the  susceptibility  of  the  same  individual 
differs  at  different  times. 

"From  our  point  of  view,  the  blood,  as  it  is  found  within  the  vessels  of  a 
living  animal,  is  not  simply  a  culture  fluid  maintained  at  a  fixed  tempera- 
ture, but  under  these  circumstances  is  a  tissue,  the  histological  elements  of 
which  present  a  certain  vital  resistance  to  pathogenic  organisms  which  may 
be  introduced  into  the  circulation. 

"  If  we  add  a  small  quantity  of  a  culture  fluid  containing  the  bacteria  of 
putrefaction  to  the  blood  of  an  animal,  withdrawn  from  the  circulation  into 
a  proper  receptacle  and  maintained  in  a  culture  oven  at  blood  heat,  we  will 
find  that  these  bacteria  multiply  abundantly,  and  evidence  of  putrefactive 

1  "  What  is  the  Explanation  of  the  Protection  from  Subsequent  Attacks,  result- 
ing from  an  Attack  of  Certain  Diseases,  etc  ?  ''  American  Journal  of  the  Medical 
Sciences,  April,  1881,  p.  37(5. 


SUSCEPTIBILITY   AND    IMMUNITY.  241 

decomposition  will  soon  be  perceived.  But  if  we  inject  a  like  quantity  of 
the  culture  fluid  with  its  contained  bacteria  into  the  circulation  of  a  living- 
animal,  not  only  does  no  increase  and  no  putrefactive  change  occur,  but  the 
bacteria  introduced  quickly  disappear,  and  at  the  end  of  an  hour  or  two  the 
most  careful  microscopical  examination  will  not  reveal  the  presence  of  a 
single  bacterium.  This  difference  we  ascribe  to  the  vital  properties  of  the 
fluid  as  contained  in  the  vessels  of  a  living  animal;  and  it  seems  probable 
that  the  little  masses  of  protoplasm  known  as  white  blood  corpuscles  are  the 
essential  histological  elements  of  the  blood,  so  far  as  any  manifestation  of 
vitality  is  concerned.  The  ivriter  has  elsewhere  (1881)  suggested  that  the 
disappearance  of  the  bacteria  from  the  circulation,  in  the  experiment 
referred  to,  may  be  effected  by  the  white  corpuscles,  which,  it  is  well  known, 
pick  up,  after  the  manner  of  amoebae,  any  particles,  organic  or  inorganic, 
which  come  in  their  way.  And  it  requires  no  great  stretch  of  credulity  to 
believe  that  they  may,  like  an  amoeba,  digest  and  assimilate  the  protoplasm 
of  the  captured  bacterium,  thus  putting  an  end  to  the  possibility  of  its  do* 
ing  any  harm. 

"  In  the  case  of  a  pathogenic  organism  we  may  imagine  that,  when  cap- 
tured in.  this  way,  it  may  share  a  like  fate  if  the  captor  is  not  paralyzed  by 
some  potent  poison  evolved  by  it,  or  overwhelmed  by  its  superior  vigor  and 
rapid  multiplication.  In  the  latter  e~ent  the  active  career  of  our  conserva- 
tive white  corpuscle  would  be  quickly  terminated  and  its  protoplasm  would 
serve  as  food  for  the  enemy.  It  is  evident  that  in  a  contest  of  this  kind  the 
balance  of  power  would  depend  upon  circumstances  relating-  to  the  inherited 
vital  characteristics  of  the  invading  parasite  and  of  the  invaded  leucocyte." 

In  the  same  chapter  the  writer  quotes  from  his  paper  on  acquired 
immunity,  published  in  1881,  as  follows  : 

"The  difficulties  into  which  this  hypo  thesis  [the  exhaustion  theory  of  Pas- 
teur] leads  us  certainly  justify  us  in  looking  further  for  an  explanation  of  the 
phenomena  in  question.  This  explanation  is,  I  believe,  to  be  found  in  the 
peculiar  properties  of  the  protoplasm,  which  is  the  essential  framework  of 
every  living  organism.  The  properties  referred  to  are  the  tolerance  which 
living  protoplasm  may  acquire  to  certain  agents  which,  ir.  the  first  instance, 
have  an  injurious  or  even  fatal  influence  upon  its  vital  activity  ;  and  the 
property  which  it  possesses  of  transmitting-  its  peculiar  qualities,  inherent  or 
acquired,  through  numerous  generations,  to  its  offshoots  or  progeny. 

"Protoplasm  is  the  essential  living  portion  of  the  cellular  elements  of  ani- 
mal and  vegetable  tissues ;  but  as  our  microscopical  analysis  of  the  tissues  has 
not  gone  beyond  the  cells  of  which  they  are  composed,  and  is  not  likely  to 
reveal  to  us  the  complicated  molecular  structure  of  the  protoplasm,  upon 
which,  possibly,  the  properties  under  consideration  depend,  it  will  be  best, 
for  the  present,  to  limit  ourselves  to  a  consideration  of  the  living  cells  of  the 
body.  These  cells  are  the  direct  descendants  of  the  pre-existent  cells,  and 
may  all  be  traced  back  to  the  sperm  cell  and  the  germ  cell  of  the  parents. 
Now,  the  view  which  I  am  endeavoring  to  elucidate  is  that,  during  a  non- 
fatal  attack  of  one  of  the  specific  diseases,  the  cellular  elements  implicated, 
which  do  not  succumb  to  the  destructive  influence  of  the  poison,  acquire  a 
tolerance  to  this  poison  which  is  transmissible  to  their  progeny,  and  which 
is  the  reason  of  the  exemption  which  the  individual  enjoys  from  future 
attacks  of  the  same  disease. 

"  The  known  facts  in  regard  to  the  hereditary  transmission  by  cells  of  ac- 
quired properties  make  it  easy  to  believe  in  the  transmission  of  such  a 
tolerance  as  we  imagine  to  be  acquired  during  the  attack;  and  if  it  is  shown 
by  analogy  that  there  is  nothing  improbable  in  the  hypothesis  that  such  a 
tolerance  is  acquired,  we  shall  have  a  rational  explanation,  not  of  heredity 
and  of  the  mysterious  properties  of  protoplasm,  but  of  the  particular  result 
under  consideration.  The  transmission  of  acquired  properties  is  shown  in 
the  budding  and  grafting  of  choice  fruits  and  flowers,  produced  by  cultiva- 

16 


242  SUSCEPTIBILITY   AND   IMMUNITr. 

tion,  upon  the  wild  stock  from  which  they  originated.  The  acquired  proper- 
ties are  transmitted  indefinitely;  and  the  same  sap  which  on  one  twig  nour- 
ishes a  sour  crab  apple,  on  another  one  of  the  same  branch  is  elaborated  into 
a  delicious  pippin. 

"  The  tolerance  to  narcotics — opium  and  tobacco — and  to  corrosive  poisons 
— arsenic — which  results  from  a  gradual  increase  of  dose,  may  be  cited  as  an 
example  of  acquired  tolerance  by  living  protoplasm  to  poisons  which  at  the 
outset  would  have  been  fatal  in  much  smaller  doses. 

"The  immunity  which  an  individual  enjoys  from  any  particular  disease 
must  be  looked  upon  as  a  power  of  resistance  possessed  by  the  cellular  ele- 
ments of  those  tissues  of  his  body  which  would  yield  to  the  poison  in  the 
case  of  an  unprotected  person." 

This  theory  of  immunity,  advanced  by  the  author  in  1881,  has 
received  considerable  support  from  investigations  made  since  that 
date,  and  especially  from  the  experimental  demonstration  by  Sal- 
mon, Roux,  and  others  that,  as  suggested  in  the  paper  from  which  I 
have  quoted,  immunity  may  result  from  the  introduction  into  the 
body  of  a  susceptible  animal  of  the  soluble  products  of  bacterial 
growth — filtered  cultures. 

The  theory  of  vital  resistance  to  the  toxic  products  evolved  by 
pathogenic  bacteria  is  also  supported  by  numerous  experiments 
which  show  that  natural  or  acquired  immunity  may  be  overcome 
when  these  toxic  products  are  introduced  in  excess,  or  when  the  vital 
resisting  power  of  the  animal  has  been  reduced  by  various  agencies. 

Thus  Bouchard  has  shown  that  very  small  doses  of  a  pure  culture 
of  the  Bacillus  pyocyanus  are  fatal  to  rabbits,  when  at  the  same  time 
a  considerable  quantity  of  a  filtered  culture  of  the  same  bacillus  is 
injected  into  a  vein.  The  animal  could  have  withstood  the  filtered 
culture  alone  or  the  bacilli  injected  beneath  its  skin ;  but  when  its 
vital  resisting  power  (paralysis  of  phagocytes  ?)  has  been  partially 
overcome  by  the  filtered  culture  injected  into  a  vein  the  bacilli  mul- 
tiply abundantly  and  a  fatal  result  follows. 

The  same  result  may  be  obtained  by  injecting  sterilized  cultures 
of  a  different  microorganism.  Thus  Roger  has  shown  that  the  rab- 
bit, which  has  a  natural  immunity  against  symptomatic  anthrax, 
succumbs  to  infection  when  inoculated  with  a  culture  of  the  bacillus 
of  this  disease,  if  at  the  same  time  it  receives  an  injection  of  a  ster- 
ilized or  non-sterilized  culture  of  Bacillus  prodigiosus. 

Monti  has  succeeded  in  killing  animals  with  old  and  attenuated 
cultures  of  the  Streptococcus  pyogenes  or  of  Staphylococcus  pyo- 
genes  aureus,  by  injecting  at  the  same  time  a  culture  of  Proteus  vul- 
garis.  A  similar  result  may  be  obtained  by  subjecting  animals  to 
physical  agencies  which  reduce  the  vital  resisting  power  of  the  tis- 
sues. Thus  Nocard  and  Roux  found  by  experiment  that  an  attenu- 
ated culture  of  the  anthrax  bacillus,  which  was  not  fatal  to  guinea- 
pigs,  killed  these  animals  when  injected  into  the  muscles  of  the 
thigh  after  they  had  been  bruised  by  mechanical  violence.  Charrin 


SUSCEPTIBILITY   AND   IMMUNITY.  243 

and  Roger  found  that  white  rats,  which  are  unsusceptible  to  anthrax, 
became  infected  and  frequently  died  if  they  were  exhausted,  previous 
to  inoculation,  by  being  compelled  to  turn  a  revolving  wheel  for  a 
considerable  time.  Pasteur  found  by  experiment  that  fowls,  which 
have  a  natural  immunity  against  anthrax,  become  infected  and  per- 
ish if  they  are  subjected  to  artificial  refrigeration  after  inoculation. 
This  has  been  confirmed  by  the  more  recent  experiments  of  Wagner 
(1890).  According  to  Canalis  and  Morpurgo,  pigeons  which  are  en- 
feebled by  inanition  easily  contract  anthrax  as  a  result  of  inocula- 
tion. Arloing  states  that  sheep  which  have  been  freely  bled  con- 
tract anthrax  more  easily  than  others  ;  and  Serafini  found  that  when 
dogs  were  freely  bled  the  bacillus  of  Friedlander,  injected  into  the 
trachea  or  the  pleural  cavity,  entered  and  apparently  multiplied  to 
some  extant  in  the  blood,  whereas  without  such  previous  bleeding 
they  were  not  to  be  found  in  the  circulating  fluid. 

Again,  as  already  stated  in  a  previous  section,  the  simultaneous 
injection  of  certain  chemical  substances  overcomes  the  vital  resist- 
ing power  of  the  tissues  or  fluids  of  the  body  in  such  a  way  that 
infection  and  death  may  occur  as  a  result  of  inoculations  into  animals 
which  have  a  natural  or  acquired  immunity  against  the  pathogenic 
microorganism  introduced.  Thus  Arloing,  Cornevin,  and  Thomas 
have  shown  that  rabbits  succumb  to  symptomatic  anthrax  when  lac- 
tic acid  is  injected  at  the  same  time  with  the  bacillus  into  the  muscles. 
Nocard  and  Roux  have  obtained  the  same  result  by  injecting  various 
other  substances,  and  their  experiments  show  that  the  result  is  due 
to  the  injurious  effects  of  the  substance  injected  upon  -the  tissues, 
and  not  to  an  increased  virulence  on  the  part  of  the  pathogenic  ba- 
cillus. The  experiments  of  L3O  are  of  a  similar  nature.  By  inject- 
ing phloridzin  into  rats  he  caused  them  to  lose  their  natural  immu- 
nity against  anthrax.  Certain  anaesthetic  agents  have  also  been 
shown  to  produce  a  similar  result.  Platania  communicated  anthrax 
to  immune  animals— dogs,  frogs,  pigeons— by  bringing  them  under 
the  influence  of  curare,  chloral,  or  alcohol ;  and  Wagner  obtained  a 
similar  result  in  his  experiments  on  pigeons  to  which  he  had  admin- 
istered chloral. 

More  direct  experimental  evidence  in  favor  of  the  view  under  con- 
sideration is  that  obtained  by  Beumer  in  his  experiments  with  steril- 
ized cultures  of  the  typhoid  bacillus.  He  found  that  after  the  re- 
peated injection  of  non-lethal  doses  mice  were  able  to  resist  an 
amount  of  this  toxine  which  was  fatal  to  animals  of  the  same  spe- 
cies not  so  treated.  But,  on  the  other  hand,  Gamaleia  found,  in  his 
experiments  upon  guinea-pigs  which  had  been  made  immune  against 
the  pathogenic  action  of  a  spirillum,  called  by  him  Vibrio  Metschni- 
kovi,  that  these  animals  have  no  increased  tolerance  for  the  toxic 


244  SUSCEPTIBILITY   AND   IMMUNITY. 

products  of  this  microorganism.  Although  immune  against  infec- 
tion by  the  living  microbe,  they  were  killed  by  the  same  quantity  of 
a  sterilized  culture  as  was  fatal  to  guinea-pigs  which  had  not  been 
rendered  immune. 

Charrin  has  obtained  similar  results  in  experiments  with  filtered 
cultures  of  Bacillus  pyocyanus.  Rabbits  which  had  an  artificial 
immunity  against  the  pathogenic  action  of  the  bacillus  were  killed 
by  doses  of  a  sterilized  culture  such  as  were  fatal  to  other  rabbits  of 
the  same  size  not  immune.  In  subsequent  experiments  by  Charrin 
and  Gameleia  "  vaccinated "  rabbits  were  found  to  be  even  more 
susceptible  to  the  toxic  action  of  filtered  cultures  than  were  those 
not  vaccinated.  Recently  (1891)  Metschnikoff  has  followed  up  this 
line  of  experiment,  and  has  shown  that  when  considerable  amounts 
of  filtered  cultures  of  Bacillus  pyocyanus  are  injected  subcutaneously 
in  rabbits  a  certain  tolerance  to  the  toxic  action  of  the  same  cul- 
tures is  established  in  some  instances.  But  his  results  do  not  give 
any  substantial  support  to  the  view  that  immunity  depends  upon  an 
acquired  tolerance  to  the  toxic  action  of  the  chemical  products  con- 
tained in  cultures  of  the  pathogenic  bacteria  with  which  he  experi- 
mented— Bacillus  pyocyanus  and  Vibrio  Metschnikovi. 

In  view  of  the  results  of  experimental  researches  above  recorded, 
and  of  other  recent  experiments  which  show  that,  in  certain  cases  at 
least,  acquired  immunity  depends  upon  the  formation  of  an  anti- 
fcoxine  in  the  body  of  the  immune  animal,  we  are  convinced  that  the 
theory  of  immunity  under  discussion,  first  proposed  by  the  writer  in 
1881,  cannot  be  accepted  as  a  sufficient  explanation  of  the  facts  in 
general.  At  the  same  time  we  are  inclined  to  attribute  considerable 
importance  to  acquired  tolerance  to  the  toxic  products  of  pathogenic 
bacteria  as  one  of  the  factors  by  which  recovery  from  an  infectious 
disease  is  made  possible  and  subsequent  immunity  established. 

The  "  vital-resistance  theory"  of  the  present  writer,  as  set  forth 
in  the  above-quoted  extracts  from  his  published  papers,  is  essentially 
the  same  as  that  advocated  by  Buchner  at  a  later  date  (1883).  Buch- 
ner  supposes  that  during  the  primary  infection,  when  an  animal  re- 
covers, a  "reactive  change"  has  been  produced  in  the  cells  of  the 
body  which  enables  it  to  protect  itself  from  the  pathogenic  action 
of  the  same  microorganism  when  subsequently  introduced. 

Of  course  when  we  ascribe  immunity  to  the  "  vital  resistance  "  of 
the  cellular  elements  of  the  body,  we  have  not  explained  the 
modus  operandi  of  this  vital  resistance  or  "  reactive  change,"  but 
have  simply  affirmed  that  the  phenomenon  in  question  depends  upon 
some  acquired  property  residing  in  the  living  cellular  elements  of 
the  body.  We  have  suggested  that  that  which  has  been  acquired 
is  a  tolerance  to  the  action  of  the  toxic  products  produced  by  patho- 


SUSCEPTIBILITY  AND   IMMUNITY.  245 

genie  bacteria.  But,  as  already  stated,  in  the  light  of  recent  experi- 
ments this  theory  now  appears  to  us  to  be  untenable  as  a  general 
explanation  of  acquired  immunity. 

The  Theory  of  Phagocytosis. — The  fact  that  in  certain  infectious 
diseases  due  to  bacteria  the  parasitic  invaders,  at  the  point  of  inocu- 
lation or  in  the  general  blood  current,  are  picked  up  by  the  leuco- 
cytes and  in  properly  stained  preparations  may  be  seen  in  their  in- 
terior, has  been  known  for  some  years.  In  mouse  septicaemia — an 
infectious  disease  described  by  Koch  in  his  work  on  "Traumatic 
Infectious  Diseases,"  published  in  1878 — the  slender  bacilli  which  are 
the  cause  of  the  disease  are  found  in  large  numbers  in  the  interior  of 
the  leucocytes.  Koch  says,  in  the  work  referred  to  :  "  Their  rela- 
tion to  the  white  blood  corpuscles  is  peculiar  ;  they  penetrate  these 
and  multiply  in  their  interior.  One  often  finds  that  there  is 
hardly  a  single  white  corpuscle  in  the  interior  of  which  bacilli  can- 
not be  seen.  Many  corpuscles  contain  isolated  bacilli  only  ;  others 


FIG.  78.— Bacillus  of  mouse  septicaemia  in  leucocytes  from  blood  of  mouse  (Koch). 

have  thick  masses  in  their  interior,  the  nucleus  being  still  recog- 
nizable ;  while  in  others  the  nucleus  can  be  no  longer  distinguished  ; 
and,  finally,  the  corpuscle  may  become  a  cluster  of  bacilli,  breaking 
up  at  the  margin — the  origin  of  which  one  could  not  have  explained 
had  there  been  no  opportunity  of  seeing  all  the  intermediate  steps 
between  the  intact  white  corpuscle  and  these  masses  "  (Fig.  78).  It 
will  be  noted  that  in  the  above  quotation  Koch  affirms  that  the 
bacilli  penetrate  the  leucocytes  and  multiply  in  their  interior.  Now, 
the  theory  of  phagocytosis  assumes  that  the  bacilli  are  picked  up  by 
the  leucocytes  and  destroyed  in  their  interior,  and  that  immunity  de- 
pends largely  upon  the  power  of  these  " phagocytes"  to  capture  and 
destroy  living  pathogenic  bacilli. 

The  writer  suggested  this  as  an  hypothesis  as  long  ago  as  1881, 
in  a  paper  read  before  the  American  Association  for  the  Advance- 
ment of  Science,  in  the  following  language: 

"  It  has  occurred  to  me  that  possibly  the  white  corpuscles  may 
have  the  office  of  picking  up  and  digesting  bacterial  organisms  which 


246  SUSCEPTIBILITY   AND   IMMUNITY. 

by  any  means  find  their  way  into  the  blood.  The  propensity  exhib- 
ited by  the  leucocytes  for  picking  up  inorganic  granules  is  well 
known,  and  that  they  may  be  able  not  only  to  pick  up  but  to  assimi- 
late, and  so  dispose  of,  the  bacteria  which  come  in  their  way,  does 
not  seern  to  me  very  improbable,  in  view  of  the  fact  that  amcabsB, 
which  resemble  them  so  closely,  feed  upon  bacteria  and  similar  or- 
ganisms." ' 

At  a  later  date  (1884)  Metschnikoff  offered  experimental  evi- 
dence in  favor  of  this  view,  and  the  explanation  suggested  in  the 
above  quotation  is  commonly  spoken  of  as  the  Metschnikoff  theory. 

The  observations  which  first  led  Metschnikoff  to  adopt  this  view 
were  made  upon  a  species  of  daphnia  which  is  subject  to  fatal  infec- 
tion by  a  torula  resembling  the  yeast  fungus.  Entering  with  the 
food,  this  fungus  penetrates  the  walls  of  the  intestine  and  invades  the 
tissues.  In  certain  cases  the  infection  does  not  prove  fatal,  owing,  as 
Metschnikoff  asserts,  to  the  fact  that  the  fungus  cells  are  seized  upon 
by  the  leucocytes,  which  appear  to  accumulate  around  the  invading 
parasite  (chemiotaxis)  for  this  special  purpose.  If  they  are  success- 
ful in  overpowering  and  destroying  the  parasite  the  animal  recovers ; 
if  not,  it  succumbs  to  the  general  infection  which  results.  In  a  simi- 
lar manner,  Metschnikoff  supposes,  pathogenic  bacteria  are  destroyed 
when  introduced  into  the  body  of  an  immune  animal.  The  colorless 
blood  corpuscles,  which  he  designates  phagocytes,  accumulate  at  the 
point  of  invasion  and  pick  up  the  living  bacteria,  as  they  are  known 
to  pick  up  inorganic  particles  injected  into  the  circulation.  So  far 
there  can  be  no  doubt  that  Metschnikoff  is  right.  The  presence  of 
bacteria  in  the  leucocytes  in  considerable  numbers,  both  at  the  point 
of  inoculation  and  in  the  general  circulation,  has  been  repeatedly 
demonstrated  in  animals  inoculated  with  various  pathogenic  bacteria. 
The  writer  observed  this  in  his  experiments,  made  in  1881,  in  which 
rabbits  were  inoculated  with  cultures  of  his  Micrococcus  Pasteuri  ; 
and  it  was  this  observation  which  led  him  to  suggest  the  theory 
which  has  since  been  so  vigorously  supported  by  Metschnikoff.  But 
the  presence  of  a  certain  number  of  bacteria  within  the  leucocytes 
does  not  prove  the  destructive  power  of  these  cells  for  living  patho- 
genic organisms.  As  urged  by  Weigert,  Baumgarten,  and  others, 
it  may  be  that  the  bacteria  were  already  dead  when  they  were  picked 
up,  having  been  destroyed  by  some  agency  outside  of  the  blood  cells. 
As  heretofore  stated,  we  have  now  experimental  evidence  that  blood 

1  "  A  Contribution  to  the  Study  of  Bacterial  Organisms  commonly  found  upon 
Exposed  Mucous  Surf  aces  and  in  the  Alimentary  Canal  of  Healthy  Individuals."  Il- 
lustrated by  photomicrographs.  Proceedings  of  the  American  Association  for  Ad- 
vancement of  Science,  1881,  Salem,  1882,  xxx.,  83-94.  Also  in  Studies  from  the 
Biological  Laboratory,  Johns  Hopkins  University,  Baltimore,  vol.  ii..  No.  2,  1882. 


SUSCEPTIBILITY   AND   IMMUNITY.  247 

serum,  quite  independently  of  the  cellular  elements  contained  in  it 
in  the  circulation,  has  decided  germicidal  power  for  certain  patho- 
genic bacteria,  and  that  the  blood  serum  of  the  rat  and  other  animals 
which  have  a  natural  immunity  against  anthrax  is  especially  fatal 
to  the  anthrax  bacillus. 

Numerous  experiments  have  been  made  during  the  past  two  or 
three  years  with  a  view  to  determining  whether  pathogenic  bacteria 
are,  in  fact,  destroyed  within  the  leucocytes  after  being  picked  up, 
and  different  experimenters  have  arrived  at  different  conclusions. 
In  the  case  of  mouse  septicaemia,  already  alluded  to,  and  in  gonor- 
rhoea, one  would  be  disposed  to  decide,  from  the  appearance  and  ar- 
rangement of  the  pathogenic  bacteria  in  the  leucocytes,  that  they  are 
not  destroyed,  but  that,  on  the  other  hand,  they  multiply  in  the  in- 
terior of  these  cells,  which  in  the  end  succumb  to  this  parasitic  in- 
vasion. In  both  of  the  diseases  mentioned  we  find  leucocytes  so 
completely  filled  with  the  pathogenic  microorganisms  that  it  is  diffi- 
cult to  believe  that  they  have  all  been  picked  up  by  a  voracious  pha- 
gocyte, which  has  stuffed  itself  to  repletion,  while  numerous  other 
leucocytes  from  the  same  source  and  in  the  same  microscopic  field  of 
view  have  failed  to  capture  a  single  bacillus  or  micrococcus.  More- 
over, the  staining  of  the  parasitic  invaders,  and  the  characteristic  ar- 
rangement of  the  "  gonococcus  "  in  stained  preparations  of  gonorrhceal 
pus,  indicate  that  their  vitality  has  not  been  destroyed  in  the  interior 
of  the  leucocytes  or  pus  cells,  and  we  can  scarcely  doubt  that  the 
large  number  found  in  certain  cells  is  due  to  multiplication  in  situ 
rather  than  to  an  unusual  activity  of  these  particular  cells.  But  in 
certain  infectious  diseases,  and  especially  in  anthrax,  the  bacilli  in- 
cluded within  the  leucocytes  often  give  evidence  of  degenerative 
changes,  which  would  support  the  view  that  they  are  destroyed  by 
the  leucocytes,  unless  these  changes  occurred  before  they  were  picked 
up,  as  is  maintained  by  Nuttall  and  others.  We  cannot  consider 
this  question  as  definitely  settled,  but,  in  view  of  the  importance 
attached  to  the  theory  of  phagocytosis  by  many  pathologists  and  bac- 
teriologists, we  reproduce  here  a  recent  paper  by  Metschnikoff  in 
which  his  views  are  fully  set  forth  : 

LECTURE  ON  PHAGOCYTOSIS  AND   IMMUNITY.1 

It  is  not  possible  to  study  the  bacteriology  of  disease  without  noticing 
that,  while  in  many  cases  the  invading  microorganisms  are  to  be  found 
solely  in  the  fluids  of  the.  body,  in  not  a  few  affections  they  present  them- 
selves in  the  interior  of  certain  cells,  and  this  either  partially — some  being 
within  the  cells,  others  free  in  the  blood  plasma  and  the  lymph  that  bathes 
the  various  tissues — or  exclusively,  all  the  bacteria  that  are  visible  being 

1  Delivered  at  the  Institut  Pasteur,  December  29th,  1890,  by  Dr.  Elias  Metschni- 
koff, Chef  rte  Service  de  1'Institut  Pasteur,  Paris  ;  late  Professor  of  Zoology  in  the 
University  of  Odessa. 


248  SUSCEPTIBILITY   AND    IMMUNITY. 

intraceUular.  Many  of  the  facts  bearing  upon  the  terms  of  this  relationship 
between  tissue  cell  and  microorganism  are  now  well  known,  yet  it  is  worth 
while  to  recapitulate  the  more  important,  in  order  to  show  that  from  them  it 
is  possible  to  gain  a  general  law  ;  and  what  is  more,  that  from  a  study  of 
such  facts  some  insight  may  be  gained  into  the  phenomena  of  immunity. 

It  may,  in  the  first  place,  be  postulated  that  whenever  a  microorganism 
is  discoverable  within  a  cell  its  passage  thither  has  been  by  means  of  proto- 
plasmic or  amoeboid  movements,  either  on  the  part  of  the  microbe  or  of  the 
cell  itself.  The  first  alternative  is  the  rarer,  although  it  certainly  exists,  and 
of  this  the  malarial  parasite  affords  an  excellent  example;  for  here  in  the 
amoeboid  stage  of  its  existence  the  hsematozoon  makes  its  way  into  the  in- 
terior of  a  cell  that  possesses  no  active  movements  of  its  own,  namely,  the 
red  blood  corpuscle,  and  from  the  substance  of  this  corpuscle  the  parasite 
gains  its  nourishment.  Other  sporozoa  furnish  instances  almost  equally 

good.  Moz-e  commonly,  however,  as  in  the  case  of  all  bacteria,  where  we 
ave  to  deal  with  microorganisms  which,  even  when  mobile,  are  destitute  of 
protoplasmic  appendages,  it  is  the  cells  which  play  the  active  part ;  certain 
cells  include  the  parasites.  Of  such  the  amcebiform  leucocyte  of  the  blood 
and  lymph  is  the  most  typical  example,  capable,  as  it  is,  of  sending  out 
pseudopodia  in  all  directions,  while  a  closely  allied  form  is  the  cell  of  the 
splenic  pulp.  But  there  are  also  cells — as,  for  instance,  those  forming  the 
endothelial  lining  of  the  vessels — which  are  very  definitely  fixed,  which 
nevertheless  can  give  off  protoplasmic  processes  from  their  free  surface  and 
so  capture  and  include  bacteria. 

All  these  may  be  spoken  of  as  phagocytes,  and  may  be  divided  into  the 
two  broad  groups  of  fixed  phagocytes  (endothelial  cells,  etc.)  and  free  (leu- 
cocytes). Not  that  the  terms  "phagocyte"  and  "leucocyte"  are  synonymous, 
for  of  the  latter  three  main  forms  may  be  distinguished,  of  which  one  is 
practically  immobile  and  never  takes  up  bacteria.  This  is  the  lymphocyte, 
characterized  by  its  relatively  small  size,  its  large  single  nucleus,  and  the 
small  amount  of  surrounding  protoplasm.  The  two  remaining  (phagocytic) 
forms  are,  first,  the  large  uninuclear  leucocyte,  whose  prominent  nucleus  is 
at  times  lobed  or  reniform,  which  stains  well  with  aniline  dyes  and  possesses 
much  protoplasm  and  active  amoeboid  movements — the  macrophage — and, 
second,  the  microphage,  a  small  form,  also  staining  well,  but  either  multi- 
nuclear  or  with  one  nucleus  in  the  process  of  breaking  up.  If 'now  we  com- 
pare the  endothelial  cells  with  these,  it  is  evident  that  their  properties  con- 
nect them  closely  with  the  macrophage  ;  and,  in  fact,  there  is  now  little  or 
no  doubt  that  a  very  large  proportion  of  the  macrophages  are  of  endothelial 
origin. 

Leaving  aside  the  subject  of  amoeboid  microbes  and  their  life  within  ani- 
mal cells,  it  is  to  the  phagocytes  and  their  relation  to  the  bacteria  that  I  wish 
specially  to  draw  your  attention. 

Taking  as  wide  a  view  as  possible  of  this  relationship,  we  can  first  deter- 
mine that  the  more  malignant  the  microorganism  the  rarer  is  its  presence 
within  the  phagocyte.  Thus  in  those  which  of  all  diseases  are  the  most 
rapidly  fatal — in  chicken  cholera  affecting  birds  and  rabbits,  in  hog  cholera 
("cholera  des  pores")  given  to  pigeons  and  rabbits,  in  the  anthrax  of  mice 
and  other  specially  sensitive  animals,  in  the  "septicemie  vibrionienne"  of 
guinea-pigs  and  birds,  and  in  yet  other  diseases  of  peculiarly  swift  course— 
the  corresponding  bacteria  are  only  very  exceptionally  to  be  found  within 
the  cells,  but  remain  free  in  the  neighborhood  of  their  introduction  arid 
thence  invade  the  blood.  For  all  the  above-mentioned  diseases  are  not 
localized,  but,  on  the  contrary,  present  the  characters  of  general  acute  sep- 
ticaemia, causing  death  within  twenty  to  thirty-six  hours,  or,  in  certain 
cases,  even  within  six  hours. 

And  when  we  pass  to  those  diseases  in  which  the  bacteria  are  to  be  found 
either  in  part  or  almost  wholly  within  the  phagocytes,  the  same  law  still 
applies  ;  for  in  such  cases  the  disease  has  lost  its  suddenness,  tending  to 
have  a  slower  course,  or,  indeed,  to  be  of  a  chronic  nature.  Even  in  those 


SUSCEPTIBILITY   AND   IMMUNITY.  .     249 

affections  in  which  an.  acute  course  is  accompanied  by  considerable  phago- 
cytosis, the  fatal  termination  is  far  from  occurring-  at  the  same  early  period 
as  in  the  diseases  recorded  above.  Thus  mouse  septicaemia,  characterized  as 
it  is  by  frequent  intracellular  bacteria,  has  a  duration  in  the  mouse  two  and 
a  half  times  as  long-  as  that  of  anthrax  in  the  same  animal.  But  in  general  a 
well-marked  phagocytosis  is  associated  with  diseases  presenting  an  essen- 
tially chronic  development ;  it  is  in  affections  such  as  tuberculosis,  leprosy, 
rhinoscleroma,  glanders,  that  the  specific  bacteria  are  most  readily  taken  up 
by  the  phagocytes ;  it  is  here  that,  at  the  seat  of  the  disease,  we  meet  with  in- 
numerable macrophages — epithelioid  cells  in  which  lie  the  individual  micro- 
organisms. 

Further,  if  we  consider  the  phenomena  associated  with  the  resolution  of 
an  infectious  disease,  this  in  verse  relationship  between  the  malignancy  of  the 
malady  and  the  occurrence  of  phagocytosis  is,  if  possible,  yet  more  clearly 
demonstrated.  Notice,  for  instance,  what  obtains  during  the  progress  of  re- 
lapsing fever,  a  malady  still  fairly  common  in  Russia  and  other  Sclavonic 
countries,  and  one  which,  while  presenting  many  difficulties  to  the  bacteri- 
ologist, in  that  the  specific  spirochaete  has  so  far  resisted  cultivation,  and  in 
that  it  cannot  be  communicated  to  the  ordinary  animals  of  the  laboratory,  is 
nevertheless  in  many  respects  not  ill -adapted  for  our  present  purpose.  Herev 
during  the  sudden  access  of  the  fever,  the  spirilla  are  present  in  the  blood  in 
enormous  numbers;  they  all  are  free  in  the  plasma,  and  not  a  single  intra- 
cellular spirillum  is  to  be  met  with.  During  the  apyretic  stage  (and  in  the 
monkey  this  is,  at  the  same  time,  the  stage  of  resolution)  not  a  single  free  spiril- 
lum is  discoverable  in  the  blood,  while  the  phagocytes  of  the  spleen  contain 
the  microbes.  The  like  phenomena  repeat  themselves  in  all  those  cases  where 
it  is  possible  to  follow  the  fate  of  the  microorganisms  of  acute  disease  during 
the  stage  of  recovery.  Thus  rats  and  pigeons  very  frequently  survive  an 
attack  of  anthrax,  and,  where  this  occurs,  the  bacteria,  which  #t  the  com- 
mencement of  the  disease  were  for  the  most  part  free,  now,  during  resolution, 
are  for  the  most  part  included  within  leucocytes  and  splenic  phagocytes. 

Nor  is  this  all.  Analogous  phenomena  as  a  rule  attend  immunity,  which 
most  often  is  but  recovery  in  operation  from  the  very  onset  of  a  disease. 
The  more  closely  one  studies  this  condition  of  immunity  the  more  is  one  led 
to  the  conviction  that  immunity  and  recovery  are  very  intimately  con- 
nected ;  that  one  can  pass  by  slight  gradations  from  the  resolution  of  disease 
to  the  production  of  immunity.  So  it  is  that,  in  inoculating  refractory  ani- 
mals with  the  microbe  to  whose  action  they  have  been  rendered  immune,  it 
is  found  that  the  parasite  begins  to  develop,  but  that  from  the  onset  a  reac- 
tion on  the  part  of  the  organism  shoivs  itself,  accompanied  by  a  considerable 
emigration  of  leucocytes,  which  soon  include  the  bacteria  in  great  numbers. 

This  relationship  of  phagocytosis  to  acquired  immunity  is  in  the  highest 
degree  instructive.  Where  a  given  species  of  animal  is  specially  sensitive 
to  the  onslaught  of  one  or  other  microorganism,  there,  during  the  course  of 
the  disease,  the  phagocytes  are  inoperative,  including  none,  or  almost  none, 
of  the  bacteria.  On  the  other  hand,  when  by  previous  vaccination  these 
animals  have  been  rendered  refractory,  their  phagocytes  have  acquired  the 
property  of  including  the  same  bacteria.  As  an  example  of  this  I  may  cite 
the  action  of  the  bacillus  of  anthrax  and  of  the  Vibrio  Metschnikovi.  In 
ordinary  rabbits  the  development  of  anthrax  is  only  followed  by  a  very 
feeble  phagocytosis,  while  in  vaccinated  rabbits  this  phagocytosis  is  very  ex- 
tensive. Corresponding  but  yet  more  strongly  marked  differences  are  to  be 
made  out  between  the  unvaccinated  guinea-pig — an  animal  most  readily 
affected  by  the  vibrionic  septicaemia — and  the  guinea-pig  vaccinated  against 
the  same ;  after  inoculation  with  the  Vibrio  Metschnikovi  none  of  the  vibrios 
are  to  be  found  in  the  cells  of  the  former ;  in  the  latter  the  phagocytes  are 
simply  replete  with  the  microbes. 

The  facts  enumerated  thus  far  would  seem  to  prove  that  there  exists  a 
certain  antagonism  between  the  microbes  and  the  phagocytes,  and  this  view 
is  confirmed  by  the  fact  that  in  general  the  microbes  find  the  interior  of  the 


250  SUSCEPTIBILITY   AND   IMMUNITY. 

phagocytes  an  unfavorable  medium  for  their  development  and  continued 
existence.  Very  often  it  is  possible  to  determine  absolutely  that  the  parasites 
are  killed  within  the  phagocytes ;  after  inoculating  refractory  animals  with 
bacteria,  an  afflux  of  white  corpuscles  toward  the  region  of  inoculation,  fol- 
lowed by  the  inclusion  of  the  bacteria  and  by  their  death,  is  seen  to  occur. 
These  stages  can  be  well  followed  where  the  anthrax  bacilli  are  taken  into 
the  phagocytes  of  animals  that  are,  or  have  been  rendered,  immune.  They 
occur  also  with  a  long  series  of  other  microorganisms  studied  in  this  connec- 
tion, and,  among  others,  in  the  case  of  the  tubercle  bacillus  invading  animals 
that  are  more  or  less  resistant.  The  giant  cells  of  tuberculosis  are,  in  fact, 
huge  multinuclear  phagocytes,  and  here  the  intracellular  destruction  of  the 
bacilli  is  the  more  clearly  demonstrable,  inasmuch  as  the  microorganisms 
exhibit  such  very  evident  signs  of  degeneration ;  the  bacilli  swell,  their  en- 
veloping membrane  becomes  much  thickened  and  highly  refractive,  and  in 
time  the  contents  lose  their  power  of  fixing  the  staining  material,  so  that, 
eventually,  nothing  is  left  but  slightly  yellowish  forms,  recalling,  in  pro- 
portions and  position,  the  enlarged  bacilli;  and  these  shadowy  bodies  unite 
into  small  masses  of  an  amber-like  appearance.  Analogous  transformations 
never  being  observable  outside  the  phagocytes — that  is  to  say,  either  in  cul- 
tures or  in  caseating  masses — these  changes  may  well  be  regarded  as  due  to 
a  specific  action  upon  the  part  of  the  giant  cells. 

The  broad  fact  that  the  invasion  of  the  organism  by  microbes  most  often 
induces,  on  the  one  hand,  an  inflammatory  reaction  with  its  associated  emi- 
gration of  leucocytes,  and  that,  on  the  other  hand,  the  phagocytes  are 
capable  of  including  and  destroying  the  invaders,  leads  us  to  admit  that  the 
afflux  of  phagocytes  to  the  invaded  region,  and  their  bactericidal  properties, 
are  mechanisms  which  serve  to  ward  off  bacterial  attack  and  to  maintain  the 
integrity  of  the  organism.  Where  the  phagocytes  do  not,  either  immediately 
or  eventually,  intervene,  but  leave  the  field  free  to  the  microbes,  these  last 
multiply  without  hindrance  and  succeed  in  killing  the  animal  within,  it  may 
be,  an  excessively  short  period.  Thus  the  microorganism  of  hog  cholera, 
which  is  left  quite  untouched,  kills  the  pigeon  in  the  course  of  a  few  hours 
— often  within  five  hours  after  inoculation ;  chicken  cholera  kills  not  only 
pigeons  but  also  rabbits  in  an  equally  short  period.  In  other  diseases  in 
which  the  phagocytes  appear  upon  the  scene  in  relatively  large  numbers, 
and  even  include  the  microorganisms,  the  latter  gain  the  day  whenever  and 
wherever  the  phagocytes  are  incapable  of  destroying  them  or  of  preventing 
their  growth. 

This  manifest  bactericidal  action  is  to  be  compared  with  the  phenomena 
of  intracellular  digestion  characteristic  of  amoeboid  cells  in  general,  and  of 
leucocytes  and  other  microbic  phagocytes  in  particular.  These  cells  have 
the  power  of  digesting  with  ease  red  corpuscles  and  other  organized  ele- 
ments, just  as  have  the  amoebae  proper  and  other  protozoa.  Among  these 
last  are  many  which  have  been  found  to  include  and  transform  bacteria  in 
exactly  the  same  way  as  do  the  phagocytes  of  the  higher  animals. 

Now,  in  determining  the  intervention  or  non-intervention  of  the  leuco- 
cytes in  this  war  between  the  organism  and  the  bacteria,  a  very  great  part 
is  played  by  the  sensitiveness  of  these  cells  to  external  influences,  and  es- 
pecially to  the  chemical  composition  of  their  environment.  The  leucocytes 
are  powerfully  attracted  by  many  microorganisms  and  the  resultants  of 
their  growth,  and  as  powerfully  repelled  by  others  and  their  resultants,  or, 
as  it  is  expressed,  they  have  a  positive  chemiotaxis  for  certain  microbes,  a 
negative  chemiotaxis  for  others.  The  existence  of  these  chemiotactic  pro- 
perties has  been  so  clearly  proved  of  late  by  the  researches  of  Leber,  Mas- 
sart  and  Bordet,  and  Gabritschevski  that  I  need  not  enter  into  a  fuller  ex- 
planation of  the  subject  here.  Where  negative  chemiotaxis  manifests  itself, 
there,  being  shunned  by  the  white  corpuscles,  the  parasites  freely  propagate 
themselves  and  induce  the  death  of  their  host.  Nevertheless  this  chemio- 
taxis is  not  immutable,  and  the  cells  can  become  accustomed  to  substances 
from  which  they  shrank  at  first — a  negative  may  thus  be  transformed  into  a 


SUSCEPTIBILITY  AND   IMMUNITY.  251 

positive  chemiotactic  state.  Such  obtains  in  acquired  immunity  ;  the  cells 
which  in  the  unvaccinated  animal  never  included  the  bacteria,  now  in  the 
vaccinated  take  them  up  readily.  .  .  . 

There  is  not  a  single  portion  of  the  theory  which  I  have  just  expounded 
but  has  encountered  a  lively  opposition.  Even  the  fundamental  fact  that 
the  phagocytes  are  capable  of  including  the  microbes  has  had  doubts  thrown 
upon  it ;  it  has  been  held  that  the  latter  insinuate  themselves  into  the  for- 
mer. Only  after  successive  series  of  observations  upon  the  phagocytes  and 
the  living  microbes  has  it  been  proved  that  assuredly  it  is  the  phagocytes 
which,  by  the  aid  of  their  pseudopodia,  themselves  include  the  microorgan- 
isms. The  observer  can  see  the  whole  process  in  the  case  of  immobile  ba- 
cilli— can  see  the  leucocyte  approach,  send  out  pseudopodia,  and  gradually 
include  the  individual  bacillus.  Or,  conversely,  in  cases  of  negative  che- 
miotaxis,  one  can,  in  blood  taken  from  the  monkey  during  the  access  of  re- 
lapsing fever,  observe  the  actively  moving  spirilla  come  into  contact  with  a 
leucocyte,  and  even  become  attached  by  one  end  to  its  surface  ;  yet,  how- 
ever active  the  movement,  one  never  finds  that  the  spirillum  succeeds  in 
piercing  the  surface  and  gaining  an  entrance.  If  it  be  suggested  that  this 
entry  may  take  place  in  consequence  of  the  force  of  active  growth  and  elon- 
gation of  bacilli,  then,  apart  from  the  fact  that  here  but  one  set  of  cases  is 
embraced,  it  can  be  determined  that  this  force  is  too  feeble — it  can  be  seen 
that,  during  the  active  growth  of  the  anthrax  organism  in  the  blood,  the 
elongating  chains  of  bacilli  curve  in  and  out  between  the  corpuscles,  but 
never  penetrate  the  cells. 

From  another  side  the  objection  has  been  formulated  that  in  many  cases 
the  organism  gets  rid  of  its  invaders  without  the  aid  of  the  phagocytes. 
According  to  those  who  support  this  objection,  this  happens  in  the  anthrax 
of  pigeons  (Czaplewski)  and  of  refractory  rats  (Be"hring,  Franck),  in  symp- 
tomatic anthrax  of  various  refractory  animals  (Rogowicz),  and  in  the  septi- 
caemia of  vaccinated  guinea  pigs,  due  to  the  Vibrio  Metschnikovi  (R.  Pfeif- 
fer).  A  reexamination  of  the  cases  here  adduced  has,  however,  shown 
that  in  each  a  very  considerable  phagocytosis  can  be  proved,  and  that  the 
negative  results  of  the  above  observers  have  been,  due  to  insufficient  methods 
of  observation. 

While  accepting  that  the  phagocytes  do  truly  absorb  the  microorgan- 
isms, other  opponents  of  the  theory  have  urged  that  these  cells  are  only 
capable  of  including  microorganisms  already  killed  by  other  means,  and 
that  living  microbes  are  solely  to  be  found  within  the  cells  in  those  cases 
where  there  has  been  a  fatal  ending— in  tuberculosis,  mouse  septicaemia;  and 
so  on.  Against  this  may  be  brought  the  fact  determined  by  Lubarsch,  that 
the  phagocytes  of  several  animals,  refractory  to  anthrax,  take  up  living  ba- 
cilli that  have  been  injected,  with  greater  eagerness  than  they  include  those 
which  have  been  killed  before  injection.  But,  further,  this  objection  may 
be  disposed  of  by  direct  observation  of  bacteria  undergoing  development 
from  within  the  interior  of  phagocytes  after  the  latter  have  oeen  destroyed 
by  a  substance  which  is  at  the  same  time  a  favorable  medium  for  bacterial 
growth — as,  for  instance,  beef  broth.  Such  observations  have  been  made 
upon  pigeons  rendered  immune  to  anthrax. 

During  the  last  year  or  two  great  stress  has  been  laid  upon  the  fact  that 
the  body  humors  themselves  possess  most  marked  bactericidal  properties, 
and,  in  fact,  against  the  theory  of  phagocytosis  has  been  brought  another, 
baoed  upon  this  power  of  the  humors  to  destroy  the  microorganisms.  Ob- 
server after  observer  has  remarked  that  in  blood  plasma,  defibrinated  blood, 
blood  serum,  and  in  the  blood  as  a  whole,  in  the  removed  aqueous  humor 
and  other  fluids  and  exudations  of  the  body,  many  species  of  bacteria  perish 
after  a  longer  or  shorter  interval  ;  and  forthwith  an  endeavor  has  been 
made  to  find  in  these  facts  some  elucidation  of  the  phenomena  of  immunity. 
Yet  the  more  deeply  one  examines  into  the  question  the  more  one  is  con- 
vinced that  no  relationship  exists  between  the  two.  Thus  it  happens  often 
that  the  bactericidal  property  is  more  developed  in  susceptible  species  than 


252  SUSCEPTIBILITY   AND   IMMUNITY.  . 

in  refractory  ;  so,  with  regard  to  the  anthrax  bacilli,  in  the  very  sensitive 
rabbit  the  bactericidal  properties  of  the  humors  are  more  pronounced  than 
they  are  in  the  refractory  dog  ;  and  Behring  and  Nissen,  the  two  who  al- 
most simultaneously  first  drew  our  attention  to  these  phenomena,  in  their 
combined  research,  recently  published,  admit  that,  as  against  the  bacteria 
of  anthrax,  pneumonia,  and  diphtheria,  this  bactericidal  property  exists  to 
the  same  degree  in  the  juices  of  animals  of  the  same  species,  whether  they 
be  susceptible  or  have  been  rendered  immune.  Often,  again,  it  has  been 
determined  that  the  blood  removed  from  the  organism  has  a  greater  power 
of  destroying  bacteria  than  it  has  within  the  organism.  A  small  quantity 
of  blood  withdrawn  from  the  body  will,  in  certain  instances,  kill  a  mass  of 
bacilli  greater  than  that  which,  injected  into  the  circulation,  would  inevi- 
tably cause  death.  Evidently,  therefore,  in  this  bactericidal  influence  extra- 
vascular  phenomena  enact  an  important  role — phenomena,  that  is,  which 
have  no  connection  with  what  occurs  in  the  living  refractory  organism. 

From  another  point  of  view  strong  arguments  have  been  directed  against 
this  theory  of  the  tissue  fluids.  It  has  been  shown,  especially  by  the  re- 
searches of  M.  Haffkine,  that  the  death  of  the  bacteria  transported  into  or- 
ganic fluids  is  largely  due  to  the  sudden  change  of  medium,  and  that,  in 
passing  from  one  medium  to  another  by  successive  slight  modifications  in 
the  fluid  of  growth,  it  is  easy  to  make  bacteria  live  in  fluids  which,  when 
the  change  of  environment  has  been  abrupt,  swiftly  lead  to  their  destruc- 
tion. 

In  order  to  gain  an  idea  as  to  the  part  played  in  the  refractory  animal  by 
the  fluids  and  the  phagocytes  respectively,  the  endeavor  has  been  made  to 
separate  the  two  by  placing  under  the  skin  of  frogs  (which  are  naturally 
immune  to  anthrax)  minute  packets  formed  of  filter  paper  or  of  animal 
membrane,  and  containing  the  bacilli.  The  paper,  while  permitting  the 
passage  of  fluid,  wards  off  the  wandering  amoeboid  cells  for  a  certain  time. 
Shielded  in  this  way  from  the  phagocytes,  though  exposed  to  the  action  of 
the  juices,  the  bacilli  grow  well  and  produce  the  characteristic  felted  mass 
of  anthrax  filaments.  Baumgarten  has  not  been  able  to  confirm  this  experi- 
ment, but  Hueppe  and  Lubarsch  have  repeatedly  verified  it. 

But  it  is  not  even  necessary  to  take  these  precautions  in  order  to  assure 
one's  self  that  anthrax  spores  germinate  in  the  juices  of  refractory  animals. 
Recently,  for  instance,  M.  Trapeznikotf  has  found  that,  when  these  spores 
are  injected  into  the  dorsal  lymph  sac  of  the  frog,  they  constantly  tend  to 
develop  into  bacilli,  whose  further  growth  is  stopped  by  the  phagocytes, 
which  include  them,  along  with  such  spores  as  have  not  had  lime  to  germi- 
nate. Eventually  the  bacilli  so  absorbed  are  digested  by  their  hosts,  while 
the  included  spores  remain  intact,  although  incapable  of  giving  birth  to 
bacilli  for  so  long  a  time  as  the  phagocytes  remain  alive.  And  I  might  ad- 
duce other  similar  cases.  Such  a  comparative  examination  proves  that  in 
the  living  body  the  bactericidal  property  resides  in  the  phagocytes  and  not 
in  the  fluids. 

Still,  it  may  be  urged  that  possibly  these  cells,  which  can  thus  devour  and 
destroy  the  living  microbes,  are  only  in  a  position  to  attack  bacteria  whose 
virulence  has  already  been  lessened  by  other  means.  Were  this  so,  the  mi- 
crobes present  in  a  refractory  organism  should  behave,  not  like  parasites, 
but  as  simple,  inoffensive  saprophytes.  Hence  these  microbes — powerless 
to  produce  upon  a  refractory  soil  the  toxic  substances  which  render  them 
pathogenic  and  dangerous — should  easily  be  included  and  destroyed;  so 
that,  according  to  this  hypothesis,  which  "has  frequently  been  brought  for- 
ward, the  phagocytes  play  a  purely  secondary  and  dependent  part,  waiting 
until  the  microbes  are  weakened  before  they  seize  upon  them.  In  favor  of 
this  view  the  fact  has  been  cited  that  certain  microorganisms  cultivated  in 
the  blood,  or  serum,  of  vaccinated  animals  become  attenuated,  so  that  they 
no  longer  induce  a  fatal  disease.  The  Bacillus  anthracis  grown  in  the  blood 
of  vaccinated  sheep  no  longer  kills  rabbits,  and,  according  to  Roger,  the 
Streptococcus  erysipelatos  grown  in  the  blood  of  vaccinated  rabbits  only 


SUSCEPTIBILITY   AND   IMMUNITY.  253 

occasions  a  slight  and  passing  disturbance  in  susceptible  members  of  the 
same  species.  But  here  again  we  are  dealing  with  fluids  withdrawn  from 
the  body,  and  so  modified  in  various  ways.  Let  us  make  an  observation 
more  strictly  to  the  point.  Take,  for  instance,  a  rabbit  vaccinated  against 
anthrax  and  inoculate  it  with  anthrax  bacilli,  thus  allowing  these  to  exist 
directly  within  the  refractory  organism.  Such  bacilli  as  are  not  destroyed 
preserve  their  virulence  for  a  sufficiently  long  period,  and  it  is  possible  to 
kill  a  guinea-pig  with  a  drop  of  exudation,  taken  from  the  region  of  injection 
thirty  hours  after  subcutaneous  inoculation,  eight  days  after  inoculation 
into  the  anterior  chamber  of  the  eye.  A  sojourn  of  so  long  duration  within 
the  vaccinated  organism,  then,  has  not  deprived  the  microbes  of  their  viru- 
lence, although  twenty-four  hours  suffice  to  completely  attenuate  the 
bacilli  cultivated  in  the  removed  blood  of  vaccinated  sheep. 

Years  ago  it  was  established  in  M.  Pasteur's  laboratory  that  the  refrac- 
tory organism,  instead  of  being  an  unfavorable  soil  for  the  preservation  of 
virulence,  tends  the  rather  to  reinforce  this  property.  To  exalt  the  viru- 
lence of  an  attenuated  microorganism,  one  always  employs,  not  animals 
very  susceptible  to  the  specific  disease,  but  those  which  are  slightly  suscep- 
tible, or  it  may  be,  under  many  circumstances,  refractory.  In  this  manner 
the  most  active  anthrax  virus  has  usually  been  obtained  by  passage  through 
birds,  notably  fowls  ;  the  greatest  virulence  of  chicken  cholera  was  gained 
by  passage  through  the  vaccinated  cock ;  and  quite  recently  M.  Malm  has 
shown  that  passage  of  the  anthrax  bacillus  through  the  organisms  of  dogs, 
which  of  all  mammals  are  the* most  refractory  in  this  respect,  increases  its 
virulence  in  a  most  remarkable  manner,  so  that  the  general  law  may  be  laid 
down  that  an  organism  which  is  but  slightly  susceptible  or  is  refractory  is 
able  not  only  to  preserve,  but  even  to  exalt,  the  virulence  of  bacteria.  The 
principal  argument  in  favor  of  the  hypothesis  that  pathogenic  microor- 
ganisms become  simple  inoffensive  saprophytes  when  they  find  themselves 
in  a  refractory  region,  loses  therefore  its  raison  d'etre. 

M.  Bouchard,  in  his  objection  to  the  theory  of  phagocytosis,  may  be  re- 
garded as  introducing  but  a  modification  of  this  hypothesis.  He  holds  that 
pathogenic  bacteria  placed  under  favorable  conditions  give  rise  to  substances 
which  hinder  the  inflammatory  process,  and  that  only  when  these  inhibi- 
tory substances  are  inadequately  represented  do  the  cells  intervene.  When, 
therefore,  the  organism  rendered  refractory  by  vaccination  becomes  an  un- 
favorable soil  for  the  production  of  these  inhibitory  bodies,  the  bacteria  can 
no  longer  prevent  the  inflammatory  reaction  ;  free  emigration  of  the  leuco- 
cytes ensues,  these  cells  seize  upon  the  impotent  microbes  and  put  a  stop  to 
their  further  growth.  In  this  theory  the  part  played  by  the  phagocytes  is 
again  secondary,  depending  upon  a  dearth  of  anti-inflammatory  substance. 

If  the  theory  could  be  accepted  in  certain  cases,  it  is  nevertheless  inap- 
plicable as  a  general  rule.  In  all  those  affections  which  are  characterized  by 
the  absence  of  leucocytes  upon  the  field  of  battle  there  is  certainly  no  lack 
of  inflammation.  The  very  reverse  obtains.  In  anthrax  affecting  small 
mammals,  just  as  in  the  vibrionic  septicaemia  of  pigeons  and  guinea-pigs,  and 
other  analogous  diseases,  we  find  that  there  is  a  very  distinct  dilatation  of 
the  vessels,  accompanied  by  great  exudation  ;  the  inflammatory  reaction  is 
well  marked ;  nothing  is  wanting  save  the  determination  of  the  white  coi'- 
puscles.  Or,  employing  yet  further  that  affection  which  is,  as  it  were,  the 
touchstone  of  the  bacteriologist,  a  still  clearer  proof  of  our  contention  is  to 
be  gained  if  we  inoculate  a  rabbit  on  the  one  ear  with  a  small  quantity  of 
virulent,  on  the  other  with  a  like  quantity  of  attenuated,  anthrax  virus.  In 
the  course  of  a  few  hours  the  external  signs  of  inflammation  are  far  more 
conspicuous  in  the  former  ;  the  vessels  are  greatly  enlarged  and  there  is 
literally  a  huge  exudation  of  clear  serous  fluid  into  the  part ;  in  the  latter 
the  external  signs  are  less  prominent,  but  examination  of  the  seat  of  inocu- 
lation shows  it  to  be  packed  with  leucocytes.  Consequently,  the  phenome- 
non we  are  discussing  is  to  be  explained,  not  by  an  absence  of  the  inflamma- 
tory process,  but  much  more  satisfactorily  by  a  negative  chemiotaxis  of  the 


354  SUSCEPTIBILITY  AND   IMMUNITY. 

leucocytes,  which,  instead  of  being  attracted  by  the  bacterial  products,  are 
repelled  ;  where  the  animal  is  vaccinated  or  refractory  a  much  slighter  in- 
flammation is  sufficient  to  produce  an  abundant  emigration  of  the  leu- 
cocytes. 

Recently  Behring  has  brought  forward  another  view  which  would  ex- 
plain immunity  in  a  wholly  different  way.  According  to  him,  the  bac- 
teria can  live,  and  even  preserve  their  virulence,  in  the  refractory  organism, 
but  the  toxines  excreted,  by  them  now  undergo  a  modification  so  as  to  be 
rendered  completely  inoffensive  for  the  animal.  And  to  this  "toxicide 
property  "  of  the  organism  is  to  be  attributed  the  essential  quality  of  the 
immune  state.  It  is  impossible  to  pronounce  upon  the  arguments  that  have 
led  up  to  this  theory,  for  as  yet  they  have  not  been  circumstantially  set 
forth ;  but  already  one  can  declare  that  such  a  theory  is  in  no  wise  applicable 
to  the  phenomena  of  immunity  in  general.  In  three  diseases  remarkable 
for  their  pronounced  toxic  character — vibrionic  septicaemia,  pyocyanic  dis- 
ease, and  hog  cholera  affecting  the  rabbit— as  shown  by  the  experiments  of 
Charrin,  Gamaleia,  and  Selander,  the  toxines  are  so  little  attacked  by  the  re- 
fractory organism  that  the  same  quantity  of  these  substances  (freed  from 
bacteria)  suffices  to  kill  an  animal  very  susceptible  to  one  or  other  disease, 
and  an  animal  vaccinated  against  it  and  thus  completely  immune.  So,  too, 
non-fatal  doses  of  these  toxines  produce  in  animals  of  the  two  categories  the 
same  febrile  and  inflammatory  reactions.  The  proof  is  clear  that  there  is  no 
special  destruction  of  toxines  in  the  refractory  animal,  and  that  the  "toxicide 
property,"  if  it  exists,  is  not  one  whit  more  developed  after  vaccination  than 
before.  Passing  in  review  all  these  counter  theories,  we  see  that  each  of 
them  can  only  be  applied  to  a  certain  number  of  facts  ;  in  some  an  attenu- 
ating or  even  bactericidal  influence  of  the  juices  is  relied  upon,  in  others  an 
anti-inflammatory  action,  in  yet  others  a  toxicide  property.  Still  the  pha- 
gocytic  reaction  is  the  only  constant  in  all  those  cases  of  immunity  and 
recovery  that  have  as  yet  been  sufficiently  studied,  and  while  certain  of  the 
factors  mentioned  (the  attenuating  and  toxicide  properties)  do  not  in  the 
least  touch  upon  the  continued  existence  or  otherwise  of  the  microorganism, 
the  bactericidal  power  of  the  phagocyte  puts  an  end  to  the  parasite  itself,  and 
thus  at  a  given  moment  prevents  further  manifestation  of  its  virulence,  or 
preserves  the  animal  attacked  at  a  time  when  the  toxicide  properties  would  be 
found  wanting,  arid  the  microbe  remaining  alive  would  consequently  gain 
the  upper  hand. 

But  while  thus  placing  before  you  the  important  part  played  by  the  pha- 
gocytes, I  do  not  wish  it  to  be  thought  that  these  cells  are  unaided  in  their 
•contest  by  other  defensive  means  possessed  by  the  organism.  This  is  far 
from  being  my  view.  Thus,  in  the  febrile  reaction,  we  see  a  puissant  auxil- 
iary very  definitely  favoring  the  work  of  the  phagocytes.  This  febrile  re- 
action has  only  to  be  inhibited — as  was  done  by  M.  Pasteur  in  the  anthrax 
of  fowls — and  animals  naturally  refractory  to  the  affection  succumb  to  the 
ravages  of  the  bacilli.  It  is  not  possible  at  the  present  time  to  state  fully 
and  accurately  all  these  influences  which  are  associated  in  aiding  phago- 
cytic  action,  but  already  we  have  the  right  to  maintain  that,  in  the  prop- 
erty of  its  amoeboid  cells  to  include  and  to  destroy  microorganisms,  the 
animal  body  possesses  a  formidable  means  of  resistance  and  defence 
ajainst  these  infectious  agents.1 

We  are  disposed  to  agree  with  Metschnikoff  in  his  final  conclu- 
sion, as  above  stated  in  italics.  But  in  view  of  experimental  evi- 
dence, to  be  referred  to  later,  we  cannot  accept  the  so-called  Metsch- 
nikoff theory  as  a  sufficient  explanation  for  the  facts  relating  to 
natural  and  acquired  immunity  in  general,  and  must  regard  phago- 
cytosis simply  as  a  factor  which,  in  certain  infectious  diseases,  ap- 
1  From  the  British  Medical  Journal. 


SUSCEPTIBILITY   AND   IMMUNITY.  255 

pears  to  play  an  important  part  in  enabling  immune  animals  to  resist 
invasion  by  pathogenic  bacteria. 

Going  back  to  the  demonstrated  fact  that  susceptible  animals  may 
be  made  immune  by  inoculating  them  with  the  toxic  products  pro- 
duced during  the  growth  of  certain  pathogenic  bacteria,  we  may 
suppose  either  that  immunity  results  from  the  continued  presence  of 
these  toxic  products  in  the  body  of  the  inoculated  animal,  or  from  a 
tolerance  acquired  at  the  time  of  the  inoculation  and  subsequently 
retained — by  transmission  from  cell  to  cell,  as  heretofore  suggested. 
Under  the  first  hypothesis — retention  theory — immunity  may  be  ex- 
plained as  due  to  a  continued  tolerance  on  the  part  of  the  cellular  ele- 
ments of  the  body  to  the  toxic  substances  introduced  and  retained ; 
or  to  the  effect  of  these  retained  toxic  products  in  destroying  the 
pathogenic  bacteria,  or  in  neutralizing  their  products  when  these  are 
subsequently  introduced  into  the  body  of  the  immune  animal.  "We 
cannot  understand  how  toxic  substances  introduced  in  the  first  in- 
stance can  neutralize  substances  of  the  same  kind  introduced  at  a 
later  date.  There  is  something  in  the  blood  of  the  rat  which,  accord- 
ing to  Behring,  neutralizes  the  toxic  substances  present  in  a  filtered 
culture  of  the  tetanus  bacillus  ;  but  whatever  this  substance  may  be, 
it  is  evidently  different  from  the  toxic  substance  which  it  destroys, 
and  there  is  nothing  in  chemistry  to  justify  the  supposition  last 
made.  Is  it,  then,  by  destroying  the  pathogenic  microorganism 
that  these  inoculated  and  retained  toxic  products  preserve  the  animal 
from  future  infection  ?  Opposed  to  this  supposition  is  the  fact  that 
the  blood  of  an  animal  made  immune  in  this  way,  when  removed 
from  the  body,  does  not  prove  to  have  increased  germicidal  power  as 
compared  with  that  of  a  susceptible  animal  of  the  same  species. 
Again,  these  same  toxic  substances  in  cultures  of  the  anthrax  bacillus, 
the  tetanus  bacillus,  the  diphtheria  bacillus,  etc. ,  do  not  destroy  the 
pathogenic  germ  after  weeks  or  months  of  exposure.  And  when  we 
inoculate  a  susceptible  animal  with  a  virulent  culture  of  one  of  these 
microorganisms,  the  toxic  substances  present  do  not  prevent  the  rapid 
development  of  the  bacillus  ;  indeed,  instead  of  proving  a  germicide, 
they  favor  its  development,  which  is  more  abundant  and  rapid  than 
when  attenuated  cultures  containing  less  of  the  toxic  material  are 
used  for  the  inoculation.  In  view  of  these  facts  we  are  unable  to 
adopt  the  view  that  acquired  immunity  results  from  the  direct  action 
of  the  products  of  bacterial  growth,  introduced  and  retained  in  the 
body  of  the  immune  animal,  upon  the  pathogenic  microorganism 
when  subsequently  introduced  or  upon  its  toxic  products. 

But  there  is  another  explanation  which,  although  it  may  appear 
a  priori  to  be  quite  improbable,  has  the  support  of  recent  experimen- 
tal evidence.  This  is  the  supposition  that  some  substance  is  formed 


356  SUSCEPTIBILITY   AND   IMMUNITY. 

in  the  body  of  the  immune  animal  which  neutralizes  the  toxic 
products  of  the  pathogenic  microorganism.  How  the  presence  of 
these  toxic  products  in  the  first  instance  brings  about  the  formation 
of  an  "  antitoxine  "  by  which  they  are  neutralized  is  still  a  mystery  ; 
but  that  such  a  substance  is  formed  appears  to  be  proved  by  the  re- 
cent experiments  of  Ogata,  Behring  and  Kitasato,  Tizzoni  and  Cat- 
tani,  G.  and  F.  Klemperer,  and  others. 

Ogata  and  Jasuhara,  in  a  series  of  experiments  made  in  the  Hy- 
gienic Institute  at  Tokio  (1890),  discovered  the  important  fact  that 
the  blood  of  an  animal  immune  against  anthrax  contains  some  sub- 
stance which  neutralizes  the  toxic  products  of  the  anthrax  bacillus. 
When  cultures  were  made  in  the  blood  of  dogs,  frogs,  or  of  white 
rats,  which  animals  have  a  natural  immunity  against  anthrax,  they 
were  found  not  to  kill  mice  inoculated  with  them.  Further  experi- 
ments showed  that  mice  inoculated  with  virulent  anthrax  cultures 
did  not  succumb  to  anthrax  septicaemia  if  they  received  at  the  same 
time  a  subcutaneous  injection  of  a  small  quantity  of  the  blood  of  an 
immune  animal.  So  small  a  dose  as  one  drop  of  frog's  blood  or  one- 
half  drop  of  dog's  blood  proved  to  be  sufficient  to  protect  a  mouse 
from  the  fatal  effect  of  an  anthrax  inoculation.  And  the  protective 
inoculation  was  effective  when  made  as  long  as  seventy-two  hours 
before  or  five  hours  after  infection  with  an  anthrax  culture.  Fur- 
ther, it  was  found  that  mice  which  had  survived  anthrax  infection  as 
a  result  of  this  treatment  were  immune  at  a  later  date  (after  several 
weeks)  when  inoculated  with  a  virulent  culture  of  the  anthrax 
bacillus. 

Behring  and  Kitasato  have  obtained  similar  results  in  their  ex- 
periments upon  tetanus  and  diphtheria,  and  have  shown  that  the 
blood  of  an  immune  animal,  added  to  virulent  cultures  before  in- 
oculation into  susceptible  animals,  neutralizes  the  pathogenic  power 
of  these  cultures. 

They  have  shown  by  experiment  that  the  blood  of  a  rabbit  which 
has  an  acquired  immunity  against  tetanus,  mixed  with  the  virulent 
filtrate  from  a  culture  of  the  tetanus  bacillus,  neutralizes  its  toxic 
power.  One  cubic  centimetre  of  this  filtrate  was  mixed  with  five 
cubic  centimetres  of  serum  from  the  blood  of  an  immune  rabbit  and 
allowed  to  stand  for  twenty-four  hours  ;  0. 2  cubic  centimetre  of  this 
injected  into  a  mouse  was  without  effect,  while  0.0001  cubic  centi- 
metre of  the  filtrate  without  such  admixture  was  infallibly  fatal  to 
mice.  The  mice  inoculated  with  this  mixture  remained  immune  for 
forty  to  fifty  days,  after  which  they  gradually  lost  their  immunity. 
The  blood  or  serum  from  an  immune  rabbit,  when  preserved  in  a 
dark,  cool  place,  retained  its  power  of  neutralizing  the  tetanus  tox- 
albumin  for  about  a  week,  after  which  time  it  gradually  lost  this 


SUSCEPTIBILITY   AND    IMMUNITY.  257 

power.  The  blood  of  chickens,  which  have  a  natural  immunity 
against  tetanus,  was  found  not  to  have  a  similar  power.  Behring 
and  Kitasato  have  also  shown  that  the  serum  of  a  diphtheria-immune 
rabbit  destroys  the  potent  toxalbumin  in  diphtheria  cultures.  It 
does  not,  however,  possess  any  germicidal  power  against  the  diph- 
theria bacillus. 

Ogata,  in  a  recent  publication  (1891),  reports  that  he  has  succeeded 
in  isolating  from  the  blood  of  dogs  and  of  chickens  a  substance  to 
which  he  ascribes  the  immunity  of  these  animals  from  certain  infec- 
tious diseases,  and  the  power  of  their  blood  to  protect  susceptible 
animals  from  the  same  diseases.  This  substance  is  soluble  in  water 
and  in  glycerin,  but  insoluble  in  alcohol  or  ether,  by  which  it  is  pre- 
cipitated without  being  destroyed.  Its  activity  is  neutralized  by 
acids,  but  not  by  weak  alkaline  solutions.  Ogata  supposes  the  sub- 
stance isolated  by  him  to  be  the  active  agent  in  blood  serum  by 
which  certain  pathogenic  bacteria  are  destroyed,  as  shown  by  the 
experiments  of  Nuttall,  Buchner,  and  others.  Hankin  had  previously 
isolated  an  albuminoid  substance  from  the  spleen  and  blood  of  the 
rat,  to  which  he  ascribes  the  immunity  of  this  animal  from  anthrax. 
This  substance,  according  to  the  author  named,  is  a  globulin  ;  it  is 
insoluble  in  alcohol  and  in  distilled  water,  and  does  not  dialyze. 

Tizzoni  and  Cattani  ascribe  the  protection  of  animals  which  have 
acquired  an  immunity  against  tetanus  to  the  presence  of  an  albu- 
minous substance  which  they  call  the  tetanus-antitoxine.  This  they 
have  isolated  from  the  blood  of  immune  animals.  They  arrive  at 
the  conclusion  that  it  is  a  globulin,  or  a  substance  which  is  carried 
down  with  the  globulin  precipitate,  and  that  it  is  different  from  the 
globulin,  above  referred  to,  obtained  by  Hankin  from  animals  im- 
mune against  anthrax. 

G.  and  F.  Klemperer  have  recently  (1891)  published  an  important, 
memoir  in  which  they  give  an  account  of  their  researches  relating 
to  the  question  of  immunity,  etc. ,  in  animals  subject  to  the  form 
of  septicaemia  produced  by  the  Micrococcus  pneumonise  crouposae. 
They  were  able  to  produce  immunity  in  susceptible  animals  by 
introducing  into  their  bodies  filtered  cultures  of  this  micrococcus,  and 
proved  by  experiment  that  this  immunity  had  a  duration  of  at  least 
six  months.  They  arrive  at  the  conclusion  that  the  immunity  in- 
duced by  injecting  filtered  cultures  is  not  directly  due  to  the  toxic 
substances  present  in  these  cultures,  but  that  they  cause  the  produc- 
tion in  the  tissues  of  an  antitoxine  which  has  the  power  of  neutraliz- 
ing their  pathogenic  action.  The  toxic  substance  present  in  cultures 
of  the  "diplococcus  of  pneumonia"  they  call  "  pneumotoxine ";  the 
substance  produced  in  the  body  of  an  artificially  immune  animal,  by 
17 


258  SUSCEPTIBILITY   AND   IMMUNITY. 

which  this  pneumotoxine  is  destroyed  if  subsequently  introduced,  they 
call  "  anti-pneumotoxine. " 

Emmorich,  in  a  communication  made  at  the  recent  (1891)  Inter- 
national Congress  for  Hygiene  and  Demography,  in  London,  reports 
results  which  correspond  with  those  of  G.  and  F.  Klemperer  so 
far  as  the  production  of  immunity  is  concerned,  and  also  gives  an 
account  of  experiments  made  by  Donissen  in  which  the  injection 
of  twenty  to  twenty-five  cubic  centimetres  of  blood  or  expressed 
tissue  juices,  filtered  through  porcelain,  from  an  immune  rabbit  into 
an  unprotected  rabbit,  subsequently  to  infection  with  a  bouillon  cul- 
ture of  "  diplococcus  pneumonise,"  prevented  the  development  of 
fatal  septicaemia.  Even  when  the  injection  was  made  twelve  to  fif- 
teen hours  after  infection,  by  inhalation,  the  animal  recovered. 

Emmerich  and  Mastraum  had  previously  reported  similar  results 
in  experiments  made  upon  mice  with  the  Bacillus  erysipelatos  suis 
(rothlauf  bacillus).  White  mice  are  very  susceptible  to  the  patho- 
genic action  of  this  bacillus.  But  mice  which,  subsequently  to  in- 
fection, were  injected  with  the  expressed  and  filtered  tissue  juices  of 
an  immune  rabbit,  recovered,  while  the  control  animals  succumbed. 
According  to  Emmerich,  the  result  in  these  experiments  was  due  to 
a  destruction  of  the  pathogenic  bacilli  in  the  bodies  of  the  infected 
animals  ;  and  the  statement  is  made  that  at  the  end  of  eight  hours 
after  the  injection  of  the  expressed  tissue  juices  all  bacilli  in  the  body 
of  the  infected  animal  were  dead.  The  same  liquid  did  not,  however, 
kill  the  bacilli  when  added  to  cultures  external  to  the  body  of  an 
animal.  The  inference,  therefore,  seems  justified  that  the  result  de- 
pends, not  upon  a  substance  present  in  the  expressed  juices  of  an 
immune  animal,  but  upon  a  substance  formed  in  the  body  of  the 
animal  into  which  these  juices  are  injected. 

We  have,  however,  an  example  of  induced  immunity  in  which 
the  result  appears  to  depend  directly  upon  the  destruction  of  the 
pathogenic  microorganism  in  the  body  of  the  immune  animal.  In 
guinea-pigs  which  have  an  acquired  immunity  against  Vibrio  Metsch- 
nikovi  the  blood  serum  has  been  proved  to  possess  decided  germicidal 
power  for  this  "  vibrio,"  whereas  it  multiplies  readily  in  the  blood 
serum  of  non-immune  guinea-pigs  (Behring  and  Nissen). 

There  is  experimental  evidence  that  animals  may  acquire  an  arti- 
ficial immunity  against  the  toxic  action  of  certain  toxalbumins  from 
other  sources  than  bacterial  cultures.  Thus  Sewell  (1887)  has  shown 
that  a  certain  degree  of  tolerance  to  the  action  of  rattlesnake  venom 
may  be  established  by  inoculating  susceptible  animals  with  small 
doses  of  the  "  hemialbumose "  to  which  it  owes  its  toxic  potency. 
In  this  connection  we  may  remark  that  there  is  some  evidence  to 
show  that  persons  who  are  repeatedly  stung  by  certain  poisonous 


SUSCEPTIBILITY   AND    IMMUNITY.  2591 

insects — mosquitoes,  bees — acquire  a  greater  or  less  degree  of  im- 
munity; from  the  distressing  local  effects  of  their  stings. 

Recently  (1891)  Ehrlich,  of  Berlin,  has  reported  his  success  in 
establishing  immunity  in  guinea-pigs  against  two  toxalbumins  of 
vegetable  origin  :  one — ricin — from  the  castor-oil  bean  (Ricinus 
communis),  the  other — abrin — from  the  jequirity  bean.  The  toxic 
potency  of  ricin  is  somewhat  greater  than  that  of  abrin,  and  it  is 
estimated  by  Ehrlich  that  one  gramme  of  this  substance  would  suffice 
to  kill  one  and  a  half  millions  of  guinea-pigs.  When  injected  be- 
neath the  skin,  in  dilute  solution,  it  produces  intense  local  inflamma- 
tion, resulting  in  necrosis  of  the  tissues.  Mice  are  less  susceptible 
than  guinea-pigs  and  are  more  easily  made  immune.  This  is  most 
readily  effected  by  giving  them  small  and  gradually  increasing  doses 
with  their  food.  As  a  result  of  this  treatment  the  animal  resists 
subcutaneous  injections  of  two  hundred  to  four  hundred  times  the 
fatal  dose  for  animals  not  having  this  artificial  immunity.  The  fatal 
dose  of  abrin  is  about  double  that  of  ricin.  When  injected  into  mice 
in  the  proportion  of  one  cubic  centimetre  to  twenty  grammes  of  body 
weight  a  solution  of  one  part  in  one  hundred  thousand  of  water 
proved  to  be  a  fatal  dose.  The  local  effects  are  also  less  pronounced 
when  solutions  of  abrin  are  used  ;  they  consist  principally  in  an  ex- 
tensive induration  of  the  tissues  around  the  point  of  injection  and  a 
subsequent  falling  off  of  the  hair  over  this  indurated  area.  When 
introduced  into  the  conjunctival  sac,  however,  abrin  produces  a 
local  inflammation  in  smaller  amounts  than  ricin,  a  solution  of  1 : 800 
being  sufficient  to  cause  a  decided  but  temporary  conjunctivitis. 
Solutions  of  1 :  50  or  1 : 100  of  either  of  these  toxalbumins,  introduced 
into  the  eye  of  a  mouse,  give  rise  to  a  panophthalmitis  which  com- 
monly results  in  destruction  of  the  eye.  But  in  mice  which  have 
been  rendered  immune  by  feeding  them  for  several  weeks  with  food 
containing  one  of  these  toxalbumins,  no  reaction  follows  the  intro- 
duction into  the  eye  of  the  strongest  possible  solution,  or  of  a  paste 
made  by  adding  abrin  to  a  little  ten-per-cent  salt  solution.  Ehrlich 
gives  the  following  explanation  of  the  remarkable  degree  of  im- 
munity established  in  his  experiments  by  the  method  mentioned: 

"  All  of  these  phenomena  depend,  as  may  be  easily  shown,  upon 
the  fact  that  the  blood  contains  a  body — antiabrin — which  completely 
neutralizes  the  action  of  the  abrin,  probably  by  destroying  this  body.*' 

In  a  more  recent  paper  Ehrlich  has  given  an  account  of  subse- 
quent experiments  which  show  that  the  young  of  mice  which  have 
an  acquired  immunity  for  these  vegetable  toxalbumins  may  acquire 
immunity  from  the  ingestion  of  the  mother's  milk  ;  and  also  that 
immunity  against  tetanus  may  be  acquired  in  a  very  brief  time  by 
young  mice  through  their  mother's  milk.  In  his  tetanus  experi- 


260  SUSCEPTIBILITY   AND   IMMUNITY. 

ments  Ehrlich  used  blood  serum  from  an  immune  horse  to  give  im- 
munity to  the  mother  mouse  when  her  young  were  already  seven- 
teen days  old.  Of  this  blood  serum  two  cubic  centimetres  were 
injected  at  a  time  on  two  successive  days.  The  day  after  the  first 
injection  one  of  the  sucklings  received  a  tetanus  inoculation  by 
means  of  a  splinter  of  wood  to  which  spores  were  attached.  The 
animal  remained  in  good  health,  while  a  much  larger  control  mouse 
inoculated  in  the  same  way  died  of  tetanus  at  the  end  of  twenty-six 
hours.  Other  sucklings,  inoculated  at  the  end  of  forty-eight  and  of 
seventy-two  hours  after  the  mother  had  received  the  injection  of 
blood  serum,  likewise  remained  in  good  health,  while  other  control 
mice  died. 

A  most  interesting  question  growing  out  of  these  extraordinary 
experimental  results  at  once  presents  itself  :  Does  the  animal  which 
is  immune  for  one  of  these  toxalbumins  also  exhibit  immunity  as  re- 
gards the  toxic  action  of  the  other  ?  This  question  Ehrlich  has  an- 
swered. His  experiments  show  that  animals  which  are  immune 
against  one  of  these  substances  are  quite  as  susceptible  to  the  toxic 
action  of  the  other  as  if  they  did  not  possess  this  immunity — i.e.,  the 
antitoxine  of  ricin  does  not  destroy  abrin,  and  vice  versa.  As  an 
illustration  of  this  fact  he  states  that  in  one  experiment  a  rabbit  was 
made  immune  against  ricin  to  such  an  extent  that  the  introduction  into 
its  eye  of  this  substance  in  powder  produced  no  inflammatory  reac- 
tion ;  but  the  subsequent  introduction  of  a  solution  of  abrin  of 
1  : 10,000  caused  a  violent  inflammation. 

Evidently  these  facts  are  of  the  same  order  as  those  relating  to 
immunity  from  infectious  diseases,  and,  taken  in  connection  with  the 
experimental  data  previously  referred  to,  give  strong  support  to  the 
view  that  the  morbid  phenomena  in  all  diseases  of  this  class  are  due 
to  the  specific  toxic  action  of  substances  resembling  the  toxalbumins 
already  discovered  ;  and  that  acquired  immunity  from  any  one  of 
these  diseases  results  from  the  formation  of  an  antitoxine  in  the  body 
of  the  immune  animal. 

Hankin  calls  these  substances  produced  in  the  bodies  of  immune 
animals  "  defensive  proteids,"  and  proposes  to  classify  them  as  fol- 
lows :  First,  those  occurring  naturally  in  normal  animals,  which  he 
calls  sozins  ;  second,  those  occurring  in  animals  that  have  acquired 
an  artificial  immunity — these  he  calls  phylaxins.  Each  of  these 
classes  of  defensive  proteids  is  further  subdivided  into  those  which 
act  upon  the  pathogenic  microorganism  itself  and  those  which  act 
upon  its  toxic  products.  These  subclasses  are  distinguished  by  the 
prefixes  myco  and  toxo  attached  to  the  class  name. 

In  accordance  with  this  classification  a  mycosozin  is  a  defensive 


SUSCEPTIBILITY   AND   IMMUNITY.  261 

proteid,  found  in  the  body  of  a  normal  animal,  which  has  the  power 
of  destroying  bacteria. 

A  toxosozin  is  a  defensive  proteid,  found  in  the  body  of  a  normal 
animal,  which  has  the  power  of  destroying  the  toxic  products  of  bac- 
terial growth. 

A  mycophylaxin  is  a  defensive  proteid  produced  in  the  body  of 
an  animal  which  has  an  acquired  immunity  for  a  given  infectious 
disease,  which  has  the  power  of  destroying  the  pathogenic  bacteria 
to  which  the  disease  is  due. 

A  toxophylaxin  is  a  defensive  proteid  produced  in  the  body  of 
an  animal  which  has  an  acquired  immunity  for  a  given  infectious 
disease,  which  has  the  power  of  destroying  the  toxic  products  of  the 
pathogenic  bacteria  to  which  the  disease  is  due. 

Buchner  had  previously  proposed  the  name  "  alexines  "  for  these 
defensive  proteids. 

The  importance  of  the  experimental  evidence  above  referred  to  in 
explaining  the  phenomena  of  natural  and  acquired  immunity  is  ap- 
parent. The  facts  stated  also  suggest  a  rational  explanation  of  re- 
covery from  an  attack  of  an  acute  infectious  disease.  But  the  idea 
that  during  such  an  attack  an  antidote  to  the  disease  poison  is  de- 
veloped in  the  tissues  is  yet  so  novel,  and  the  experimental  evidence 
in  support  of  this  view  is  of  such  recent  date,  that  it  would  be  pre- 
mature to  accept  this  explanation  as  applying  to  immunity  in  gene- 
ral. It  seems  difficult  to  believe  that  an  individual  who  has  passed 
through  attacks  of  measles,  mumps,  whooping  cough,  scarlet  fever, 
small-pox,  etc.,  has  in  his  blood  or  tissues  a  store  of  the  antitoxine  of 
each  of  these  diseases,  formed  during  the  attack  and  retained  during 
the  remainder  of  his  life,  or  continuously  produced  so  long  as  the 
immunity  lasts.  Moreover,  in  those  diseases  to  which  the  experi- 
mental evidence  above  recorded  relates — diphtheria,  tetanus,  pneu- 
monia— as  they  occur  in  man,  no  lasting  immunity  has  been  shown 
to  result  from  a  single  attack,  and  in  this  regard  they  do  not  come 
into  the  same  class  with  the  eruptive  fevers  and  other  diseases  in 
which  a  single  attack  usually  protects  during  the  lifetime  of  the  in- 
dividual. 

In  those  instances  in  which  acquired  immunity  has  been  shown 
to  be.  due  to  the  production  in  the  body  of  the  immune  animal  of  an 
antitoxine,  it  is  still  uncertain  "whether  there  is  a  continuous  produc- 
tion of  the  protective  proteid,  or  whether  that  formed  during  the 
attack  remains  in  the  body  during  the  subsequent  immunity.  The 
latter  supposition  appears  at  first  thought  improbable  ;  but  when  we 
remember  that  the  protective  proteids  which  have  been  isolated  by 
Hankin  from  the  blood  and  spleen  of  rats,  and  by  Tizzoni  and  Cat- 
tani  from  the  blood  of  animals  made  immune  against  tetanus,  do 


202  SUSCEPTIBILITY   AND    IMMUNITY. 

not  dialyze,  it  does  not  seem  impossible  that  these  substances  might 
be  retained  indefinitely  within  the  blood  vessels.  On  the  other  hand, 
the  passage  of  the  tetanus  antitoxine  into  the  mother's  milk,  as 
shown  by  Ehrlich's  experiments  upon  mice,  indicates  a  continuous 
supply,  otherwise  the  immunity  of  the  mother  would  soon  be  lost. 

The  writer  has  recently  (May,  1892)  obtained  experimental  evi- 
dence that  the  blood  of  vaccinated,  and  consequently  immune,  calves 
contains  something  which  neutralizes  the  specific  virulence  of  vac- 
cine virus,  both  bovine  and  humanized.  Four  drops  of  blood  serum 
from  a  calf  which  had  been  vaccinated  two  weeks  previously,  mixed 
with  one  drop  of  liquid  lymph  recently  collected  in  a  capillary  tube, 
after  contact  for  one  hour  was  used  to  vaccinate  a  calf ;  the  same 
animal  was  also  vaccinated  with  lymph,  preserved  on  three  quills, 
which  was  mixed  with  four  drops  of  serum  from  the  immune  calf 
and  left  for  one  hour.  The  result  of  these  vaccinations  was  entirely 
negative,  while  vaccinations  upon  the  same  calf  made  with  virus 
from  the  same  source,  and  mixed  with  the  same  amount  of  blood 
serum  from  a  non-immune  calf,  gave  a  completely  successful  and 
typical  result. 

The  experimental  evidence  detailed  gives  strong  support  to  the 
view  that  acquired  immunity  depends  upon  the  formation  of 
antitoxines  in  the  bodies  of  immune  animals.  As  secondary 
factors  it  is  probable  that  tolerance  to  the  toxic  products  of  patho- 
genic bacteria  and  phagocytosis  have  considerable  importance,  but  it 
is  evident  that  the  principal  role  cannot  be  assigned  to  these  agencies. 


PLATE  IV. 

Fias.  1,  2,  and  3. — Leucocytes  from  the  spleen  of  an  inoculated  monkey, 
containing-  Spirillum  Obermeieri.  (Soudake witch.) 

FIGS.  4  and  5. — Leucocytes  ("  macrophages "')  from  a  preparation  of 
muscle  from  a  pigeon  which  succumbed  to  an  anthrax  inoculation.  In  Fig. 
4  the  bacilli  are  deeply  stained  ;  in  Fig.  5  they  are  pale.  (Metschnikoff.) 

FIG.  6. — Leucocyte  from  a  frog  seventy-two  hours  after  the  injection  of 
anthrax  spores.  (Trapeznikoff.) 

FIGS.  7  and  8. — Leucocytes  from  a  chicken  four  hours  after  the  injection 
of  anthrax  spores.  (Trapeznikoff.) 


STERNBERG'S  BACTERIOLOGY. 


Plate  I 


Fig.l. 


Fig.  2. 


Fig  3. 


Jp  ^  : 


Fig.  5. 


Fig. 8. 


Fig.  7. 


PHAGOCYTES. 


IV. 
PYOGENTC  BACTERIA. 

THE    demonstration  made  by   Ogston,  Rosenbach,   Passet,  and 
others  that  micrococci  are  constantly  present  in  the  pus  of  acute 
abscesses,  led  to  the  inference  that  there  can  be  no  pus  formation  in 
the  absence  of  microorganisms  of  this  class.     But  it  is  now  well 
established,  by  the  experiments  of  Grawitz,   De   Bary,  Steinhaus, 
Scheurlen,   Kaufmann,  and  others,  that  this  inference  was  a  mis- 
taken one,  and  that  certain  chemical  substances  introduced  beneath 
the  skin  give  rise  to  pus  formation  quite  independently  of  bacteria. 
Among  the  substances  tested  which  have  given  a  positive  result  are 
nitrate  of  silver,  oil  of  turpentine,  strong  liquor  ammonias,   cada- 
verin,  etc.     The  demonstration  has  also  been  made  by  numerous  in- 
vestigators that  cultures  of  pus  cocci,  when  sterilized  by  heat,  still 
give  rise  to  pus  formation  when  injected  subcutaneously.     This  was 
first  established  by  Pasteur  in  1878,  who  found  that  sterilized  cul- 
tures of  his  "microbe  generateur  du  pus"  induced  suppuration  as 
well  as  cultures  containing  the  living  microbe.     This  fact  lias  since 
been  confirmed,  as  regards  the  pus  staphylococci  and  various  bacilli, 
by  a  number  of  bacteriologists.     Wyssokowitsch  produced  abscesses 
containing  sterile  pus  by  injecting  subcutaneously  agar  cultures  of 
the  anthrax  bacillus  sterilized  by  heat.     Buchner  obtained  similar 
results  in  a  series  of  forty  experiments  from  the  injection  of  steril- 
ized cultures  of  Friedlander's  bacillus  ("  pneumococcus "),  and  has 
shown  that  the  pus-forming  property  belongs  to  the  bacterial  cells 
and  not  to  a  soluble  chemical  substance  produced  by  them.     When 
cultures  were  filtered  by  means  of  a  Chamberlain  filter  the  clear 
fluid  which  passed  through  the  porous  porcelain  was  without  effect, 
while  the  dead  bacteria  retained  by  the  filter  produced  aseptic  pus 
infiltration  in  the  subcutaneous    tissues  within  forty-eight    hours 
after  having  been  injected.     Subsequent  experiments  gave  similar 
results  with  seventeen  different  species  tested,  including  Staphylo- 
coccus  pyogenes  aureus,  Staphylococcus  cereus  flavus,  Sarcina  auran- 
tiaca,   Bacillus    prodigiosus,   Bacillus   Fitzianus,   Bacillus    subtilis, 
Bacillus  coli  communis,  Bacillus  acidi  lactici,  etc.     From  the  experi- 


201  PYOGENIC   BACTERIA. 

ments  made  to  determine  the  exact  cause  of  pus  formation  following- 
the  injection  of  sterilized  cultures  Buchner  arrives  at  the  conclusion 
that  it  is  due  to  the  albuminous  contents  of  the  bacterial  cells. 

While  it  is  demonstrated  that  a  large  number  of  microorganisms, 
either  living  or  in  sterilized  cultures,  may  give  rise  to  the  formation 
of  pus,  the  extended  researches  of  Rosenbach,  Passet,  and  other 
bacteriologists  show  that  few  species  are  usually  concerned  in  the 
formation  of  acute  abscesses,  furuncles,  etc.,  in  man.  Of  these  the 
two  most  important,  by  reason  of  their  frequent  occurrence  and  path- 
ogenic power,  are  Staphylococcus  pyogenes  aureus  and  Strepto- 
coccus pyogenes ;  next  to  these  comes  Staphylococcus  pyogenes 
albus,  and  the  following  species  are  occasionally  found  :  Staphylo- 
coccus pyogenes  citreus,  Staphylococcus  cereus  flavus,  Staphylococcus 
cereus  albus,  Micrococcus  tenuis,  Bacillus  pyogenes  foetidus,  Micro- 
coccus  tetragenus,  Micrococcus  pneumonise  crouposse.  Two  or  more 
species  are  often  found  in  the  same  abscess  ;  thus  Passet,  in  thirty- 
three  cases  of  acute  abscess,  found  Staphylococcus  aureus  and  albus 
associated  in  eleven,  albus  alone  in  four,  albus  and  citreus  in  two, 
Streptococcus  pyogenes  alone  in  eight,  albus  and  streptococcus  in 
one,  and  albus,  citreus,  and  streptococcus  in  one.  Hoffa  found,  in 
twenty-two  cases  of  inguinal  bubo,  aureus  in  ten,  albus  in  nine,  and 
citreus  in  three.  Bumm,  in  ten  cases  of  puerperal  mastitis,  found 
aureus  in  seven  and  Streptococcus  pyogenes  in  three.  Rosenbach 
found  staphylococci  alone  sixteen  times,  Streptococcus  pyogenes  alone 
fifteen  times,  staphylococci  and  streptococci  associated  five  times, 
and  Micrococcus  tenuis  three  times  in  thirty-nine  acute  abscesses  and 
phlegmons  examined  by  him. 

Robb  and  Ghrisky  have  shown  that  under  the  most  rigid  antisep- 
tic treatment  microorganisms  are  constantly  found  attached  to  su- 
tures when  these  are  removed  from  wounds  made  by  the  surgeon, 
and  that  a  skin  abscess  frequently  results  from  the  presence  of  the 
most  common  of  these  microorganisms — Staphylococcus  epidermidis 
albus. 

The  authors  named  state  their  conclusions  as  follows  : 

"A  wound,  at  some  time  of  its  existence,  always  contains  organisms. 
They  occur  either  on  the  stitches  or  in  the  secretions. 

"  The  number  of  bacteria  is  influenced  by  the  constricting  action  of  the 
ligatures  or  drainage  tube,  or  anything  interfering  with  the  circulation  of 
the  tissues. 

' '  The  virulence  of  the  organisms  present  will  influence  the  progress  of 
the  wound. 

"The  body  temperature  is  invariably  elevated  if  the  bacteria  are  viru- 
lent; and,  indeed,  in  cases  where  many  of  the  less  virulent  organisms  are 
found,  almost  without  exception  there  is  some  rise  of  temperature." 

The  organism  most  frequently  found — Staphylococcus  epidermi- 


PYOGENIC   BACTERIA.  265 

dis  albus — has  but  slight  virulence.  Out  of  forty-five  cases  in  which 
a  bacteriological  examination  was  made  this  micrococcus  was  ob- 
tained in  pure  cultures  in  thirty-three  ;  in  five  cases  it  was  associated 
with  Staphylococcus  pyogenes  aureus,  in  one  case  with  Streptococ- 
cus pyogenes,  in  three  cases  Streptococcus  pyogenes  was  obtained 
alone. 

In  abscesses  resulting  from  inflammation  of  the  middle  ear  the 
micrococcus  commonly  known  under  the  name  of  "  diplococcus 
pneumonise  " — Micrococcus  pneumonia}  crouposse — has  been  obtained 
in  pure  cultures  in  a  considerable  number  of  cases  when  the  pus  has 
been  examined  immediately  after  paracentesis  of  the  tympanic  mem- 
brane. We  shall  not,  however,  describe  this  among  the  pyogenic 
bacteria,  but  will  give  an  account  of  it  in  the  following  section  (Bac- 
teria in  Croupous  Pneumonia,  etc.).  Bacillus  pyocyanus,  which  is 
described  by  some  authors  among  the  pyogenic  bacteria,  is  found 
only  in  the  pus  of  open  wounds,  where  its  presence  is  evidently  acci- 
dental. We  shall  describe  it  among  the  chromogenic  saprophytes. 

1.  STAPHYLOCOCCUS  PYOGENES  AUREUS. 

Synonym. — Micrococcus  of  infectious  osteomyelitis  (Becker). 

Observed  by  Ogston  (1881)  in  the  piis  of  acute  abscesses,  but  not 
differentiated  from  the  associated  staphylococci  and  the  streptococ- 
cus of  pus.  Obtained  by  Becker  from  the  pus  of  osteomyelitis  (1883). 
Isolated  from  the  pus  of  acute  abscesses  and  accurately  described  by 
Rosenbach  (1884)  and  by  Passet  (1885). 

The  Staphylococcus  pyogenes  aureus  is  a  facultative  parasite,  and 
is  the  most  common  pyogenic  micrococcus  found  in  suppurative  pro- 
cesses generally.  But  it  is  also  a  common  and  widely  distributed 
saprophyte,  which  finds  the  conditions  necessary  for  its  existence  on 
the  external  surface  of  the  human  body  and  of  moist  mucous  mem- 
branes. This  is  shown  by  the  researches  of  numerous  bacteriolo- 
gists. Thus  Ullmann  found  it  upon  the  skin  and  in  the  secretions  of 
the  mouth  of  healthy  persons,  and  also  in  the  dust  of  occupied  apart- 
ments, in  water,  etc. ;  Bockhart  obtained  it  in  cultures  from  the 
surface  of  the  body  and  from  the  dirt  beneath  the  finger  nails  of 
healthy  persons  ;  Biondi,  Vignal,  and  others  in  the  salivary  secre- 
tions ;  B.  Frankel  in  mucus  from  the  pharynx  ;  Von  Besser  and 
Wright  in  nasal  mucus  ;  Escherich  in  the  alvine  discharges  of 
healthy  infants  ;  C.  Frankel  in  the  air  ;  and  Liibbert  in  the  soil.  Its 
presence  in  the  air,  in  water,  or  in  the  soil  is,  however,  quite  excep- 
tional, and  is  probably  to  be  considered  the  result  of  accident,  its 
normal  habitat  as  a  saprophyte  appearing  to  be  rather  upon  the  sur- 
face of  the  body  and  of  mucous  membranes. 
18 


366  PYOGENIC   BACTERIA. 

Morphology. — Spherical  cells  having  a  diameter  of  0.7  /<  (Hade- 
lich)  to  0.9  //  (0.87  /<  Passet),  solitary,  in  pairs,  or  in  irregular 
groups,  occasionally  in  chains  of  three  or  four  elements  or  in  groups 
of  four.  The  dimensions  vary  somewhat  in  dif- 
ferent culture  media,  being  larger  in  a  favorable 
than  in  an  unfavorable  medium.  The  individual 
cells,  as  pointed  out  by  Hadelich,  consist  of  two 
hemispherical  portions  separated  from  each  other 
FIG.  79.-staphyiococ-  by  a  very  narrow  cleft,  which  is  not  visible  when 
fromPya0ged™win7eUbS;  the  cells  are  deeply  stained,  but  may  be  demon- 
Rosenbach.  strated,  with  ,a  high  power,  by  staining  for  a  short 

time  (two  minutes'  or  less)  in  a  solution  of  f  uchsin  in  aniline  water. 

This  micrococcus  stains  quickly  in  aqueous  solutions  of  the  basic 
aniline  colors,  and  may  also  be  stained  with  acid  carmine  and  haema- 
toxylin.  It  is  not  decolorized  by  iodine  solution  when  stained  with 
methyl  violet — Gram's  method. 

Biological  Characters. — Staphylococcus  pyogenes  aureus  grows 
either  in  the  presence  or  absence  of  oxygen,  and  is  consequently  a 
facultative  anaerobic.  It  multiplies  rapidly  at  a  temperature  of  18° 
to  20°  C.  in  milk,  flesh  infusions,  and  various  other  liquid  media, 
and  in  nutrient  gelatin  or  agar.  It  liquefies  gelatin,  and  in  stick 
cultures  liquefaction  occurs  all  along  the  line  of  puncture,  forming  a 
pouch  which  is  largest  above  and  at  the  end  of  three  or  four  days  has 
extended  to  the  full  capacity  of  the  test  tube  at  the  surface.  The 
liquefied  gelatin  in  this  pouch  is  at  first  opaque  from  the  presence  of 
little  agglomerations  of  micrococci  in  suspension,  but  after  a  time 
these  are  deposited  and  the  gelatin  becomes  transparent.  During 
the  period  of  active  growth,  the  cocci  accumulate  near  the  surface  of 
the  gelatin,  and,  in  contact  with  the  air,  the  characteristic  golden-yel- 
low pigment  is  produced.  By  the  subsidence  of  the  colored  masses 
of  cocci  from  this  superficial  stratum  a  yellow  deposit  is  gradually 
formed  at  the  bottom  of  the  pouch  of  liquefied  gelatin  (Fig.  80).  This 
pigment,  which  is  the  principal  character  distinguishing  the  micro- 
coccus  under  consideration  from  certain  other  liquefying  staphylo- 
cocci,  is  only  formed  in  the  presence  of  oxygen.  Upon  the  surface 
of  nutrient  agar  development  occurs  in  the  form  of  a  moist,  shining 
layer,  with  more  or  less  wavy  outlines,  having  at  first  a  pale-yellow 
color,  which  soon  deepens  to  an  orange-  or  golden-yellow.  The  col- 
onies which  develop  upon  agar  plates  are  spherical  and  opaque,  and 
usually  acquire  the  golden -yellow  color  within  a  few  days.  Colonies 
on  gelatin  plates  or  in  Esmarch  roll  tubes  first  appear  as  small  white 
dots,  which  later  are  more  or  less  granular  in  appearance  and  present 
the  yellow  color,  especially  towards  the  centre  ;  but,  owing  to  the 
extensive  liquefaction  of  the  gelatin  caused  by  them,  their  develop- 


PYOGENIC   BACTERIA. 


267 


ment  can  only  be  followed  for  two  or  three  days.     Upon  potato,  at  a 
temperature  of  35°  to  37°  C.,  a  rather  thick,  moist  layer  of  consider- 
able extent  forms  at  the  end  of  twenty-four  to  forty-eight  hours  ; 
this  is  also  at  first  of  a  pale-yellow,  and  later 
of  an  orange-yellow  color.     The  temperature 
mentioned  is  most  favorable  for  the  rapid 
development   of  this  micrococeus,  although 
multiplication  may  occur  at  a  comparatively 
low  temperature  and  is  tolerably  abundant  at 
the  ordinary  room  temperature. 

Cultures  of  the  "golden  staphylococcus," 
and  especially  those  upon  potato,  give  off  a 
peculiar  odor  which  resembles  that  of  sour 
paste.  When  cultivated  in  milk  it  gives  rise 
to  the  formation  of  lactic  and  butyric  acids 
and  to  coagulation  of  the  casein.  No  poison- 
ous ptomaines  or  toxalbumins  have  been  iso- 
lated from  cultures  of  this  micrococcus,  but, 
like  other  liquefying  bacteria,  it  forms  a  sol- 
uble peptonizing  ferment,  by  which  gelatin 
may  be  liquefied  independently  of  the  living 
microorganism.  While  the  Staphylococcus 
aureus  gives  rise  to  the  production  of  acids — 

principally  lactic  acid — in  media  containing  staphylococcus  pyogenes  aui-eus 
glucose  or  lactose,  it  has  also  been  shown  by  (Baum&arten)- 
Brieger  that  ammonia  is  one  of  the  products  of  its  vital  activity. 
Unlike  some  other  pathogenic  bacteria,  it  is  able  to  grow  in  a  medium 
having  a  distinctly  acid  reaction.  A  non-poisonous  basic  substance 
has  been  isolated  by  Brieger  from  old  cultures  in  meat  infusion  which 
differs  from  any  of  the  ptomaines  obtained  by  him  from  other  sources. 

The  thermal  death-point  of  this  micrococcus,  in  recent  cultures  in 
flesh-peptone-gelatin,  as  determined  by  the  writer,  is  between  56°  and 
58°  C.,  the  time  of  exposure  being  ten  minutes.  When  in  a  desic- 
cated condition  a  much  higher  temperature  is  required — 90°  to  100°  C. 
— for  its  destruction  ;  and  it  retains  its  vitality  for  more  than  ten 
days  when  dried  upon  a  cover  glass  (Passet).  It  retains  its  vitality 
for  a  long  time  in  cultures  in  nutrient  gelatin  or  agar,  and  may  grow 
when  transplanted  from  such  cultures  even  at  the  end  of  a  year. 

Very  numerous  experiments  have  been  made  to  determine  the 
proportion  of  various  chemical  agents  required  to  destroy  the  vitality 
or  to  restrain  the  growth  of  this  important  pyogenic  micrococcus. 
The  extended  researches  of  Liibbert  (188G)  with  reference  to  the 
antiseptic  power  of  agents  added  to  a  suitable  culture  medium — nu- 
trient gelatin — gave  the  following  results  :  Development  was  pre- 


FIG.    80.— Gelatin    culture   of 


268  PYOGENIC   BACTERIA. 

vented  by  the  agents  named  in  the  proportion  given  :  Nitric  acid, 
1  :  797  ;  phosphoric  acid,  1  :  750  ;  boracic  acid,  1  :  327  ;  oxalic  acid, 
1  : 433  ;  acetic  acid,  1  :  720  ;  citric  acid,  1  :  433  ;  lactic  acid,  1  :  350  ; 
benzoic  acid,  1  : 400 ;  salicylic  acid,  1  : 655  ;  iodine  dissolved  with 
potassium  iodide,  1:1,100;  arsenite  of  potash,  1:733;  mercuric 
chloride,  1  :  81,400  ;  chloral  hydrate,  1  : 133  ;  carbolic  acid,  1  :  814  ; 
thymol,  1  : 11,000  ;  resorcin,  1  : 122  ;  hydrochinon,  1  :  353  ;  kairin, 
1  : 407  ;  antipyrin,  1  : 26  ;  muriate  of  quinine,  1  : 550  ;  muriate  of 
morphia,  1  : 60.  For  the  destruction  of  vitality  very  much  larger 
amounts  are  required.  In  Bolton's  experiments  (1887)  a  one-per-cent 
solution  of  carbolic  acid  was  successful  after  two  hours'  exposure, 
but  two  per  cent  failed  to  completely  destroy  vitality  in  the  same 
time  ;  one  per  cent  of  sulphate  of  copper  was  also  successful,  and  but 
a  single  colony  developed  after  exposure  to  a  solution  of  1  : 200.  In 
the  experiments  of  Gartner  and  Plagge  the  Staphylococcus  aureus  in 
bouillon  cultures  is  said  to  have  been  killed  in  a  few  seconds  (eight) 
by  a  solution  of  mercuric  chloride  of  the  proportion  of  1  : 1,000  ;  Behr- 
ing  found  it  was  killed  by  the  acid  sublimate  solution  of  La  Place, 
in  the  proportion  of  1  : 1,000,  in  ten  minutes ;  Tarnier  and  Vignal 
found  that  a  solution  of  1  : 1,000  was  successful  in  two  minutes. 
Abbott  (1891)  has  shown  that  in  the  same  culture  there  may  be  a 
considerable  difference  in  the  resisting  power  of  the  cocci,  and  that 
while  frequently  all  are  destroyed  in  five  minutes  by  a  1  : 1,000  solu- 
tion, it  occurs  quite  as  frequently  that  some  may  survive  after  an  ex- 
posure of  ten,  twenty,  and  even  thirty  minutes. 

Pathogenesis. — Subcutaneous  inoculation  with  a  small  quantity 
of  a  culture  of  Staphylococcus  pyogenes  aureus  is  without  result  in 
rabbits,  guinea-pigs,  or  mice,  but  when  a  considerable  quantity  is 
injected  beneath  the  skin  of  a  rabbit  or  a  guinea-pig  an  abscess  is 
produced,  which  usually  results  in  recovery,  but  may  give  rise  to 
general  infection  and  the  death  of  the  animal.  Injection  into  a 
vein  or  into  the  cavity  of  the  abdomen  in  the  animals  mentioned 
usually  induces  a  fatal  result  within  a  few  days.  The  most  charac- 
teristic pathological  changes  are  found  in  the  kidneys,  which  con- 
tain numerous  small  collections  of  pus  and  under  the  microscope 
present  the  appearances  resulting  from  embolic  nephritis.  Many  of 
the  capillaries  and  some  of  the  smaller  arteries  of  the  cortex  are 
plugged  up  with  thrombi  consisting  of  micrococci.  Metastatic  ab- 
scesses may  also  be  found  in  the  joints  and  muscles.  The  micro- 
cocci  may  be  recovered  in  pure  cultures  from  the  blood  and  the 
various  organs  ;  but  they  are  not  numerous  in  the  blood,  and  a  sim- 
ple microscopical  examination  will  often  fail  to  demonstrate  their 
presence. 

Animals  frequently  survive  the  injection  of  a  small  quantity  of 


PYOGENIC   BACTERIA. 


269 


a  pure  culture  made  directly  into  the  circulation,  and  there  is  evi- 
dence that  the  pathogenic  potency  of  this  micrococcus  may  vary 
considerably  as  a  result  of  conditions  relating  to  its  origin  and  culti- 
vation in  the  animal  body  or  in  artificial  media.  When  injected  in 
considerable  quantities  it  may  be  obtained  in  cultures  from  the 
urine,  but  not  sooner  than  six  or  eight  hours  after  the  injection,  and 
not  until  the  formation  of  purulent  foci  in  the  kidneys  has  already 
occurred  (Wyssokowitsch). 

The  pyogenic  properties  of  this  micrococcus  have  been  demon- 
strated upon  man  by  the  experiments  of  Garre,  of  Bockhart,  and  of 
Bumm.  The  first-named  observer  inoculated  a  small  wound  at  the 
edge  of  one  of  his  finger  nails  with  a  minute  quantity  of  a  pure  cul- 
ture, and  a  subepidermal,  purulent  inflammation  extending  around 


FIG.  81.— Vertical  section  through  a  Mibcutaneous  abscess  caused  by  inoculation  witb  staphylo- 
cocci,  in  the  rabbit,  forty-eight  hours  after  infection;  margin  towards  the  normal  tissue,  x  95o. 
(Baumgarten.) 

tiie  margin  of  the  nail  resulted  from  the  inoculation.  Staphylococ- 
cus  aureus  was  recovered  in  cultures  from  the  pus  thus  formed.  A 
more  extensive  and  extremely  satisfactory  experiment  was  subse- 
quently made  by  Garre,  who  applied  a  considerable  quantity  of  a 
pure  culture  obtained  from  the  above-mentioned  source — third  gene- 
ration— to  the  uninjured  skin  of  his  left  forearm.  At  the  end  of 
four  days  a  large  carbuncle,  surrounded  by  isolated  furuncles,  de- 
veloped at  the  point  where  the  culture  had  been  applied.  This  ran 
the  usual  course,  and  it  was  several  weeks  before  it  had  completely 
healed.  No  less  than  seventeen  scars  remained  to  give  evidence  of 
the  success  of  the  experiment. 

In  Bockhart's  experiments  a  similar  but  milder  result  was  ob- 
tained, the  conditions  having  been  somewhat  different.     A  small 


270  PYOGENIC   BACTERIA. 

quantity  of  an  agar  culture  was  suspended  in  0. 5-per-cent  salt  solu- 
tion, and  this  was  rubbed  upon  the  uninjured  skin  of  the  left  fore- 
arm. By  gentle  scratching  with  a  disinfected  finger  nail  the  epithe- 
lium was  removed  in  places  over  the  area  to  which  the  micrococcus 
had  been  applied.  As  a  result  of  this  procedure  numerous  impe- 
tigo pustules  and  occasionally  a  genuine  furuncle  developed.  Por- 
tions of  the  skin  containing  the  smaller  pustules  were  excised  and 
examined  microscopically.  As  a  result  of  this  examination  Bock- 
hart  concluded  that  the  cocci  penetrate  by  way  of  the  hair  follicles, 
the  sebaceous  and  sudoriparous  glands,  or,  where  the  epidermis  had 
been  removed  by  scratching,  directly  to  the  deeper  layers  of  the  skin. 

In  Bumm's  experiments,  made  upon  himself  and  several  other 
persons,  Staphylococcus  aureus  suspended  in  sterilized  salt  solution 
was  injected  beneath  the  skin.  An  abscess  resulted  in  every  case. 

The  very  extended  researches  made  by  bacteriologists  during  the 
past  five  or  six  years  show  that  the  golden  staphylococcus  is  the 
most  common  pyogenic  microorganism.  Its  presence  has  been  de- 
monstrated not  only  in  furuncles  and  carbuncles,  but  also  in  various 
pustular  affections  of  the  skin  and  mucous  membranes — impetigo, 
sycosis,  phlyctenular  conjunctivitis  ;  in  purulent  conjunctivitis  and 
inflammation  of  the  lacrymal  sac  ;  in  acute  abscesses  formed  in  the 
lymphatic  glands,  the  parotid  gland,  the  tonsils,  the  mammae,  etc. ; 
in  metastatic  abscesses  and  purulent  collections  in  the  joints  ;  in  em- 
pyema  ;  in  infectious  osteomyelitis  ;  and  in  ulcerative  endocarditis. 
The  evidence  relating  to  its  presence  and  etiological  import  in  the 
last-mentioned  affections  demands  special  consideration. 

Infectious  osteomyelitis  appears  from  the  researches  of  Becker, 
Rosenbach,  Krause,  Passet,  and  others,  to  be  usually  due  to  the  pre- 
sence of  Staphylococcus  aureus,  although  Kraske  has  shown  that  in 
certain  cases  this  is  associated  with  other  microorganisms.  Becker, 
who  obtained  this  micrococcus  from  the  pus  of  osteomyelitis  in  1883, 
was  the  first  to  show  by  experiment  that  the  same  affection  might  be 
induced  in  rabbits  by  injecting  cultures  of  the  micrococcus  into  the 
circulation,  after  having  crushed  or  fractured  a  bone  in  one  of  its 
legs.  The  animal  usually  died  in  from  twelve  to  fourteen  days  and 
presented  the  usual  appearances  of  osteomyelitis  at  the  fractured 
point.  The  abundant  yellowish-white  pus  contained  the  golden 
staphylococcus  which  was  described  by  Becker,  and  subsequently 
known  in  the  bacteriological  laboratories  of  Germany  as  the  "  mi- 
crococcus of  infectious  osteomyelitis."  Becker's  experimental  re- 
sults have  been  confirmed  by  Krause  and  Rosenbach;  and  Rodet,  by 
injecting  smaller  quantities  of  a  culture  into  the  circulation,  has  suc- 
ceeded in  producing  an  osteomyelitis  without  previous  injury  to  the 
bone. 


PYOGENIC   BACTERIA.  271 

Ulcerative  endocarditis  has  been  shown  by  the  researches  of 
numerous  bacteriologists  to  be  occasionally  accompanied  by  a  mycotic 
invasion  of  the  affected  tissues  by  the  golden  staphylococcus ;  in 
other  cases  Streptococcus  pyogenes  is  present.  The  researches  of 
Weichselbaum,  and  of  E.  Frankel  and  Sanger,  also  show  that  it  is 
present  in  a  certain  proportion  of  the  cases,  at  least,  of  endocarditis 
verrucosa,  although  in  smaller  numbers.  That  the  diseased  condi- 
tion of  the  cardiac  valves  in  ulcerative  endocarditis  is  due  to  mycotic 
invasion  is  now  generally  admitted  and  is  supported  by  experimental 
evidence.  Rosenbach  first  (1873)  produced  an  endocarditis  in  lower 
animals  by  mechanical  injury  to  the  cardiac  valves,  effected  by  in- 
troducing a  sound  through  the  aorta.  Following  his  method,  Wys- 
•sokowitsch  (1885),  after  injuring  the  cardiac  valves  in  rabbits,  in- 
jected into  the  circulation  pure  cultures  of  various  bacteria.  He 
obtained  positive  results  with  Staphylococcus  aureus  and  Strepto- 
coccus pyogenes  only.  When  these  micrococci  were  injected  into 
the  trachea  or  subcutaneously  the  result  was  negative,  as  was  the 
case  when  very  few  cocci  were  injected  into  a  vein,  or  when  two 
days  or  more  were  allowed  to  elapse  after  injury  to  the  cardiac- 
valves.  Subsequently  Weichselbaum,  Prudden,  and  Frankel  and 
Sanger  obtained  confirmatory  results,  thus  establishing  the  fact  that 
when  the  valves  are  first  injured  mechanically  (or  chemically— 
Prudden)  the  injection  into  a  vein  of  a  pure  culture  of  Staphylococcus 
aureus  gives  rise  to  a  genuine  ulcerative  endocarditis.  It  has  been 
further  shown  by  Ribbert  that  the  same  result  may  be  obtained  with- 
out previous  injury  to  the  valves  by  injecting  into  a  vein  the  staphy- 
lococcus from  a  potato  culture  suspended  in  water.  In  his  experi- 
ments not  only  the  micrococci  from  the  surface  but  the  superficial 
layer  of  the  potato  was  scraped  off  with  a  sterilized  knife  and  mixed 
with  distilled  water  ;  and  the  successful  result  is  ascribed  to  the  fact 
that  the  little  agglomerations  of  micrococci  and  infected  fragments 
of  potato  attach  themselves  to  the  margins  of  the  valves  more  readily 
than  isolated  cocci  would  do.  In  these  experiments  the  mitral  and 
tricuspid  valves  were  affected,  while  the  semilunar  valves  remained 
intact.  In  ulcerative  endocarditis  it  is  evident  that  cocci  detached 
from  the  diseased  valves  must  find  their  way  into  the  circula- 
tion. As  a  matter  of  fact,  masses  of  micrococci  are  carried  away  by 
the  blood  stream  and  form  emboli  in  various  parts  of  the  body,  which 
become  secondary  foci  of  infection  and  give  rise  to  local  necrotic 
changes  and  accumulations  of  pus.  While  this  undoubtedly  occurs. 
it  is  generally  admitted  that  the  mycotic  infection  of  the  cardiac 
valves  is  usually  a  secondary  affection,  resulting  from  the  transpor- 
tation of  micrococci  in  the  blood  current  from  some  other  infected 
focus.  But  there  is  no  general  development  of  micrococci  in  the  cir- 


272  PYOGENIC   BACTERIA. 

culating  fluid,  and  in  man,  as  in  animals  infected  experimentally,  a 
microscopic  examination  of  the  blood  for  microorganisms  usually 
gives  a  negative  result.  Culture  experiments  may,  however,  demon- 
strate their  presence.  Thus  recent  investigations  by  Netter,  Eisel- 
berg,  and  others  show  that  the  pus  cocci  are  usually  present  in  the 
blood  in  small  numbers,  as  demonstrated  by  culture  experiments,  in 
septic  infection  from  wounds. 

2.  STAPHYLOCOCCUS  PYOGENES  ALBUS. 

Isolated  by  Rosenbach  (1884)  from  the  pus  of  acute  abscesses,  in 
which  it  is  sometimes  tiie  only  microorganism  present,  and  some- 
times associated  with  other  pus  cocci.  In  thirty-three  acute  abscesses 
examined  by  Passet  (1885)  it  was  associated  with  Staphylococcus 
aureus  in  eleven,  with  Staphylococcus  citreus  in  two,  with  Strepto- 
coccus pyogenes  in  one,  with  both  Staphylococcus  citreus  and  Strep- 
tococcus pyogenes  in  one,  and  was  obtained  alone  from  four. 

In  its  morphology  this  micrococcus  is  identical  with  the  preced- 
ing, but  it  is  distinguished  from  it  by  the  absence  of  pigment  and 
by  being  somewhat  less  pathogenic.  Surface  cultures  upon  nutrient 
agar  or  potato  have  a  milk-white  color.  It  liquefies  gelatin  in  the 
same  way  as  does  the  golden  Staphylococcus,  but  the  deposit  at  the 
bottom  of  the  liquefied  gelatin  is  without  color.  In  the  temperature 
conditions  favorable  to  its  growth,  and  in  its  biological  characters 
generally,  with  the  exceptions  noted,  it  is  not  to  be  distinguished 
from  the  species  previously  described.  According  to  Fliigge,  it  is 
more  common  than  aureus  among  many  of  the  lower  animals. 

Pathogenesis. — Fortunati  has  tested  the  comparative  pathogenic 
power  of  Staphylococcus  aureus  and  Staphylococcus  albus  by  inocu- 
lations into  the  cornea  of  rabbits.  A  purulent  infiltration  of  the 
cornea  and  panophthalmitis  resulted  when  Staphylococcus  aureus 
was  inoculated  upon  the  surface  of  the  cornea  by  scratching  with  an 
infected  needle,  but  inoculations  made  in  the  same  way  with.  Staphy- 
lococcus albus  healed  spontaneously  or  gave  rise  to  a  perforating 
ulcer.  After  paracentesis  of  the  cornea  with  an  instrument  infected 
with  Staphylococcus  aureus  panophthalmitis  developed  in  thirty  hours; 
the  same  result  occurred  at  the  end  of  sixty  to  seventy-two  hours 
when  the  instrument  was  infected  with  Staphylococcus  albus.  When 
a  sterilized  instrument  was  used  the  result  was  negative.  In  bacteri- 
ological researches  made  by  Gallenga,  in  cases  of  panophthalmitis  i?i 
man,  Staphylococcus  albus  was  found  in  ten  cultures  and  Staphy- 
lococcus aureus  in  nine. 

Staphylococcus  Epidermidis    Albus    (Welch). 
The  recently  published  researches  of  Welch  show  that  a  white 
staphylocoocns,    probably    identical    with  Staphylococcus  pyogenes 


PYOGENIC    BACTERIA.  273 

albus  of  Rosenbach,  is  the  most  common  microorganism  upon  the 
surface  of  the  body,  and  that  "  it  is  very  often  present  in  parts  of  the 
epidermis  deeper  than  can  be  reached  by  any  known  means  of  cuta- 
neous disinfection  save  the  application  of  heat. "  With  reference  tc 
this  coccus  Welch  says  : 

"So  far  as  our  observations  extend — and  already  they  amount  to  a 
large  number — this  coccus  may  be  regarded  as  a  nearly,  if  not  quite,  con- 
stant inhabitant  of  the  epidermis.  It  is  now  clear  Avhy  I  have  proposed  to 
call  it  tbe  Staphylococcus  epidermidis  albus.  It  possesses  such  feeble  pyo 
genie  capacity,  as  is  shown  by  its  behavior  in  wounds  as  well  as  by  experi- 
ments on  rabbits,  that  the  designation  Staphylococcus  pyogenes  albus  does 
not  seem  appropriate.  Still,  I  am  not  inclined  to  insist  too  much  upon  this 
point,  as  very  probably  this  coccus,  which  has  hitherto  been  unquestionably 
identified  by  Bossowski  and  others  with  the  ordinary  Staphylococcus  pyo 
genes  albus  of  Rosenbach,  is  an  attenuated  or  modified  form  of  the  latter 
organism,  although,  as  already  mentioned,  it  presents  some  points  of  differ- 
ence from  the  classical  description  of  the  white  pyogenic  coccus." 

According  to  Welch,  this  coccus  differs  from  Staphylococcus  pyo- 
genes aureus  not  only  in  color,  but  also  in  the  fact  that  it  liquefies 
gelatin  more  slowly,  does  not  so  quickly  cause  coagulation  of  milk, 
and  is  far  less  virulent  when  injected  into  the  circulation  of  rabbits. 
It  has  been  shown  by  the  researches  of  Bossowski  and  of  Welch 
that  this  coccus  is  very  frequently  present  in  aseptic  wounds,  and 
that  usually  it  does  not  materially  interfere  with  the  healing  of 
wounds,  although  sometimes  it  appears  to  cause  suppuration  along 
the  drainage  tube,  and  it  is  the  usual  cause  of  "  stitch  abscess." 
Bossowski,  in  fifty  cases  of  wounds  treated  antiseptically,  obtained 
bacteria  from  the  discharges  in  forty,  and  in  twenty-six  of  these 
cases  he  found  Staphylococcus  pyogenes  albus  ;  Staphylococcus  au- 
reus was  found  nine  times,  Streptococcus  pyogenes  in  two,  and  vari- 
ous non-pathogenic  bacteria  in  eight.  In  forty-five  laparotom}T 
wounds  examined  by  Ghrisky  and  Robb,  in  which  strict  antiseptic 
precautions  had  been  observed,  bacteria  were  f  ovkid  in  thirty -one,  and 
in  nineteen  of  this  number  Staphylococcus  albus  was  present, 
Staphylococcus  aureus  in  five,  Bacillus  coli  communis  in  six,  and 
Streptococcus  pyogenes  in  three. 

3.      STAPHYLOCOCCUS   PYOGENES   CITREUS. 

Isolated  by  Passet  (1885)  from  the  pus  of  acute  abscesses.  In  thirty - 
three  cases  examined  it  was  found  associated  with  Staphylococcus  albus  in 
two  and  with  Staphylococcus  albus  and  Streptococcus  pyogenes  in  one. 

In  its  morphology  this  coccus  is  identical  with  the  two  preceding  species, 
from  which  it  is  distinguished  by  the  formation  of  a  lemon-yellow  pigment, 
instead  of  a  golden  or  orange-yellow  as  in  Staphylococcus  aureus.  The 
pigment  is  only  formed  in  the  presence  of  oxygen.  This  coccus  is  said  by 
Frankel  to  liquefy  gelatin  more  slowly  than  the  previously  described  species 
—Staphylococcus  aureus  and  Staphylococcus  albus. 

As  to  its  pathogenic  properties  we  have  no  definite  information.  It  is 
included  among  the  pyogenic  bacteria  because  of  its  occasional  presence  in 

19 


PYOGENIC   BACTERIA. 

the  pus  of  acute  abscesses,  although  it  has  heretofore  only  been  found  in  as- 
sociation with  other  microorganisms. 

4.     MICROCOCCUS   PYOGENES   TENUIS. 

Obtained  by  Rosenbach  (1884)  from  pus  in  three  cases  out  of  thirty- nine 
examined. 

Morphology. — Micrococci,  somewhat  irregular  in  size,  but  larger  than 
Staphylococcus  albus,  and  seldom  associated  in  masses.  Frequently  the  in- 
dividual cocci  present  the  appearance  of  consisting  of  two  deeply  stained 
masses  separated  from  each  other  by  a  paler  interspace.  Cultures  upon  the 
surface  of  nutrient  agar  form  a  very  thin,  transparent  layer  of  about  one 
millimetre  in  breadth  along  the  line  of  inoculation ;  this  resembles  a  thin 
layer  of  varnish. 

Pathogenesis  undetermined. 

5.    STREPTOCOCCUS   PYOGENES. 

Synonyms. — Micrococcus  of  erysipelas  (Fehleisen)  ;  Streptococcus 
erysipelatos  ;  Streptococcus  of  pus  ;  Streptococcus  longus  (Von  Lin- 
gelsheim). 

Obtained  by  Fehleisen  from  the  skin  involved  in  cases  of  erysipe- 
las (1883),  and  by  Rosenbach  (1884)  and  Passet  (1885)  from,  the  pus 
of  acute  abscesses.  The  characters  of  the  "  streptococcus  of  erysipe- 
las" of  Fehleisen  and  the  "  Streptococcus  pyogenes  "  of  Rosenbach 
and  Passet  are  generally  admitted  to  be  identical,  although  some 
bacteriologists  still  describe  them  separately  and  cultures  from  the 
two  sources  are  still  retained  in  bacteriological  laboratories  under  the 
names  originally  given  them. 

Rosenbach  found  Streptococcus  pyogenes  alone  in  fifteen  cases. 
and  associated  with  staphylococci  in  five  cases,  out  of  thirty -nine 
cases  examined  of  acute  pus  formation.  Passet,  in  thirty-three 
similar  cases,  obtained  the  streptococcus  alone  in  eight  and  associated 
Avith  staphylococci  in  two.  Subsequent  researches  show  that  this 
micrococcus  is  frequently,  if  not  constantly,  present  in  puerperal 
metritis  ;  that  it  is  the  most  frequent  microorganism  associated  with 
ulcerative  endocarditis  ;  that  it  is  frequently  present  in  diphtheritic 
false  membranes,  and  especially  in  those  cases  of  diphtheritic  inflam- 
mation which  are  secondary  to  scarlet  fever  and  measles  (Prudden). 
Numerous  investigations  made  by  bacteriologists  during  the  past  few 
years  indicate  that  this  is  a  very  important  and  widely  distributed 
pathogenic  microorganism.  It  has  also  been  frequently  found  upon 
exposed  mucous  surfaces — mouth,  nose,  vagina — of  healthy  in- 
dividuals. 

According  to  the  recent  researches  (1891)  of  Von  Lingelsheim,  the 
Streptococcus  pyogenes  differs  from  Streptococcus  erysipelatos  in  be- 
ing pathogenic  both  for  mice  and  rabbits,  while  the  latter  is  pathogenic 
for  rabbits  only.  The  author  named,  as  a  result  of  extended  and 


PYOGENIC   BACTERIA. 


275 


carefully  conducted  comparative  studies,  arrives  at  the  following 
conclusions : 

"  According  to  my  observations,  there  are  two  great  groups  among  the 
streptococci.  These  cannot  be  distinguished  one  from  the  other  in  cultures 
in  highly  albuminous  media  (pus,  blood  serum),  but  present  constant  dif- 
ferences when  cultivated  in  bouillon.  The  decisive  characteristics  in  this 
medium  are  :  macroscopic,  the  cloudiness  of  the  medium  ;  microscopic,  the 
length  of  the  chains.  The  two  groups  are  with  difficulty  distinguished  in 
agar  cultures ;  more  easily  in  gelatin,  in  which  the  streptococcus  which 
forms  short  chains  causes  a  slight  liquefaction,  while  the  Streptococcus 
longus  does  not.  Upon  potato  Streptococcus  brevis  alone  shows  a  visible 
growth.  .  .  .  We  see  here  a  group  of  streptococci  which  we  separate  from 
the  others,  because  of  their  microscopic  and  cultural  differences,  under  the 
name  of  Streptococcus  brevis,  which  is  also  distinguished  by  having  no 
pathogenic  action  upon  the  animals  usually  experimented  upon.  We 
recognize,  on  the  other  hand,  the  streptococci  which  we  have  grouped  to- 
gether as  Streptococcus  longus  as  all  pathogenic  and  about  in  equal  degree 
fora  certain  species  of  animal  (rabbits);  but  by  experiments  upon  other 
species  (mice)  we  arrive  at  the  conclusion  that  there  must  also  be  differences 
between  these  streptococci.  It  appears  that  the  streptococci  which  are  dis- 
tinguished by  their  high  degree  of  pathogenic  power  upon  mice  are  also 
those  which  are  distinguished  in  bouillon  cultures  by  the  formation  of  con- 
glomerate masses.  We  find  among  these  also  one  which  is  distinguished 
by  especial  virulence  for  mice,  and  that  this  one  is  distinguished  in  cultures 
by  its  scanty  growth  upon  ox  serum." 

Von  Lingelsheim  gives  the  following  classification  of  the  strepto- 


cocci 


STREPTOCOCCI. 


Not  pathogenic. 
Streptococcus  brevis. 


Pathogenic. 

Streptococcus  longus. 


Pathogenic  for  mice  and  rabbits. 

(a)  Streptococcus  murisepticus. 

(b)  Streptococcus  pyogenes. 


Pathogenic  for  rabbits. 

Streptococcus  erysipelatos. 


Morphology. — Spherical  cocci,  from  0.4  /t  to  1  JJL  in  diameter,  but 
varying  considerably  in  dimensions  in  different  cultures,  and  even 
in  a  single  chain.  Multiply  by  binary  division, 
in  one  direction  only,  forming  chains,  in  which 
the  elements  are  commonly  associated  in  pairs. 
Under  certain  circumstances,  instead  of  form- 
ing chains,  a  culture  may  contain  only,  or 
chiefly,  diplococci ;  but  usually  chains  contain- 
ing from  four  to  twenty  or  more  elements  are 
formed,  and  these  are  frequently  associated 
in  tangled  masses.  Occasionally  one  or  more 
cells  in  a  chain  greatly  exceed  their  fellows  in 
size,  and  some  bacteriologists  suppose  that 
these  cells  serve  as  reproductive  spores — arthro- 
spores — but  this  has  not  been  definitely  proven. 

Sfains  readily  with  the  aniline  colors  and  by  Gram's  method. 


FIG.  82. — Pus  containing 
streptococci.  X  800. 
(Flugge.) 


276 


PYOGENIC   BACTERIA. 


Biological  Characters. — Grows  readily  in  various  liquid  and 
solid  culture  media,  including  all  of  those  usually  employed  in  bac- 
teriological researches.  The  most  favorable  temperature  for  its  de- 
velopment is  from  30°  to  37°  C.,  but  it  multiplies  freely  at  the  ordi- 
nary room  temperature — 10°  to  18°  C. 

Streptococcus  pyogenes  is  a  facultative  anaerobic,  growing 
both  in  the  presence  and  absence  of  oxygen.  It 
does  not  liquefy  gelatin,  and  in  gelatin  stick 
cultures  it  grows  along  the  line  of  puncture, 
forming  numerous  small,  spherical,  translu- 
cent, whitish  colonies,  which  are  closely  crowd- 
ed together  at  the  upper  portion  of  the  line  of 
growth,  and  often  distinctly  separated  from 
each  other  below ;  upon  the  surface  there  is 
often  no  growth,  or  a  scanty  development  may 
occur  about  the  point  of  entrance  of  the  inocu- 
lating needle.  The  minute  colonies  along  the 
line  of  puncture  are  already  visible  at  the  end 
of  twenty-four  hours  in  cultures  kept  in  the 
incubating  oven  at  30°  to  35°  C.,  and  at  the  end 
of  three  or  four  days  they  have  reached  their 
full  development,  forming  a  semi -opaque,  white, 
granular  column,  upon  the  margins  of  which 
the  separate  colonies  are  seen  projecting  into  the 
gelatin.  On  gelatin  plates  very  small,  translu- 
cent colonies  are  developed,  which  upon  the  sur- 
face spread  out  to  form  a  flat,  transparent  disc 
of  about  one-half  millimetre.  Under  a  low  mag- 
nifying power  these  colonies  are  seen  to  be  slight- 
ly granular  and  have  a  yellowish  color.  At  a 
later  date  they  become  darker  and  less  trans- 
parent, and  the  margin  may  show  irregular  projections  made  up  of 
tangled  masses  of  cocci  in  chains.  The  characters  of  growth  in 
nutrient  agar  and  in  jellified  blood  serum  are  similar  to  those  in  gela- 
tin, and  on  agar  plates  colonies  are  formed  similar  to  those  above 
described,  except  that  they  are  somewhat  smaller  and  more  trans- 
parent. Fehleisen  and  De  Simone  state  that  the  erysipelas  coccus 
may  develop  upon  the  surface  of  cooked  potato,  but  most  authorities 
— Fltigge,  C.  Frankel,  Passet,  Baumgarten — agree  that  no  growth 
occurs  upon  potato.  Milk  is  a  favorable  medium  for  the  growth  of 
this  micrococcus,  and  the  casein  is  coagulated  by  it.  A  slightly  acid 
reaction  of  the  culture  medium  does  not  prevent  its  development. 
The  thermal  death-point,  as  determined  by  the  writer,  is  between 
52°  and  54°  C. ,  the  time  of  exposure  being  ten  minutes.  •  According 


FIG.  83.— Streptococcus 
of  erysipelas  in  nutrient 
gelatin;  stick  culture  at 
end  of  four  days  at  16°- 
18°  C.  (Baumgarten). 


PYOGENIC   BACTERIA.  27? 

to  Be  Simone,  a  temperature  of  39.5°  to  41°  C.  maintained  for  two 
days  is  fatal  to  this  micrococcus. 

Manfredi  and  Traversa  have  injected  filtered  cultures  into  frogs, 
guinea-pigs,  and  rabbits  for  the  purpose  of  ascertaining  if  any  solu- 
ble toxic  substance  is  produced  during  the  growth  of  Streptococcus 
pyogenes.  They  report  that  in  some  cases  convulsions  and  in  others 
paralysis  resulted  from  these  injections. 

Yon  Lingelsheim  has  recently  (1891)  reported  the  following  re- 
sults obtained  in  an  extended  series  of  experiments  made  to  deter- 
mine the  germicidal  power  of  various  chemical  agents  as  tested  upon 
this  microorganism — time  of  exposure  two  hours  :  Hydrochloric  acid 
1  : 250,  sulphuric  acid  1  : 250,  caustic  soda  1  : 130,  ammonia  1  : 25, 
mercuric  chloride  1  : 2,500,  sulphate  of  copper  1  : 200,  chloride  of 
iron  1  : 500,  terchloride  of  iodine  1  :  750,  peroxide  of  hydrogen  1  :  50, 
carbolic  acid  1  :  300,  cresol  1  :  250,  lysol  1  :  300,  creolin  1  : 130,  naph- 
thylamin  1  : 125,  malachite  green  1  :  3,000,  pyoktanin  1  :  700. 


Fia.  84.— Section  from  margin  of  an  erysipelatous  inflammation,  showing  streptococci  in 
lymph  spaces.  From  a  photograph  by  Koch.  X  900. 

Pathogenesis. — When  inoculated  into  the  cornea  of  rabbits 
Streptococcus  pyogenes  gives  rise  to  keratitis.  Inoculations  into  the 
ear  of  the  same  animal  usually  give  rise  to  a  localized  erysipelatous 
inflammation  accompanied  by  an  elevation  of  temperature  in  the  in- 
oculated ear ;  at  the  end  of  thirty-six  to  forty-eight  hours  the  in- 
flamed area,  which  has  well-defined  margins  and  a  bright-red  color, 
extends  from  the  point  of  inoculation  along  the  course  of  the  veins  to 
the  root  of  the  ear.  This  appearance  passes  away  in  the  course  of  a 
few  days  and  the  animal  recovers.  Subcutaneous  injections  into  mice 
( >r  rabbits  are  usually  without  result,  and  the  last-named  animal  also 
withstands  injections  of  considerable  quantities  into  the  general  cir- 
culation through  a  vein.  When,  however,  the  animal  has  previously 
been  weakened  by  the  injection  of  toxic  substances  the  streptococcus 
may  multiply  in  its  body  and  cause  its  death  (Flugge). 

Fehleisen  has  inoculated  cultures,  obtained  in  the  first  instance 
from  the  skin  of  patients  with  erysipelas,  into  patients  in  hospital 
suffering  from  lupus  and  carcinoma,  and  has  obtained  positive  re- 
sults, a  typical  erysipelatous  inflammation  having  developed 


278  PYOGENIC  BACTERIA. 

around  the  point  of  inoculation  after  a  period  of  incubation  of  from 
fifteen  to  sixty  hours.  This  was  attended  with  chilly  sensations  and 
an  elevation  of  temperature.  Persons  who  had  recently  recovered 
from  an  attack  of  erysipelas  proved  to  be  immune. 

Sections  made  from  the  ear  of  an  inoculated  rabbit,  or  of  skin  taken 
from  the  affected  area  in  erysipelas  in  man,  show  the  streptococci  in 
considerable  numbers  in  the  lymph  channels,  but  not  in  the  blood 
vessels.  They  are  more  numerous,  according  to  Koch  and  to  Fehl- 
eisen,  upon  the  margins  of  the  erysipelatous  area,  and  may  even  be 
seen  in  the  lymph  channels  a  little  beyond  the  red  margin  which 
marks  the  line  of  progress  of  the  infection. 

The  researches  of  Weichselbaum  and  others  show  that  Strepto- 
coccus pyogenes  is  the  infecting  microorganism  in  a  certain  propor- 
tion of  the  cases  of  ulcerative  endocarditis.  The  author  named 
found  it  in  four  cases  out  of  fifteen  examined,  and  in  two  cases  of 
endocarditis  verrucosa  out  of  thirteen.  In  a  previously  reported  series 
of  sixteen  cases  (fourteen  of  ulcerative  endocarditis  and  two  of  ver- 
rucosa) the  streptococcus  was  found  in  six. 

In  diphtheritic  false  membranes  this  streptococcus  is  very  com- 
monly present,  and  in  certain  cases  attended  with  a  diphtheritic  exu- 
dation, in  which  the  Bacillus  diphtherias  has  not  been  found  by  com- 
petent bacteriologists,  it  seems  probable  that  Streptococcus  pyogenes 
is  the  pathogenic  microorganism  responsible  for  the  local  inflamma- 
tion and  its  results.  Thus  in  a  series  of  twenty-four  cases  studied  by 
Prudden  in  1889  the  bacillus  of  Loffler  was  not  found,  "but  a  strep- 
tococcus apparently  identical  with  Streptococcus  pyogenes  was  found 
in  twenty-two."  Chantemesse  and  Widal  have  also  reported  cases 
in  which  a  fibrinous  exudate  resembling  that  of  diphtheria  was  as- 
sociated with  a  streptococcus.  "  These  forms  of  so-called  diphtheria 
are  most  commonly  associated  with  scarlatina  and  measles,  erysipe- 
las, and  phlegmonous  inflammation,  or  occur  in  individuals  exposed 
to  these  diseases  ;  but  whether  exclusively  under  these  conditions  is 
not  yet  established"  (Prudden). 

Loffler  has  described  under  the  name  of  Streptococcus  articu- 
lorurn  a  micrococcus  obtained  by  him  from  the  affected  mucous 
membrane  in  cases  of  diphtheria,  and  which  he  believes  to  be  acci- 
dentally present  and  without  any  etiological  import  in  this  disease. 
In  its  characters  it  closely  resembles  Streptococcus  pyogenes  and  is 
perhaps  a  variety  of  this  widely  distributed  species.  Its  characters 
are  described  by  Fliigge  as  follows  : 


"  Cultivated  in  nutrient  gelatin,  it  forms  at  the  end  of  three  days  small, 
transparent,  light-gray  drops,  upon  the  margin  of  which,  under  the  micro- 
scope, the  cocci  in  twisted  chains  may  be  observed.  As  many  as  one  hun- 


PYOGENIC   BACTERIA.  279 

dred  elements  may  be  found  in  a  single  chain,  and  some  of  these  are  distin- 
guished by  their  size;  occasionally  whole  chains  are  made  up  of  these  large 
cocci,  and  when  closely  observed  some  of  these  may  present  indications  of 
division  transversely  to  the  axis  of  tbe  chain.  Subcutaneous  inoculation  of 
cultures  into  mice  results  in  the  death  of  a  considerable  number  of  these  ani- 
mals— more  than  half ;  and  the  streptococci  are  found  in  the  spleen  and  other 
organs.  Inoculation  into  the  ear  of  rabbits  causes  an  erysipelatous  inflam- 
mation. When  injected  into  the  circulation  of  these  animals  through  a  vein 
joint  affections  are  developed  in  from  four  to  six  days,  and  a  purulent  ac- 
cumulation occurs  in  which  the  streptococci  are  found.  In  two  rabbits  in- 
oculated in  the  same  way  with  a  culture  of  the  streptococcus  of  erysipelas, 
Loffler  has  observed  a  similar  result." 

Recent  researches  indicate  that  infection  by  Streptococcus  pyo- 
genes  through  the  endometrium  is  the  usual  cause  of  puerperal 
fever.  Thus  Clivio  and  Monti  demonstrated  its  presence  in  five 
cases  of  puerperal  peritonitis.  Czerniewski  found  it  in  the  lochia  of 
a  large  number  (thirty-five  out  of  eighty-one)  of  women  suffering 
from  puerperal  fever,  but  in  the  lochia  of  fifty-seven  healthy  puer- 
peral women  he  was  only  able  to  find  it  once.  In  ten  fatal  cases  he 
found  it  in  every  instance,  both  in  the  lochial  discharge  during  life 
and  in  the  organs  after  death.  Widal  carefully  studied  a  series  of 
sixteen  cases  and  arrived  at  the  conclusion  that  this  was  the  infect- 
ing microorganism  in  all.  Bumm  and  other  observers  have  given 
similar  evidence.  Eiselsberg  and  Emmerich  have  succeeded  in  de- 
monstrating the  presence  of  the  streptococcus  in  hospital  wards  con- 
taining cases  of  erysipelas.  That  puerperal  fever  may  result  from 
infection  through  the  finger  of  the  accoucheur,  when  he  has  previ- 
ously been  in  contact  with  cases  of  erysipelas,  has  long  been  taught, 
and,  in  view  of  the  facts  above  recorded,  is  not  difficult  to  under- 
stand. But  in  view  of  the  fact  that  the  streptococcus  of  pus  has  been 
found  in  vaginal  mucus  and  in  the  buccal  and  nasal  secretions  of 
healthy  persons,  it  may  appear  strange  that  cases  of  puerperal  fever 
not  traceable  to  infection  from  erysipelas  or  from  preceding  cases 
do  not  occur  more  frequently.  This  is  probably  largely  due  to  an 
attenuation  of  the  pathogenic  power  of  the  streptococcus  when  it 
leads  a  saprophytic  existence.  Widal  asserts  that,  when  cultivated 
in  artificial  media  for  a  few  weeks,  the  cultures  no  longer  have  their 
original  virulence,  and  Bumm  has  made  the  same  observation.  On 
the  other  hand,  in  "  streptococcus-peritonitis  "  occurring  as  a  result 
of  puerperal  infection  Bumm  states  that  the  thin,  bright-yellow, 
odorless  fluid  contained  in  the  cavity  of  the  abdomen  is  extremely 
virulent ;  a  very  slight  trace,  a  fragment  of  a  drop,  injected  into  the 
abdominal  cavity  of  a  rabbit,  is  sufficient  within  twenty-four  hours 
to  cause  a  general  septic  inflammation  with  a  bloody  serous  exuda- 
tion, quickly  terminating  in  the  death  of  the  animal  ;  injected  sub- 
cutaneously  it  gives  rise  to  an  enormous  phlegmon  which  also 


280  PYOGENIC   BACTERIA. 

quickly  proves  fatal.  But  cultures  of  Streptococcus  pyogenes,  after 
it  has  been  carried  through  successive  generations  in  artificial  media, 
injected  beneath  the  skin  of  a  rabbit,  usually  produce  no  result,  or 
at  most  an  abscess  of  moderate  dimensions. 

It  seems  probable  that  the  micrococcus  isolated  by  Fliigge  from 
necrotic  foci  in  the  spleen  of  a  case  of  leucocythgemia,  and  described 
by  him  under  the  name  of  Streptococcus  pyogenes  malignus,  was 
simply  a  very  pathogenic  variety  of  the  streptococcus  of  pus.  He 
was  not  able  to  differentiate  it  from  Streptococcus  pyogenes  by  its 
morphology  or  growth  in  culture  media,  but  it  proved  far  more 
pathogenic  when  tested  upon  animals.  Mice  inoculated  subcutane- 
ously  with  a  minute  quantity  of  a  pure  culture  died,  without  excep- 
tion, in  three  to  five  days.  A  large  abscess  was  formed  at  the  point 
of  inoculation,  and  the  blood  of  the  animal  contained  numerous  cocci 
in  pairs  and  chains.  Rabbits  inoculated  in  the  ear  showed  at  first 
the  same  local  appearances  as  result  from  inoculations  with  strepto- 
coccus of  pus  and  of  erysipelas,  but  after  two  or  three  days  symp  - 
toms  of  general  infection  were  developed,  and  death  occurred  at  the 
end  of  three  or  four  days.  At  the  autopsy  the  cocci  were  found  in 
the  blood,  and  frequently  there  were  purulent  collections  in  the 
joints  containing  the  same  microorganism.  Krause  has  also  de- 
scribed a  streptococcus  which  only  differs  from  Streptococcus  pyo- 
genes of  Rosenbach  and  Passet  by  the  greater  virulence  manifested 
by  its  cultures. 

The  fact  that  pathogenic  bacteria  may  attain  an  intensified  de- 
gree of  virulence  by  cultivation  in  the  bodies  of  susceptible  animals 
was  demonstrated  by  Davaine  many  years  ago,  and  is  fully  estab- 
lished by  the  experiments  of  Pasteur  and  others.  It  is  true  of  the 
anthrax  bacillus,  of  the  writer's  Micrococcus  Pasteuri,  and  of  other 
well-known  pathogenic  microorganisms.  The  reverse  of  this — at- 
tenuation of  virulence  as  a  result  of  cultivation  in  artificial  media- 
is  also  well  established  for  several  pathogenic  species.  Now  it 
appears  that  the  attenuated  streptococcus  is  far  less  likely  to  give 
rise  to  erysipelas  or  to  puerperal  infection  than  is  the  same  micro- 
organism as  obtained  from  a  case  of  one  or  the  other  of  these  infec- 
tious diseases.  The  same  is  probably  true  also  of  Staphylococcus 
aureus  and  other  facultative  parasites  which  are  found  as  sapro- 
phytes upon  the  surface  of  the  body  and  upon  exposed  mucous  mem- 
branes in  healthy  persons.  And  it  is  not  improbable  that  attenuated 
varieties  of  these  micrococci  which  find  their  way  into  open  wounds, 
or  into  the  uterine  cavity  shortly  after  parturition,  if  they  escape 
destruction  by  the  sanguineous  discharge,  acquire  increased  patho- 
genic power  from  their  multiplication  in  it,  as  a  result  of  which  they 
are  able  to  invade  the  living  tissues.  But  it  appears  probable  that 


PYOGENIC   BACTERIA.  281 

infection  through  open  wounds  does  not  depend  alone  upon  the 
potency  of  the  pathogenic  micrococci  present  in  them,  but  also  upon 
the  absorption  of  chemical  poisons  produced  by  septic  (putrefactive) 
bacteria,  which  weaken  the  vital  resisting  power  of  the  tissues. 
Gottstein,  as  a  result  of  experiments  made  by  him,  is  of  the  opinion 
that  the  resorption  of  broken-down  red  blood  corpuscles  favors  infec- 
tion by  pathogenic  bacteria  present  in  wounds  ;  and  he  has  shown 
that  the  injection  into  animals  of  certain  toxic  substances  which  de- 
stroy the  red  corpuscles  in  the  circulation  makes  them  susceptible  to 
the  pathogenic  action  of  certain  bacteria  which  are  harmless  for 
them  under  ordinary  circumstances.  Thus  a  guinea-pig,  an  animal 
which  is  immune  against  the  bacillus  of  fowl  cholera,  succumbed  to  an 
inoculation  made  after  first  injecting  subcutaneously  0.06  gramme  of 
hydracetin  dissolved  in  alcohol.  At  the  autopsy  hgemorrhagic  exu- 
dations were  found  in  the  serous  cavities,  haemorrhagic  infarctions 
in  the  lungs,  and  quantities  of  the  bacillus  injected  were  found  in 
the  blood  and  in  fluid  from  the  cavity  of  the  abdomen. 

In  man  the  ever-present  pus  cocci  are  more  likely  to  invade  the 
tissues,  forming  furuncles,  carbuncles,  and  pustular  skin  eruptions, 
or  erysipelatous  and  phlegmonous  inflammations,  when  the  standard 
of  health  is  reduced  from  any  cause,  and  especially  when  by  absorp- 
tion or  retention  various  toxic  organic  products  are  present  in  the 
body  in  excess.  It  is  thus  that  we  would  explain  the  liability  to  these 
local  infections,  as  complications  or  sequelae  of  various  specific  infec- 
tious diseases,  in  the  victims  of  chronic  alcoholism,  in  those  exposed 
to  septic  emanations  from  sewers,  etc. ,  and  probably  in  many  cases 
from  the  absorption  of  toxic  products  formed  in  the  alimentary  canal 
as  a  result  of  the  ingestion  of  improper  food,  or  of  abnormal  fermen- 
tative changes  in  the  contents  of  the  intestine,  or  from  constipation. 

The  Pus  Cocci  in  Inflammations  of  Mucous  Membranes. — 
To  what  extent  the  pus  cocci  are  responsible  for  inducing  and  main- 
taining non-specific  inflammations  of  mucous  membranes  has  not 
been  determined  ;  but  having  demonstrated  the  pyogenic  properties 
of  these  cocci,  their  presence  in  the  purulent  discharges  from  inflamed 
mucous  membranes  can  scarcely  be  considered  as  unimportant,  not- 
withstanding the  fact  that  they  are  also  frequently  found  in  secre- 
tions from  healthy  mucous  surfaces.  They  are  likewise  found  upon 
the  skin  of  healthy  persons,  and  yet  we  have  unimpeachable  experi- 
mental evidence  that  they  may  produce  a  local  inflammation,  at- 
tended with  pus  formation,  when  injected  subcutaneously,  or  even 
when  freely  applied  to  the  uninjured  surface. 

In  otitis  media  Levy  and  Schrader  obtained  Staphylococcus 
albus  in  pure  cultures  in  three  cases  out  of  ten  in  which  paracentesis 
was  performed,  and  in  two  others  it  was  present  in  association  with 
20 


282  PYOGENIC   BACTERIA. 

other  microorganisms.  In  eighteen  cases  of  otitis  media  in  young 
children  Netter  found  Staphylococcus  aureus  six  times  and  Strepto- 
coccus pyogenes  thirteen  times.  Scheibe,  in  eleven  cases  in  which 
perforation  had  not  yet  taken  place,  found  Staphylococcus  albus  in 
two  and  various  other  microorganisms  in  the  remaining  cases  ;  Sta- 
phylococcus aureus  was  not  present  in  any.  Habermann  obtained 
aureus  associated  with  other  bacteria  in  a  single  case  of  purulent 
otitis  media.  In  a  series  of  eight  cases  occurring  as  a  sequela  of 
influenza  Scheibe  obtained  Streptococcus  pyogenes  in  two,  "  diplo- 
coccus  pneumonias  "  in  two,  Staphylococcus  aureus  in  one,  Strepto- 
coccus pyogenes  and  Staphylococcus  albus  together  in  two,  and  Strep- 
tococcus pyogenes  in  association  with  an  undescribed  micrococcus  in 
one.  In  all  of  these  cases  a  slender  bacillus  was  also  present,  as 
shown  by  microscopical  examination,  which  did  not  grow  in  any  of 
the  culture  media  employed.  Bordoni-Uffreduzzi  and  Gradenigo 
have  tabulated  the  results  obtained  by  various  bacteriologists  who 
have  examined  pus  obtained  through  the  previously  intact  tympanic 
membrane.  In  thirty  -two  cases  of  this  character  the  microorganism 
most  frequently  found  was  diplococcus  pneumonise  (Micrococcus 
pneumonias  crouposae  of  the  present  writer),  which  was  present  in  a 
pure  culture  in  thirteen  and  associated  with  Staphylococcus  aureus 
in  one,  with  Staphylococcus  albus  in  one,  and  with  Streptococcus 
pyogenes  in  one.  In  the  other  sixteen  cases  the  pyogenic  cocci  were 
present  in  ah1  but  two,  in  which  bacilli  were  found — Bacillus  tenuis 
in  one,  a  non-liquefying  bacillus  in  one.  In  twenty-seven  cases  in 
which  the  pus  was  withdrawn  from  one  to  thirty  days  after  paracen- 
tesis  or  spontaneous  rupture  of  the  membrane,  the  pyogenic  cocci 
were  present  in  twenty  and  diplococcus  pneumonias  in  seven. 

In  acute  nasal  catarrh  Paulsen  found  Staphylococcus  aureus  in 
seven  cases  out  of  twenty-four  examined,  and  E.  Frankel  in  two  out  of 
four  ;  but  it  must  be  remembered  that  Von  Besser  has  shown  that  this 
micrococcus  is  frequently  present  in  the  secretions  from  the  healthy 
nasal  mucous  membrane,  and  we  have  experimental  evidence  that 
the  pus  organisms,  when  introduced  into  the  conjunctival  sac  of 
rabbits  (Widmark),  do  not  give  rise  to  catarrhal  inflammation.  On 
the  other  hand,  Widmark  found  that  when  inoculated  into  the  comea 
of  rabbits  an  intense  conjunctivitis  resulted,  together  with  keratitis 
and  perforation  of  the  cornea  in  fifteen  per  cent  of  the  cases.  The 
same  author  in  his  bacteriological  researches  obtained  the  pyogenic 
staphylococci  from  the  circumscribed  abscesses  of  blepharadenitis, 
while  in  inflammation  of  the  lacrymal  sac  Streptococcus  pyogenes 
was  usually  present. 

Shougolowicz,in  the  bacteriological  examination  of  twenty-six  cases 
of  trachoma,  found  Staphylococcus  albus  in  twelve,  Staphylococcus 


PYOGENIC    BACTERIA. 


283 


aureus  in  nine,  Staphylococcus  citreus  in  three,  and  Staphylococcus 
cereus  albus  in  three.  These  pus  organisms  were  in  a  number  of 
the  cases  associated  with  other  well-known  saprophytes,  and  in  seven 
cases  a  short  bacillus  not  previously  described  was  found.  That 
various  bacilli  are  found  in  the  conjunct! val  sac  of  healthy  eyes 
and  in  different  forms  of  conjunctivitis  has  been  shown  by  Fick, 
whose  results  do  not  correspond  in  this  respect  with  those  of  Gif- 
ford,  who  found  almost  exclusively  micrococci.  Whatever  may  be 
the  final  conclusion  as  to  the  role  of  the  pus  cocci  heretofore  de- 
scribed in  the  etiology  of  acute  or  chronic  conjunctivitis,  there  can  be 
no  doubt  of  the  power  of  the  "  gonococcus  "  to  induce  a  virulent  in- 
flammation of  the  conjunctivas  when  introduced  into  healthy  eyes. 


6.     MICROCOCCTJS   GONORRHCEJ3 

Synonym.  —  Gonococcus  (Neisser). 

Discovered  by  Neisser  (1879)  in  gonorrhceal  pus  and  described  by 
him  under  the  name  of  "  Gonococcus."    Cultivated  by  Bumm  (1885), 
and  infective  virulence  proved  by  inocula- 
tion into  man.    Constantly  present  in  viru- 
lent gonorrhoeal  discharges,  for  the  most 
part  in  the  interior  of  the  pus  cells  or  at- 
tached to  the  surface  of  epithelial  cells. 

Morphology.  —  Micrococci,  usually  join- 
ed in  pairs  or  in  groups  of  four,  in  which 
the  elements  are  flattened  —  "  biscuit- 
shaped.  "  The  flattened  surfaces  face  each 
other  and  are  separated,  in  stained  pre- 
parations,  by  an  unstained  interspace. 

SnT      ,.  ,  ,,  .    ,     ,         •        /ii  -       -  -. 

Ihe  diameter  or  an  associated  pair  ot  cells  pure  culture,  x  about  1,000;  6,gono- 
varies  from  0.8  to  1.6  /^  in  the  long  dia-  cocci  in  pus  ceils  and  epithelial  ceil 

..      _  from  case  of  gonorrhoeal   ophthal- 

meter  —  average  about  1.25  ^—  and   trom  mia.  c  formand  mode  Of  division 
0.6  to  0.8  jn  in  the  line  of  the  interspace  of  gonococci-schematic.  (Bumm.) 
between  the  biscuit-shaped  elements,  which 

sometimes  present  a  slight  concavity  of  the  flattened  surfaces.  Mul- 
tiplication occurs  alternately  in  two  planes,  and  as  a  result  of  this 
groups  of  four  are  frequently  observed.  But  diplococci  are  more 
numerous  and  are  considered  as  the  characteristic  mode  of  grouping. 
Single,  spherical,  undivided  cells  are  rarely  seen. 

It  must  be  remembered  that  the  morphology  of  this  micrococcus 
as  above  described  does  not  suffice  to  distinguish  it,  for  Bumm  has 
shown  that  "  the  biscuit  form  is  not  at  all  specific  for  the  gonococcus, 
but  is  shared  with  it  by  a  number  of  microorganisms,  which  consist 
of  two  hemispherical  elements  with  the  flattened  surfaces  facing  each 


FlG-    85-  -«.    gonococci   from 


284  PYOGENIC  BACTERIA. 

other  and  separated  by  a  cleft,  and  some  of  these  correspond  in  their 
morphology,  in  every  detail,  with  the  gonococcus." 

Stains  quickly  with  the  basic  aniline  colors,  especially  with 
methyl  violet,  gentian  violet,  and  f  uchsin ;  not  so  quickly  with 
methylene  blue,  which  is,  however,  one  of  the  most  satisfactory 
staining  agents  for  demonstrating  its  presence  in  pus.  Beautiful 
double-stained  preparations  may  be  made  from  gonorrhoeal  pus, 
spread  upon  a  cover  glass  and  "  fixed,"  secunduin  art  em,  by  the  use 
of  methylene  blue  and  eosin.  Does  not  stain  by  Gram's  method — 
i.e.,  the  cocci  are  decolorized,  after  having  been  stained  with  an  ani- 
line color,  by  being  immersed  in  the  iodine  solution  employed  in 
Gram'ft  method  of  staining.  But  this  character  cannot  be  depended 
upon  alone  for  establishing  the  diagnosis,  for  Bumin  has  shown  that 


FIG.  86. — "  Gonococcus  "  in  gonorrhceal  pus.    From  a  photomicrograph  by  Frankel  and  Pfeiffer 
X  1,000. 

other  diplococci  are  occasionally  found  in  gonorrhoeal  pus  which  do 
not  stain  by  this  method.  It  serves  to  distinguish  them,  however,  from 
the  common  pus  cocci  heretofore  described — Staphylococcus  aureus, 
Staphylococcus  albus,  Staphylococcus  citreus — which  retain  their 
color  when  treated  in  the  same  way.  A  more  trustworthy  diagnostic 
character  is  that  these  biscuit-shaped  diplococci  are  found  within  the 
pus  cells,  sometimes  one  or  two  pairs  only,  but  more  frequently  in 
considerable  numbers,  and  occasionally  hi  such  numbers  as  to  com- 
pletely fill  the  cell.  No  similar  picture  is  presented  by  pus  from  any 
other  source,  with  the  exception  of  that  from  a  form  of  "  puerperal 
cystitis "  which  Bumm  has  described.  But  in  this  the  diplococci 
contained  in  the  pus  cells  were  to  be  distinguished  by  the  fact  that 
they  retained  their  color  when  treated  by  Gram's  method.  Owing 


PYOGENIC   BACTERIA.  285 

to  the  difficulty  of  cultivating  this  micrococcus,  and  the  importance, 
under  certain  circumstances,  of  not  making  a  mistake  in  its  diag- 
nosis, these  characters  are  of  exceptional  value. 

Biological  Characters. — The  "gonococcus"  does  not  grow  in 
flesh  infusions,  in  nutrient  gelatin  or  agar,  but  it  may  be  cultivated 
upon  blood  serum,  and,  according  to  Bumm,  grows  more  readily  upon 
human  blood  serum  than  upon  that  of  the  lower  animals.  This 
he  obtained  for  his  experiments  from  the  placenta  of  a  recently  de- 
livered woman  by  passing  two  ligatures  around  the  cord  before 
separating  the  child  from  its  placental  attachment,  and  dividing  it 
between  them.  But  even  upon  blood  serum  obtained  in  this  way  it 
is  not  a  simple  matter  to  obtain  a  pure  culture.  When  other  micro- 
cocci  are  present,  even  in  small  numbers,  they  take  the  precedence 
and  overgrow  the  surface  of  the  culture  medium  before  the  gono- 
coccus  has  made  any  visible  growth.  It  is  therefore  necessary  to 
start  a  culture  with  pus  containing  this  micrococcus  only  and  in 
considerable  numbers.  And  the  pus  should  not  be  spread  out  in  a 
thin  layer,  but  should  be  distributed  upon  the  surface  in  little  drops 
or  masses,  in  which  the  development  commences.  A  temperature 
of  30°  to  34°  C.  is  most  favorable  for  the  development  of  this  micro- 
coccus,  and  Bumm  recommends  the  transfer  to  fresh  culture  material 
in  from  eighteen  to  twenty-four  hours.  The  cultures  thrive  best  in 
a  moist  atmosphere,  and  it  is  well  to  place  the  tubes  containing  them 
in  a  large  glass  jar  partly  filled  with  distilled  water  and  having  a 
tightly  fitting  cover.  The  growth  under  the  most  favorable  condi- 
tions is  slow,  and  frequently  no  development  occurs  when  pus  con- 
taining numerous  gonococci  is  placed  upon  blood  serum  in  an  incu- 
bating oven  ;  or  after  a  slight  multiplication  development  ceases  and 
the  cocci  undergo  degenerative  changes  and  quickly  disappear. 

Cultures  upon  the  surface  of  blood  serum  form  a  very  thin,  often 
scarcely  visible  layer,  with  a  smooth,  moist,  shining  surface,  and 
by  reflected  light  a  grayish-yellow  color.  The  growth  at  the  end  of 
twenty-four  hours  may  extend  for  a  distance  of  a  millimetre  along 
the  line  of  inoculation,  but  at  the  end  of  two  or  three  days  no  fur- 
ther development  occurs  and  the  cocci  soon  lose  their  vitality.  This 
micrococcus,  then,  is  aerobic.  Whether  it  may  also  be  a  facultative 
anaerobic  has  not  been  definitely  determined,  but  it  does  not  grow 
along  the  line  of  puncture  when  stick  cultures  are  made  in  blood  se-  . 
rum.  Its  rapid  and  abundant  multiplication  in  gonorrhoeal  infection 
of  mucous  membranes,  and  the  difficulties  attending  its  cultivation 
in  artificial  media,  show  that  the  gonococcus  is  a  strict  parasite. 

Lestikow  and  Loffler,  prior  to  the  publication  of  Bumm's  impor- 
tant monograph,  had  reported  successful  results  in  cultivating  the 
gonococcus  upon  a  mixture  of  blood  serum  and  gelatin.  Bockhart 


286  PYOGENIC   BACTERIA. 

has  since  recommended  a  mixture  of  nutrient  agar  (two  parts),  lique- 
fied at  a  temperature  of  50°  C.,  with  blood  serum  (two  to  three 
parts)  at  20°  C.  By  quickly  mixing  with  this  a  little  pus  .containing 
the  gonococcus  he  was  able  to  obtain  colonies  upon  plate  cultures, 
made  by  pouring  the  liquid  medium  upon  sterile  glass  plates  in  the 
usual  manner. 

Development  does  not  occur  below  25°  or  above  38°  C.  The 
writer  has  shown  that  a  temperature  of  60°  C.  maintained  for  ten 
minutes  destroys  the  infective  virulence  of  gonorrhoeal  pus. 

Pathogenesis. — That  the  gonococcus  is  the  cause  of  the  specific 
inflammation  and  purulent  discharge  characteristic  of  gonorrhoea  is 
now  generally  admitted  upon  the  experimental  evidence  obtained  by 
Bumm.  Having  succeeded  in  obtaining  it  in  pure  cultures  from 
gonorrhoeal  pus,  he  made  successful  inoculations  in  the  healthy  ure- 
thra in  two  cases — once  with  a  third  culture  and  once  with  one 
which  had  been  transferred  through  twenty  successive  generations. 


FIG.  87.— Gonorrhceal  conjunctivitis,  second  day  of  sickness;  section  through  the  mucous  mem- 
brane of  upper  eyelid;  invasion  of  the  epithelial  layer  by  gonococci.    (Bumm.) 

In  both  cases  a  typical  gonorrhoea  developed  as  a  result  of  the  inocu- 
lation. 

Schrotter  and  Winkler  (1890)  report  their  success  in  cultivating 
the  gonococcus  upon  albumin  from  the  egg  of  the  pewit — "  Kibitz.'' 
In  the  culture  oven  at  38°  C.  a  thin,  transparent,  whitish  layer  was 
already  visible  at  the  end  of  six  hours  and  rapidly  extended  ;  the 
growth  was  less  abundant  at  the  end  of  three  days,  and  had  entirely 
ceased  by  the  fifth  day.  Attempts  to  cultivate  the  same  microor- 
ganism in  albumin  from  hens'  eggs  gave  a  negative  result. 

Aufuso  (1891)  has  cultivated  the  gonococcus  in  fluid  obtained 
from  the  knee  joint  in  a  case  of  chronic  synovitis,  but  failed  to  culti- 
vate it  in  the  fluid  of  ascites.  A  culture  of  the  twelfth  generation 
made  upon  the  culture  medium  mentioned,  solidified  by  heat,  was 
introduced  into  the  urethra  of  a  healthy  man  and  gave  rise  to  a 
characteristic  attack  of  gonorrhoea. 

The  mucous  membranes  in  man  which  are  subject  to  gonorrhoeal 
infection  are  those  of  the  urethra,  the  conjunctiva,  the  cervix  uteri, 


PYOGENIC   BACTERIA.  287 

and  the  vagina  in  children — the  vagina  in  adults  is  not  involved. 
Inoculations  of  gonorrhoeal  pus  into  the  vagina  or  conjunctival  sac  of 
the  lower  animals — dogs,  rabbits,  horses,  apes — are  without  result. 

The  very  numerous  researches  which  have  been  made  by  compe- 
tent bacteriologists  show  that  the  gonococcus  is  constantly  present  in 
gonorrhoeal  discharges,  and  in  view  of  the  facts  above  stated  its  etio- 
logical  import  appears  to  be  fully  established.  Bumm  has  studied 
the  development  of  blennorrhcea  neonatorum,  and  has  shown  that 
soon  after  infection  the  presence  of  gonococci  may  be  demonstrated 
in  the  superficial  epithelial  cells'of  the  mucous  membrane  and  be- 
tween them  ;  that  they  soon  penetrate  to  the  deeper  layers,  and  that 
by  the  end  of  forty-eight  hours  the  entire  epithelial  layer  is  invaded 
by  the  diplococci,  which  penetrate  by  way  of  the  connecting  mate- 
rial— "  Kittsubstance  " — between  the  cells.  They  also  multiply  in 
the  superficial  layers  of  connective  tissue  and  give  rise  to  an  inflam- 
matory reaction,  which  is  shown  by  an  abundant  escape  of  leuco- 
cytes from  the  dilated  capillary  network.  The  penetration  of  the 
gonococci  to  the  deeper  layers  of  the  mucous  membrane  of  the  ure- 
thra, and  even  to  the  corpus  cavernosum,  was  observed  by  Bockhart 
in  a  case  studied  by  him  in  which  death  occurred  during  an  acute 
attack  of  gonorrhoea.  But  Bumm  concludes  from  his  researches 
that  this  is  not  usual,  and  that  the  invasion  is  commonly  limited  to 
the  superficial  layers  of  the  mucous  membrane. 

Staphylococcus  pyogenes  aureus  is  not  infrequently  associated 
with  the  gonococcus  in  late  gonorrhoeal  discharges,  and  the  abscesses 
which  occasionally  develop  as  a  complication  of  gonorrhoea,  in  the 
prostate,  the  inguinal  glands,  or  around  the  urethra,  are  probably 
due  to  its  presence,  which  has  been  demonstrated  in  the  pus  from 
such  abscesses  in  a  number  of  cases.  The  same  is  true  of  the  joint 
affections  and  endocarditis  which  sometimes  occur  in  the  course  of 
an  attack  of  gonorrhoea.  Although  some  authors  have  claimed  to 
find  the  gonococcus  in  these  so-called  metastatic  gonorrhoeal  inflam- 
mations, the  evidence  is  not  satisfactory,  and  it  seems  probable  that 
the  Staphylococcus  aureus  is  the  usual  microorganism  concerned  in 
these  affections. 


V. 
BACTERIA  IN   CROU^OUS  PNEUMONIA. 

THE  following  account  of  "  The  Etiology  of  Croupous  Pneumo- 
nia "  is  from  a  paper  read  by  the  writer  at  the  annual  meeting  of  the 
Medical  Society  of  the  State  of  New  York,  at  Albany,  N.  Y.,  Feb- 
ruary 6th,  1889  : 

Acute  pneumonia  is  now  generally  regarded  by  the  leading  clinical  au- 
thorities and  pathologists  in  this  country  and  in  Europe  as  a  specific  infec- 
tious disease.  Green,  in  his  article  on  " Inflammation  of  the  Lungs"  in 
Quain's  "Dictionary  of  Medicine,"  says:  "It  is  maintained  by  some  ob- 
servers that,  like  the  specific  fevers,  it  is  due  to  a  specific  cause.  Pneumonia, 
whilst  differing  from  these  fevers  in  not  being  contagious,  resembles  them 
in  the  typical  character  of  its  clinical  phenomena  and,  to  a  less  extent,  of  its 
local  lesion.  The  changes  in  the  lung  occurring  in  pneumonia  cannot  be 
induced  by  artificial  injury  of  the  organ,  and  it  must  therefore  be  admitted 
that  there  is  something  special  in  the  inflammatory  process." 

This  "something  special  "has  been  demonstrated  by  recent  researches, 
and  it  is  the  object  of  the  present  paper  to  give  a  historical  account  of  the  de- 
velopment of  our  knowledge  with  reference  to  this  specific  infectious  agent, 
and  of  the  experimental  evidence  upon  which  the  claim  is  founded  that  the 
microorganism  referred  to  bears  an  etiological  relation  to  the  disease  in 
question. 

Evidently,  if  pneumonia  is  a  specific  infectious  disease,  the  microorgan- 
ism which  causes  it  is  widely  distributed,  and  the  development  of  an  attack 
depends  rather  upon  secondary  predisposing  and  exciting  causes  than  upon 
the  accidental  introduction  of  the  specific  agent. 

It  cannot  be  maintained  that  the  disease,  as  a  general  rule,  is  transmitted 
from  individual  to  individual — i.e..  by  personal  contagion.  Clinical  expe- 
rience is  entirely  opposed  to  this  view,  although  we  have  ample  evidence 
that  it  may  occur  as  an  epidemic  among  individuals  who  are  exposed  to  the 
same  conditions  of  environment — as  in  jails,  barracks,  etc.  Thus  at  Chris- 
tiania,  Sweden,  an  epidemic  of  pneumonia  occurred  in  1847  in  the  prison, 
during  which  sixty-nine  of  the  prisoners  were  attacked.  And  again  in  1866 
and  1867,  during  a  period  of  six  months  (December,  1866,  to  May,  1867),  a 
similar  epidemic  was  observed  in  the  same  prison — sixty -two  cases.  Other 
prison  epidemics  recorded  are  those  at  Frankfort  in  1875  (seventy-five  cases) 
and  in  1876  (ninety -eight  cases) ;  at  Maringen  in  1875  (eighty-three  cases) 
and  in  1878  (fifty-eight  cases) ;  at  the  prison  of  D'Ansberg  in  1880  (one  hun- 
dred and  sixty -one  cases,  with  forty-six  deaths,  in  a  period  of  five  months). 

Again,  we  have  numerous  records  of  village  epidemics  and  of  epidemics 
confined  to  single  houses.  In  outbreaks  of  this  character,  as  in  epidemics 
of  typhoid  fever,  of  cholera,  and  of  yellow  fever,  there  is  a  succession  of 
cases  occurring  at  different  intervals,  but  it  does  not  follow  that  these  cases 
bear  any  direct  relation  to  each  other.  On  the  contrary,  everything  indi- 
cates that,  as  in  the  diseases  mentioned,  in  the  presence  of  the  infectious 


BACTERIA   IN   CROUPOUS   PNEUMONIA.  289 

agent  common  predisposing  causes  relating  to  the  environment,  acting  upon 
persons  having  various  degrees  of  resisting  power,  induce  attacks  at  various 
intervals  ;  or  it  may  be  that  in.  the  presence  of  the  specific  cause  and  predis- 
posing influences  an  exciting  cause,  such  as  exposure  to  cold,  alcoholic  ex- 
cess, etc. ,  is  the  immediate  factor  in  the  development  of  an  attack. 

Without  stopping  to  discuss  further  the  facts  relating  to  the  epidemic 
prevalence  of  the  disease  under  consideration,  I  call  attention  to  the  well- 
established  fact  that  pneumonia  prevails  over  a  wide  area  of  the  inhabited 
surface  of  the  earth,  and  that  by  far  the  larger  number  of  cases  occur  inde- 
pendently of  any  recognized  connection  with  previous  cases,  and  of  ten  un- 
der circumstances  in  which  such  connection  can  be  very  positively  excluded. 
And,  on  the  other  hand,  the  direct  transmission  of  the  disease  by  the  sick  to 
those  most  closely  associated  with  them,  as  nurses,  etc.,  if  it  occurs  at  all,  is 
evidently  a  rare  exception  to  the  general  rule. 

We  must  then  conclude,  as  stated  at  the  outset,  that  if  pneumonia  is  a 
specific  infectious  disease  the  microorganism  which  causes  it  is  widely  dis- 
tributed. As  a  matter  of  fact,  the  pathogenic  micrococcus  which,  from  the 
evidence  now  at  hand,  appears  to  be  the  specific  etiological  agent  in  acute 
pneumonia  has  been  found  in  the  buccal  secretions  of  healthy  individuals 
in  various  parts  of  the  world — in  America,  in  France,  in  Italy,  and  in  Ger- 
many, and  no  doubt  more  extended  researches  will  show  that  it  is  extremely 
common. 

This  statement  may  appear  at  the  outset  to  make  the  view  that  the  micro- 
coccus  in  question  is  the  cause  of  croupous  pneumonia  quite  untenable. 
For,  it  may  be  asked,  how  is  it  that  the  individuals  who  have  this  microor- 
ganism in  their  buccal  secretions  escape  an  attack  of  pneumonia  ?  In  the 
present  state  of  our  knowledge  this  question  no  longer  presents  any  serious 
difficulties.  We  know,  for  example,  that  the  pus  organisms— Staphylococcus 
pyogenes  aureus,  albus,  and  citreus — are  very  frequently  found  in  the  buc- 
cal secretions  and  on  the  surface  of  the  body  of  healthy  individuals,  and 
that,  although  these  micrococci  are  recognized  as  the  cause  of  furuncles  and 
of  all  sorts  of  acute  abscesses,  they  only  give  rise  to  the  formation  of  such 
abscesses  under  certain  special  conditions  relating  to  the  general  health  of 
the  individual,  or  to  a  traumatism  by  which  their  introduction  to  vulnerable 
parts  is  effected.  Again,  the  tetanus  bacillus  is  a  widely  distributed  micro- 
organism which  has  been  found  in  the  earth,  and  especially  in  rich  loam,  in 
various  parts  of  the  globe.  But  the  hands  of  farmers  and  gardeners  are  con- 
stantly soiled  with  such  earth  without  their  contracting  tetanus.  In  this 
instance  it  has  long  been  recognized  that  a  traumatism  is  an  essential  factor 
in  the  chain  of  events  which  leads  to  the  development  of  tetanus,  and  now 
we  believe,  on  satisfactory  experimental  evidence,  that  it  is  not  the  trauma- 
tism per  se,  or  the  injury  to  the  nerves,  or  exposure  to  cold,  which  in  certain 
cases  gives  rise  to  this  infectious  malady,  but  that  the  result  depends  upon 
the  introduction  of  a  specific  infectious  agent  at  the  time  the  wound  was  re- 
ceived or  subsequently — the  tetanus  bacillus  of  Nicolaier. 

In  the  case  of  the  tubercle  bacillus,  also,  it  is  extremely  probable,  in  the 
light  of  our  present  knowledge,  that  this  bacillus,  in  a  living  condition,  not 
infrequently  finds  a  lodgment  in  the  mouth,  upon  the  Schneiderian  mucous 
membrane,  or  in  the  larger  bronchial  tubes  of  most  individuals  who  live  in 
populous  communities.  Here  also  the  infectious  agent  is  only  one  factor, 
although  an  essential  one,  in  the  production  of  the  infectious  disease.  It 
must  be  introduced  to  the  vulnerable  location,  and  must  find  a  favorable 
nidus  in  the  tissues  invaded.  We  have  good  reason  to  believe  that  in  this, 
as  well  as  in  other  infectious  diseases,  there  are  wide  differences,  inhe- 
rited or  acquired,  in  the  susceptibility  of  the  tissues  to  invasion  when  the 
infectious  agent  has  been  introduced  to  a  favorable  location. 

In  a  paper  read  before  the  Pathological  Society  of  Philadelphia  in  April, 

1885,  in  discussing  the  relation  of  my  Micrococcus  Pasteuri  to  croupous 

pneumonia,  I  say:  "It  seems  extremely  probable  that  this  micrococcus  is 

concerned  in  the  etiology  of  croupous  pneumonia,  and  that  the  infectious 

21 


290  BACTERIA  IN   CROUPOUS   PNEUMONIA. 

nature  of  this  disease  is  due  to  its  presence  in  the  fibrinous  exudate  into  the 
pulmonary  alveoli. 

"  But  this  cannot  be  considered  as  definitely  established  by  the  experi- 
ments which  have  thus  far  been  made  upon  the  lower  animals.  The  con- 
stant '  presence  of  this  micrococcus  in  the  buccal  secretions  of  healthy  per- 
sons indicates  that  some  other  factor  is  required  for  the  development  of  an 
attack  of  pneumonia ;  and  it  seems  probable  that  this  other  factor  acts  by  re- 
ducing the  vital  resisting  power  of  the  pulmonary  tissues,  and  thus  making 
them  vulnerable  to  the  attacks  of  the  microbe.  This  supposition  enables  vis 
to  account  for  the  development  of  the  numerous  cases  of  pneumonia  which 
cannot  be  traced  to  infection  from  without.  The  germ  being  always  pre- 
sent, auto-infection  is  liable  to  occur  when,  from  alcoholism,  sewer-gas 
poisoning,  crowd  poisoning,  or  any  other  depressing  agency,  the  vitality  of 
the  tissues  is  reduced  below  the  resisting  point.  We  may  suppose,  also,  that 
a  reflex  vaso-motor  paralysis,  affecting  a  single  lobe  of  the  lung,  for  exam- 
ple, and  induced  by  exposure  to  cold,  may  so  reduce  the  resisting  power  of 
the  pulmonary  tissue  as  to  permit  this  micrococcus  to  produce  its  character- 
istic effects. 

"Again,  we  may  suppose  that  a  person  whose  vital  resisting  power  is 
reduced  by  any  of  the  causes  mentioned  may  be  attacked  by  pneumonia 
from  external  infection  with  material  containing  a  pathogenic  variety  of 
this  micrococcus  having  a  potency,  permanent  or  acquired,  greater  than  that 
possessed  by  the  same  organism  in  normal  buccal  secretions." 

This  is  the  theory  by  which  I  have  attempted  to  explain  the  etiological 
role  of  this  micrococcus  in  croupous  pneumonia.  Let  us  now  consider  the 
principal  facts  which  have  led  to  a  belief  in  its  causal  relation  to  this  disease. 

Friedlander,  in  1882,  observed,  in  eight  fatal  cases  of  pneumonia  in  which 
he  made  autopsies,  microorganisms,  having  an  oval  form,  in  the  exudate  into 
the  pulmonary  alveoli;  they  were  in  pairs  or  in  short  chains.  Without  af- 
firming that  this  microorganism  is  the  cause  of  pneumonia,  Friedliinder 
seems  to  have  considered  it  extremely  probable  that  it  bore  an  etiological  re- 
lation to  this  disease. 

During  the  same  year  Leyden  and  Gunther  announced  at  a  meeting  of 
the  Medical  Society  of  Berlin  (November  20th,  1882)  that  they  had  found  the 
same  micrococcus  in  the  fibrinous  exudate  of  pneumonia,  obtained  through 
the  thoracic  walls  by  means  of  a  Pravaz  syringe.  At  the  same  time  G-unther 
stated  that  the  elliptical  cocci,  in  specimens  stained  with  gentian  violet,  were 
surrounded  with  a  colorless  capsule. 

The  following  year  Matruy  published  his  observations.  In  sixteen  cases 
he  had  found  an  elongated  coccus  in  the  fibrinous  exudate  of  pneumonia,  and 
always  having  a  very  transparent  capsule.  He  had  also  encountered  the 
same  microorganism  in  the  sputa  of  patients  with  other  diseases,  but  not  so 
abundantly  as  in  pneumonia. 

On  November  19th,  1883,  Friedlander  communicated  to  the  Medical  Soci- 
ety of  Berlin  the  results  of  his  culture  and  inoculation  experiments.  His 
"  pneumococcus  "  was  characterized  by  the  presence  of  a  capsule  which,  as 
he  says,  "  always  takes  the  form  of  the  microorganism;  if  this  is  round  the 
capsule  is  round ;  if  it  is  elliptical  the  capsule  is  an  ellipse."  This  capsule, 
however,  was  only  found  in  preparations  made  from  the  blood  of  an  inocu- 
lated animal  or  from  the  fibrinous  exudate  into  the  alveoli ;  in  cultures  it 
was  no  longer  seen.  The  cultures  in  flesh-peptone  gelatin  presented  a  nail- 
shaped  growth  which  was  believed  to  be  characteristic.  Growth  was  rapid 
in  a  variety  of  culture  media  at  the  ordinary  room  temperature  (65°  to 
75°  F.),  and  in  a  gelatin  culture  medium  no  liquefaction  occurred. 

The  following  results  were  obtained  by  Friedlander  in  his  inoculation  ex- 
periments: In  one  series  of  experiments  the  "  pneumococci,"  mixed  with 
distilled  water,  were  injected  through  the  thoracic  walls  into  the  lungs. 
Nine  rabbits  inoculated  in  this  way  gave  an  entirely  negative  result.  Six 

'I  should  have  said  frequent  instead  of  "  constant  presence." 


BACTERIA   IN   CROUPOUS   PNEUMONIA.  291 

out  of  eleven  guinea-pigs  are  said  to  have  succumbed  and  to  have  presented 
the  lesions  of  pneumonia.  All  of  the  mice  injected  died  within  twenty -four 
hours,  and  at  the  autopsy  the  lungs  were  found  to  be  congested  and  to  pre- 
sent foci  of  red  hepatization.  In  a  second  series  of  experiments  upon  mice 
they  were  made  to  inhale  a  spray  containing  the  pneumococci  in  suspension. 
Several  of  these  animals  died  and  are  said  to  have  presented  a  typical  pneu- 
monia. The  ' '  pneumococcus, "  surrounded  by  its  characteristic  capsule,  was 
found  in  the  lungs,  the  spleen,  the  blood,  and  the  liquid  contained  in  the 
pleural  cavity. 

Upon  this  evidence  Friedlander's  "pneumococcus,"  which  is  now  usually 
described  as  a  bacillus,  was  very  generally  accepted  as  the  specific  cause  of 
fibrinous  pneumonia,  and  cultures  were  distributed  throughout  the  labora- 
tories of  Europe  bearing  the  label,  "  Pneumococcus  of  Friedlander."  For 
some  time  after  the  publication  of  Friedlander's  paper  all  observations  made 
with  reference  to  the  presence  of  oval  cocci  or  of  encapsulated  cocci  in  the 
fibrinous  exudate  of  pneumonia  were  supposed  to  confirm  his  discovery. 
But  now  we  know  that  there  is  another  oval  coccus  which  is  far  more  fre- 
quently present  in  the  exudate  of  acute  pneumonia,  which  also  presents  the 
appearance  of  being  surrounded  by  a  transparent  capsule — less  pronounced, 
however,  than  that  of  Friedlander's  bacillus— but  which  is  entirely  distinct 
from  that  of  Friedlander  and  is  probably  the  true  pneumococcus.  I  shall 
give  the  distinctive  characters  of  this  microorganism  later. 

At  the  same  time  that  Friedlander  was  pursuing  his  researches  in  Berlin, 
Talamon,  a  French  physician,  was  engaged  in  similar  researches  in  the  lab- 
oratory of  the  Hotel-Dieu.  His  results  were  communicated  to  the  Anato- 
mical Society  of  Paris  on  November  30th,  1883,  a  few  days  after^  Friedlan- 
der's communication  to  the  Medical  Society  of  Berlin  (Germain  See). 

"  Talamon  did  not  describe  his  microbe  as  having  a  capsule;  according 
to  him,  the  pneumonia-coccus  is  characterized  by  its  form.  When  seen  in 
the  fibrinous  exudate  the  microbe  has  an  elliptical  form,  like  a  grain  of 
wheat.  Cultivated  in  a  liquid  medium — an  alkaline  solution  of  extract  of 
beef — it  is  elongated  and  attenuated,  and  presents  the  appearance  of  a  grain  of 
barley.  On  account  of  this  appearance  Talamon  has  proposed  to  call  it  the 
lanceolate  coccus.  This  organism  is  encountered  in  the  pneumonic  exudate 
obtained  after  death,  or  drawn  daring  life  by  means  of  a  Pravaz  syringe 
from  the  hepatized  portions  of  the  lung.  Once  only,  out  of  twenty-five 
cases,  it  was  found  in  the  blood  of  a  patient  at  the  moment  of  death." 

Talamon's  inoculation  experiments  in  dogs  and  guinea-pigs  gave  a  nega- 
tive result,  but  out  of  twenty  rabbits  injected  through  the  walls  of  the 
thorax  into  the  lungs  eight  showed  the  chai-acteristic  lesions  of  fibrinous 
pneumonia.  Prof.  See  says,  with  reference  to  the  evidence  in  the  case  of 
these  rabbits  as  compared  with  that  obtained  by  Friedlander  in  his  mice: 
"  The  rather  brief  description  of  the  lesions  obtained  by  Friedlander  in  the 
mice  inoculated  by  him  leaves  some  doubt  in  the  mind;  for  the  presence  of 
foci  (noyaux)  of  induration  in  congested  lungs  is  not  sufficient  to  character- 
ize fibrinous  pneumonia.  But  the  lungs  of  the  rabbits  presented  by  Tala- 
mon to  the  Anatomical  Society  in  support  of  his  communication  leave  no 
room  for  discussion.  As  he  observed,  it  was  not  at  all  a  question  of  foci  of 
congestion,  or  of  broncho-pneumonia,  such  as  one  observes  habitually  in 
rabbits  which  die  of  septicaemia,  but  a  veritable  lobar  fibrinous  pneumonia 
with  pleurisy  and  pericarditis  of  the  same  nature.  The  naked-eye  examina- 
tion, as  well  as  the  microscope,  showed  no  difference  in  the  lesions  produced 
in  the  rabbit  and  the  pneumonia  of  man." 

On  another  page  Prof.  See  says  :  ' '  Af anassiew  repeated  in  the  laboratory 
of  Prof.  Cornil  the  experiments  of  Friedlander  and  of  Talamon  ;  by  the  cul- 
ture in  peptonized  gelatin  of  the  pneumonic  exudate  taken  from  the  cadaver 
he  obtained  two  species  of  organisms,  round  micrococci  of  large  and  small 
dimensions,  and  oval  cocci  which  corresponded  to  the  microbes  described  by 
the  two  authors "  (Friedlander  and  Talamon)  "whose  researches  we  have 
just  reviewed."  This  quotation  indicates  that  Prof,  See  did  not  question  the 


292  BACTERIA  IN   CROUPOUS   PNEUMONIA. 

identity  of  the  oval  or  "  lanceolate  "  coccus  found  by  Talamon  in  pneumonic 
exudate,  and  which  iu  his  experiments  produced  typical  pneumonia  in  rab- 
bits, and  the  so-called  "  pneumococcus  "  of  Friedlander,  which,  according 
to  his  account,  gave  a  negative  result  when  injected  into  rabbits,  but  caused 
pneumonia  in  mice  when  injected  dh'ectly  into  the  lungs.  Prof.  See  was 
not  alone  in  making  this  inference,  which  has  turned  out  to  be  a  mistaken 
one.  The  identity  of  the  oval  cocci,  which  had  now  been  seen  in  the  pul- 
monary exudate  by  numerous  observers,  with  the  microorganism  which 
Friedlander  had  isolated  and  cultivated  from  material  obtained  post  mortem 
from  hepatized  lungs,  was  generally  admitted ;  and  all  of  the  observations 
relating  to  the  presence  of  oval  cocci,  having  a  more  or  less  distinct  capsule, 
in  the  exudate  of  fibrinous  pneumonia,  were  supposed  to  give  support  to  the 
alleged  discovery  of  Friedlander.  Now  we  know  that  the  oval  coccus  most 
frequently  found  in  such  material  is  not  that  of  Friedlander,  but  that  it  is 
identical  with  a  coccus  first  observed  by  the  writer  in  September,  1880,  in. 
the  blood  of  rabbits  injected  with  his  own  saliva  and  subsequently  (1885) 
named  by  him  Micrococcus  Pasteuri. 

This  was,  without  doubt,  the  coccus  which  produced  pneumonia  in  Tala- 
mon's  experiments  upon  rabbits ;  and  we  must  give  him  the  credit  of  having 
first  experimentally  demonstrated  the  fact  that  fibrinous  pneumonia  may  be 
induced  by  the  introduction  of  this  microorganism  into  the  parenchyma  of 
the  lung  in  these  animals. 

Salvioli,  whose  experiments  were  also  made  in  1884,  had  a  uniformly 
fatal  result  from  the  injection  of  pneumonic  sputum  into  rabbits  (four).  He 
also  observed  the  oval  coccus  in  the  material  injected,  and  in  the  blood  of 
the  animals  which  succumbed  to  his  injections,  but  did  not  recognize  the 
identity  of  this  coccus  with  that  which  my  own  experiments  and  those  of 
Pasteur,  Vulpian,  and  others  had  shown  to  be  present  in  normal  human 
saliva  and  to  induce  a  fatal  form  of  septicaemia  in  rabbits.  On  the  other 
hand,  he  also  appears  to  have  taken  it  for  granted  that  the  oval  micrococcus 
encountered  by  him,  and  which,  under  certain  circumstances,  was  sur- 
rounded by  a  transparent  capsule,  was  the  "  pneumococcus  "  of  Friedlander. 
Klein  appears  to  have  made  the  same  mistaken  inference.  This  is  shown 
by  the  following  quotation  from  his  paper  published  in  1885: 

"In  seeking  to  ascertain  what  might  be  the  relation  between  the  so-called 
pneumococci  and  croupous  pneumonia,  I  have  made  extensive  examination 
of  the  lungs  and  blood  of  persons  dead  of  the  disease,  and  also  of  the  sputum 
of  living  patients  at  various  stages  of  their  illness.  ...  In  some  of  the  air 
vesicles,  though  few  and  far  between,  there  were  present  undoubtedly  the 
capsulated  cocci  spoken  of  by  Friedlander  and  others  as  pneumococci.  .  .  . 
As  regards  the  living  patients,  if  we  examine  typical  sputum  of  croupous 
pneumonia  we  find,  besides  numerous  red  blood  discs  and  white  blood  cor- 
puscles, also  a  few  epithelial  cells,  and  in  the  general  gelatinous  matrix 
numbers  of  microorganisms,  chiefly  belonging  to  the  species  micrococci.  .  .  . 

"These  are,  as  far  as  size  and  arrangement  go,  of  two  principal  types: 
(a)  Oval  micrococci  about  0.001  millimetre  in  length,  occurring  isolated,  but 
more  commonly  as  dumbbells  and  slightly  curved  chains  of  four,  six,  and 
even  eight  elements.  .  .  .  But  in  all  these  micrococci  the  elements  are  dis- 
tinctly surrounded  by  a  hyaline  zone  which,  in  stained  preparations,  can  be 
made  out  as  an  unstained  halo,  though  in  some  stained  specimens  it  as- 
sumes a  tint  that  is  fainter  than  that  of  the  micrococcus  itself;  this  corre- 
sponds to  the  capsule  of  Friedlander,  and  for  this  reason  he  called  them, 
capsule  micrococci." 

In  a  footnote  to  the  paper  from  which  I  have  quoted  Klein  says : 

"While  this  paper  is  passing  through  the  press  I  receive  from  Dr.  Stern- 
berg,  of  Baltimore,  a  paper  in  which  he  conclusively  proves  that  the  mi- 
crococci of  human  saliva,  which  produce  in  some  instances  septicaemia  on 
inoculation  into  rabbits,  are  identical  with  the  pneumococci  of  Friedlander, 
Salvioli,  and  others." 

My  own  experiments  with  pneumonic  sputum  were  made  in  January, 


BACTERIA  IN  CROUPOUS   PNEUMONIA.  293 

1885,  and  led  me  to  the  identification  of  the  oval  coccus  found  in  this  ma- 
terial with  the  coccus  found  in  my  own  saliva  (by  inoculations  into  rabbits) 
in  September,  1880,  and  subsequently  studied  by  me  in  an  extended  series 
of  experiments  made  during  the  following  years,  1880-84. 

But,  at  the  same  time,  I  fell  into  the  error  of  inference,  previously  made 
by  Prof.  See,  by  Salvioli,  and  others,  and  assumed  that  the  "pneumo- 
coccus  "  which  Friedlander  had  obtained  from  the  same  source  was  the  same, 
although  I  found  it  difficult  to  reconcile  the  experimental  data,  inasmuch 
as  he  had  obtained  uniformly  negative  results  in  his  inoculations  into 
rabbits.  To  explain  this  discrepancy  I  suggested  that  Friedlander's  pneu- 
mococcus  was  probably  a  variety  having  a  different  degree  of  pathogenic 
power. 

This  supposition  seemed  to  find  support  in  the  fact,  which  I  had  previ- 
ously observed,  that  my  Micrococcus  Pasteuri  became  attenuated,  as  to  its 
pathogenic  power,  when  the  cultures  were  kept  for  some  time;  and  that 
there  seemed,  from  the  experimental  evidence  before  me,  to  be  different 
pathogenic  varieties  in  the  buccal  secretions  of  different  individuals.  At 
this  time  I  had  not  seen  a  culture  of  Friedlander's  bacillus.  Later,  in  the 
autumn  of  1885,  when  I  made  its  acquaintance  in  Dr.  Koch's  laboratory,  I 
recognized  my  mistake  and  hastened  to  correct  the  error.1 

For  a  detailed  account  of  my  experiments  with  pneumonic  exudate  I 
must  refer  to  my  paper  published  in  the  ' '  Transactions  of  the  Pathological 
Society  of  Philadelphia"  (vol.  xii.)  and  in  the  American  Journal  of  the 
Medical  Sciences  (July,  1885). 

With  reference  to  my  conclusion  that  the  oval  coccus  of  Talamon  and 
of  Salvioli  was  identical  with  my  Micrococcus  Pasteuri,  I  may  say  that 
this  conclusion  has  been  sustained  by  the  subsequent  investigations  of 
Frankel,  Weichsel  baum,  Bordoni-Uffreduzzi,  Netter,  Grameleia,  and  others. 

Frankel's  first  paper  relating  to  the  presence  of  this  microorganism  in 
pneumonic  exudate  was  published  in  1885. 

Having  ascertained  that  his  own  saliva  contained  this  oval  micrococcus, 
he  was  induced  to  make  an  extended  and  interesting  series  of  experiments 
which  led  him  to  the  conclusion  that  this  microorganism  is  far  more  con- 
stantly present  in  the  exudate  of  fibrinous  pneumonia  than  is  the  so-called 
" pneumococcus "  of  Friedlander.  He  says: 

"  Finally,  as  regards  the  relative  frequency  of  the  two  hitherto  investi- 
gated microorganisms  in  cases  of  pneumonia,  no  positive  statement  can  yet 
be  made.  Nevertheless  I  am  inclined  to  regard  the  lancet-shaped  pneu- 
mococcus, which  is  identical  with  the  microbe  of  sputum  septicaemia,  as  the 
more  frequent,  and  the  usual  infectious  agent  of  pneumonia,  on  the  ground 
that  this  organism  is  so  much  more  frequently  found  in  the  sputum  of  pneu- 
monic patients  than  in  that  of  healthy  individuals.  This  conclusion  is 
further  supported  by  the  fact  that  it  has  not  hitherto  been  possible  to  isolate, 
directly  from  the  rusty  sputum,  Friedlander's  bacilJus." 

The  extended  researches  of  Weichselbaum,  published  in  1886,  give  strong 
support  to  the  view  that  this  coccus  is  the  usual  infectious  agent  in  croupous 
pneumonia.  He  examined,  in  all,  the  exudate  in  one  hundred  and  twenty- 
nine  cases  of  pneumonia. 

In  ninety-four  of  these  cases  the  micrococcus  in  question,  called  by 
Weichselbaum  "diplococcus  pneumonias,"  was  obtained  (fifty-four  times  in 
cultures);  in  twenty-one  cases  he  obtained  a  streptococcus,  and  in  nine  only 
was  the  bacillus  of  Friedlander  encountered. 

Wolf,  whose  studies  were  made  in  Weichselbaifm's  laboratory,  reported 
the  result  of  his  researches  in  1887.  He  found  the  "diplococcus  pneumonias" 
in  sixty-six  out  of  seventy  cases  of  croupous  pneumonia  examined,  and  the 
"pneumococcus  of  Friedlander  "  in  three  cases. 

Netter,  whose  paper  was  published  in  November,  1887,  found  Micrococcus 

1  See  ray  paper  published  in  the  American  Journal  of  the  Medical  Sciences 
for  July,  1886. 


284  BACTERIA   IN   CROUPOUS   PNEUMONIA. 

Pasteuri  in  seventy-five  per  cent  of  his  cases  of  pneumonia,  and  in  the  sputum 
of  convalescents  from  this  disease  its  presence  was  verified  in  sixty  per  cent 
of  the  cases  by  inoculation  experiments  in  rabbits.  He  makes  the  interest- 
ing observation  that  the  sputum  of  recent  convalescents  is  less  virulent  for 
rabbits  than  that  collected  at  a  later  period. 

Gameleia,  who  has  recently  published  in  the  Annales  of  the  Pasteur 
Institute  an  important  paper  upon  the  etiology  of  fibrinous  pneumonia,  veri- 
fied the  presence  of  Micrococcus  Pasteuri  in  twelve  fatal  cases  in  which  he 
collected  material  post  mortem.  He  states  that  in  a  series  of  forty  con- 
secutive cases  Dr.  Goldenberg,  whose  experiments  were  made  in  his  laboratory, 
found  this  micrococcus  in  every  case  by  inoculation  experiments  in  rabbits  or 
in  mice.  According  to  Gameleia,  inoculations  in  mice  are  more  reliable  than 
those  made  in  rabbits,  as  the  mouse  is  the  more  susceptible  animal.  He  says: 
"The  author,  Weichselbaum,  who  has  made  the  most  extended  research 
upon  the  etiology  of  pneumonia,  used  in  his  researches  the  method  of  culti- 
vation upon  gelatin.  We  must  adopt  the  opinion  of  Baumgarten,  who  does 
not  accord  any  decided  value  to  the  negative  results  of  Weichselbaum  with 
reference  to  the  constant  presence  of  Streptococcus  Pasteuri.  Netter,  who 
adopted  the  method  of  inoculating  the  pneumonic  sputum  into  rabbits,  and 
who  only  found  the  microbe  of  Pasteur  in  seventy-five  per  cent  of  his  cases, 
was  wrong,  in  our  opinion,  in  making  use  of  an  animal  which  is  too  resist- 
ant to  determine  the  presence  of  small  quantities  of  virus.  This  opinion  is 
confirmed  by  the  fact  that  Netter  rendered  some  rabbits  refractory  by  his 
inoculations  with  material  in  which  he  had  not  found  the  specific 
microbe. 

"  En  resume,  taking  our  stand  upon  the  positive  results  which  we  have 
always  obtained,  as  well  as  upon  the  superiority  of  the  method  of  research 
(inoculations  in  mice)  which  we  have  adopted,  we  believe  ourselves  au- 
thorized to  conclude  that  fibrinous  pneumonia  is  always  dependent  upon 
the  microbe  of  Pasteur." 

Friinkel,  Weichselbaum,  and  other  recent  authors,  while  maintaining 
that  Micrococcus  Pasteuri  is  the  most  frequent  etiological  agent  in  the  pro- 
duction of  pneumonia,  have  been  disposed  to  admit  that  in  a  certain  propor- 
tion of  the  cases  the  bacillus  of  Friedlander,  and  possibly  other  microorgan- 
isms, may  bear  the  same  relation  to  the  pneumonic  process.  Gameleia,  on 
the  other  hand,  believes  that  the  bacillus  of  Friedlander  is  a  simple  sapro- 
phyte, the  occasional  presence  of  which  in  pneumonic  exudate  is  without 
etiological  import.  He  remarks  as  follows : 

"  We  may  be  brief  as  regards  the  second  objection  made  against  the  etio- 
logical unity  of  fibrinous  pneumonia,  viz.,  with  reference  to  the  etiological 
rights  of  the  microbe  of  Friedlander.  This  microbe  is  found  in  normal  sali- 
va, it  is  a  true  saprophyte,  and  may  at  times  invade  the  diseased  or  dead 
lung.  Weichselbaum  only  found  it  in  seven  per  cent  of  his  cases,  and  al- 
most always  associated  with  other  microbes,  for  he  only  encountered  it  pure 
in  three  cases.  As  to  the  researches  of  the  authors  who  preceded  Frankel, 
it  is  sure  that  the  microbe  which  they  often  found  in  sections  of  diseased 
lungs,  and  which  they  called  the  microbe  of  Friedlander,  was  in  fact  the  mi- 
crobe of  Pasteur,  since  it  was  colored  by  the  method  of  Gram,  which  decol- 
orizes the  bacillus  of  Friedlander.  Many  of  the  positive  results,  then, 
which  have  been  reported  relative  to  the  last-mentioned  microorganism, 
ought  to  be  put  to  the  account  of  the  other." 

This  opinion  the  present  writer  has  entertained  since  his  researches  made 
in  1885. 

The  experimental  evidence  offered  by  Gameleia  in  favor  of  the  etiologi- 
cal role  of  this  micrococcus  is  most  important. 

It  will  be  remembered  that  Talamon  produced  typical  pneumonia  in 
eight  rabbits,  in  1883,  by  inoculating  them  through  the  thoracic  walls  with 
pneumonic  exudate.  Gameleia  says: 

"  The  number  of  my  rabbits  iu  which  pneumonia  was  induced  is  about 
two  hundred." 


BACTERIA   IN   CROUPOUS   PNEUMONIA.  295 

The  writer  found  in  his  experiments,  made  in  1881,  that  in  making  a 
series  of  inoculations  in  rabbits  the  virus  increased  in  virulence,  and  that, 
on  the  other  hand,  the  micrococcus  lost  its  virulence  when  the  cultures 
were  kept  for  some  time.  This  fact  has  been  verified  by  the  subsequent  re- 
searches of  Fraukel  and  of  Gameleia.  The  last-named  author  has  shown  that 
to  induce  pneumonia  in  very  susceptible  animals,  like  the  rabbit,  an  attenu- 
ated variety  of  the  microbe  should  be  injected,  for  the  most  virulent  cul- 
tures quickly  cause  death  by  septicaemia.  As  he  expresses  it :  "Animals 
which  are  too  susceptible,  like  the  rabbit  and  the  mouse,  do  not  have  pneu- 
monia, because  they  do  not  offer  a  local  reaction ;  the  virus  is  generalized  in 
their  bodies  and  they  die  of  an  acute  septicaemia  " 

On  the  other  hand,  Gameleia  has  shown  that  "  animals  which  are  but 
little  susceptible  to  the  pneumonic  virus  offer  a  local  resistance  which  gives 
rise  to  very  pronounced  reactionary  phenomena  (extended  fibrino-granular 
opdema),  and  consequently  they  present,  as  a  result  of  intrapulmonary  infec- 
tion, a  typical  fibrinous  pneumonia.  Such  animals  are  the  dog  and  the 
sheep." 

In  his  experiments  upon  these  animals  Gameleia  obtained  the  following 
results: 

The  sheep  was  found  to  survive  subcutaneous  inoculations,  unless  very 
large  doses  (five  cubic  centimetres)  of  the  most  potent  virus  were  ad- 
ministered. But  intrapulmonary  inoculation  was  always  followed  by  typi- 
cal fibrinous  pneumonia,  which  in  the  majority  of  cases  proved  fatal. 

The  microbe  was  rarely  found  in  the  blood,  and  successive  inoculations 
from  one  sheep  to  another  were  not  successful.  Death  occurred,  after  an 
intrapulmonary  inoculation,  on  the  third,  fourth,  or  fifth  day.  The  pneu- 
monia produced  was  lobar,  and  was  attended  with  an  extensive  fibrinous 
exudation  in  which  the  coccus  was  found  in  great  abundance.  In  all,  fifty 
sheep  were  experimented  upon. 

The  writer  found  in  his  experiments,  made  in  1881,  that  the  dog  resists 
inoculations  with  this  coccus.  Gameleia  also  obtained  negative  results  when 
moderate  doses  were  injected  beneath  the  skin,  but  states  that  "  intrathoracic 
infection  always  causes  a  frank,  fibrinous  pneumonia  which  is  rarely  fatal ; 
recovery  usually  occurs  in  from  ten  to  fifteen  days,  after  the  animal  has 
passed  through  all  the  stages  of  red  and  gray  hepatization  which  character- 
izes this  affection  in  man."  Twelve  dogs  were  experimented  upon. 

This  micrococcus,  then,  which  in  very  susceptible  animals  (mouse,  rabbit) 
invades  the  blood  and  quickly  causes  death  by  septicaemia,  when  injected 
through  the  thoracic  walls  in  less  susceptible  animals  (dog,  sheep),  or  in  an 
attenuated  form  in  the  rabbit,  gives  rise  to  the  local  lesions  which  character- 
ize fibrinous  pneumonia. 

Man  comes  in.  the  category  of  slightly  susceptible  animals,  as  is  shown 
by  the  comparatively  small  mortality  from  pneumonia,  and  the  fact  that  the 
micrococcus  found  intheexudateinto  the  pulmonary  alveoli  does  not  invade 
the  blood,  unless  in  rare  instances.  We  may  therefore  agree  with  Gameleia 
in  the  following  statement : 

"It  is  clear  that  the  results  obtained  in  the  dog  and  the  sheep,  animals 
which  have  but  a  slight  susceptibility,  are  most  applicable  to  human  patho- 
logy." 

In  my  paper  read  before  the  Pathological  Society  of  Philadelphia  in 
April,  1885,  from  which  I  have  already  quoted,  I  say:  "  It  seems  extremely 
probable  that  this  micrococcus  is  concerned  in  the  etiology  of  croupous  pneu- 
monia. .  .  .  But  this  cannot  be  considered  as  definitely  established  by  the 
experiments  which  have  thus  far  been  made  upon  the  lower  animals." 

The  experiments  of  Gameleia  go  far  toward  settling  this  question  in  a 
definite  manner,  and,  considered  in  connection  with  those  of  Talamon  and 
Salvioli,  and  the  extended  researches  of  Frankel,  Weichselbaum,  and  Netter, 
leave  but  little  doubt  that  this  is  the  true  infectious  agent  in  acute  lobar 
pneumonia. 


296  BACTERIA   IN   CROUPOUS   PNEUMONIA. 


7.       BACILLUS   OF   FRIEDLANDER. 

Synonyms. — Pneumococcus  (Friedlander);  Bacillus  pneumonias 
(Fliigge). 

Obtained  by  Friedlander  and  Frobenius  in  pure  cultures  (1883) 
from  the  exudate  into  the  pulmonary  alveoli  in  cases  of  croup- 
ous  pneumonia.  Subsequent  researches  show  that  it  is  only  present 
in  a  small  proportion  of  the  cases — nine  times  in  one  hundred  and 
twenty-nine  cases  examined  by  Weichselbaum,  three  times  in  seventy 
cases  examined  by  Wolf. 

Morphology. — Short  rods  with  rounded  ends,  often  so  short  as 

to  resemble  micrococci,  especially  in  very 

($JM         recent  cultures  ;  commonly  united  in  pairs 

°^  ^°  ^©(^/^     or  chains  of  four,  and  under  certain  cir- 

^0°o  Q°  ^(o)     ffi     cumstances  surrounded  by  a  transparent 

Ji  j{  capsule.      The    gelatinous  envelope  —  so- 

FIO.  88. -Baciiiusof  Friedlander;     called  capsule — is  not  seen  in  preparations 

o,  from  a  culture;  6,  from  blood  of    made  f  rom  cultures  in  artificial  media,  but 

mouse,  showing  capsule.   (Fliigge.)       .  .  . 

is  very  prominent  in  properly  stained  prepa- 
rations from  the  blood  of  an  inoculated  animal.  It  often  has  a  diame- 
ter equal  to  or  greater  than  that  of  the  enclosed  cell,  and  appears  to 
consist  of  a  substance  resembling  mucin,  which  is  soluble  in  water  or 
dilute  alcohol.  Where  several  cells  are  united  in  a  chain  they  may 
all  be  enclosed  in  a  common  envelope,  or  each  may  have  its  own  cap- 
sule. This  capsule  is  not  peculiar  to  Friedlander's  bacillus,  as  he 
at  first  supposed,  but  is  found  in  other  bacilli  and  also  in  the  writer's 
Micrococcus  Pasteuri. 

Friedlander's  bacillus  stains  readily  with  the  aniline  colors,  but 
is  decolorized  by  the  iodine  solution  used  in  Gram's  method.  In 
preparations  from  the  blood  of  an  inoculated  animal,  stained  by  an 
aniline  color,  the  capsule  appears  as  an  unstained  envelope  surround- 
ing the  stained  cell,  but  by  special  treatment  the  capsule  may  also  be 
stained.  Friedlander's  method  is  as  follows  :  The  section  or  cover- 
glass  preparation  is  placed  for  twenty-four  hours  in  a  solution  of 
gentian  violet  and  acetic  acid,  containing  fifty  parts  of  a  concentrated 
alcoholic  solution  of  gentian  violet,  one  hundred  parts  of  distilled 
water,  and  ten  parts  of  acetic  acid.  The  stained  preparation  is 
washed  for  a  minute  or  two  in  a  one-per-cent  solution  of  acetic  acid, 
dehydrated  with  alcohol,  cleared  up  with  oil  of  cloves  or  cedar,  and 
mounted  in  balsam.  The  bacillus  is  quickly  stained  in  dried  cover- 
glass  preparations  by  immersion  in  aniline- water-gentiaii-violet  solu- 
tion (two  or  three  minutes).  The  stained  preparation  should  be  de- 
colorized by  placing  it  in  absolute  alcohol  for  half  a  minute,  and  then 
washed  in  distilled  water. 


BACTERIA   IN   CROUPOUS   PNEUMONIA. 


297 


Biological  Characters. — This  bacillus  does  not,  so  far  as  is 
known,  form  reproductive  spores ;  it  is  non-motile  and  does  not 
liquefy  gelatin.  It  is  aerobic  and  a  facultative  anaerobic.  In 
gelatin  stick  cultures  it  presents  the  "nail-shaped"  growth  first 
described  by  Friedlander,  which  is  not,  however,  peculiar  to  this 
bacillus.  The  head  of  the  nail  is  formed  by  the 
development  around  the  point  of  entrance  of  the 
inoculating  needle  of  a  rounded,  white  mass  hav- 
ing a  smooth,  shining  surface,  and  its  stem  by  the 
growth  along  the  line  of  puncture.  This  consists 
of  closely  crowded,  opaque,  white,  spherical  colo- 
nies. Gas  bubbles  sometimes  develop  in  gelatin 
cultures,  and  in  old  cultures  the  gelatin  about  the 
line  of  growth  acquires  a  yellowish-brown  color. 
The  growth  in  nutrient  agar  resembles  that  in 
gelatin.  Upon  the  surface  of  blood  serum  abun- 
dant grayish-white,  viscid  masses  are  developed. 
Upon  potato  the  growth  is  abundant,  quickly  cov- 
ering the  entire  surface  with  a  thick,  yellowish- 
white,  glistening  layer  which  often  contains  gas 
bubbles  when  the  temperature  is  favorable.  Col- 
onies in  gelatin  plates  appear  at  the  end  of  twenty- 
four  hours  as  small,  white  spheres,  which  increase 
rapidly  in  size,  and  upon  the  surface  form  round- 
ed, smooth,  glistening,  white  masses  of  consider- 
able size.  Under  the  microscope  the  colonies  pre- 
sent a  somewhat  irregular  outline  and  a  slightly  Flo-  89  — Friedlander'a 

0  *    bacillus;  stick  culture  in 

granular  appearance.  Growth  occurs  at  compara-  gelatin;  end  of  four  days 
tively  low  temperatures— 16°  to  20°  C.—  but  is  more  at  16°-18°  c-  (Baumgar- 
rapid  in  the  incubating  oven.  The  thermal  death- 
point,  as  determined  by  the  writer,  is  about  56°  C.  In  the  ordinary 
culture  media  it  retains  its  vitality  for  a  long  time,  and  may  grow 
when  transplanted  to  fresh  culture  material  after  having  been  pre- 
served for  a  year  or  more.  At  a  temperature  of  40°  C.  development 
ceases. 

Pathogenesis. — In  Friedlander's  experiments  the  bacillus  from 
pure  cultures,  suspended  in  water,  was  injected  through  the  thoracic 
wall  rinto  the  right  lung  of  dogs,  rabbits,  guinea-pigs,  and  mice. 
Rabbits  proved  to  be  immune ;  one  dog  out  of  five,  six  guinea-pigs 
out  of  eleven,  and  all  of  the  mice  (thirty -two)  succumbed  to  the 
inoculation.  At  the  autopsy  the  pleural  cavities  were  found  to  con- 
tain a  sero-purulent  fluid  ;  the  lungs  were  intensely  congested,  con- 
tained but  little  air,  and  in  places  showed  limited  areas  of  red  infil- 
tration ;  the  spleen  was  considerably  enlarged ;  the  bacillus  was 


298  BACTERIA  IN  CROUPOUS  PNEUMONIA. 

found  in  great  numbers  in  the  lungs,  the  fluid  in  the  pleural  cavi- 
ties, and  in  the  blood  obtained  from  the  general  circulation  or  from 
the  various  organs  of  the  body.  Similar  appearances  presented  them- 
selves in  the  case  of  the  guinea-pigs  which  succumbed  to  the  inocu- 
lation. 

These  results  show  that  the  bacillus  under  consideration  is  path- 
ogenic for  mice  and  for  guinea-pigs,  but  they  are  by  no  means 
sufficient  to  prove  that  it  is  capable  of  producing  a  genuine  croupous 
pneumonia  in  man,  and  it  is  still  uncertain  whether  its  occasional 
presence  in  the  exudate  into  the  pulmonary  alveoli  in  cases  of  this 
disease  has  any  etiological  importance. 

8.    MICROCOCCUS   PNEUMONIA   CROUPOS^E. 

Synonyms. — Micrococcus  Pasteuri  (Sternberg)  ;  Micrococcus  of 
sputum  septicaemia  (Frankel)  ;  Diplococcus  pneumoiiise  (Weichsel- 
baum)  ;  Bacillus  septicus  sputigenus  (Fliigge)  ;  Bacillus  salivarius 
septicus  (Biondi)  ;  Lancet-shaped  micrococcus  (Talamon)  ;  Strepto- 
coccus lanceolatus  Pasteuri  (Gameleia). 

Discovered  by  the  present  writer  in  the  blood  of  rabbits  inocu- 
lated subcutaneously  with  his  own  saliva  in  September,  1880  ;  by 
Pasteur  in  the  blood  of  rabbits  inoculated  with  the  saliva  of  a  child 
which  died  of  hydrophobia  in  one  of  the  hospitals  of  Paris  in  De- 
cember, 1880  ;  identified  with  the  micrococcus  in  the  rusty  sputum  of 
pneumonia,  by  comparative  inoculation  and  culture  experiments,  by 
the  writer  in  1885  (paper  published  in  the  American  Journal  of  the 
Medical  Sciences,  July  1st,  1885).  Proved  to  be  the  cause  of  croup- 
ous pneumonia  in  man  by  the  researches  of  Talamon,  Salvioli,  Stern- 
berg,  Frankel,  Weichselbaum,  Netter,  Gameleia,  and  others. 

The  Presence  of  Micrococcus  Pasteuri  in  the  Salivary  Secre- 
tions of  Healthy  Individuals. — In  September,  1880,  while  engaged 
in  investigations  relating  to  the  etiology  of  the  malarial  fevers,  I  in- 
jected a  little  of  my  own  saliva  beneath  the  skin  of  two  rabbits  as  a 
control  experiment.  To  my  surprise  the  animals  died,  and  I  found 
in  their  blood  a  multitude  of  oval  microorganisms,  united  for  the 
most  part  in  pairs,  or  in  chains  of  three  or  four  elements.  These 
experiments  are  recorded  in  my  paper  entitled  "  Experimental  Inves- 
tigations Relating  to  the  Etiology  of  the  Malarial  Fevers,"  published 
in  the  Report  of  the  National  Board  of  Health  for  1881,  pp.  7-4,  75. 

Following  up  my  experiments  made  in  New  Orleans  (in  Septem- 
ber, 1880),  in  Philadelphia  (January,  1881),  and  in  Baltimore  (March, 
1881),  I  obtained  the  following  results  : 

"  The  saliva  of  four  students,  residents  of  Baltimore  (in  March), 
gave  negative  results  ;  eleven  rabbits  injected  with  the  saliva  of  six 
individuals  in  Philadelphia  (in  January)  gave  eight  deaths  and  three 


BACTERIA   IN   CROUPOUS   PNEUMONIA.  299 

negative  results;  but  in  the  fatal  cases  a  less  degree  of  virulence  was 
shown  in  six  by  a  more  prolonged  period  between  the  date  of  injec- 
tion and  the  date  of  death.  This  was  three  days  in  one,  four  days 
in  four,  and  seven  days  in  one." 

In  a  paper  published  in  the  Journal  of  the  Royal  Microscopical 
Society  (June,  1886)  I  say  : 

"  My  own  earlier  experiments  showed  that  there  is  a  difference  in 
the  pathogenic  potency  of  the  saliva  of  different  individuals,  and  I 
have  since  learned  that  the  saliva  of  the  same  individual  may  differ 
in  this  respect  at  different  times.  Thus  during  the  past  three  years 
injections  of  my  own  saliva  have  not  infrequently  failed  to  cause  a 
fatal  result,  and  in  fatal  cases  death  is  apt  to  occur  after  a  some- 
what longer  interval,  seventy -two  hours  or  more  ;  whereas  in  my 
earlier  experiments  the  animals  infallibly  died  within  forty-eight 
hours." 

The  presence  of  my  Micrococcus  Pasteuri  was  demonstrated  in 
the  blood  of  the  rabbits  which  succumbed  to  the  inoculations. 

Claxton,  in  a  series  of  experiments  made  in  Philadelphia  in  1882, 
injected  the  saliva  of  seven  individuals  into  eighteen  rabbits.  Five 
of  these  died  within  five  days,  and  nine  at  a  later  period. 

Frankel,  whose  first  publication  was  made  in  1885,  discovered 
the  presence  of  this  micrococcus  in  his  own  salivary  secretions  in  1883, 
and  has  since  made  extended  and  important  researches  with  refe- 
rence to  it.  The  saliva  of  five  healthy  individuals  and  the  sputa 
of  patients  suffering  from  other  diseases  than  pneumonia,  injected 
into  eighteen  rabbits,  induced  fatal  "sputum  septicaemia "  in  three 
only.  When  he  commenced  his  experiments  his  saliva  was  uni- 
formly fatal  to  rabbits,  but  a  year  later  it  was  without  effect. 

Wolf  injected  the  saliva  of  twelve  healthy  individuals,  and  of 
three  patients  with  catarrhal  bronchitis,  into  rabbits,  and  induced 
"  sputum  septicaemia  "  in  three. 

Netter  examined  the  saliva  of  one  hundred  and  sixty-five  healthy 
persons,  by  inoculation  experiments  in  rabbits,  and  demonstrated 
the  presence  of  this  micrococcus  in  fifteen  per  cent  of  the  number. 

Vignal,  in  his  recent  elaborate  paper  upon  the  microorganisms 
of  the  mouth,  says  : 

"  Last  year  I  encountered  this  microbe  continually  in  my  mouth 
during  a  period  of  two  months,  then  it  disappeared,  and  I  did  not 
find  it  again  until  April  of  this  year,  and  then  only  for  fifteen  days, 
when  it  again  disappeared  without  appreciable  cause." 

The  Presence  of  Micrococcus  Pneumonice  Crouposce  in  Pneu- 
monic Sputum. — Talamon,  in  1883,  demonstrated  the  presence  of  this 
micrococcus  in  pneumonic  sputum,  described  its  morphological  char- 
acters, and  produced  typical  croupous  pneumonia  in  rabbits  by  in- 


300  BACTERIA  IN   CROUPOUS   PNEUMONIA. 

jecting  material  containing  it  into  the  lungs  through  the  thoracic 
walls. 

Salvioli,  in  1884,  demonstrated  its  presence  in  pneumonic  sputum 
by  injections  into  rabbits. 

In  1885  the  writer  made  a  similar  demonstration,  and  by  compara- 
tive experiments  showed  that  the  micrococcus  present  in  the  blood 
of  rabbits  inoculated  with  the  rusty  sputum  of  pneumonia  was  iden- 
tical with  that  which  he  had  discovered  in  1880  in  rabbits  inoculated 
with  his  own  saliva. 

The  same  year  (1885)  A.  Frankel  made  a  similar  demonstration, 
and  published  a  paper  containing  valuable  additions  to  our  knowl- 
edge relating  to  the  biological  characters  of  this  microorganism  (first 
publication  appeared  July  13th,  1885). 

In  1886  Weichselbaum  published  the  results  of  his  extended  re- 
searches relating  to  the  presence  of  this  micrococcus  in  the  fibrinous 
exudate  of  croupous  pneumonia.  He  obtained  it  in  ninety-four  cases 
(fifty-four  times  in  cultures)  out  of  one  hundred  and  twenty-nine  cases 
examined. 

Wolf  (1887)  found  it  in  sixty-six  cases  out  of  seventy  examined. 

Netter  (1887)  in  seventy-five  per  cent  of  his  cases,  and  in  the  sputum 
of  convalescents  from  pneumonia  in  sixty  per  cent  of  the  cases  ex- 
amined, by  inoculations  into  rabbits. 

Gameleia  (1887)  in  twelve  fatal  cases  of  pneumonia  in  which  he 
collected  material  from  the  lungs  at  the  post-mortem  examination. 

Goldenberg,  whose  researches  were  made  in  Gameleia's  labora- 
tory, found  it  in  pneumonic  sputum  in  forty  consecutive  cases,  by 
inoculations  into  rabbits  and  mice. 

The  Presence  of  Micrococcus  Pneumonice  Crouposce  in  Menin- 
gitis.— Numerous  bacteriologists  have  reported  finding  diplococci  in 
the  pus  of  meningitis,  and  frequently  the  microorganisms  have  been 
fully  identified  as  "  diplococcus  pneumonias."  Thus  Netter  (1889),  in 
a  resume  of  the  results  of  researches  made  by  him  in  twenty-five 
cases  of  purulent  meningitis,  reports  as  follows  : 

Thirteen  cases  were  examined  microscopically,  by  cultures,  and 
by  inoculations  into  susceptible  animals  ;  six  cases  by  microscopical 
examination  and  experiments  on  animals;  and  the  remainder  only  by 
microscopical  examination.  Four  of  the  cases  were  complicated 
with  purulent  otitis,  six  with  pneumonia,  three  with  ulcerative  endo- 
carditis. The  "  pneumococcus  "  was  found  in  sixteen  of  the  twenty- 
five  cases ;  in  four  Streptococcus  pyogenes  was  present ;  in  two 
Diplococcus  intracellularis  meningitidis  of  Weichselbaum ;  in  one 
Friedlander's  bacillus  ;  in  one  Newmann  and  Schaffer's  motile  ba- 
cillus ;  in  one  a  small  curved  bacillus. 

In  forty-five  cases  collected  from  the  literature  of  the  subject  by 


BACTERIA   IN   CROUPOUS   PNEUMONIA.  301 

Xetter  this  micrococcus  was  present  in  twenty-seven,  Streptococcus 
pyogenes  in  six,  and  the  Diplococcus  intracellularis  meningitidis  of 
Weichselbaum  in  ten. 

Monti  (1889),  in  four  cases  of  cerebro-spinal  meningitis,  demon- 
strated the  presence  of  the  same  micrococcus.  In  three  of  his  cases 
pneumonia  was  also  present.  In  two  Staphylococcus  pyogenes  aureus 
was  associated  with  the  "  diplococcus  pneumonise." 

Micrococcus  Pneumonice  Crouposce  in  Ulcerative  Endocar- 
ditis.— Weichselbaum,  in  a  series  of  twenty-nine  cases  examined 
(1888),  found  "  diplococcus  pneumonias"  in  seven. 

Micrococcus  Pneumonice  Crouposce  in  Acute  Abscesses. — In  a 
case  of  parotitis  occurring  as  a  complication  of  croupous  pneumonia 
this  micrococcus  was  obtained  from  the  pus  in  pure  cultures  by  Testi 
(1889);  and  in  another  case  in  which,  as  a  complication  of  pneumonia, 
there  developed  a  purulent  pleuritis,  abscess  of  the  parotid  on  both 
sides,  and  multiple  subcutaneous  abscesses,  the  pus  from  all  of  the 
sources  named  contained  the  "diplococcus"  in  great  numbers,  as 


FIG.  90.  FIG.  91.  FIG.  92. 

FIG.  90.— Micrococcus  pneumonise  crouposae  from  blood  of  rabbit  inoculated  with  normal  human 
saliva  (Dr.  S.).  X  1,000. 

FIG.  91. — Micrococcus  pneumonise  crouposse  from  blood  of  rabbit  inoculated  subcutaneously 
with  fresh  pneumonic  sputum  from  a  patient  in  the  seventh  day  of  the  disease.  X  1,000. 

FIG.  &2.— Surface  culture  of  Micrococcus  pneumonise  crouposse,  on  nutrient  agar,  showing  the 
development  of  long  cha:ns.  X  1,000. 1 

shown  not  only  by  microscopical  examination  but  by  inoculation  into 
rabbits. 

In  a  case  of  tonsillitis  resulting  in  the  formation  of  an  abscess 
Gabbi  (1889)  obtained  the  same  coccus  in  pure  cultures. 

In  otitis  media  this  micrococcus  has  been  found  in  a  consider- 
able number  of  cases  in  the  pus  obtained  by  paracentesis  of  the 
tympanic  membrane,  and  quite  frequently  in  pure  cultures — by  Zau- 
fal  (1889)  in  six  cases;  Levy  and  Schrader  (1889)  in  three  out  of  ten 
cases  in  which  paracentesis  was  performed;  by  Netter  (1889)  in  five 
out  of  eighteen  cases  occurring  in  children. 

Monti  (1889)  and  Belfanti  (1889)  report  cases  of  arthritis  of  the 
wrist  joint,  occurring  as  a  complication  of  pneumonia,  in  which  this 
micrococcus  was  obtained  in  pure  cultures.  Ortmann  and  Samter 

1  The  above  figures  are  from  Dr.  Sternberg's  paper  published  in  the  American 
Journal  of  the  Medical  Sciences  for  July  and  October,  1885. 


302 


BACTERIA   IN   CROUPOUS   PNEUMONIA. 


(1889),  in  a  case  of  purulent  inflammation  of  the  shoulder  joint  follow- 
ing pneumonia  and  pleurisy,  obtained  the  "  diplococcus  pneumonise  " 
in  pure  cultures. 

Morphology. — Spherical  or  oval  cocci,  usually  united  in  pairs,  or 
in  chains  consisting  of  three  or  four  elements.  Longer  chains,  con- 
taining ten  or  more  elements,  are  sometimes  formed,  especially  in 
cultures  upon  the  surface  of  nutrient  agar,  and  it  may  therefore  be 
regarded  as  a  streptococcus.  As  observed  in  the  blood  of  inoculated 
animals  it  is  usually  in  pairs  consisting  of  oval  or  lance-oval  elements, 
which  are  surrounded  by  a  transparent  capsule.  Owing  to  the  elon- 
gated form  of  the  cocci  when  in  active  growth,  it  has  been  regarded 
by  some  authors  as  a  bacillus  ;  but  in  cultures  in  liquid  media,  when 
development  by  binary  division  has  ceased,  the  cells  are  spherical,  or 
nearly  so,  and  in  cultures  on  the  surface  of  nutrient  agar  the  indivi- 
dual cells  more  nearly  approach  a  spherical  form  than  in  the  blood 
of  an  inoculated  animal.  The  "  lanceolate  "  form  was  first  referred  to 
by  Talamon,  who  described  it  as  having  the  form  of  a  grain  of  wheat, 
or  even  still  more  elongated  like  a  grain  of  barley,  as  seen  in  the 
fibrinous  exudate  of  croupous  pneumonia.  The  transparent  material 
surrounding  the  cells — so-called  capsule — is  best  seen  in  stained  pre- 
parations from  the  fibrinous  exudate  of  croupous  pneumonia  or  from 
the  blood  of  an  inoculated  animal.  It  appears  as  an  unstained  mar- 
ginal band  surrounding  the  elliptical  cells,  and  varies  greatly  as  to 
its  extent  in  different  preparations.  This  capsule  probably  consists 
of  a  substance  resembling  mucin,  and,  being  soluble  in  water,  its  ex- 
tent depends  partly  upon  the  methods  employed  in  preparing  speci- 
mens for  microscopical  examination.  It  is  occasionally  seen  in 

stained  preparations  from  the  surface  of  cul- 
tures on  blood  serum ;  and  in  drop  cultures 
examined  under  the  microscope,  by  using  a 
small  diaphragm,  it  may  be  seen  to  surround 
the  cocci  as  a  scarcely  visible  halo. 

This  micrococcus  stains  readily  with  the 
aniline  colors  ;  and  also  by  Gram's  method, 
which  constitutes  an  important  character  for 
distinguishing  it  from  Friedlander's  bacillus, 
with  which  it  has  often  been  confounded  on 
account  of  the  morphological  resemblance  of 
the  two  microorganisms. 
Biological  Characters. — Grows  in  the  presence  of  oxygen — 
aerobic — but  is  also  a  facultative  anaerobic.  Like  other  micro- 
cocci,  it  has  no  spontaneous  movements.  It  grows  in  a  variety  of 
culture  media  when  they  have  a  slightly  alkaline  reaction,  but  will 
not  develop  in  a  medium  which  contains  the  slightest  trace  of  free 


FIG.  93. — Micrococcus  pneu- 
monise crouposae,  showing  cap- 
sule, attached  to  pus  cells  from 
exudate  in  pleural  cavity  of 
inoculated  rabbit.  (Salvioli.) 


BACTERIA    IN  CROUPOUS   PNEUMONIA. 


303 


acid,  Nor  will  it  grow  at  the  ordinary  room  temperature.  Scanty 
development  may  occur  at  a  temperature  of  22°  to  24°  C. ,  but  a 
temperature  of  35°  to  37°  C.  is  most  favorable  for  its  growth,  which 
is  very  rapid  in  a  suitable  liquid  medium.  In  an  infusion  made  from 
the  flesh  of  a  chicken  or  a  rabbit  it  multiplies,  in  the  incubating 
oven,  with  remarkable  rapidity  ;  at  the  end  of  six  to  twelve  hours 
after  inoculation  the  previously  transparent  fluid  will  be  found  to 
present  a  slight  cloudiness  and  to  be  filled  throughout  with  the  cocci 
in  pairs  and  short  chains.  It  does  not  produce  a  milky  opacity  in 
liquid  media,  like  the  pus  cocci,  for  example,  but  the  fluid  becomes 
slightly  clouded  ;  multiplication  ceases  at  the  end  of  about  forty- 
eight  hours  or  less,  and  the  liquid  medium  again  becomes  transpa- 
rent as  a  result  of  the  subsidence  of  the  cocci  to  the  bottom  of  the 
receptacle. 

It  may  be  cultivated  in  flesh-peptone-gelatin,  containing  fifteen 
per  cent  of  gelatin,  at  a  temperature  of  24°  C.,  or  in  liquefied  gela- 
tin (ten  per  cent)  in  the  incubating  oven. 
In  gelatin  (fifteen  per  cent)  stick  cultures 
small  white  colonies  develop  all  along  the 
line  of  puncture,  and  in  gelatin  plates 
small,  spherical,  slightly  granular,  whitish 
colonies  are  formed  :  the  gelatin  is  not 
liquefied.  In  agar  plates  extremely  mi- 
nute colonies  are  developed  in  the  course 
of  forty-eight  hours,  which  resemble  little, 
transparent  drops  of  fluid,  and  under  the 
microscope  some  of  these  are  observed  to 
have  a  compact,  finely  granular  central 
portion  surrounded  by  a  paler,  transparent, 
finely  granular  marginal  zone.  Upon  the 
surface  of  nutrient  agar  or  coagulated  blood  serum  development 
occurs  in  the  form  of  minute,  transparent,  jelly-like  drops,  which 
form  a  thin  layer  along  the  line  of  inoculation  in  "streak  cultures"  ; 
and  in  agar  stick  cultures  the  growth  along  the  line  of  puncture  is 
rather  scanty,  almost  homogeneous,  and  semi-transparent.  Upon 
potato  no  development  occurs,  even  in  the  incubating  oven.  Milk  is 
a  favorable  culture  medium,  and  the  casein  is  coagulated  as  a  result 
of  its  presence. 

It  ceases  to  grow  on  solid  media  at  about  40°  C.,  and  in  favorable 
liquid  media  at  42°  C.  Its  thermal  death-point,  as  determined  by 
the  writer,  is  52°  C.,  the  time  of  exposure  being  ten  minutes.  It 
loses  its  vitality  in  cultures  in  a  comparatively  short  time — four  or 
five  days  on  agar — and  is  very  sensitive  to  the  action  of  germicidal 
agents.  Its  pathogenic  power  also  undergoes  attenuation  very 


FIG.  94  — Single  colony  of  Micro- 
coccus  pneumonise  crouposse  upon 
agar  plate,  twenty-four  hours  old. 
X  100.  (Frankel  and  Pfeiffer.) 


304  BACTERIA   IN   CROUPOUS   PNEUMONIA. 

quickly  when  it  is  cultivated  in  artificial  media,  but  may  be  restored 
by  passing  it  through  the  bodies  of  susceptible  animals.  Attenua- 
tion of  virulence  may  also  be  effected  by  exposing  bouillon  cultures 
to  a  temperature  of  42°  C.  for  twenty-four  hours,  or  by  five  days' 
exposure  to  a  temperature  of  41°  C. 

Emmerich  has  recently  (1891)  reported  to  the  Congress  of  Hygiene 
and  Demography  in  London  the  results  of  experiments  made  by 
him  relating  to  immunity  in  rabbits  and  mice.  Rabbits  were  ren- 
dered immune  by  the  intravenous  injection  of  a  very  much  diluted 
but  virulent  culture  of  the  micrococcus.  The  flesh  of  these  immune 
rabbits  was  rubbed  up  into  a  fine  paste,  and  the  juices  obtained  by 
compressing  it  in  a  clean,  sterilized  cloth.  This  bloody  juice  was  kept 
for  twelve  hours  at  a  temperature  of  10°  C.,  and  then  sterilized  by 
passing  it  through  a  Pasteur  filter.  Some  of  this  juice  was  injected 
into  a  rabbit,  which  with  twenty-five  others  was  then  made  to  re- 
spire an  atmosphere  charged  with  a  spray  of  a  bouillon  culture  of 
the  micrococcus.  As  a  result  of  this  all  of  the  rabbits  died  except  the 
one  which  had  previously  been  injected  with  the  immunizing  juice. 
In  a  similar  experiment  upon  mice  six  of  these  animals,  which  had 
previously  been  injected  with  the  immunizing  juice,  survived  the  in- 
jection of  a  full  dose  of  a  virulent  culture,  while  a  control  mouse, 
not  previously  injected  with  the  juice,  promptly  died  after  receiving 
the  same  quantity  of  the  virulent  culture. 

The  writer  in  1881,  in  experiments  made  to  determine  the  value 
of  various  disinfectants,  as  tested  upon  this  micrococcus,  obtained 
experimental  evidence  that  its  virulence  is  attenuated  by  the  action 
of  certain  antiseptic  agents.  Commenting  upon  the  results  of  these 
experiments  in  my  chapter  on  "  Attenuation  of  Virus,"  in  '•'  Bacte- 
ria "  (1884),  I  say  : 

"Sodium  hyposulphite  and  alcohol  were  the  chemical  reagents  "which 
produced  the  result  noted  in  these  experiments  ;  but  it  seems  probable  that 
a  variety  of  antiseptic  substances  will  be  found  to  be  equally  effective  when 
used  in  the  proper  proportion.  Subsequent  experiments  have  shown  that 
neither  of  these  agents  is  capable  of  destroying  the  vitality  of  this  septic 
micrococcus  in  the  proportion  used  (one  per  cent  of  sodium  hyposulphite  or 
one  part  of  ninety-five-per-cent  alcohol  to  three  parts  of  virus),  and  that 
both  have  a  restraining  influence  upon  the  development  of  this  microorgan- 
ism in  culture  fluids." 

The  following  results  were  obtained  by  the  writer  in  his  experi- 
ments (1881  and  1883)  to  determine  the  germicidal  and  antiseptic 
value  of  the  agents  named,  as  tested  upon  this  micrococcus. 

Alcohol. — A  twenty-four-per-cent  solution  was  effective  upon 
bouillon  cultures  in  two  hours. 

Boric  Acid. — A  saturated  solution  failed  to  destroy  vitality  after 
two  hours'  exposure,  but  1  :  400  restrained  development. 


BACTEKIA   IN  CROUPOUS   PNEUMONIA.  305 

Carbolic  Acid. — A  one-per-cent  solution  destroys  vitality  in  two 
hours,  and  1  :  500  restrains  development. 

Cupric  Sulphate  destroys  the  virulence  of  the  coccus  in  the 
blood  of  a  rabbit  in  the  proportion  of  1  :  400  in  half  an  hour. 

Ferric  Sulphate  failed  to  destroy  vitality  in  a  saturated  solution, 
but  restrained  development  in  the  proportion  of  1  :  200. 

Hydrochloric  Acid  destroys  the  virulence  of  the  blood  of  a  rab- 
bit containing  this  micrococcus  in  the  proportion  of  1  :  200. 

Iodine,  in  aqueous  solution  with  potassium  iodide,  destroys  vital- 
ity in  the  proportion  of  1: 1,000  and  prevents  development  in  1:  4,000. 

Mercuric  Chloride. — One  part  in  forty  thousand  prevents  the 
development  of  this  micrococcus,  and  1  :  20,000  was  found  to  destroy 
vitality  in  two  hours. 

Nitric  Acid. — One  part  in  four  hundred  destroyed  the  virulence 
of  rabbit's  blood  containing  this  micrococcus. 

Caustic  Potash. — A  two-per-cent  solution  destroyed  vitality  in 
two  hours. 

Potassium  Permanganate. — A  two-per-cent  solution  destroyed 
the  virulence  of  rabbit's  blood  containing  this  coccus. 

Salicylic  Acid,  dissolved  by  the  addition  of  sodium  biborate. — 
A  solution  of  1  :  400  prevented  development. 

Sulphuric  Acid. — One  part  in  two  hundred  destroys  vitality,  and 
1  :  800  prevents  development. 

In  a  recent  paper  by  Bordoni-Uffreduzzi  relating  to  the  resisting 
power  of  pneumonic  virus  for  desiccation  and  light,  the  following 
results  are  given:  Pneumonic  sputum  attached  to  cloths,  when  dried 
in  the  air  and  exposed  to  diffuse  daylight,  retained  its  virulence,  as 
shown  by  injections  in  rabbits,  for  a  period  of  nineteen  days  in  one 
series  of  experiments  and  for  fifty-five  days  in  another.  Exposed  to 
direct  sunlight  the  same  material  retained  its  virulence  after  twelve 
hours'  exposure.  Cultures  have  far  less  resistance,  and  the  protec- 
tion afforded  by  the  dried  albuminous  material  in  which  the  micro- 
cocci  were  embedded,  in  the  experiments  referred  to,  probably  ac- 
counts for  the  virulence  being  retained  so  long  a  time. 

Recently  (1892)  Kruse  and  Pansini  have  published  an  elaborate 
paper  giving  an  account  of  their  researches  relating  to  "  diplo- 
coccus  pneumonisB  "  and  allied  streptococci.  We  give  below  a  sum- 
mary statement  of  their  results  : 

Many  varieties  were  obtained  by  the  observers  named  in  their  cultures 
from  various  sources — from  the  lungs  of  individuals  dead  from  pneumonia, 
from  pleuritic  exudate,  from  pneumonic  sputa,  from  bronchitic  sputa,  from 
the  saliva  of  healthy  persons,  from  the  secretion  in  a  case  of  subacute  nasal 
catarrh,  from  the  urine  of  a  patient  with  nephritis. 

Pure  cultures  were  obtained  by  the  use  of  agar  plates  or  by  inoculations 
into  rabbits.  In  all  about  thirty  varieties  were  obtained  and  cultivated 
22 


306  BACTERIA   IN   CROUPOUS   PNEUMONIA. 

through  many  successive  generations.  As  a  rule,  the  different  varieties, 
which  at  first  were  seen  to  have  the  form  of  diplococci,  when  cultivated  for 
a  length  of  time  in  artificial  media  presented  the  form  of  streptococci  ;  and 
the  elements  which  at  first  were  lancet-shaped  showed  a  tendency  to  become 
spherical. 

The  more  virulent  varieties  usually  presented  the  form  of  diplococci 
with  lancet-shaped  elements,  or  of  short  chains.  A  variety  which  formed 
long  chains  could  be  pronounced,  in  advance  of  the  experiments  on  animals, 
to  possess  comparatively  little  virulence.  When  by  inoculations  in  animals 
the  virulence  of  such  a  variety  was  restored,  the  tendency  to  form  chains 
was  less  pronounced. 

Although,  as  a  rule,  no  development  occurs  at  20°  C. ,  certain  varieties 
were  obtained  which,  after  long  cultivation  in  artificial  media,  showed  a  de- 
cided growth  at  18°  C. 

Decided  differences  were  shown  by  the  cultures  from  various  sources  as 
regards  their  growth  in  milk.  Out  of  eighty-four  cultures  from  various 
sources  eleven  did  not  produce  coagulation.  ^  As  a  rule,  cultures  which  caused 
coagulation  of  milk  were  virulent  for  rabbits,  and  when  such  cultures  lost 
their  virulence  they  usually  lost  at  the  same  time  the  power  of  coagulating 
milk.  Virulent  cultures  die  out  sooner  than  those  which  have  become  at- 
tenuated by  continuous  cultivation  in  artificial  media;  the  first,  on  the  sur- 
face of  agar,  usually  fail  to  grow  at  the  end  of  a  week,  while  the  attenuated 
cultures  may  survive  for  three  weeks  or  more. 

Pathogenesis. — This  micrococcus  is  very  pathogenic  for  mice  and 
for  rabbits,  less  so  for  guinea-pigs.  The  injection  of  a  minute  quan- 
tity— 0.2  cubic  centimetre  or  less — of  a  virulent  culture  beneath  the 
skin  of  a  rabbit  or  a  mouse  usually  results  in  the  death  of  the  animal 
in  from  twenty-four  to  forty-eight  hours.  The  following  is  from  the 
writer's  first  published  paper  (1881),  and  refers  to  the  pathological 
appearances  in  rabbits  : 

"  The  course  of  the  disease  and  the  post-mortem  appearances  indicate  that 
it  is  a  form  of  septicaemia.  Immediately  after  the  injection  there  is  a  rise  of 
temperature,  which  in  a  few  hours  may  reach  2°  to  3°  C.  (3.6°  to  5.4°  F.); 
the  temperature  subsequently  falls,  and  shortly  before  death  is  often  several 
degrees  below  the  normal.  There  is  loss  of  appetite  and  marked  debility 
after  twenty-four  hours,  and  the  animal  commonly  dies  during  the  second 
night  or  early  in  the  morning  of  the  second  day  after  the  injection.  Death 
occurs  still  more  quickly  when  the  blood  from  a  rabbit  recently  dead  is  in- 
jected. Not  infrequently  convulsions  immediately  precede  death. 

"The  most  marked  pathological  appearance  is  a  diffuse  inflammatory 
oadema  or  cellulitis,  extending  in  all  directions  from  the  point  of  injection, 
but  especially  to  the  dependent  portions  of  the  body.  Occasionally  there  is 
a  little  pus  near  the  puncture,  but  usually  death  occurs  before  the  cellulitis 
reaches  the  point  of  producing  pus.  The  subcutaneous  connective  tissue 
contains  a  quantity  of  bloody  serum,  which  possesses  virulent  properties  and 
which  contains  a  multitude  of  micrococci.  There  is  usutlly  more  or  less  in- 
flammatory adhesion  of  the  integument  to  the  subjacent  tissues.  The  liver 
is  sometimes  dark-colored  and  gorged  with  blood,  but  more  frequently  it  is 
of  a  lighter  color  than  normal  and  contains  much  fat.  The  spleen  is  either 
normal  in  appearance  or  enlarged  and  dark-colored.  Changes  in  this  organ 
are  more  marked  in  those  cases  which  are  of  the  longest  duration. 

' '  The  blood  commonly  contain  s  an  immense  number  of  micrococci,  usual!  y 
joined  in  pairs  and  having  a  diameter  of  about  0. 5  /*.  These  are  found  in 
blood  drawn  from  superficial  veins,  from  arteries,  and  from  the  cavities  of 
the  heart  immediately  after  death,  and  in  a  few  cases  their  presence  has  been 


BACTERIA   IN   CROUPOUS   PNEUMONIA. 


307 


verified  during-  life.  Observations  thus  far  made,  however,  indicate  that  it 
is  only  during  the  last  hours  of  life  that  these  parasites  multiply  in  the  cir- 
culating fluid,  and  in  a  certain  proportion  of  the  cases  a  careful  search  has 
failed  to  reveal  their  presence  in  the  blood  in  post-mortem  examinations 
made  immediately  after  the  death  of  the  animal." 

In  animals  which  are  not  examined  until  some  hours  after  death 
a  considerable  increase  in  the  number  of  micrococci  occurs  post  mor- 
tem. The  fact  that  this  micrococcus  varies  very  much  as  to  its 
pathogenic  power,  as  a  result  of  conditions  relating  to  the  medium  in 
which  it  develops,  was  insisted  upon  in  my  first  published  paper,  and 
has  been  fully  established  by  later  researches  (Frankel,  Gameleia). 
Susceptible  animals  inoculated  with  attenuated  cultures  acquire  an 
immunity  against  virulent  cultures. 


FIG.  95. — Micrococcus  pneumonia?  crouposse  in  blood  of  rabbit  inoculated  with  pneumonic  spu- 
tum.    X  1,000. 

In  dogs  subcutaneous  injections  usually  give  a  negative  result, 
or  at  most  a  small  abscess  forms  at  the  point  of  inoculation.  In  a 
single  experiment,  however,  the  writer  has  seen  a  fatal  result  in  a 
dog  from  the  injection  of  one  cubic  centimetre  of  bloody  serum  from 
the  subcutaneous  connective  tissue  of  a  rabbit  recently  dead.  This 
shows  the  intense  virulence  of  the  micrococcus  when  cultivated  in 
the  body  of  this  animal.  Pneumonia  never  results  from  subcutane- 
ous injections  into  susceptible  animals,  but  injections  made  through 
the  thoracic  walls  into  the  substance  of  the  lung  may  induce  a  typi- 
cal fibrinous  pneumonia.  This  was  first  demonstrated  by  Talamon 
(1883),  who  injected  the  fibrinous  exudate  of  croupous  pneumonia, 
obtained  after  death,  or  drawn  during  life  by  means  of  a  Pravaz 
syringe  from  the  hepatized  portions  of  the  lung,  into  the  lungs  of 


308  BACTERIA  IN  CROUPOUS   PNEUMONIA. 

rabbits.  According  to  See,  eight  out  of  twenty  animals  experi- 
mented upon  exhibited  "a  veritable  lobar,  fibrinous  pneumonia, 
with  pleurisy  and  pericarditis  of  the  same  nature."  Gameleia  has 
also  induced  pneumonia  in  a  large  number  of  rabbits,  and  also  in  the  < 
dog  and  the  sheep,  by  injections  directly  into  the  pulmonary  tissue. 
Sheep  were  found  to  survive  subcutaneous  inoculations,  unless  very 
large  doses  (five  cubic  centimetres)  of  the  most  potent  virus  were  in- 
jected. But  intrapulmonary  inoculations  invariably  induced  a  typi- 
cal fibrinous  pneumonia  which  usually  proved  fatal.  In  dogs  simi- 
lar injections  gave  rise  to  a  "  frank,  fibrinous  pneumonia  which 
rarely  proved  fatal,  recovery  usually  occurring  in  from  ten  to  fifteen 
days,  after  the  animal  had  passed  through  the  stages  of  red  and 
gray  hepatization  characteristic  of  this  affection  in  man." 

Monti  claims  to  have  produced  typical  pneumonia  in  rabbits  by 
injecting  cultures  of  this  micrococcus  into  the  trachea. 

From  the  evidence  obtained  in  these  experimental  inoculations, 
and  that  recorded  relating  to  the  presence  of  this  micrococcus  in  the 
fibrinous  exudate  of  croupous  pneumonia,  we  are  justified  in  con- 
cluding that  it  is  the  usual  cause  of  this  disease,  and  consequently 
have  described  it  under  the  name  Micrococcous  pneumoniae  crou- 
posee.  We  prefer  this  to  the  name  commonly  employed  by  German 
authors — "  diplococcus  pneumonise" — because  this  micrococcus,  al- 
though commonly  seen  in  pairs,  forms  numerous  short  chains  of 
three  or  four  elements  in  cultures  in  liquid  media,  and  upon  the  sur- 
face of  nutrient  agar  may  grow  out  into  long  chains.  It  would, 
therefore,  more  properly  be  called  a  streptococcus  than  a  diplococcus. 

Recently  (1891)  G.  and  F.  Klemperer  have  published  an  impor- 
tant memoir  relating  to  the  pathogenic  action  of  this  micrococcus. 
They  succeeded  in  conferring  immunity  upon  susceptible  animals  by 
inoculating  them  with  filtered  cultures  of  the  micrococcus,  and  in 
some  instances  this  immunity  had  a  duration  of  six  months.  A 
curious  fact  developed  in  their  researches  was  that  the  potency  of 
the  substance  contained  in  the  filtered  cultures  was  increased  by 
subjecting  these  to  a  temperature  of  41°  to  42°  C.  for  three  or  four 
days,  or  to  a  higher  temperature  (60°  C.)  for  an  hour  or  two.  When 
injected  into  a  vein  after  being  subjected  to  such  a  temperature  im- 
munity was  complete  at  the  end  of  three  or  four  days  ;  but  the  same 
material  not  so  heated  required  larger  doses  and  a  considerably 
longer  time  (fourteen  days)  to  confer  immunity  upon  a  susceptible 
animal.  The  un warmed  material  caused  a  considerable  elevation  of 
temperature,  lasting  for  some  days.  The  authors  mentioned  con- 
clude from  their  investigations  that  the  toxic  substance  present  in 
cultures  of  Micrococcus  pneumonise  crouposse  is  a  proteid  substance, 
which  they  propose  to  call  pneumotoxin.  The  substance  produced 


BACTERIA  IN  CROUPOUS   PNEUMONIA.  309 

in  the  body  of  an  immune  animal,  as  a  result  of  protective  inocula- 
tions, upon  which  the  immunity  of  these  animals  depends,  is  also  a 
proteid,  which  they  call  anti-pneumotoxin.  This  they  isolated  from 
the  blood  serum  of  immune  animals.  By  experiment  they  were  able 
to  demonstrate  that  the  blood  serum  containing  this  protective  pro- 
teid, when  injected  into  other  animals,  rendered  them  immune  ;  and 
also  that  it  arrested  the  progress  of  the  infectious  malady  induced  by 
inoculating  susceptible  animals  with  virulent  cultures  of  the  micro- 
coccus.  When  injected  into  the  circulation  of  an  infected  animal 
its  curative  action  was  manifested  by  a  considerable  reduction  of 
the  body  temperature. 


VI. 

PATHOGENIC  MICROCOCCI  NOT  DESCRIBED  IN 
SECTIONS   IV.    AND  V. 

9.     DIPLOCOCCUS   INTRACELLULARIS   MENINGITIDIS. 

DISCOVERED  by  Weichselbaum  (1887)  in  the  exudate  of  cerebro- 
spinal  meningitis  (six  cases),  for  the  most  part  within  the  cells. 

Morphology. — Micrococci,  usually  united  in  pairs,  in  groups  of 
four,  or  in  little  masses ;  sometimes  solitary  and  larger  (probably 
being  upon  the  point  of  dividing).  Distinguished  by  their  presence 
in  the  interior  of  pus  cells  in  the  exudate,  in  this  respect  resembling 
the  gonococcus. 

Stain  best  with  Loffler's  alkaline  solution  of  methylene  blue. 
Do  not  retain  their  color  when  treated  with  iodine  solution  (Gram's 
method). 

Biological  Characters. — This  micrococcus  does  not  grow  at  the 
room  temperature,  but  upon  nutrient  agar  an  abundant  development 
occurs  in  the  incubating  oven.  Upon  the  surface  of  agar  a  tolerably 
luxuriant,  viscid  growth,  which  by  reflected  light  is  gray  and  by 
transmitted  light  grayish- white  ;  along  the  line  of  puncture  growth 
occurs  only  near  the  surface,  indicating  that  this  micrococcus  will 
not  grow  in  the  absence  of  oxygen.  Upon  plates  made  from  agar- 
agar  (one  per  cent)  and  gelatin  (two  per  cent)  very  small  colonies  are 
formed  in  the  interior  of  the  mass,  and  larger  ones,  of  a  grayish 
color,  on  the  surface.  The  former,  under  the  microscope,  are  seen  to 
be  round  or  slightly  irregular,  finely  granular,  and  of  a  yellowish- 
brown  color.  The  superficial  colonies  have  a  yellowish-brown  nu- 
cleus, surrounded  by  a  more  transparent  zone.  The  growth  upon 
coagulated  blood  serum  is  very  scanty,  as  is  that  in  bouillon ;  no 
growth  occurs  upon  potato.  This  micrococcus  quickly  loses  its  power 
of  reproduction  in  artificial  cultures — within  six  days — and  should 
be  transplanted  to  fresh  material  at  short  intervals — two  days. 

Pathogenesis. — Mice  are  especially  susceptible,  and  usually  die 
within  forty-eight  hours  after  inoculation.  Also  pathogenic  for 
guinea-pigs,  rabbits,  and  dogs. 


PATHOGENIC    MICROCOCGI    NOT    HERETOFORE    DESCRIBED.       311 

10.    STAPHYLOCOCCUS    SAL.IVARIUS   PYOGENES. 

Obtained  by  Biondi  (1887)  from,  an  inoculation  abscess  in  a  guinea-pig- 
injected  subcutaneously  with  saliva  from  a  child  suffering  from  scarlatina 
anginosa. 

Morphology. — Spherical  cocci,  0.3  to  0.5.  ft  in  diameter,  usually  solitary  in 
the  pus  of  abscesses  or  in  irregular  agglomerations. 

Stains  best  by  Gram's  method. 

Biological  Characters. — Grows  at  a  comparatively  low  temperature 
(12°  to  14°  C.),  and  more  rapidly  in.  the  incubating  oven.  In  gelatin  stick 
cultures,  at  the  room  temperature,  growth  occurs  along  the  line  of  punc- 
ture, and  at  the  end  of  eight  days  liquefaction  commences  in  the  form  of 
a  funnel,  at  the  bottom  of  which  little,  white,  shining  masses  accumu- 
late, while  at  the  surface  of  the  liquefied  gelatin  a  white,  viscid  layer  forms. 
In  gelatin  plates  spherical,  well-defined,  opalescent,  whitish  colonies  are 
formed,  which  cause  a  tardy  liquefaction  of  the  surrounding  gelatin.  Upon 
agar-agar  the  growth  is  rapid,  in  the  form  of  a  thick  layer  along  the  line  of 
inoculation  in  streak  cultures,  which  has  a  breadth  of  about  one  millimetre 
at  the  end  of  twenty -four  hours  in  the  incubating  oven,  and  presents  an 
orange-yellow  color  at  the  centre,  fading  out  to  white  at  the  margins.  The 
yellow  color  is  not  by  any  means  as  pronounced  as  in  similar  cultures  of 
Staphylococcus  pyogenes  aureus,  and  liquefaction  of  gelatin  is  much  slower. 

Pathogenesis. — Produces  a  local  abscess  when  inoculated  into  dogs,  rab- 
bits, guinea-pigs,  or  mice.  When  injected  into  the  anterior  chamber  of  the 
eye  of  rabbits,  hypopyon,  followed  by  spontaneous  perforation  of  the  cor- 
nea, resulted.  Injected  into  the  circulation  of  a  guinea-pig  (0.2  to  0.4  cubic 
centimetre)  it  gave  rise  to  general  infection,  and  death  at  the  end  of  eight  to 
ten  days. 

11.    MICROCOCCUS   OF   PROGRESSIVE   TISSUE   NECROSIS   IN   MICE. 

Obtained  by  Koch  (1879)  from  mice  inoculated  subcutaneously  with  putrid 
blood. 

Morphology. — Round  cells,  0.5  A  in  diameter,  united  in  chains,  or  at  times 
in  crowded  masses. 

Biological  Characters  not  given. 

Pathogenesis. — Causes  necrosis  of  the  tissues  in  the  vicinity  of  the  point 
of  inoculation  in  mice,  which  extends  rapidly  and  causes  the  death  of  the 
animal  in  about  three  days.  The  blood  and  internal  organs  remain  free  from 
micrococci.  (Possibly  a  very  pathogenic  variety  of  Streptococcus  pyogenes?) 

12.    MICROCOCCUS  OF  PROGRESSIVE  ABSCESS  FORMATION  IN 

RABBITS. 


Obtained  by  Koch  (1879)  from  rabbits 
inoculated  with  putrid  blood. 

Morphology. — Minute  cocci,  about  0.15  " 
in  diameter,  usually  associated  in  thick, 
cloud-like  zooglcea  masses. 

Biological  Characters  not  given. 

Pathogenesis. — In  rabbits  an  extensive 
abscess  forms  in  the  vicinity  of  the  point  of  in- 
oculation, and  the  animal  dies  in  about  twelve 
days.  The  walls  of  the  abscess  are  formed  of  a 
thin  layer  of  micrococci  associated  in  zoog- 
loea  masses;  the  interior  contains  finely  gran- 
ular, cheesy  material,  in  which  the  cocci  ap- 
pear to  have  degenerated  and  perished.  The  tf_ —  _ 

contents  of  the  abscess  injected  into  other  FIG.  96.— Micrococcus  of  progressive 
rabbits  produce  a  similar  result.  The  micro-  tissue  necrosis  in  mice;  section  of  the 
coccus  does  not  invade  the  blood.  o£>;ch5cart  Be  °el's; "' 8treptococci- 


312 


PATHOGENIC   MICROCOCCI 


Fio.  97.  —  Micrococcus  of 
pyaemia  in  rabbits,  in  capil- 
lary from  the  cortical  portion 
of  the  kidney.  X  700.  (Koch.) 


13.      MICROCOCCUS   OF   PYJEMIA   IN  RABBITS. 

Obtained  by  Koch  (1879)  in  rabbits  inoculated 
subcutaneously  with  putrefying  flesh  infusion. 

Morphology. — Round  cells,  0.25  «  in  diameter, 
solitary  or  in  pairs,  which  usually  surround  the 
blood  corpuscles  in  a  characteristic  manner. 

Biological  Characters  not  given. 

Pathogenesis. — When  injected  subcutaneously. 
in  rabbits  the  blood  is  invaded  and  death  occurs 
from  general  infection.  At  the  autopsy  a  puru- 
lent infiltration  is  found  at  the  point  of  injection, 
there  is  peritonitis,  and  metastatic  abscesses  are 
found  in  the  lungs  and  liver.  Numerous  micro- 
cocci,  closely  surrounding  the  blood  corpuscles, 
are  found  in  the  capillaries  of  the  various  organs, 
the  blood  of  the  heart,  etc.  Two  or  three  drops  of 
blood  from  the  heart  of  a  rabbit  recently  dead,  in- 
jected into  another  animal  of  the  same  species, 
cause  its  death  in  about  forty  hours. 


14.      MICROCOCCUS   OF   SEPTICAEMIA   IN   RABBITS. 

Obtained  by  Koch  (1879)  from  rabbits  inoculated  subcutaneously  with 
putrefying  flesh  infusion. 

Morphology. — Oval  cells,  haying  a  long  diameter  of  0.8  to  1.0  /z. 

Biological  Characters  not  given. 

Pathogenesis. — Produces  general  infection  and  death  in  rabbits  and  mice. 
At  the  autopsy  slight  oedema  is  observed  at  the  point  of  inoculation ;  the 
spleen  is  greatly  enlarged ;  no  peritonitis  and  no  embolic  processes  are  found, 
such  as  characterize  the  pathogenic  action  of  the  last-described  species  (No. 
13) ;  nor  do  the  cocci  accumulate  around  the  red  blood  corpuscles.  They  are 
found  in  the  capillaries  of  the  various  organs  in  masses,  and  especially  in 
the  glomeruli  of  the  kidneys. 


15.      MICROCOCCUS  SALIVARIUS  SEPTICUS. 

Obtained  by  Biondi  (1887)  from  the  saliva  of  a  case  of  puerperal  septicae- 
mia, by  inoculations  into  animals. 

Morphology. — Spherical  or  slightly  oval  cocci,  which,  when  in  rapid  mul- 
tiplication, show  slight  lateral  protrusions. 

Biological  Characters. — Grows  in  nutrient  gelatin  or  agar  at  a  tem- 
perature of  18°  to  20°  C.,  and  more  rapidly  in  the  incubating  oven.  Does  not 
liquefy  gelatin.  In  gelatin  plates  forms  spherical,  grayish- white  colonies, 
which  may  acquire  a  dark  color.  In  gelatin  stick  cultures  grows  along  the 
line  of  puncture  in  the  form  of  a  column  made  up  of  crowded  white  colo- 
nies. Very  scanty  growth  on  potato. 

Stains  with  all  the  aniline  colors  and  by  Gram's  method. 

Pathogenesis. — Produces  general  infection  and  death  in  from  four  to  six 
days  when  inoculated  into  mice,  guinea-pigs,  or  rabbits.  The  cocci  are 
found  in  great  numbers,  often  assembled  in  masses,  in  the  capillaries  of  the 
various  organs,  but  no  evidence  of  inflammatory  reaction  of  the  tissues  is  to 
be  observed. 

16.      MICROCOCCUS  SUBFLAVUS   (Fliigge). 

Synonym. — Yellowish-white  diplococcus  (Bumm). 

Obtained  by  Bumm  (1885)  from  the  lochial  discharge  of  puerperal  women 
and  from  vaginal  mucus.  Has  also  been  obtained  from  the  urine  in  cases 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND   V.  313 

of  vesical  catarrh,  and  in  the  vesicles  of  pemphigus  ;  also  by  Frankel  in  the 
vaginal  secretion  of  children  suffering  from  colpitis  not  of  gonorrhoeal  origin. 

Morphology. — Diplococci,  associated  in  biscuit-shaped  pairs,  separated  by 
a  cleft,  and  closely  resembling  the  gonococcus  of  Neisser.  Cells  from  0.5  to 
1.5  n  in  diameter. 

Stains  with  the  aniline  colors  and  by  Gram's  method— by  which  char- 
acter it  may  be  distinguished  from  the  micrococcus  of  gonorrhoea. 

BiQlogical  Characters. — Grows  at  the  room  temperature  upon  the  sui'face 
of  nutrient  gelatin;  small,  grayish-white  colonies  appear  along  the  line  of 
inoculation  at  the  end  of  twenty-four  hours,  which  later  form  a  continent 
layer,  first  of  a  pale  yellow  and  finally  of  an  ocherous  color.  In  the  course 
of  a  few  days  liquefaction  of  the  gelatin  commences  in  the  vicinity  of  the 
growth.  Coagulated  blood  serum  is  also  liquefied  by  this  micrococcus. 

Pathogenesis. — Inoculationsuoon  mucous  membranes  susceptible  to  gon- 
orrhoeal infection  are  without  result.  But  by  injecting  the  diplococcus  from 
pure  cultures,  in  suspension  in  distilled  water,  beneath  the  skin  in  man, 
Bumrn  obtained  as  a  result  local  abscess  formation — abscesses  varying  in 
size  from  that  of  a  pigeon's  egg  to  that  of  a  man's  fist.  The  diplococcus  was 
present  in  great  numbers  in  the  pus  of  these  abscesses. 

17.      MICROCOCCUS   OF   TRACHOMA  (?). 

Obtained  by  Sattler  (1885)  from  the  contents  of  the  trachomatous  follicles 
in  cases  of  Egyptian  ophthalmia;  also  by  Michel  (1886),  who  has  given  a 
more  exact  description  of  this  micrococcus,  and  has  made  inoculation  experi- 
ments which  he  believes  establi-h  its  etiological  relation  to  the  form  of  oph- 
thalmia with  which  it  is  associated  (?). 

Morphology. — Very  small,  biscuit  shaped  micrococci,  in  pairs— diplococci 
— separated  by  a  very  narrow  dividing  line.  (This  description  would  apply 
to  some  of  the  more  common  pus  cocci,  e.g.,  Staphylococcus  pyogenes  aureus, 
which  have  also  been  shown  to  consist  of  two  hemispherical  halves  separated 
by  a  narrow  line  of  division.) 

Biological  Characters. — Grows  slowly  upon  nutrient  gelatin  at  the  room 
temperature,  and  does  not  liquefy  this  medium,  upon  the  surface  of  which 
a  grayish-white,  broadly  extended,  glistening  layer  is  formed,  which  later 
has  a  yellowish  tint  and  tulip-shaped  margins.  Spherical  colonies  are  formed 
along  the  line  of  puncture,  which  are  arranged  in  a  linear  series,  like  a 
chaplet.  In  blood  serum  it  grows  along  the  line  of  puncture  as  a  white, 
band-like  stripe,  which  subsequently  spreads  out  in  the  form  of  white  clouds. 
The  growth  is  more  rapid  upon  nutrient  agar  or  blood  serum  in  the  incu- 
bating oven.  The  development  upon  potato  is  very  scanty.  The  cultures 
are  viscid,  drawing  out  into  long  threads  when  touched  with  a  platinum 
needle.  This  micrococcus  does  not  grow  in  the  absence  of  oxygen — aerobic. 

Stains  by  the  aniline  colors  and  by  Gram's  method. 

Pathogenesis. — Not  pathogenic  for  rabbits  when  injected  subcutaneously 
or  into  the  anterior  chamber  of  the  eye ;  but,  according  to  Sattler  and  to 
Michel,  when  inoculated  by  puncture  into  the  conjunctivae  in  man  it  causes 
a  follicular  inflammation  resulting  in  typical  trachoma.  But  Michel  was 
not  able  to  demonstrate  the  presence  of  this  micrococcus  in  all  of  his  cases, 
and  extensive  researches  made  since  by  Baumgarten  and  by  Kartulis  (1887) 
show  that  in  many  cases  of  trachoma,  and  even  in  Egyptian  ophthalmia 
(Kartulis) ,  it  cannot  be  found.  According  to  the  last-named  author,  the  viru- 
lent ophthalmia  which  prevails  in  Egypt  is  gonorrhoeal  in  its  origin,  and  he 
has  demonstrated  the  presence  of  the  gonococcus  in  a  large  series  of  cases. 
A  milder,  but  infectious,  acute  catarrhal  conjunctivitis  is  characterized  by 
the  presence  of  a  minute  bacillus,  resembling  the  bacillus  of  mouse  septi- 
caemia, and  found  in  the  pus  cells.  A  third  group  of  chronic  cases  with 
trachoma,  in  the  researches  of  Kartulis,  failed  to  show  the  presence  of  Sat- 
tler's  trachoma  coccus  or  any  other  microorganisms  in  the  contents  of  the 
diseased  follicles, 
23 


314  PATHOGENIC   MICROCOCCI 

18.    MICROCOCCUS   TETRAGENUS. 

First  described  by  Gaffky  (Fliigge).  Obtained  by  Koch  and 
Gaffky  (1831)  from  a  cavity  in  the  lung  in  a  case  of  pulmonary 
phthisis. .  Since  found  occasionally  in  normal  saliva  (three  times  in 
fifty  persons  examined  by  Biondi),  and  in  the  pus  of  acute  abscesses 
(Steinhaus,  Park,  Vangel).  Rather  common  in  the  sputum  of  phthi- 
sical cases. 

Morphology. — Micrococci,  having  a  diameter  of  about  one  yu, 
which  divide  in  two  directions,  forming  tetrads,  which  are  enclosed 
in  a  transparent,  jelly-like  envelope — especially  well  developed  as 
seen  in  the  blood  and  tissues  of  inoculated  animals.  In  cultures  the 
cocci  are  seen  in  the  various  stages  of  division,  as  large  single  cells, 


FIG.  98. — Micrococcus  tetragenus;  section  of  lung  of  mouse,    x  800.    (Fliigge.) 

pairs  of  oval  elements,  or  groups  of  four  resulting  from  the  trans- 
verse division  of  these  latter. 

Stains  quickly  with  aniline  colors,  and  in  preparations  from  the 
blood  of  an  inoculated  animal  the  transparent  envelope  may  also  be 
feebly  stained.  Stains  also  by  Gram's  method. 

Biological  Characters. — This  micrococcus  grows,  rather  slowly, 
in  nutrient  gelatin  at  the  ordinary  room  temperature,  without  lique- 
faction of  the  gelatin.  Upon  gelatin  plates  small  white  colonies  are 
developed  in  from  twenty-four  to  forty-eight  hours,  which  under  the 
microscope,  with  a  low  power,  are  seen  to  be  spherical  or  lemon- 
shaped,  finely  granular,  and  with  a  mulberry-like  surface.  When 
they  come  to  th6  surface  they  form  white,  elevated,  and  rather  thick 
masses  having  a  diameter  of  one  to  two  millimetres.  In  gelatin 
stick  cultures  a  broad  and  thick  white  mass  forms  upon  the  surface, 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND   V.  315 

and  along  the  line  of  puncture  a  series  of  round,  milk-white  or  yel- 
lowish masses  form,  which  usually  remain  distinct,  but  may  become 
confluent.  Upon  the  surface  of  agar  the  growth  is  similar  to  that 
upon  gelatin,  or  in  streak  inoculations  may  consist  of  a  series  of 
spherical,  white  colonies.  Upon  cooked  potato  a  thick,  viscous  layer 
is  formed  of  milk-white  color  ;  the  growth  upon  blood  serum  is  also 
abundant,  especially  in  the  incubating  oven.  This  micrococcus  is  a 
facultative  anaerobic. 

Pathogenesis. — Subcutaneous  inoculation  of  a  culture  of  this 
micrococcus  in  minute  quantity  is  fatal  to  white  mice  in  from  two  to 
six  days.  The  animals  remain  apparently  well  for  the  first  day  or 
two,  then  remain  quiet  and  somnolent  until  death  occurs.  The  cocci 
are  found  in  comparatively  small  numbers  in  the  blood  of  the  heart, 
but  are  more  numerous  in  the  spleen,  lungs,  liver,  and  kidneys,  from 
which  organs  beautiful  stained  preparations  may  be  made  show- 
ing the  tetrads  surrounded  by  their  transparent  capsule.  Common 
house  mice  and  field  mice  are,  for  the  most  part,  immune,  as  are  the 
rabbit  and  the  dog.  Guinea-pigs  sometimes  die  from  general  infec- 
tion, and  sometimes  a  local  abscess  is  the  only  result  of  a  subcutane- 
ous inoculation. 

19.     MICROCOCCUS  BOTRYOGENUS   (Rabe). 

Synonyms. — Micrococcus  of  "  myko-desmoids  "  of  the  horse;  Mi- 
crococcus askoformans  (Johne)  ;  Ascococcus  Johnei  (Cohn). 

First  described  by  Bellinger  (1870)  ;  morphological  characters  and 
location  in  the  diseased  tissues  described  by  Johne  (1884)  ;  biological 
characters  determined  by  Rabe  (1886). 

Is  found  in  certain  diffused  or  circumscribed  growths  in  the  con- 
nective tissue  of  horses — "  myko-desmoids." 

Morphology. — Micrococci,  having  a  diameter  of  1  to  1.5  /*,  usu- 
ally united  in  pairs. 

In  the  tissues  the  cocci  are  united  in  colonies  of  fifty  to  one  hun- 
dred /f  in  diameter,  and  these  are  associated  in  mulberry-like  masses 
visible  to  the  naked  eye.  The  separate  colonies  are  enclosed  in  a 
homogeneous,  transparent  envelope — as  in  Ascococcus  Billrothii. 
This  is  not  the  case,  however,  in  cultures  in  artificial  media. 

Stains  with  the  aniline  colors. 

Biological  Characters. — In  gelatin  plate  cultures  spherical, 
sharply  defined,  silver-gray  colonies  are  developed  ;  later  these  have 
a  yellowish  color  and  a  metallic  lustre,  and  the  plate  presents  the  ap- 
pearance of  being  powdered  with  grains  of  pollen.  It  gives  off  a 
peculiar  fruit-like  odor,  reminding  one  of  the  odor  of  strawberries. 
In  gelatin  stick  cultures  growth  occurs  along  the  line  of  puncture  as 
a  pale  grayish- white  line,  which  later  becomes  milk-white ;  an  air 


316  PATHOGENIC    MICROCOCCI 

bubble  forms  near  the  surface  of  the  gelatin  ;  very  slight  liquefac- 
tion occurs  in  the  immediate  vicinity  of  the  line  of  growth,  and  after 
a  time  the  grayish-white  thread  sinks  into  an  irregular  mass,  lying 
at  the  bottom  of  the  puncture.  Upon  nutrient  agar  scarcely  any  de- 
velopment occurs.  Upon  potato  the  growth  is  abundant,  in  the  form 
of  a  pale-yellow,  circular  layer,  and  the  culture  gives  off  the  peculiar 
odor  above  described. 

PatJiogenesis. — When  inoculated  into  guinea-pigs  general  infec- 
tion and  death  result.  In  sheep  and  goats  it  produces  a  local  in- 
flammatory oedema  and  sometimes  necrosis  of  the  tissues.  In  horses 
inoculated  subcutaneously  an  inflammatory  oedema  first  occurs,  fol- 
lowed at  the  end  of  from  four  to  six  weeks  by  the  development  of  new 
growths  in  the  connective  tissue,  resembling  the  tumors  found  in 
cases  of  the  disease  in  the  animal  from  which  the  micrococcus  in 
question  was  first  cultivated.  These  tumors  contain  characteristic 
mulberry-like  conglomerations  of  colonies  made  up  of  the  coccus. 

20.     MICROCOCCUS   OF   MANFREDI. 

Synonym. — Micrococcus  of  progressive  granuloma  formation. 

Obtained  by  Manfredi  (188G)  from  the  sputum  of  two  cases  of 
croupous  pneumonia  following  measles. 

Morphology. — Oval  micrococci,  having  a  diameter  of  0.6  to  1.0  p 
and  from  1.0  to  1.5  /*  in  length  ;  usually  associated  in  pairs,  and  oc- 
casionally in  short  chains  containing  three  or  four  elements. 

Stains  with  the  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — Aerobic ;  does  not  liquefy  gelatin. 
Upon  gelatin  plates  forms  small,  spherical  colonies,  at  first  grayish- 
white,  which  spread  out  upon  the  surface  as  thin,  transparent  plates, 
which  by  transmitted  light  have  a  bluish,  by  reflected  light  a  pearl- 
gray  color.  Later  these  become  thicker  and  have  a  pearly  lustre. 
Under  the  microscope  (forty  to  fifty  diameters)  the  colonies  are  seen 
to  be  slightly  granular  and  the  margins  have  an  irregular  outline. 
In  gelatin  stick  cultures  a  scanty  growth  occurs  along  the  line  of 
puncture,  and  a  rather  thin  and  limited  growth  about  the  point  of 
inoculation.  Upon  blood  serum  a  thin,  greenish-yellow  layer,  which 
has  irregular  margins  and  a  slightly  granular,  shining  surface,  is 
developed.  The  growth  upon  potato,  at  37°  C.,  is  scanty,  and  con- 
sists of  a  very  thin,  moist  layer,  which  has  a  yellowish  color  and  is 
slightly  granular.  Growth  occurs  in  favorable  media — bouillon, 
gelatin — at  temperatures  of  18°  to  48°  0.,  but  ceases  at  a  temperature 
of  48°  to  50°  C. 

Pathogenesis. — Pathogenic  for  dogs,  rabbits,  guinea-pigs,  mice, 
and  birds.  In  mammals  the  principal  pathological  appearance  re- 
sulting from  infection  consists  in  the  formation  of  "  granulation  tu- 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND   V.  317 

mors  "  in  the  parenchymatous  organs.  These  vary  in  size  from  that 
of  a  millet  seed  to  that  of  a  pea,  and  undergo  caseation.  They  con- 
tain the  micrococcus  and  are  infectious.  Mammals  die  in  from  nine 
to  fifteen  days  ;  birds  in  from  one  to  three  or  four,  and  without  the 
formation  of  the  characteristic  granuloma,  but  with  general  infec- 
tion of  the  blood.  Cultures  which  have  been  kept  for  several  months 
retain  their  pathogenic  power. 

21.  MICROCOCCUS  OF  BOVINE   MASTITIS    (Kitt). 

Obtained  by  Kitt  (1885)  from  the  udder  of  cows  suffering  from  mastitis 
and  giving  milk  mixed  with  pus. 

Morphology. — Micrococci,  having  a  diameter  of  0.2  to  0.5  jit,  solitary, 
united  in  pairs,  in  irregular  groups,  and  occasionally  in  chains. 

Stains  with  the  aniline  colors. 

Biological  Characters. — Does  not  liquefy  gelatin.  Upon  gelatin  plates 
forms  spherical,  translucent,  glistening  colonies,  the  size  of  a  hemp  seed  to 
that  of  a  pin's  head ;  in  gelatin  stick  cultures  a  nail-shaped  growth  occurs, 
the  mass  at  the  point  of  puncture  being  opaque  and  of  a  white  color.  Upon 
potato,  colonies  are  quickly  developed  which  have  a  grayish- white  or  dirty 
yellow  color,  and  after  a  few  days  have  a  shining,  wax-like  appearance. 
Grows  rapidly  in  milk,  causing  an  acid  reaction;  in  six  hours  in  the  incu- 
bating oven  the  milk  is  pervaded  by  the  micrococcus,  or  in  twelve  hours  at 
20°  C. 

Pathogenesis. — Injection  of  pure  cultures,  suspended  in  distilled  water, 
into  the  mammary  glands  of  cows,  produces  typical,  acute,  purulent  mas- 
titis (Kitt).  The  micrococcus  produced  the  same  result  after  having  been 
cultivated  in  artificial  media  for  a  year.  Subcutaneous  inoculations  in  cows, 
pigs,  guinea-pigs,  rabbits,  and  mice  were  without  result.  Injections  into 
the  mammary  gland  of  goats  were  also  without  effect. 

22.  MICROCOCCUS  OF  BOVINE  PNEUMONIA   (?). 

Isolated  by  Poels  and  Nolen  (1886)  from  the  lungs  of  cattle  suffering 
from  '  *  Lungenseuche  "  (infectious  nleuro-pneumonia  of  cattle). 

Morphology. — Micrococci,  varying  considerably  in  size — average  dia- 
meter 0.9  M;  solitary,  in  pairs,  or  in  chains  containing  several  elements;  sur- 
rounded by  a  transparent  capsule,  which  stains  with  difficulty. 

Stains  with  all  the  aniline  colors,  and  with  difficulty  by  Gram's  method. 

Biological  Characters. —  oes  not  liquefy  gelatin,  and  grows  like  the  ba- 
cillus of  Friedlander  in  gelatin  stick  cultures  (nail-shaped  growth).  In  gela- 
tin plates  the  colonies  are  spherical,  white,  and  have  a  very  faint  yellowish 
tinge.  Grows  more  rapidly  on  agar  in  the  incubating  oven,  and  upon  po- 
tato in  the  form  of  a  very  pale-vellowish  layer.  Is  destroyed  by  a  tempera- 
ture of  66°  C.  maintained  for  fifteen  minutes. 

Pathogenesis. — Pure  cultures  injected  into  the  lungs  of  dogs,  rabbits, 
and  guinea-pigs  are  said  to  give  rise  to  pneumonic  inflammation,  and  simi- 
lar results  were  obtained  by  injection  into  the  trachea  of  dogs  and  by  in- 
halation experiments.  Injection  of  a  pure  culture  into  the  lungs  of  a  cow 
caused  extensive  pneumonic  changes;  but  these  did  not  entirely  correspond 
with  the  appearances  found  in  the  lungs  of  cattle  suffering  from  infectious 
pneumonia.  Cattle  inoculated  with  a  pure  culture,  by  means  of  a  sterilized 
lance,t,  did  not  fall  sick,  but  are  believed  by  Poels  and  Nolen  to  have  been 
protected  from  the  disease  by  such  inoculations. 

The  specific  relation  of  the  microcpccus  above  described  to  the  disease 
with  which  it  was  associated,  in  the  researches  of  the  authors  mentioned,  has 
not  been  established  by  subsequent  investigations. 


318  PATHOGENIC   MICROCOCCI 

23.    STREPTOCOCCUS   SEPTICUS   (Flilgge). 

Found  by  Nicolaier  and  by  G-uarneri  in  unclean  soil  during  researches 
made  in  Flugge's  laboratory  in  Gottingen. 

Morphology. — Cannot  be  distinguished  from  Streptococcus  pyogenes,  but 
does  not  so  constantly  form  chains,  being  found  in  the  tissues  of  inoculated 
animals,  for  the  most  part  in  pairs. 

Biological  Characters. — Grows  more  slowly  than  Streptococcus  pyogenes ; 
in  gelatin  plates  very  minute  colonies  first  appear  at  the  end  of  three  or  four 
days,  or  along  the  line  of  puncture  in  gelatin  stick  cultures  after  five  or  six 
days.  Does  not  liquefy  gelatin. 

Pathogenesis. — Is  very  pathogenic  for  mice  and  for  rabbits,  causing  death 
from  general  infection  in  two  or  three  days. 

24.    STREPTOCOCCUS   BOMBYCIS. 

Synonym. — Microzyma  bombycis  (Bechamp). 

Found  in  the  bodies  of  in  fected  silkworms  suffering  from  la  flachene 
(maladie  des  morts-plats).  Etiological  relation  established  by  Pasteur. 

Morphology. — Oval  cells,  not  exceeding  1.5  /*  in  diameter,  in  pairs  or  in 
chains. 

Biological  Characters. — Not  determined  with  precision. 

Pathogenesis. — The  infected  silkworm  ceases  to  eat,  becomes  weak,  and 
dies.  Its  body  is  soft  and  diffluent,  and  at  the  end  of  twenty-four  to  forty- 
eight  hours  is  filled  with  a  dark  brown  fluid  and  with  gas. 

25.    NO8EMA   BOMBYCIS. 

Synonyms. — Micrococcus  ovatus ;  Panhistophyton  ovatum. 

Found  in  the  blood  and  all  of  the  organs  of  silkworms  infected  with 
pebrine  (Fleckenkrankheit). 

First  observed  by  Cornalia.     Etiological  relation  established  by  Pasteur. 

Morphology. — Shining,  oval  cells,  three  to  four  u  long  and  two //  broad; 
solitary,  in  pairs,  or  in  irregular  groups. 

Biological  Characters. — Not  determined  with  precision. 

Pathogenesis. — Dark  spots  appear  upon  the  skin  of  infected  silkworms, 
which  lose  their  appetite,  become  slender  and  feeble,  and  soon  die.  The 
oval  corpuscles  are  found  in  all  of  the  organs,  and  also  in  the  eggs  of 
butterflies  hatched  from  infected  larvae.  Some  authors  are  of  the  opinion 
that  the  oval  corpuscles  found  in  this  disease  do  not  belong  to  the  bacte- 
ria, but  to  an  entirely  different  class  of  microorganisms — the  Psorospermia 
(Metschnikoff). 

26.    MICROCOCCUS   OF  HEYDENREICH. 

Synonyms. — Micrococcus  of  Biskra  button — Fr.  "  clou  de  Biskra  ";  Ger. 
"  Pendesche  Geschwur." 

Found  by  Heydenreich  (1888)  in  pus  and  serous  fluid  obtained  from  the 
tumors  and  ulcers  in  the  Oriental  skin  affection  known  as  Biskra  button. 

Morphology. — Diplococci,  from  0.86  to  1  ju  in  length,  surrounded  by  a 
capsule ;  sometimes  associated  to  form  tetrads. 

Stains  with  the  usual  a,niline  colors. 

Biological  Characters . — An  aerobic,  liquefying  micrococcus  Grows  in 
the  usual  culture  media  at  the  room  temperature.  In  gelatin  stick  cultures, 
at  20°  C.,  at  the  end  of  forty -eight  hours  growth  occurs  along  the  line  of 
puncture  in  the  form  of  small,  crowded  colonies,  which  produce  a  grayish- 
white  line;  upon  the  surface  a  thin,  circular  layer  of  a  yellowish-white 
color  is  developed.  At  the  end  of  three  to  four  days  liquefaction  commences 
near  the  surface,  where  a  funnel  is  formed  which  extends  until  about  the 
fourteenth  day,  when  the  gelatin  is  completely  liquefied.  Upon  the  surface 


NOT  DESCRIBED   IN   SECTIONS   IV.    AND   V.  319 

of  agar,  at  37°  C.,  a  grayish- white  or  yellowish  layer  is  formed  at  the  end  of 
twenty -four  hours,  which  has  a  varnish-like  lustre.  Upon  potato,  at  30°  to 
35°  C.,  at  the  end  of  forty-eight  hours  a  white  or  yellow  layer  has  de- 
veloped. 

Pathogenesis. — According  to  Heydenreich,  inoculations  in  rabbits,  dogs, 
chickens,  horses,  and  sheep  cause  a  skin  affection  which  is  identical  With 
that  which  characterizes  Biskra  button  in  man.  When  rubbed  into  the 
healthy  skin  of  man  it  also  produces  the  development  of  abscesses. 


27.    MICROCOCCUS  OP  DEMME. 

Synonym. — Diplococcus  of  pemphigus  acutus  (Demme). 

Obtained  by  Demme  (1886)  from  the  contents  of  the  bullse  in  a  case  of 
pemphigus. 

Morphology. — Micrococci  of  from  0.8  to  1.4  ju.  in  diameter;  usually  united 
in  pairs  resembling  the  "  gonococcus "  and  having  a  length  of  1.8to3/*, 
very  opaque  and  not  surrounded  by  a  capsule ;  usually  associated  in  irregu- 
lar masses. 

Biological  Characters. — Aerobic  micrococci.  Do  not  grow  at  the  room 
temperature.  Upon  agar  plates,  at  37°  C.,  at  the  end  of  thirty-six  to  forty- 
eight  hours  milk-white,  spherical  colonies,  which  project  above  the  surface, 
are  developed ;  later  chib-shaped  outgrowths  form  around  the  periphery  of 
the  colony,  giving  it  the  appearance  of  a  rosette,  or  sometimes  of  a  bunch  of 
grapes.  At  the  end  of  two  weeks  the  surface  is  covered  with  smooih  projec- 
tions and  has  a  cream-like  color.  In  streak  cultures  upon  agar  a  similar 
growth  occurs  along  the  impfstrich,  having  club-like  projections  and  stalac- 
tite-like outgrowths.  Growth  also  occurs  upon  potato  at  a  temperature  of 
37°  C.  This  micrococcus  develops  slowly  in  the  incubating  oven,  and 
scarcely  any  growth  occurs  at  a  temperature  below  32°  C. 

Pathogenesis. — The  injection  of  a  pure  culture  into  the  lungs  of  guinea- 
pigs  gave  rise  to  emaciation  and  debility  and  to  the  formation  of  foci  of 
broncho-pneumonia,  the  size  of  a  pea,  in  the  lungs. 

28.  STREPTOCOCCUS  OF  MANNEBERG. 

Obtained  by  Manneberg  (1888)  from  the  urine  in  acute  cases  of  Bright's 
disease. 

Morphology. — Micrococci,  about  0.9  n  in  diameter,  solitary,  in  pairs,  or 
in  chains  of  six  to  ten  elements.  Does  not  differ  in  morphology  from  Strep- 
tococcus pyogenes. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic  micro- 
coccus,  which  slowly  produces  a  viscid  softening  of  nutrient  gelatin.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  In  gelatin  stick  cul- 
tures forms  a  white  stripe  along  the  line  of  puncture,  which  consists  of  small 
colonies.  At  the  end  of  three  or  four  weeks  a  funnel  is  formed  containing 
very  viscid  liquefied  gelatin,  and  at  the  same  time  brush-like  outgrowths  are 
seen  along  the  line  of  development.  Upon  the  surface  of  agar  the  growth 
resembles  that  of  Streptococcus  pyogenes,  but  is  somewhat  more  abundant. 
Upon  potato,  at  37°  C.,  at  the -end  of  four  or  five  days  white,  drop-like  colo- 
nies are  developed  of  about  0.5  millimetre  in  diameter;  these  become  con- 
fluent and  form  a  slimy  layer.  Milk  becomes  strongly  acid  and  coagulates 
within  twelve  hours  when  inoculated  with  this  micrococcus. 

Pathogenesis. — Subcutaneous  injection  of  0.75  to  1  cubic  centimetre 
causes  the  formation  of  a  local  abscess  in  dogs  and  rabbits.  Intravenous 
injections  produce  inflammatory  changes  in  the  kidneys ;  at  the  end  of  three 
or  four  days  the  urine  contains  red  blood  corpuscles,  renal  ejpithelium,  blood 
casts,  albumin,  and  streptococci. 


320  PATHOGENIC   MICROCOCCI 

29.  MICROCOCCUS  ENDOCARDITIDIS  RUGATUS  (Weichselbaum). 

Obtained  by  Weichselbaum  (1890)  from  the  affected  cardiac  valves  in  a 
fatal  case  of  ulcerative  endocarditis. 

Morphology. — Micrococci,  resembling1  the  staphylococci  of  pus  in  dimen- 
sions and  mode  of  grouping;  solitary,  in  pairs,  in  groups  of  four,  or  in  ir- 
regular masses. 

Biological  Characters. — An  aerobic  micrococcus.  Does  not  grow  at  the 
room  temperature.  Upon  agar  plates,  at  37J  C. ,  at  the  end  of  three  or  four 
days  the  superficial  colonies  consist  of  a  small,  brown,  central  mass  sur- 
rounded by  a  granular,  se;ni  transparent,  grayish  marginal  zone;  gradually 
they  attain  a  characteristic  wrinkled  appearance;  the  deep  colonies,  under  a 
low  power,  are  irregular,  finely  granular,  and  contain  a  large  central,  yel- 
lowish-brown nucleus  surrounded  by  a  narrow,  grayish-brown  peripheral 
zone.  In  agar  stick  cultures  small,  spherical  colonies  are  formed  upon  the 
surface,  which  become  confluent,  forming  a  grayish-white,  wrinkled  layer 
which  has  a  stearin-like  lustre  and  is  very  viscid ;  a  scanty  growth  occurs 
along  the  line  of  puncture.  Upon  potato,  at  37°  C  ,  a  scanty  development 
occurs  in  the  form  of  a  small,  dry,  pale-brown  mass.  Upon  blood  serum 
isolated  or  confluent,  colorless  colonies  are  formed  the  size  of  a  poppy  seed; 
these  are  closely  adherent  to  the  surface  of  the  culture  medium. 

Pathogenesis. — When  injected  subcutaneously  into  the  ear  of  a  rabbit  it 
produces  tumefaction  and  redness;  in  guinea-pigs,  formation  of  pus.  When 
injected  into  the  circulation  of  dogs,  after  injury  to  the  aortic  valves,  an  en- 
docarditis is  developed. 

30.    MICROCOCCUS   OF  GANGRENOUS  MASTITIS  IN   SHEEP. 

Obtained  by  Nocard  (1887)  from  the  milk  of  sheep  suffering  from  gan- 
grenous mastitis  (rnal  de  pis  or  d'araignee),  a  fatal  disease  which  attacks 
especially  sheep  which  az-e  being  milked  for  the  manufacture  of  cheese,  at 
Roquefort  and  elsewhere  in  France. 

Morphology. — Micrococci,  solitary,  in  pairs,  or  in  irregular  groups,  resem- 
bling the  staphylococci  of  pus  in  dimensions  and  arrangement. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  at  the  room  temperature  in  the  usual  culture  me- 
dia. Upon  gelatin  plates,  at  the  end  of  forty-eight  hours,  the  colonies  are 
spherical  and  white  in  color;  under  a  low  power  the  superficial  colonies  are 
circular  in  outline,  homogeneous,  and  brown  in  color ;  they  are  surrounded 
by  a  semi-transparent  aureole  ;  liquefaction  around  the  superficial  colonies 
occurs  sooner  than  around  those  beneath  the  surface  of  the  gelatin.  In 
gelatin  stick  cultures,  at  18°  to  20°  C.,  on  the  second  day  liquefaction  of  the 
gelatin  commences  near  the  surface  ;  by  the  fifth  day  a  pouch  of  liquefied 
gelatin  has  formed,  which  has  the  shape  of  an  inverted  cone;  at  the  bottom 
of  this  an  abundant  deposit  of  micrococci  is  seen,  while  the  liquefied  gela- 
tin above  is  clouded  throughout.  In  agar  stick  cultures  development  oc- 
curs upon  the  surface  as  a  thick  white  layer,  which  gradually  extends 
over  the  entire  surface,  and  after  a  time  acquires  a  yellowish  tint;  develop- 
ment also  occurs  along  the  line  of  puncture.  Upon  potato  a  thin,  viscid, 
grayish  layer  is  slowly  developed ;  the  outline  is  irregular  and  the  edges 
thicker  than  the  central  portion  ;  the  central  portion  of  this  layer  gradually 
acquires  a  yellow  color,  while  the  periphery  remains  of  a  dirty-white  or 
grayish  color.  Blood  serum  is  liquefied  by  this  micrococcus. 

Pathogenesis. — A  few  drops  of  a  pure  culture  injected  subcutaneously  or 
into  the  mammary  gland  of  sheep  cause  an  extensive  inflammatory  oedema 
and  the  death  of  the  animal  in  from  twenty-four  to  forty-eight  hours.  A 
cubic  centimetre  iniected  into  the  mammary  gland  of  a  goat  produced  no  re- 
sult ;  the  horse,  the  ftalf ,  the  pig,  the  cat,  chickens,  and  guinea-pigs  also  proved 
to  be  immune.  Subcutaneous  injections  in  rabbits  produce  an  extensive  ab- 
scess at  the  point  of  inoculation. 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND    V.  321 

31.    STREPTOCOCCUS   OF  MASTITIS   IN   COWS. 

Obtained  by  Nocard  and  Mollereau  (1887)  from  the  milk  of  cows  suffering 
from  a  form  of  chronic  mastitis  (mammite  contagieuse). 

Morphology. — Spherical  or  oval  cocci,  a  little  less  than  one  //  in  diameter, 
usually  united  in  long  chains. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  streptococcus.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Develops  rapidly  in  milk  or  in  bouillon  at  a  temperature  of 
16°  to  30°  C.  The  milk  of  a  cow  suffering  from  the  form  of  mastitis  produced 
by  this  micrococcus,  when  drawn  with  proper  precautions  in  sterilized  test 
tubes,  at  the  end  of  twenty-four  hours  is  acid  in  reaction;  the  lower  two- 
thirds  of  the  tube  is  filled  with  an  opaque,  dirty- white,  homogeneous  deposit, 
and  above  this  is  an  opalescent,  serous  fluid  of  a  bluish  or  dirty-yellow  or 
slightly  reddish  color,  according  to  the  age  of  the  lesion.  A  drop  of  this 
milk  examined  under  the  microscope  shows  the  presence  of  the  streptococcus 
in  great  numbers.  The  addition  of  two  to  five  per  cent  of  glucose  or  of  gly- 


FIQ.  99.— Streptococcus  of  mastitis  in  cows  (Nocard). 

cerin  to  bouillon  makes  it  a  more  favorable  culture  medium ;  the  reaction 
should  be  neutral  or  slightly  alkaline,  as  this  streptococcus  does  not  grow 
readily  in  an  acid  medium,  although  it  produces  an  acid  reaction  in  media 
containing  sugar,  the  acid  formed  being  lactic.  In  gelatin  stick  cultures  the 
growth  upon  the  surface  is  scanty,  in  the  form  of  a  thin  pellicle  around  the 
point  of  puncture ;  along  the  line  of  inoculation  minute,  opaque,  granular 
colonies  are  developed,  which,  being  closely  crowded,  form  a  thick  line  with 
jagged  mai'gins. 

In  agar  stick  cultures  the  growth  is  similar  but  more  abundant.  Upon 
the  surface  of  nutrient  gelatin,  agar,  or  blood  serum  a  large  number  of  mi- 
nute, spherical,  semi-transparent  colonies  are  developed  along  the  impfstrich ; 
these  have  a  bluish  tint  by  reflected  light ;  they  may  become  confluent,  form- 
ing a  thin  layer  with  well-defined  margins.  Upon  gelatin  plates,  at  16°  to 
18°  C.,  colonies  are  first  visible  at  the  end  of  two  or  three  days ;  they  are 
spherical  and  slightly  granular,  at  first  transparent  and  later  of  a  pale-yellow 
color  by  transmitted  light,  which  gradually  becomes  brown.  At  the  end  of 
five  or  six  weeks  the  colonies  are  still  quite  small,  well  defined,  and  opaque. 

Pathogenesis. — Pure  cultures  injected  into  the  mammary  gland  of  cows 
and  goats  gave  rise  to  a  mastitis  resembling  in  its  development  that  from 
24 


322  PATHOGENIC   MICKOCOCCI 

which  the  streptococcus  was  obtained  in  the  first  instance.  Injections  into 
the  cavity  of  the  abdomen  or  into  a  vein,  of  one  cubic  centimetre  of  a  pure 
culture,  gave  a  negative  result  in  dogs,  cats,  rabbits,  and  guinea-pigs. 

32.    DIPLOCOCCUS  OF  PNEUMONIA  IN  HORSES. 

Obtained  by  Schiitz  (1887)  from  the  lungs  of  horses  affected  with  pneu- 
monia. 

Morphology. — Oval  cocci,  usually  in  pairs,  surrounded  by  a  homogene- 
ous, transparent  capsule. 

Does  not  stain  by  Gram's  method. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
at  the  room  temperature.  Upon  gelatin  plates  forms  small,  spherical,  white 
colonies. 

In  gelatin  stick  cultures  grows  along  the  line  of  puncture  as  small,  white, 
separate  colonies,  which  grow  larger  without  becoming  confluent.  Upon 
the  surface  of  agar  small  transparent  drops  are  developed  along  the  impf- 
strich. 

Pathogenesis. — The  injection  of  a  pure  culture  into  the  lung  of  a  horse 
produces  pneumonia  and  causes  its  death  in  eight  or  nine  days.  Pathogenic 
for  rabbits,  guinea-pigs,  and  mice. 

33.    STREPTOCOCCUS   CORYZ^  CONTAGIOSvE   EQUORUM. 

Obtained  by  Shiitz  (1888)  from  pus  from  the  lymphatic  glands  involved 
in  horses  suffering  from  the  disease  known  in  Germany  as  Druse  des 
Pferdes. 

Morphology.  — Oval  cocci,  in  pairs,  in  chains  containing  three  or  four 
elements,  or  in  long  chaplets. 

Stains  with  the  usual  aniline  colors — very  intensely  with  Weigert's  or 
Ehrlich's  solution. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic  micrococ- 
cus. Grows  slowly  at  the  room  temperature,  more  rapidly  at  37°  C.  Upon 
gelatin  plates  at  the  end  of  three  to  five  days  minute  colonies  become  visible ; 
these  never  exceed  the  size  of  a  pin's  head.  In  gelatin  stick  cultures  growth 
upon  the  surface  is  scanty  or  absent;  along  the  line  of  puncture  minute 
colonies  are  developed  in  rows.  Upon  agar  plates,  at  37°  C.,  at  the  end  of 
twenty-four  hours  lentil-shaped  colonies  are  developed  the  size  of  a  pin's 
head;  under  a  low  power  the  superficial  colonies  are  seen  to  have  a  well-de- 
fined, opaque  nucleus  surrounded  by  a  grayish,  transparent  marginal  zone, 
which  represents  a  half -fluid,  slimy  growth  which  does  not  extend  after  the 
third  day  and  later  disappears  entirely ;  the  deep  colonies  are  at  first  well- 
defined,  and  later  surrounded  by  wing-like  outgrowths.  Upon  blood  serum, 
at 37°  C.,  yellowish,  transparent  drops  are  first  developed;  these  become  con- 
fluent and  form  a  viscid  and  tolerably  thick  layer;  this  later  becomes  dry 
and  iridescent. 

Pathogenesis. — Pathogenic  for  horses  and  for  mice,  producing  in  these 
animals  an  abscess  at  the  point  of  inoculation,  and  metastatic  abscesses  in 
the  neighboring  lymphatic  glands.  Not  pathogenic  for  rabbits,  guinea-pigs, 
or  pigeons. 

34.  H^MATOCOCCUS  BOVIS  (Babes). 

Obtained  by  Babes  (1889)  from  the  blood  and  various  organs  of  cattle 
which  had  died  of  an  epidemic  malady  (in  Roumaiiia)  characterized  by  ha;mo- 
globinuria.  The  cocci  are  found  in  the  blood  in  great  numbers,  for  the  most 
part  enclosed  in  the  red  corpuscles. 

Morphology. — Biscuit-shaped  cocci  united  in  pairs;  sometimes  oblong  in 
form,  isolated  or  united  in  groups ;  the  free  cocci  are  surrounded  by  a  pale- 
yellowish,  shining  aureole  of  0.5  to  1  n  in  diameter. 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND   V.  323 

Stains  best  with  Loffler's  solution  of  methylene  blue ;  does  not  stain  by 
Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  very  slowly  at  the  room  temperature — not 
below  20°  C.  In  the  incubating  oven  grows  in  the  usual  culture  media.  In 
gelatin  stick  cultures  a  scanty  development  of  small,  white  colonies  occurs 
along  the  line  of  puncture.  Upon  the  surface  of  agar  small,  transparent 
drops  are  developed  along  the  impfstrich.  \Jponpotato,  at  37°  C..  a  thin, 
broad,  yellowish,  shining  layer  is  developed  in  the  course  of  a  few  days — 
scarcely  visible.  Upon  blood  serum  small,  moist,  transparent  colonies  are 
developed. 

Pathogenesis. — Pathogenic  for  rabbits  and  rats,  which  die  in  from  six  to 
ten  days  after  inoculation  with  a  pure  culture;  the  spleen  is  found  to  be  en- 
larged, the  lungs  hyperaemic,  and  a  bloody  serum  is  found  in  the  cavity  of 
the  abdomen ;  the  cocci  are  present  in  the  blood  in  considerable  numbers, 
but  are  rarely  seen  in  the  red  corpuscles.  Inoculations  in  oxen,  horses, 
goats,  sheep,  guinea-pigs,  and  birds  were  without  effect. 

35.   MICROCOCCUS  GINGIV^E  PYOGENES. 

Obtained  by  Miller  (1889)  from  the  mouth  of  a  man  suffering  from  alveo- 
lar abscess. 

Morphology. — Large  cocci  of  irregular  dimensions,  solitary  or  in  pairs. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non-lique- 
fying micrococcus.  Grows  at  the  room  temperature  in  the  usual  media.  Upon 
gelatin  plates  it  forms  spherical,  well-defined  colonies,  which  under  a  low 
power  are  at  first  slightly  colored  and  later  opaque.  In  gelatin  stick  cultures 
an  abundant  development  occurs  both  upon  the  surface  and  along  the  line 
of  puncture.  Upon  the  surface  of  agar  a  tolerably  thick,  grayish  growth 
occurs  along  the  impfstrich,  which  has  a  purplish  tint  by  transmitted  light. 

Pathogenesis. — Subcutaneous  injections  in  mice  produce  a  local  abscess 
and  necrosis  of  the  skin,  followed  sometimes  by  death.  Injections  into  the 
cavity  of  the  abdomen  produced  peritonitis  and  death  in  from  twelve  to 
twenty-four  hours. 

36.    PSEUDODIPLOCOCCUS   PNEUMONIA. 

Obtained  by  Bonome  (1888)  from  the  sero-fibrinous  exudate  in  an  autopsy 
of  an  individual  who  died  of  cerebro-spinal  meningitis.  _ 

Morphology.— Oval  cocci,  in  pairs  or  in  chains  of  five  or  six  elements, 
often  surrounded  by  a  transparent  capsule;  not  to  be  distinguished  from 
Micrococcus  pneumoniae  crouposae. 

Stains  with  the  usual  aniline  colors  and  by  Gram  s  method. 

Biological  Characters.—  An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature  (Micrococcus  pneumonias 
crouposae  does  not  grow  at  the  room  temperature) .  In  gelatin  stick  cultiires 
very  small  colonies  are  developed  along  the  line  of  puncture  at  the  end  Of 
twenty-four  to  twenty-eight  hours.  Upon  the  surface  of  agar  a  rather 
scanty,  moist  layer  is  developed  along  the  impfstrich.  Upon  potato  a  thin, 
scarcely  visible  layer  is  developed.  In  bouillon  tine  development  is  abun- 
dant; the  culture  medium  acquires  a  very  acid  reaction  and  gives  oil  a  strong 
odor  like  that  of  perspiration.  . 

Pathogenesis.— Pathogenic  for  mice,  guinea-pigs,  and  rabbits,  in  wnicn 
animals  it  produces  fatal  septicaemia;  the  spleen  is  not  enlarged,  as  is  the 
case  in  animals  inoculated  with  Micrococcus  pneumoniae  crouposae. 

37.   STREPTOCOCCUS  SEPTICUS  LIQUEFACIENS. 

Obtained  by  Babes  (1889)  from  the  blood  and  various  organs  of  a  child 
which  died  of  septicaemia  following  scarlatina. 


324  PATHOGENIC   MICROCOCCI 

Morphology. — Micrococci,  about  0.3  to  0.4  /*  in  diameter,  in  pairs  or  in 
short  chains  in  which  the  elements  are  loosely  connected. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic,  liquefying  micrococcus.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  In  gelatin  stick  cultures 
at  the  end  of  twenty-four  hours  a  thin,  granular,  whitish  stripe  is  seen  along 
the  line  of  puncture,  while  the  surface  seems  somewhat  depressed;  later 
liquefaction  of  the  gelatin  occurs  in  funnel  form ;  the  liquefied  gelatin  is  but 
slightly  clouded,  and  upon  the  walls  of  the  funnel  peculiar,  flat,  white,  leaf- 
shaped,  jagged  colonies  are  seen.  Upon  the  surface  of  agar,  at  36°  (1,  small, 
white,  tnin,  shining,  transparent  colonies  are  developed,  which  may  attain 
a  diameter  of  two  to  three  millimetres.  Upon  blood  serum  a  scarcely  visible 
granular  layer  is  developed. 

Pathogenesis. — Subcutaneous  injections  in  mice  and  rabbits  produce 
local  inflammation  with  oedema,  and  death  occurs  in  about  six  days ;  the 
streptococci  are  found  in  large  numbers  in  the  effused  serum,  in  the  blood, 
and  in  the  spleen.  After  being  cultivated  for  some  time  in  artificial  media 
the  cultures  lose  their  pathogenic  power. 

38.    MICROCOCCUS   OF   KIRCHNER. 

Obtained  by  Kirchner  (1890)  from  the  bronchial  secretions  (in  sputum)  of 
patients  suffering  from  epidemic  influenza — soldiers  in  garrison  at  Hanover. 

Morphology. — Spherical  cocci,  usually  associated  in  pairs,  and  surrounded 
by  a  capsule.  Distinguished  from  Micrococcus  pneumonias  crouposae  by  be- 
ing smaller,  quite  spherical,  and  the  elements  in  a  pair  being  more  widely 
separated  from  each  other.  Found  in  the  bronchial  secretion  in  scattered 
pairs,  or  associated  in  groups ;  occasionally  seen  in  chains. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  micrococcus;  does  not  grow  in  flesh- 
peptone-gelatin  at  the  room  temperature.  Upon  agar  plates,  at  36°  p., 
small,  grayish-white,  transparent,  spherical  colonies  are  developed,  which 
later  form  round,  grayish-white  plaques.  In  agar  stick  cultures  an  abun- 
dant development  occurs  upon  the  surface,  extending  to  the  walls  of  the 
test  tube ;  growth  also  occurs  along  the  line  of  puncture. 

Pathogenesis. — Not  pathogenic  for  rabbits  or  for  white  mice.  A  guinea- 
pig  which  received  one  cubic  centimetre  of  a  bouillon  culture  in  the  pleural 
cavity  died  at  the  end  of  twenty-four  hours ;  the  spleen  was  not  enlarged ; 
lungs  hyperasmic ;  the  micrococci  were  found  in  the  blood  and  in  the  vari- 
ous organs.  Another  guinea-pig,  which  received  one  cubic  centimetre  of  a 
bouillon  culture  in  the  cavity  of  the  abdomen,  recovered  after  a  slight  indis- 
position. 

39.   MICROCOCCUS  NO.    II.   OF  FISCHEL,. 

Obtained  by  Fischel  (1891)  from  the  blood  of  two  cases  of  influenza. 

Morphology. — Micrococci  of  from  1  to  1.25  u  in  diameter,  mostly  in 
pairs,  sometimes  in  chains. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing  micrococcus.  Grows  in  the  usual  culture  media  at  the  room  tempera  • 
ture.  Upon  gelatin  plates  minute  colonies,  visible  only  under  the  micro- 
scope, are  developed  at  the  end  of  three  days.  In  gelatin  stick  cultures  an 
abundant  milk-white  growth  occurs  along  the  line  of  puncture,  and  lique- 
faction of  the  gelatin  commences  at  the  end  of  four  days ;  this  progresses 
slowly.  Upon  agar  plates,  at  37°  C.,  superficial  colonies  are  developed  re- 
sembling a  drop  of  milk.  Upon  potato,  at  37°  C.,  at  the  end  of  eight  days  a 
thin,  shining  layer  of  a  yellowish-white  color,  and  about  one  centimetre 
broad,  is  developed;  no  growth  upon  potato  at  the  room  temperature.  No 
growth  occurs  in  liquid  blood  serum  or  in  milk.  In  sterilized  water  this 
micrococcus  is  said  by  Fischel  to  lose  its  vitality  in  eight  hours. 


NOT   DESCRIBED   IN   SECTIONS   IV.    AND   V.  325 

Pathogenesis. — Pathogenic  for  dogs  and  for  horses.  Intravenous  injec- 
tion of  three  to  four  cubic  centimetres  in  dogs  is  said  to  produce  symptoms 
resembling  those  of  distemper  in  this  animal,  viz.,  increased  temperature, 
catarrhal  conjunctivitis,  in  some  cases  keratitis,  and  in  some  a  mucous  dis- 
charge from  the  preputial  sac.  The  micrococcus  was  not  found  in  the  blood 
of  the  dogs  inoculated  by  intravenous  injection,  later  than  the  fourth  day. 

40.    STREPTOCOCCUS  OF  BONOME. 

Obtained  by  Bonorne  (1890)  from  the  exudations  of  the  cerebro-spinal 
meninges  and  from  haemorrhagic  extravasations  in  the  lungs  in  cases  of 
epidemic  cerebro-spinal  meningitis. 

This  streptococcus  is  said  by  Bonome  to  be  distinguished  from  previously 
known  streptococci  by  the  following  characters :  It  does  not  grow  readily 
in  artificial  culture  media,  and  soon  loses  its  pathogenic  power  when  pre- 
served in  a  desiccated  condition  or  cultivated  through  a  few  successive  gene- 
rations. It  differs  from  the  "  pneumococcus  "  and  "  meningococcus  "  by 
the  ball-shaped  appearance  of  its  colonies  on  agar  plates,  and  in  the  fact 
that  it  does  not  grow  upon  blood  serum ;  also  by  the  difficulty  experienced 
in  carrying  it  through  five  or  six  generations  in  artificial  media. 

Pathogenesis. — In  white  mice  and  in  rabbits  a  fibrinous  inflammation 
and  death  result  from  inoculations  with  a  pure  culture,  the  symptoms  re- 
sembling those  produced  by  similar  inoculations  with  Micrococcus  pneumo- 
nias crouposae.  It  does  not  produce  septicaemia  in  white  mice,  but  in  rabbits 
the  cocci  are  found  in  the  blood  in  chains  surrounded  by  a  capsule.  In 
guinea-pigs  and  dogs  a  local  fibrinous  inflammation  results  from  inocula- 
tions, and  the  streptococcus  is  found  in  the  gelatinous  exudate  at  the  point  of 
inoculation.  It  is  distinguished  from  the  streptococcus  of  erysipelas  by  its 
failure  to  grow  in  gelatin  or  in  blood  serum,  and  by  the  appearance  of  its 
colonies  on  agar  plates. 

41.  MICROCOCCUS   OF  ALMQUIST. 

Obtained  by  Almquist  (1891)  from  the  bullae  of  pemphigus  neonatorum, 
in  nine  children  suffering  from  this  disease  during  an  epidemic  which  oc- 
curred at  Goteborg. 

Morphology. — Micrococci  from  0.5  to  "L  ju  in  diameter,  usually  in  pairs. 

Stains  readily  with  the  aniline  colors. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micro- 
coccus.  Closely  resembles  Staphylococcus  pyogenes  aureus  in  its  morpho- 
logy and  growth  in  culture  media.  Produces  a  similar  golden-yellow  pig- 
ment. 

Pathogenesis. — According  to  Almquist,  this  micrococcus  is  distinguished 
from  Staphylococcus  pyogenes  aureus  by  its  specific  pathogenic  power.  Two 
inoculations  made  from  a  pure  culture,  by  means  of  a  lancet,  upon  his  own 
arm  gave  rise  to  a  development  of  bullae  like  those  of  pemphigus.  The 
process  showed  no  disposition  to  extend  deeper,  but  the  epidermis  was  raised 
by  a  collection  of  fluid  which  was  at  first  transparent  and  later  had  a  milky 
opacity.  From  the  contents  of  these  bullse  the  same  coccus  was  obtained  in 
pure  cultures. 

42.  STAPHYLOCOCCUS   PYOSEPTICUS. 

Obtained  by  Hericourt  and  Blchet  (1888)  from  an  abscess  in  the  skin  of  a 
dog. 

In  its  morphology  and  biological  characters  this  micrococcus  closely  re- 
sembles Staphylococcus  pyogenes  albus,  and  it  is  probably  a  pathogenic  va- 
riety of  this  common  species.  But  the  experiments  made  by  the  authors 
referred  to  show  it  to  be  decidedly  more  pathogenic  for  rabbits.  Subcutane- 
ous injections  of  a  drop  or  two  of  a  pure  culture  caused  an  extensive  inflam- 
matory oedema,  and  death  in  from  twelve  to  twenty-four  hours. 


326       PATHOGENIC   MICROCOCCI   NOT   HERETOFORE   DESCRIBED. 

43.    STREPTOCOCCUS   PERNICIOSUS  PSITTACORUM. 

Micrococcus  of  gray  parrot  disease.  Eberth  and  Wolff  have  described 
an  infectious  disease  of  gray  parrots,  which  is  said  to  be  extremely  fatal 
among  the  imported  birds.  The  disease  is  characterized  by  the  formation  of 
nodules  upon  the  surface  and  in  the  interior  of  various  organs,  and  especially 
in  the  liver.  Micrococci  of  medium  size  are  found  in  these  nodules  and  in 
blood  from  the  heart ;  these  are  sometimes  in  chains.  Microscopic  examina- 
tion of  stained  sections  shows  that  these  cocci  are  directly  related  to  the  tis- 
sue necrosis  which  characterizes  the  disease.  But  the  micrococcus  has  not 
been  cultivated  and  its  biological  characters  are  undetermined. 

44.   MICROCOCCUS  OF  FORBES. 

Forbes  (1886)  has  studied  an  infectious  disease  of  cabbage  caterpillars 
(Pieris  rapae),  which  appears  to  be  due  to  a  micrococcus  found  by  him  in 
large  numbers  in  the  bodies  of  the  infected  larvae.  This  micrococcus,  which 
resembles  the  common  staphylococci  in  form,  was  cultivated  in  liquid  media 
and  successful  inoculation  experiments  were  made. 


VII. 

THE   BACILLUS  OF  ANTHRAX. 
[Fr.,  CHARBON;    Ger.,  MILZBRAND.] 

ANTHRAX  is  a  fatal  infectious  disease  which  prevails  extensively 
among  sheep  and  cattle  in  various  parts  of  the  world,  causing  heavy 
losses.  In  Siberia  it  constitutes  a  veritable  scourge  and  is  known 
there  as  the  Siberian  plague  ;  it  also  prevails  to  a  considerable  extent 
in  portions  of  France,  Hungary,  Germany,  Persia,  and  India,  and 
local  epidemics  have  occasionally  occurred  in  England,  where  it  is 
known  under  the  name  of  splenic  fever.  It  does  not  prevail  in  the 
United  States.  In  infected  districts  the  greatest  losses  are  incurred 
during  the  summer  season. 

In  man  accidental  inoculation  may  occur  among  those  who  come 
in  contact  with  infected  animals,  and  especially  during  the  removal  of 
the  skin  and  cutting -up  of  dead  animals,  when  there  is  any  cut  or 
abrasion  upon  the  hands.  A  malignant  pustule  is  developed  as  the 
result  of  such  inoculation,  but,  as  a  rule,  general  infection  does 
not  occur,  as  is  the  case  when  inoculations  are  made  into  the  more 
susceptible  lower  animals — rabbit,  guinea-pig,  mouse.  Those  who 
handle  the  hair,  hides,  or  wool  of  infected  animals  are  also  liable  to 
contract  the  disease  by  inoculation  through  open  wounds,  or  by  the 
inhalation  of  dust  containing  spores  of  the  anthrax  bacillus.  Cases 
of  pulmonic  anthrax,  known  formerly  in  England  as  "wool-sorters' 
disease,"  have  been  occasionally  observed  in  England  and  in  Ger- 
many, and  are  now  recognized  as  being  due  to  infection  through  the 
lungs  in  the  manner  indicated. 

The  French  physician  Davaine,  who  had  observed  the  anthrax 
bacillus  in  the  blood  of  infected  animals  in  1850,  communicated  to 
the  French  Academy  of  Sciences  the  results  of  his  inoculation  experi- 
ments in  1863  and  1804,  and  asserted  the  etiological  relation  of  the 
bacillus  to  the  disease  with  which  his  investigations  showed  it  to  be 
constantly  associated.  This  conclusion  was  vigorously  contested  by 
conservative  opponents,  but  has  been  fully  established  by  subsequent 
investigations,  which  show  that  the  bacillus,  in  pure  cultures,  induces 


328 


THE   BACILLUS   OF   ANTHRAX. 


anthrax  in  susceptible  animals  as  certainly  as  does  the  blood  of  an 
animal  recently  dead  from  the  disease. 

Owing  to  the  fact  that  this  was  the  first  pathogenic  bacillus  cul- 
tivated in  artificial  media,  and  to  the  facility  with  which  it  grows  in 
various  media,  it  has  served  more  than  any  other  microorganism  for 
researches  relating  to  a  variety  of  questions  in  pathology,  general 
biology,  and  public  hygiene,  some  of  which  are  discussed  in  other 
sections  of  this  volume. 

45.      BACILLUS   ANTHRACIS. 

Synonyms. — Milzbrandbacillus,  Ger.;  Bacteridie  du  charbon,  Fr. 

First  observed  in  the  blood  of  infected  animals  by  Pollender  (1849) 

and  by  Davaine  (1850).     Etiological  relation  affirmed  by  Davaine 


FIG.  100.— Bacillus  anthracis,  from  a  culture,  showing  development  of  long  threads  in  convo- 
luted bundles.     X  300.    (Klein.) 

(1863),  and  established  by  the  inoculation  of  pure  cultures  by  Pasteur 
(1879)  and  by  many  other  investigators. 

Morphology. — Rod-shaped  bacteria  having  a  breadth  of  1  to 
1.25  /*,  and  5  to  20  /f  in  length;  or,  in  suitable  culture  media,  growing 
out  into  long,  flexible  filaments,  which  are  frequently  united  in 
twisted,  cord-like  bundles.  These  filaments  in  hanging-drop  cul- 
tures, before  the  development  of  spores,  appear  to  be  homogeneous  ; 
or  the  protoplasm  is  clouded  and  granular,  but  without  distinct  seg- 
mentation. But  in  stained  preparations  the  filaments  are  seen  to  be 
made  up  of  a  series  of  rectangular,  deeply  stained  segments.  In 
hanging-drop  cultures  the  ends  of  the  rods  appear  rounded,  but  in 
stained  preparations  from  the  blood  of  an  infected  animal  they  are 
seen  to  present  a  slight  concavity,  and  a  lenticular  interspace  is 
formed  where  two  rods  come  together.  The  diameter  of  the  roda 


THE   BACILLUS   OF  ANTHRAX. 


329 


varies  considerably  in  different  culture  media ;  and  in  old  cultures 
irregular  forms  are  frequently  seen — "  involution  forms." 

Under  favorable  conditions  endogenous  spores  are  developed  in 
the  long  filaments  which  grow  out  in  artificial  culture  media. 
These  first  appear  as  refractive  granules  distributed  at  regular  inter- 
vals in  the  segments  of  the  protoplasm,  which  gradually  disappear 
as  the  spores  are  developed ;  and  these  are  left  as  oval,  highly  re- 
fractive bodies,  held  together  in  a  linear  series  by  the  cellular  enve- 
lope, and  subsequently  set  free  by  its  dissolution.  The  germination 
of  these  reproductive  bodies  results  in  the  formation  of  rods  and 
spore-bearing  filaments  like  those  heretofore  described.  In  this  pro- 
cess the  spore  is  first  observed  to 
lose  its  brilliancy,  from  the  ab- 
sorption of  moisture,  a  promi- 
nence occurs  at  one  end  of  the 
oval  body,  and  soon  the  external 
envelope  —  exosporium — is  rup- 
tured, permitting  the  softened 
protoplasmic  contents  enclosed 
in  the  internal  spore  membrane 
— endosporium — to  escape  as  a 
short  rod,  to  which  the  empty 
exosporium  sometimes  remains 
attached. 

The  anthrax  bacillus  stains 
readily  with  the  aniline  colors 
and  also  by  Gram's  method, 
when  not  left  too  long  in  the 
decolorizing  iodine  solution. 
Loffler's  solution  of  methylene 
blue  is  an  especially  good  stain- 
ing fluid  for  this  as  well  as  for  many  other  bacilli.  Bismarck  brown 
is  well  adapted  for  specimens  which  are  to  be  photographed,  and  also 
for  permanent  preparations,  as  it  is  less  liable  to  fade  than  the  blue 
and  some  other  aniline  colors. 

Biological  Characters. — The  anthrax  bacillus  is  aerobic,  but 
not  strictly  so,  as  is  shown  by  the  fact  that  it  grows  to  the  bottom  of 
the  line  of  puncture  in  stick  cultures  in  solid  media.  It  is  non-mo- 
tile, and  is  distinguished  by  this  character  from  certain  common 
bacilli  resembling  it  in  morphology — Bacillus  subtilis — which  were 
frequently  confounded  with  it  in  the  earlier  days  of  bacteriological 
investigation. 

The  anthrax  bacillus  grows  in  a  variety  of  nutrient  media  at  a 
25 


FIG.  101.— Bacillus  anthracis,  from  a  culture, 
showing  formation  of  spores.    X  1,000.    (Klein.) 


330 


THE   BACILLUS   OF   ANTHRAX. 


temperature  of  20°  to  38°  C.     Development  ceases  at  temperatures 
below  12°  C.  or  above  45°  C. 

This  bacillus  grows  best  in  neutral  or  slightly  alkaline  media,  and 
its  development  is  arrested  by  a  decidedly  acid  reaction  of  the  cul- 
ture medium.  It  may  be  cultivated  in  infusions  of  flesh  or  of  vari- 
ous vegetables,  in  diluted  urine,  in  milk,  etc. 

In  gelatin  plate  cultures  small,  white,  opaque  colonies  are  devel- 
oped in  from  twenty-four  to  thirty-six  hours,  which  under  the  micro- 
scope are  seen  to  be  somewhat  irregular  in  outline  and  of  a  greenish 
tint ;  later  the  colonies  spread  out  upon  the  surface  of  the  gelatin, 
and  the  darker  central  portion  is  surrounded  by  a  brownish  mass  of 
wavy  filaments,  which  are  associated  in  tangled  bundles.  Mycelial- 

like  outgrowths  from  the  periphery  of 
the  colony  may  often  be  seen  extending 
into  the  surrounding  gelatin.  At  the 
end  of  two  or  three  days  liquefaction  of 
the  gelatin  commences,  and  the  colony 
is  soon  surrounded  by  the  liquefied  me- 
dium, upon  the  surface  of  which  it  floats 
as  an  irregular  white  pellicle.  In  gela- 
tin stick  cultures  growth  occurs  all 
along  the  line  of  puncture  as  a  white  cen- 
tral thread,  from  which  lateral  thread- 
like ramifications  extend  into  the  culture 
medium.  At  the  end  of  two  or  three 
days  liquefaction  of  the  culture  medium 
commences  near  the  surface,  where  the 
development  has  been  most  abundant. 
At  first  a  pasty,  white  mass  is  formed, 
but  as  liquefaction  progresses  the  upper 
part  of  the  liquefied  gelatin  becomes 
transparent  from  the  subsidence  of  the 
motionless  bacilli,  and  these  are  seen 
upon  the  surface  of  the  non-liquefied 
portion  of  the  medium  in  the  form  of 
cloudy,  white  masses,  while  below  the  line  of  liquefaction  the  charac- 
teristic branching  growth  may  still  be  seen  along  the  line  of  puncture. 
In  agar  plate  cultures,  in  the  incubating  oven  at  35°  to  37°  C., 
colonies  are  developed  within  twenty-four  hours,  which  under  the 
microscope  are  seen  to  be  made  up  of  interlaced  filaments  and  are 
very  characteristic  and  beautiful.  Upon  the  surface  of  nutrient  agar 
a  grayish-white  layer  is  formed,  which  may  be  removed  in  ribbon-like 
strips  ;  and  in  stick  cultures  in  this  medium  a  branching  growth  is 
seen,  like  that  in  gelatin,  but  without  liquefaction.  The  addition  of 


FIG.  102.— Culture  of  Bacillus  an- 
thracis  in  nutrient  gelatin  :  a,  end 
of  four  days ;  b,  end  of  eight  days. 
(Baumgarten.) 


THE   BACILLUS   OF   ANTHRAX. 


331 


a  small  quantity  of  agar  to  a  gelatin  medium  prevents  liquefaction 
of  the  gelatin  (Fliigge). 

Upon  blood  serum  a  rather  thick,  white  layer  is  formed  and 
liquefaction  slowly  occurs. 

Upon  potato  the  growth  is  abundant  as  a  rather  dry,  grayish- 
white  layer,  of  limited  extent,  having  a  somewhat  rough  surface  and 
irregular  margins. 

Spores  are  formed  only  in  the  free  presence  of  oxygen,  as  in  sur- 
face cultures  upon  potato  or  nutrient  agar,  or  in  shallow  cultures  in 
liquid  media,  and  at  a  temperature  of  20°  to  35°  C.  They  are  not 
formed  during  the  development  of  the  bacilli  in  the  bodies  of  living 


J 


Fio.  103.— Colonies  of  Bacillus  anthracite  upon  gelatin  plates :  a,  at  end  of  twenty-four  hours; 
6,  at  end  of  forty-eight  hours.    X  80.    (Flugge.) 

animals,  but  after  the  death  of  the  animal  the  bacillus  continues  to 
multiply  for  a  time,  and  spores  may  be  formed  where  the  fluids 
containing  it  come  in  contact  with  the  air — as,  for  example,  in 
bloody  discharges  from  the  nostrils  or  from  the  bowels  of  the  dead 
animal. 

Varieties  incapable  of  spore  production  have  been  produced  arti- 
ficially, by  several  bacteriologists,  by  cultivating  the  bacillus  under 
unfavorable  conditions.  Roux  was  able  to  produce  a  sporeless  va- 
riety by  successive  cultivation  in  media  containing  a  small  quantity 
of  carbolic  acid — 1  : 1,000. 

Varieties  differing  in  their  pathogenic  power  may  also  be  pro- 
duced by  cultivation  under  unfavorable  conditions.  Thus  Pasteur 


332  THE  BACILLUS   OF   ANTHRAX. 

produced  an  ''attenuated  virus"  by  keeping  his  cultures  for  a  con- 
siderable time  before  replanting  them  upon  fresh  soil,  and  supposed 
the  effect  was  due  to  the  action  of  atmospheric  oxygen.  It  seems 
probable  that  it  was  rather  due  to  the  deleterious  action  of  its  own 
products  of  growth  present  in  the  culture  media.  It  has  been 
shown  by  Chamberlain  and  Roux  that  cultivation  in  the  presence 
of  certain  chemical  substances  added  to  the  culture  medium — e.g., 
bichromate  of  potassium  0.01  per  cent — causes  an  attenuation  of 
virulence.  The  same  result  occurs  when  cultures  are  subjected  to  a 
temperature  a  little  below  that  which  is  fatal  to  the  bacillus — 50°  C. 
for  eighteen  minutes  (Chauveau);  42.5°  C.  for  two  or  three  weeks 
(Koch).  Attenuation  of  pathogenic  virulence  is  also  effected  by  cul- 
tivation in  the  body  of  a  non-susceptible  animal,  like  the  frog  (Lu- 
barsch,  Petruschky) ;  or  in  the  blood  of  a  rat  (Behring) ;  by  exposure 
to  sunlight  (Arloing);  and  by  compressed  air  (Chauveau). 

Anthrax  spores  may  be  preserved  in  a  desiccated  condition  for. 
years  without  losing  their  vitality  or  pathogenic  virulence  when  in- 
oculated into  susceptible  animals.  They  also  resist  a  comparatively 
high  temperature.  Thus  Koch  and  Wolffhiigel  found  that  dry  spores 
exposed  in  dry  air  required  a  temperature  of  140°  C.,  maintained  for 
three  hours,  to  insure  their  destruction.  But  spores  suspended  in  a 
liquid  are  destroyed  in  four  minutes  by  the  boiling  temperature, 
100°  C.  (writer's  determination). 

The  bacilli,  in  the  absence  of  spores,  according  to  Chauveau,  are 
destroyed  in  ten  minutes  by  a  temperature  of  54°  C. 

For  the  action  of  various  antiseptic  and  germicidal  agents  upon 
this  bacillus  we  must  refer  to  the  sections  especially  devoted  to  this 
subject  (Part  Second). 

Toussaint,  by  injecting  filtered  anthrax  blood  into  animals,  obtained 
evidence  that  it  contained  some  toxic  substance  which  in  his  experi- 
ments gave  rise  to  local  inflammation  without  any  noticeable  general 
symptoms.  More  recent  investigations  show  that  a  poisonous  albu- 
minous substance  (Hankin)  is  formed  during  the  growth  of  the  an- 
thrax bacillus,  and  that  cultures  containing  this  toxalbumin,  from 
which  the  bacilli  have  been  removed  by  filtration  through  porcelain, 
produce  immunity  when  injected  into  susceptible  animals,  similar  to 
that  resulting  from  inoculations  with  an  attenuated  virus.  It  is 
probable  that  the  pathogenic  power  of  the  anthrax  bacillus  depends 
largely  upon  the  presence  of  this  toxalbumin,  and  that  the  essential 
difference  between  virulent  and  attenuated  varieties  depends  upon 
the  more  abundant  production  of  this  toxic  substance  by  the  former. 
It  has  also  been  shown  that  virulent  cultures  produce  a  larger  quan- 
tity of  acid  than  those  which  have  been  attenuated  by  any  of  the 
agencies  above  mentioned  (Behring). 


THE   BACILLUS   OF   ANTHRAX.  333 

Martin  (1890)  has  studied  the  chemical  products  in  filtered  cul- 
tures of  the  anthrax  bacillus  and  obtained  the  following  results: 

1.  Protoalbumose,  deuteroalbumose,  and  a  trace  of  peptone.     The 
mixed  albumoses  were  found  not  to  be  poisonous  except  in  consider- 
able   doses — 0.3  gramme  injected  subcutaneously  killed  a  mouse 
weighing  twenty-two    grammes ;    smaller  doses  produced  a  local 
oedema.     A  fatal  dose  caused  extensive  oedema,  coma,  and  death  in 
twenty-four  hours ;  the  spleen  was  sometimes  enlarged.     Boiling 
neutralizes  to  a  considerable  extent  the  toxic  power. 

2.  An  alkaloid,  soluble  in  water  and  in  alcohol,  but  insoluble  in 
benzol,  chloroform,  or  ether.     The  solutions  have  a  strongly  alkaline 
reaction,  and  crystalline  salts  are  formed  with  various  acids.     This 
alkaloid  is  somewhat  volatile,  and  when  exposed  to  light  loses  to  a 
considerable  extent  its  toxic  properties.     It  produces  symptoms  simi- 
lar to  those  resulting  from  inoculations  with  the  albumoses,  but  is 
more  toxic  and  more  prompt  in  its  action.     The  animal  quickly  falls 
into  a  state  of  coma ;  there  is  extensive  oedema  about  the  point  of 
inoculation,  and  the  spleen  is  usually  enlarged.    The  fatal  dose  for  a 
mouse  weighing  twenty -two  grammes  is  from  0.1  to  0.15  gramme  ; 
death  occurs  within  two  or  three  hours. 

3.  In  addition  to  these  toxic  substances  small  quantities  of  leucin 
and  of  tyrosin  were  found  in  the  filtered  cultures. 

Recently  (1892)  Petermann  has  made  a  series  of  experiments  with 
filtered  cultures  of  the  anthrax  bacillus  which  lead  him  to  the  con- 
clusion that  "large  quantities  of  a  culture  in  serum  from  the  ox,  fil- 
tered through  porcelain,  injected  into  the  veins  of  a  susceptible 
animal,  have  a  preventive  action  ;  but  the  immunity  thus  conferred 
is  transitory,  not  lasting  longer  than  a  month  or  two." 

Pathogenesis. — The  anthrax  bacillus  is  pathogenic  for  cattle, 
sheep,  horses,  rabbits,  guinea-pigs,  and  mice.  White  rats,  dogs,  and 
frogs  are  immune,  as  is  also  the  Algerian  race  of  sheep.  The  spar- 
row is  susceptible  to  general  infection,  but  chickens,  under  normal 
conditions,  are  not.  Young  animals  are,  as  a  rule,  more  susceptible 
than  adults  of  the  same  species.  Man  does  not  belong  among  the 
most  susceptible  animals,  but  is  subject  to  local  infection  as  a  result 
of  accidental  inoculation — malignant  pustule — and  to  pulmonic  an- 
thrax from  breathing  air,  containing  spores  of  the  anthrax  bacillus, 
during  the  sorting  of  wool  or  hair  from  infected  animals.  In  animals 
which  have  a  partial  immunity,  natural  or  acquired,  as  a  result  of 
inoculations  with  attenuated  virus,  the  subcutaneous  introduction  of 
virulent  cultures  may  give  rise  to  a  limited  local  inflammatory  pro- 
cess, with  effusion  of  bloody  serum  in  which  the  bacillus  is  found  in 
considerable  numbers ;  but  the  blood  is  not  invaded,  and  the  animal, 
after  some  slight  symptoms  of  indisposition,  recovers.  In  susceptible 


334 


THE  BACILLUS   OF   ANTHRAX. 


animals  injections  beneath  the  skin  or  into  a  vein  give  rise  to  general 
infection,  and  the  bacilli  multiply  rapidly  in  the  circulating  fluid. 
Death  occurs  in  mice  within  twenty-four  hours,  and  in  rabbits,  as  a 
rule,  in  less  than  forty-eight  hours.  The  blood  of  the  heart  and 
large  vessels  may  be  found,  in  an  autopsy  made  immediately  after 
death,  to  contain  comparatively  few  bacilli ;  but  in  the  capillaries  of 
the  various  organs,  and  especially  in  the  greatly  enlarged  spleen,  in 
the  liver,  the  kidneys,  and  the  lungs,  they  will  be  found  in  great 
numbers,  and  well-stained  sections  of  these  organs  will  give  an  as- 
tonishing picture  under  the  microscope,  which  the  student  should  not 
fail  to  see  in  preparations  made  by  himself.  The  capillaries  in  many 
places  will  be  found  stuffed  full  of  bacilli ;  or  they  may  even  be  rup- 
tured as  a  result  of  the  distention,  and  the  bacilli,  together  with 


FIG.  104.— Bacillus  anthracis  in  liver  of  mouse,    x  700.    (Flugge.) 

escaped  blood  corpuscles,  will  be  seen  in  the  surrounding  tissues.  In 
the  kidneys  the  glomeruli,  especially,  appear  as  if  injected  with  col- 
ored threads,  and  by  rupture  these  may  find  their  way  into  the  urini- 
ferous  tubules. 

These  appearances  and  the  general  symptoms  indicate  that  the 
disease  produced  by  the  introduction  of  this  bacillus  into  the  bodies  of 
susceptible  animals  is  a  genuine  septica3mia.  As  in  other  forms  of 
septicaemia,  the  spleen  is  found  to  be  greatly  enlarged  ;  it  has  a  dark 
color  and  is  soft  and  friable.  With  this  exception  the  organs  pre- 
sent no  notable  changes,  although  the  liver  is  apt  to  be  somewhat 
enlarged.  In  the  guinea-pig  an  extensive  inflammatory  oedema,  ex- 
tending from  the  point  of  inoculation  to  the  most  dependent  parts  of 
the  body,  is  developed ;  the  subcutaneous  connective  tissue  is  infil- 
trated with  bloody  serum  and  has  a  gelatinous  appearance.  This 
animal  comes  next  to  the  mouse  in  susceptibility,  and  cultures  which 


THE   BACILLUS   OF   ANTHRAX.  335 

are  attenuated  to  such  an  extent  that  they  will  not  kill  a  rabbit  or  a 
sheep  may  still  kill  a  guinea-pig  ;  or,  if  not,  may  kill  a  mouse.  Pasteur 
has  shown  that  the  pathogenic  power  of  the  bacillus  may  be  reestab- 
lished by  inoculations  into  susceptible  animals,  and  that  an  attenu- 
ated culture  which  will  not  kill  an  adult  guinea-pig  may  be  fatal  to 
a  very  young  animal  of  this  species,  and  that  cultures  from  the  blood 
of  this  will  have  an  increased  pathogenic  virulence. 

Very  minute  quantities  of  a  virulent  culture  are  infallibly  fatal  to 
these  most  susceptible  animals,  but  for  rabbits  and  other  less  sus- 
ceptible animals  the  quantity  injected  influences  the  result,  and  re- 
covery may  occur  after  subcutaneous  or  intravenous  injection  of  a 
very  small  number  of  bacilli. 


Fio.  105.— Bacillus  anthracis  in  kidney  of  rabbit.    X  400.    (Baumgarten.) 

Infection  in  cattle  and  sheep  commonly  results  from  the  ingestion 
of  spores  while  grazing  in  infected  pastures.  The  bacillus  itself,  in 
the  absence  of  spores,  is  destroyed  in  the  stomach.  While  spores  are 
not  formed  in  the  bodies  of  living  animals,  their  discharges  contain 
the  bacillus,  and  this  is  able  to  multiply  in  them  and  to  form  spores 
upon  the  surface  of  the  ground  when  temperature  conditions  are 
favorable.  It  is  probable  that  this  is  the  usual  way  in  which  pastures 
become  infected,  and  that  the  bloody  discharges  from  the  bladder 
and  bowels  of  animals  suffering  from  the  disease  furnish  a  nidus  for 
the  external  development  of  these  reproductive  elements  ;  as  also  do 
the  fluids  escaping  from  the  bodies  of  dead  animals.  And  possibly, 
under  specially  favorable  conditions,  the  bacillus  may  lead  a  sapro- 
phytic  existence  for  a  considerable  tune  in  the  superficial  layers  of  the 
soil. 


336  THE   BACILLUS   OF   ANTHRAX. 

Buchner  has  shown  by  experiment  that  infection  in  animals  may 
result  from  respiring  air  in  which  anthrax  spores  are  in  suspension 
in  the  form  of  dust ;  and  in  man  this  mode  of  infection  occurs  in  the 
so-called  wool-sorters'  disease. 

The  question  of  the  passage  of  the  anthrax  bacillus  from  the 
mother  to  the  foetus  in  pregnant  females  has  received  considerable 
attention.  That  this  may  occur  is  now  generally  admitted,  and  ap- 
pears to  be  established  by  the  investigations  of  Strauss  and  Chamber- 
lain, Morisani,  and  others.  That  it  does  not  always  occur  is  shown, 
however,  by  the  researches  of  other  bacteriologists,  and  especially  by 
those  of  Wolff. 


VIII. 

THE   BACILLUS   OF  TYPHOID   FEVER. 

• 

RECENT  researches  support  the  view  that  the  bacillus  described 
by  Eberth  in  1880  bears  an  etiological  relation  to  typhoid  fever — 
typhus  abdominalis  of  German  authors  ;  and  pathologists  are  dis- 
posed to  accept  this  bacillus  as  the  veritable  "germ"  of  typhoid 
fever,  notwithstanding  the  fact  that  the  final  proof  that  such  is  the 
case  is  still  wanting. 

This  final  proof  would  consist  in  the  production  in  man  or  in  one 
of  the  lower  animals  of  the  specific  morbid  phenomena  which  char- 
acterize the  disease  in  question,  by  the  introduction  of  pure  cultures 
of  the  bacillus  into  the  body  of  a  healthy  individual.  Evidently  it  is 
impracticable  to  make  the  test  upon  man,  and  thus  far  we  have  no 
satisfactory  evidence  that  any  one  of  the  lower  animals  is  subject  to 
the  disease  as  it  manifests  itself  in  man.  The  experiments  of 
Friinkel  and  Simmonds  show,  however,  that  this  bacillus  is  patho- 
genic for  the  mouse  and  the  rabbit.  We  shall  refer  to  the  experi- 
ments of  these  authors  later. 

Before  the  publication  of  Eberth's  first  paper  Koch  had  observed 
this  bacillus  in  sections  made  from  the  spleen  and  liver  of  typhoid 
cases,  and  had  made  photomicrographs  from  these  sections.  His 
name  is,  therefore,  frequently  associated  with  that  of  Eberth  as  one 
of  the  discoverers  of  the  typhoid  bacillus.  Other  investigators  had  no 
doubt  previously  observed  the  same  organism,  but  some  of  them  had 
improperly  described  it  as  a  micrococcus.  Such  a  mistake  is  easily 
made  when  the  examination  is  made  with  a  low  power  ;  even  with  a 
moderately  high  power  the  closely  crowded  colonies  look  like  masses 
of  micrococci,  and  it  is  only  by  focussing  carefully  upon  the  scattered 
organisms  on  the  outer  margin  of  a  colony  that  the  oval  or  rod-like 
form  can  be  recognized. 

Several  observers  had  noted  the  presence  of  microorganisms  in 
the  lesions  of  typhoid  fever  prior  to  the  publication  of  Eberth 's  pa- 
per, and  Browicz  in  1875,  and  Fischel  in  1878,  had  recognized  the 
presence  of  oval  organisms  in  the  spleen  which  were  probably  identi- 
cal with  the  bacillus  of  Eberth. 

The  researches  of  Gaffky  (1884)  strongly  support  the  view  that 
26 


338  THE   BACILLUS   OF   TYPHOID   FEVER. 

the  bacillus  under  consideration  bears  a  causal  relation  to  typhoid 
fever.  Eberth  was  only  successful  in  finding  the  bacillus  in  the 
lymphatic  glands  or  in  the  spleen  in  eighteen  cases  out  of  forty  in 
which  he  searched  for  it.  On  the  other  hand,  he  failed  to  find  it  in 
eleven  cases  of  various  nature — partly  infectious  processes — and  in 
thirteen  cases  of  tuberculosis  in  which  the  lymphatic  glands  were 
involved,  and  in  several  of  which  there  was  ulceration  of  the  mucous 
membrane  of  the  intestine. 

Koch,  independently  of  Eberth  and  before  the  publication  of  his 
first  paper,  had  found  the  same  bacillus  in  about  half  of  the  cases 
examined  by  him,  and  had  pointed  out  the  fact  that  they  were  lo- 
cated in  the  deeper  parts  of  the  intestinal  mucous  membrane,  beyond 
the  limits  of  necrotic  changes,  and  also  in  the  spleen,  whereas  the 
long,  slender  bacillus  of  Klebs  was  found  only  in  the  necrosed  por- 
tions of  the  intestinal  mucous  membrane. 

The  researches  of  W.  Meyer  (1881)  gave  a  larger  proportion  of 
successful  results.  This  author  confined  his  attention  chiefly  to  the 
swollen  plaques  of  Peyer  and  follicles  of  the  intestine  which  had  not 
yet  undergone  ulceration.  The  short  bacillus  which  had  been  de- 
scribed by  Eberth  and  Koch  was  found  in  sixteen  out  of  twenty  cases 
examined.  The  observations  of  this  author  are  in  accord  with  those 
of  Eberth  as  to  the  presence  of  the  bacillus  in  greater  abundance  in 
cases  of  typhoid  which  had  proved  fatal  at  an  early  date. 

The  fact  that  in  these  earlier  researches  the  bacilli  were  not  found 
in  a  considerable  proportion  of  the  cases  examined  is  by  no  means 
fatal  to  the  view  that  they  bear  an  etiological  relation  to  the  disease. 
As  Gaff ky  says  in  his  paper  referred  to  : 

"  This  circumstance  admits  of  two  explanations.  Either  in  those 
cases  in  which  the  bacillus  has  been  sought  with  negative  results 
they  may  have  perished  collectively,  before  the  disease  process  which 
thev  had  induced  had  run  its  course  ;  or  the  proof  of  the  presence  of 
bacilli  was  wanting  only  on  account  of  the  technical  difficulties  which 
attend  the  finding  of  isolated  colonies." 

Gaffky's  own  researches  indicate  that  the  latter  explanation  is  the 
correct  one. 

In  twenty-eight  cases  examined  by  this  author  characteristic 
colonies  of  the  bacillus  were  found  in  all  but  two.  In  one  of  these, 
one  hundred  and  forty-six  sections  from  the  spleen,  liver,  and  kid- 
neys were  examined  without  finding  a  single  colony,  and  in  the  other 
a  like  result  attended  the  examination  of  sixty-two  sections  from  the 
spleen  and  twenty-one  sections  from  the  liver.  In  the  first  of  these 
cases,  however,  numerous  colonies  were  found  in  recent  ulcers  of  the 
intestinal  mucous  membrane,  deeply  located  in  that  portion  of  the 
tissue  which  was  still  intact.  These  recent  ulcers  were  in  the  neigh- 


THE   BACILLUS   OP   TYPHOID   FEVER.  339 

borhood  of  old  ulcers  and  are  supposed  to  have  indicated  a  relapse 
of  the  specific  process.  In  the  second  case  the  negative  result  is 
thought  by  Gaffky  to  have  been  not  at  all  surprising,  as  the  patient 
died  at  the  end  of  the  fourth  week  of  sickness,  not  directly  from  the 
typhoid  process,  but  as  a  result  of  perforation  of  the  intestine. 

Gaffky  has  further  shown  that  in  those  cases  in  which  colonies 
are  not  found  in  the  spleen,  or  in  which  they  are  extremely  rare,  the 
presence  of  the  bacillus  may  be  demonstrated  by  cultivation ;  and 
that,  when  proper  precautions  are  taken,  pure  cultures  of  the  bacil- 
lus may  always  be  obtained  from  the  spleen  of  a  typhoid  case. 
Hein  has  been  able  to  demonstrate  the  presence  of  the  bacillus  and 
to  start  pure  cultures  from  material  drawn  from  the  spleen  of  a  living 
patient  by  means  of  a  hypodermatic  syringe.  Philopowicz  has  re- 
ported his  success  in  obtaining  cultures  of  the  bacillus  by  the  same 
method. 

The  fact  that  a  failure  to  demonstrate  the  presence  of  microor- 
ganisms by  a  microscopic  examination  cannot  be  taken  as  proof  of 
their  absence  from  an  organ,  is  well  illustrated  by  a  case  (No.  18)  in 
which  the  bacillus  was  obtained  by  Gaffky  from  the  spleen  and  also 
from  the  liver,  in  pure  cultures  ;  whereas  in  cover-glass  preparations 
made  from  the  same  spleen  he  failed  to  find  a  single  rod,  and  more 
than  one  hundred  sections  of  the  spleen  were  examined  before  he 
found  a  colony. 

To  obtain  pure  cultures  from  the  spleen  Gaffky  first  carefully 
washes  the  organ  with  a  solution  of  mercuric  chloride,  1  : 1,000.  A 
long  incision  is  then  made  through  the  capsule  with  a  knife  sterilized 
by  heat.  A  second  incision  is  made  in  this  with  a  second  sterilized 
knife,  and  a  third  knife  is  used  to  make  a  still  deeper  incision  in  the 
same  track.  By  this  means  the  danger  of  conveying  organisms  from 
the  surface  to  the  interior  of  the  organ  is  avoided.  From  the  bottom 
of  this  incision  a  little  of  the  soft  splenic  tissue  is  taken  up  on  a  ster- 
ilized platinum  needle,  and  this  is  plunged  into  the  solid  culture 
medium,  or  drawn  along  the  surface  of  the  same,  or  added  to  lique- 
fied gelatin  and  poured  upon  a  glass  plate.  The  colonies  develop,  in 
an  incubating  oven,  in  the  course  of  twenty-four  to  forty-eight  hours. 

Gaffky  has  also  shown  that  the  bacillus  is  present  in  the  liver,  in 
the  mesenteric  glands,  and,  in  a  certain  proportion  of  cases  at  least, 
in  the  kidneys,  in  which  it  was  found  in  three  cases  out  of  seven. 

The  appearance  of  the  colonies  in  stained  sections  of  the  spleen 
is  shown  in  Figs.  106  and  107.  Two  colonies  are  seen  in  Fig.  10G 
(at  a,  a)  as  they  appear  under  a  low  power — about  sixty  diameters. 
In  Fig.  107  one  of  the  colonies  is  seen  more  highly  magnified — about 
five  hundred  diameters. 

Frankel  and  Simmonds  have  demonstrated  that  the  bacilli  multi- 


340 


THE   BACILLUS   OF   TYPHOID   FEVER. 


ply  in  the  spleen  after  death,  and  that  numerous  colonies  may  be 
found  in  portions  of  the  organ  which  have  been  kept  for  twenty- 
four  to  forty-eight  hours  before  they  were  placed  in  alcohol,  when 
other  pieces  from  the  same  spleen  placed  in  alcohol  soon  after  the 
death  of  the  patient  show  but  few  colonies  or  none  at  all. 

This  observation  does  not  in  any  way  weaken  the  evidence  as  to 
the  etiological  role  of  the  bacillus,  but  simply  shows  that  dead  ani- 
mal matter  is  a  suitable  nidus  for  the  typhoid  germ — a  fact  which 
has  been  repeatedly  demonstrated  by  epidemiologists  and  insisted 
upon  by  sanitarians. 

The  authors  last  referred  to  confirm  Gaffky  as  regards  the  con- 
stant presence  of  the  bacillus  in  the  spleen.  In  twenty-nine  cases 
they  obtained  it  by  plate  cultures  twenty-five  times,  and  remark 
that  in  the  four  cases  attended  with  a  negative  result  this  result  is 


FIG.  106. 


FIG.  107. 


not  at  all  surprising,  inasmuch  as  the  typhoid  process  had  termi- 
nated and  death  resulted  from  complications. 

Gaffky  did  not  succeed  in  obtaining  cultures  from  the  blood  of 
typhoid-fever  patients,  and  concludes  from  his  researches  that  if  the 
bacilli  are  present  in  the  circulating  fluid  it  must  be  in  very  small 
numbers.  He  remarks  that  possibly  the  result  would  be  different  if 
the  blood  were  drawn  directly  from  a  vein  instead  of  from  the  capil- 
laries of  the  skin.  Frankel  and  Simmonds  also  report  that  gelatin, 
to  which  blood  drawn  from  the  forefinger  of  typical  cases  had  been 
added,  remained  sterile  when  poured  upon  plates  in  the  usual  man- 
ner— Koch's  method.  The  blood  was  obtained  from  six  different  in- 
dividuals, all  in  an  early  stage  of  the  dise  se— the  second  to  the 
third  week.  A  similar  experiment  made  with  blood  obtained,  post 
mortem,  from  the  large  veins  or  from  the  heart,  also  gave  a  negative 
result  in  every  instance  save  one.  In  the  exceptional  case  a  single 


THE   BACILLUS   OP   TYPHOID    FEVER.  341 

colony  developed  upon  the  plate.  In  view  of  these  results  we  are 
inclined  to  attribute  the  successful  attempts  reported  by  some  of  the 
earlier  experimenters  (Letzerich,  Almquist,  Maragliano)  to  accidental 
contamination  and  imperfect  methods  of  research.  The  more  recent 
work  of  Tayon  does  not  inspire  any  greater  confidence.  This  author 
obtained  cultures  in  bouillon  by  inoculating  it  with  blood  drawn 
from  a  typhoid  patient,  and  found  that  these  were  fatal,  in  a  few 
hours,  to  guinea-pigs,  when  injected  into  the  peritoneal  cavity.  The 
lesions  observed  are  said  to  have  resembled  those  of  typhoid  fever — 
congestion  and  tumefaction  of  Peyer's  plaques  and  of  the  mesenteric 
glands,  congestion  of  the  liver,  the  kidneys,  etc. 

The  presence  of  the  bacillus  of  Eberth  in  the  alvine  evacuations  of 
typhoid  patients  has  been  demonstrated  by  Pfeiffer  and  by  Frankel 
and  Simmonds.  This  demonstration  is  evidently  not  an  easy  mat- 
ter, for  while  the  bacilli  are  probably  always  present  in  some  portion 
of  the  intestine  during  the  progress  of  the  disease,  it  does  not  follow 
that  they  are  present  in  every  portion  of  the  intestinal  contents.  As 
only* a  very  small  amount  of  material  is  used  in  making  plate  cul- 
tures, and  as  there  are  at  all  times  a  multitude  of  bacteria  of  various 
species  in  the  smallest  portion  of  fsecal  matter,  it  is  not  to  be  ex- 
pected that  the  typhoid  bacillus  will  be  found  upon  every  plate. 
Frankel  and  Simmonds  made  eleven  attempts  to  obtain  the  bacillus 
by  the  plate  method,  using  three  plates  each  time,  as  is  customary 
with  those  who  adhere  strictly  to  the  directions  of  the  master,  and 
were  successful  in  obtaining  the  bacillus  in  three  instances — in  two 
in  great  numbers  and  in  the  third  in  a  very  limited  number  of  colo- 
nies. 

The  numerous  attempts  which  have  been  made  to  communicate 
typhoid  fever  to  the  lower  animals  have  given  a  negative  result  in 
every  instance.  Murchison,  in  1867,  fed  typhoid-fever  discharges  to 
swine,  and  Klein  has  made  numerous  experiments  of  the  same  kind 
upon  apes,  dogs,  cats,  guinea-pigs,  rabbits,  and  white  mice,  without 
result.  Birch-Hirschfeld,  in  1874,  by  feeding  large  quantities  of 
typhoid  stools  to  rabbits,  produced  in  some  of  them  symptoms  which 
in  some  respects  resembled  those  of  typhoid  ;  but  these  experiments 
were  repeated  by  Bahrdt  upon  ten  rabbits  with  an  entirely  negative 
result.  Von  Motschukoffsky  met  with  no  better  success  in  his  at- 
tempts to  induce  the  disease  by  injecting  blood  from  typhoid  patients 
into  apes,  rabbits,  dogs,  and  cats.  Walder  also  experimented  with 
fresh  and  with  putrid  discharges  from  typhoid  patients,  and  with 
blood  taken  from  the  body  after  death,  feeding  this  material  to 
calves,  dogs,  cats,  rabbits,  and  fowls,  without  obtaining  any  posi- 
tive results.  Klebs  has  also  made  numerous  experiments  of  a  simi- 
lar nature,  and  in  a  single  instance  found  in  a  rabbit,  which  died 


342  THE   BACILLUS   OF   TYPHOID   FEVER. 

forty-seven  hours  after  receiving  a  subcutaneous  injection  of  a  cul- 
ture fluid  containing  his  "  typhoid  bacillus,"  pathological  lesions  re- 
sembling those  of  typhoid. 

Eberth  and  Gaffky  very  properly  decline  to  attach  any  import- 
ance to  this  solitary  case,  in  which,  as  the  first-named  writer  re- 
marks, a  different  explanation  is  possible,  and  the  possibility  of  an 
intestinal  mycosis  not  typhoid  in  its  nature  must  be  considered. 

Gaffky  has  also  made  numerous  attempts  to  induce  typhoid 
symptoms  in  animals  by  means  of  pure  cultures  of  Eberth's  bacillus, 
given  with  their  food  or  injected  into  the  peritoneal  cavity  or  subcu- 
taneously.  The  first  experiments  were  made  upon  five  Java  apes. 
For  a  considerable  time  these  animals  were  fed  daily  with  pure  cul- 
tures containing  spores.  The  temperature  of  the  animals  was  taken 
twice  daily.  The  result  was  entirely  negative.  No  better  success 
attended  the  experiments  upon  rabbits  (16),  guinea-pigs  (13),  white 
rats  (7),  house  mice  (11),  field  mice  (4),  pigeons  (2),  one  hen  and  a  calf. 

Cornil  and  Babes  report  a  similar  negative  result  from  pure  cul- 
tures of  the  typhoid  bacillus  injected  into  the  peritoneal  cavity  and 
into  the  duodenum  in  rabbits  and  guinea-pigs. 

Frankel  and  Simmonds  have  made  an  extended  series  of  experi- 
ments upon  guinea-pigs,  rabbits,  and  mice,  and  have  shown  that 
pure  cultures  of  the  bacillus  of  Eberth  injected  into  the  last-men- 
.tioned  animals — mice  and  rabbits —may  induce  death,  and  that  the 
bacillus  may  again  be  obtained  in  pure  cultures  from  their  organs. 
It  is  not  claimed  that  the  animals  suffer  an  attack  of  typhoid  fever 
as  the  result  of  these  injections,  but  that  their  death  is  due  to  the 
introduction  into  their  bodies  of  the  typhoid  bacillus,  and  that  this 
bacillus  is  thereby  proved  to  be  pathogenic. 

The  failure  to  produce  the  characteristic  lesions  of  typhoid  in  the 
lower  animals  is  evidently  not  opposed  to  the  view  that  this  bacillus 
is  the  specific  cause  of  such  lesions  in  man.  Frankel  and  Simmonds 
quote  from  Koch  in  support  of  this  statement,  as  follows  : 

"  In  my  opinion  it  is  not  at  all  necessary,  when  we  experiment  upon  ani- 
mals, to  obtain  precisely  the  same  symptoms  as  in  man.  In  support  of  this 
opinion  I  may  refer  to  the  infectious  diseases  which  we  are  able  to  induce 
experimentally  in  the  lower  animals.  Anthrax  runs  a  very  different  course 
in  animals  and  in  man;  tuberculosis  does  not  present  itself  in  precisely  the 
same  manner  in  one  species  of  animals  as  in  another.  Phthisis,  as  it  occurs 
in  man,  we  cannot,  in  general,  produce  in  animals ;  and,  nevertheless,  we 
cannot  assert  that  the  animals  experimented  upon  do  not  suffer  from  tuber- 
culosis, and  that  the  conclusions  which  we  draw  from  such  experiments  are 
not  perfectly  correct." 

In  Frankel  and  Simmonds'  experiments  a  considerable  quantity 
of  material  was  used,  and  the  injections  were,  for  the  most  part, 
made  into  the  peritoneal  cavity  in  mice,  or  into  the  circulation 


THE   BACILLUS   OF   TYPHOID   FEVER.  343 

through  a  vein  in  rabbits.  The  influence  of  quantity  of  material 
used  is  especially  shown  in  the  case  of  the  mice,  and  the  question 
arises  whether  the  pathogenic  power  of  the  bacillus  for  these  ani- 
mals does  not  depend  upon  the  simultaneous  injection  of  the  ptomaine 
developed  in  cultures  as  a  result  of  the  vital  activity  of  the  organ- 
ism. Thus  we  read  that  mouse  No.  4  resisted  an  injection  of  a  di- 
lute solution  of  culture  No.  1,  but  succumbed  to  a  more  concentrated 
solution — one-fifth  of  a  Pravaz  syringe.  Mouse  No.  5  was  not  killed 
by  the  injection  of  one-third  of  a  syringeful  of  a  dilute  solution,  but 
subsequently  died  from  the  injection  of  one-third  of  a  syringeful  of 
a  concentrated  solution.  Mouse  No.  16,  injected  October  10th  with 
half  of  a  syringeful  of  a  very  diluted  culture,  did  not  die.  The  in- 
jection was  repeated  on  the  17th  of  October  with  half  a  syringeful 
of  a  concentrated  solution,  with  fatal  result. 

In  all,  thirty-five  mice  were  injected,  with  a  fatal  result  in  twen- 
ty-seven cases.  In  rabbits  the  injections  were  commonly  made  in 
the  large  vein  of  the  ear,  and  the  quantity  of  material  injected  was 
considerably  greater — from  one-third  the  contents  of  a  hypodermatic 
syringe  to  two  syringefuls.  In  some  instances  death  occurred  with- 
in a  few  hours,  in  others  on  the  following  day  or  after  an  interval  of 
two  or  three  days.  It  is  noticeable  that  the  results  differ  very  great- 
ly as  to  the  date  of  death  and  the  relative  quantity  of  material  re- 
quired to  produce  a  fatal  result.  This  probably  depends  to  some 
extent  upon  the  size  of  the  animal,  and  perhaps  partly  upon  indi- 
vidual differences  in  resisting  power. 

The  experiments,  considered  together,  show  that  the  typhoid  ba- 
cillus is  not  pathogenic  for  these  animals  in  the  same  sense  as  is  the 
anthrax  bacillus  or  the  bacillus  of  rabbit  septicaemia.  These  organ- 
isms introduced  beneath  the  skin  or  into  the  circulation  in  the  small- 
est amount  infallibly  produce  death,  and  at  the  expiration  of  a  pe- 
riod of  time  which  is  tolerably  uniform. 

In  all,  seventy-nine  experiments  upon  rabbits  were  made,  with  the 
following  result  :  Five  injections  into  the  intestine,  five  into  the  sub- 
cutaneous connective  tissue,  one  into  the  lung,  and  two  inhalation 
experiments,  all  without  result;  twenty  injections  into  the  peri- 
toneal cavity  furnished  two,  and  forty-six  injections  into  the  vein  of 
the  ear  twenty  positive  results — i.  e. ,  were  fatal  to  the  animal. 

In  the  fatal  cases  the  bacilli  were  proved  to  be  present  in  the 
spleen  by  culture  experiments  and  by  microscopical  examination  of 
properly  stained  sections.  The  colonies  were  identical  in  appearance 
with  those  found  in  the  spleen  of  cases  of  typhoid  in  man.  Col- 
onies were  found  in  the  spleens  of  the  rabbits  experimented  upon 
exactly  as  in  the  human  subject — sometimes  in  the  trabeculae,  some- 
times in  the  Malpighian  bodies,  sometimes  free  in  the  splenic  pulp. 


34:4  THE   BACILLUS   OF   TYPHOID    FEVER. 

Brieger  has  made  some  very  interesting  researches  with  reference 
to  the  chemical  substances  which  are  produced  as  a  result  of  the 
physiological  processes  attending  the  growth  of  this  bacillus. 

Having  obtained  a  culture  from  the  spleen  of  a  typhoid  patient, 
and  assured  himself  by  comparison  with  a  pure  culture  given  him 
by  Koch  that  he  was  dealing  with  the  right  organism,  Brieger 
planted  the  bacillus  in  a  culture  solution  containing  grape  sugar  and 
salts — Nahrsalzen — in  which  it  thrived  admirably.  Such  a  solution 
at  30°  C.  became  clouded  at  the  end  of  twenty-four  hours,  and  gave 
off  an  evident  odor  of  ethyl  alcohol,  which  increased  from  day  to  day. 
In  addition  to  ethyl  alcohol  small  quantities  of  the  volatile  fat  acids 
were  produced — among  them  acetic  acid.  Lactic  acid  was  also 
formed  from  the  grape  sugar.  The  bacillus  grew  still  better  in  al- 
buminous culture  fluids.  It  did  not  in  these  give  rise  to  the  produc- 
tion of  sulphuretted  hydrogen  or  of  any  of  the  volatile  products  of 
putrefactive  decomposition,  such  as  indol  and  phenol.  There  was 
no  gas  formation  in  such  cultures,  even  after  standing  for  eight 
weeks,  but  a  slight  odor,  resembling  that  of  whey,  was  given  off 
from  the  cultures.  Repeatedly,  but  not  in  every  case,  Brieger  suc- 
ceeded in  obtaining  from  such  cultures  a  very  deliquescent  basic 
product.  This  was  obtained  in  only  very  small  quantities,  even 
when  the  cultures  had  remained  in  the  incubating  oven  for  a  month. 
The  physiological  properties  of  this  base  have  convinced  Brieger  that 
it  is  a  new  ptomaine.  In  guinea-pigs  this  ptomaine  produced  a  slight 
flow  of  saliva  and  frequent  respiration.  Later  the  animals  lost  con- 
trol of  their  extremities  and  of  the  muscles  of  the  trunk  ;  they  fell 
upon  their  side,  but  when  placed  upon  their  legs  were  able  to  move 
forward  a  little  ;  they,  however,  soon  fell  again  and  remained  help- 
less upon  their  side.  The  pupils  gradually  became  widely  dilated 
and  failed  to  respond  to  light ;  the  flow  of  saliva  became  more  pro- 
fuse ;  no  convulsions  occurred.  Little  by  little  the  pulsations  of  the 
heart  and  the  breathing  became  more  frequent.  During  the  entire 
course  of  these  symptoms  the  animals  had  frequent  liquid  discharges. 
Death  occurred  in  from  twenty-four  to  forty-eight  hours.  Post- 
mortem examination  showed  the  heart  to  be  contracted  in  systole, 
the  lungs  to  be  hypersemic,  the  intestine  contracted  and  pale. 

The  experimental  evidence  which  we  have  presented,  considered 
in  connection  with  established  facts  relating  to  the  propagation  of 
typhoid  fever,  seems  to  the  writer  to  be  convincing  as  regards  the 
etiological  role  of  this  bacillus. 

No  other  organism  has  been  found,  after  the  most  careful  search, 
in  the  deeper  portions  of  the  intestinal  glands  involved  in  this  disease, 
or  in  the  internal  organs  ;  on  the  other  hand,  this  bacillus  has  been 
demonstrated  to  be  constantly  present.  It  is  undoubtedly  present 


THE   BACILLUS   OF   TYPHOID   FEVER.  345 

during  the  lifetime  of  the  patients,  and  is  found  in  greater  abun- 
dance in  those  cases  which  terminate  fatally  at  an  early  date.  It  is 
not  a  putrefactive  organism,  and  is  not  developed  in  the  tissues  post 
mortem,  although  it  has  been  shown  by  Frankel  and  Simmonds  that 
it  multiplies  rapidly  in  the  spleen  after  death,  up  to  the  time  that 
putrefactive  decomposition  commences.  This  is  quite  in  accord  with 
what  we  should  a  priori  have  expected,  in  view  of  the  facts  relat- 
ing to  the  propagation  of  typhoid  fever.  These  facts  indicate  that 
the  disease  in  question  is  due  to  a  microorganism  which  is  capable  of 
multiplication  external  to  the  human  body  in  a  variety  of  organic 
media,  at  comparatively  low  temperatures,  and  that  it  is  widely  dis- 
tributed. From  the  endemic  prevalence  of  the  disease  over  vast 
areas  of  the  earth's  surface  we  may  infer  that  it  is  induced  by  a 
hardy  microorganism.  Eberth's  bacillus  complies  with  all  of  these 
conditions. 

There  are  numerous  facts  which  indicate  that  the  development  of 
an  attack  of  typhoid  and  the  severity  of  the  symptoms  depend  to 
some  extent  upon  the  quantity  of  the  infectious  material  introduced 
into  the  alimentary  canal.  Milk  or  water  which  has  been  infected 
directly  by  the  discharges  of  typhoid  patients  is  especially  danger- 
ous, and  there  is  reason  to  believe  that  repeated  or  concentrated 
doses  of  such  infectious  material  may  be  effective  when  a  single 
draught  of  the  contaminated  fluid,  or  a  greater  degree  of  dilution, 
would  be  innocuous. 

Again,  we  have  evidence  that  the  typhoid  germs  may  become 
effective  as  a  result  of  certain  favorable  circumstances  relating  to  the 
individual  or  to  his  environment.  Those  agencies  which  reduce  the 
vital  resisting  power  of  the  tissues,  and  especially  exposure  to  the 
emanations  from  putrefying  material,  to  sewer  gas,  to  vitiated  air  in 
overcrowded  and  ill- ventilated  apartments,  etc.,  are  recognized  as 
favorable  to  the  development  of  typhoid  fever  where  the  specific 
cause  is  present.  All  these  facts  seem  to  accord  with  the  experi- 
mental evidence  which  indicates  that  the  pathogenic  power  of  the 
bacillus  of  Eberth  depends  upon  the  formation  of  a  poisonous 
ptomaine  rather  than  upon  a  special  facility  for  multiplying  in  the 
tissues  of  a  living  animal.  Indeed,  it  seems  quite  probable  that  its 
power  to  invade  living  animal  tissues  depends  upon  the  toxic  action 
of  this  ptomaine  ;  or,  it  may  be,  of  other  ptomaines  produced  under- 
certain  circumstances  in  the  body  in  excess  or  introduced  from  with- 
out. Such  toxic  agents  may  serve,  when  the  specific  germ  is  intro- 
duced into  the  intestine  in  comparatively  small  numbers,  to  give  it 
the  mastery  over  the  vital  resisting  power  of  the  tissues  subject  to  in- 
vasion, and  thus  to  induce  an  attack  of  the  disease. ' 

1  The  above  account  of  researches  relating  to  the  etiology  of  typhoid  fever  is  from 
27 


346 


THE  BACILLUS  OF  TYPHOID  FEVER. 


46.  BACILLUS  TYPHI  ABDOMINALIS. 


Synonyms. — Bacillus  typhosus  ;  Typhus  bacillus. 

Eberth  (1880  and  1881)  demonstrated  the  presence  of  this  bacillus 
in  the  spleen  and  diseased  glands  of  the  intestine  in  typhoid  cada- 
vers. Gaffky  (1884)  first  obtained  it  in  pure  cultures  from  the  same 
source  and  determined  its  principal  biological  characters. 

It  is  found,  in  the  form  of  small,  scattered  colonies,  in  the  spleen, 
the  liver,  the  glands  of  the  mesentery,  the  diseased  intestinal  glands, 
and  in  smaller  numbers  in  the  kidneys,  in  fatal  cases  of  typhoid  fever; 
it  has  also  been  obtained,  by  puncture,  from  the  spleen  during  life, 
from  the  alvine  discharges  of  the  sick,  and  rarely  from  the  urine. 
It  is  not  found  in  the  blood  of  the  general  circulation,  unless,  pos- 
sibly, in  rare  cases  and  in  small  numbers. 


FIG.  108.  FIG.  109. 

FIG.  108.— Bacillus  typhi  abdomlnalis,  from  single  gelatin  colony.  X  1,000.  From  a  photo- 
micrograph. (FrankelandPfeiffer.) 

FIG.  109  —Bacillus  typhi  abdominalis,  from  single  gelatin  colony.  X  1,000.  From  a  photo- 
micrograph. (Sternberg.) 

Morphology. — Bacilli,  usually  one  to  three  /*  in  length  and  about 
0.5  to  0.8  yw  broad,  with  rounded  ends  ;  may  also  grow  out  into  long 
threads,  especially  upon  the  surface  of  cooked  potato.  The  dimen- 
sions of  the  rods  differ  considerably  in  different  media.  Spherical  or 
oval  refractive  granules  are  often  seen  at  the  extremities  of  the  rods, 
especially  in  potato  cultures  kept  in  the  incubating  oven ;  these  are 
not  reproductive  spores,  as  was  at  first  supposed.  The  bacilli  have 
numerous  flagella  arranged  around  the  periphery  of  the  cells — usually 
from  five  to  twenty,  but  many  short  rods  have  but  a  single 

a  paper  read  by  the  writer  at  the  annual  meeting  of  the  Association  of  American 
Physicians,  Washington,  D.  C.,  June  18th,  1886. 


THE  BACILLUS   OP   TYPHOID   FEVER. 


347 


terminal  flagellum.  These  flagella  are  spiral  in  form,  about  0. 1  >u  in 
thickness,  and  from  three  to  five  times  as  long  as  the  rods  (Babes). 

In  stained  preparations  unstained  "  vacuoles"  may  often  be  seen 
at  the  margins  of  the  rods,  either  along  the  sides  or  at  the  ends  ; 
these  appear  to  be  due  to  a  retraction  of  the  protoplasm  from  the  cell 
membrane. 

The  typhoid  bacillus  stains  with  the  aniline  colors,  but  more 
slowly  than  many  other  bacteria,  and  easily  parts  with  its  color  when 
treated  with  decolorizing  agents — e.g.,  iodine  solution  as  employed  in 
Gram's  method.  Loffler's  solution  of  methylene  blue  is  an  excellent 
staining  agent  for  this  bacillus,  but  permanent  preparations  fade  out 
after  a  time  ;  f uchsin,  gentian  violet,  or  Bismarck  brown,  in  aqueous 
solution,  may  also  be  used.  The  flagella  may  be  demonstrated  by 
Loffler's  method  of  staining  (p.  32). 


Fie.  110.— Bacillus  typhi  abdominal! s,  stained  by  Loffler's  method,  showing  flagella.    x  1,000. 
From  a  photomicrograph  by  Frankel  and  Pfeiffer. 

To  stain  the  bacillus  in  sections  of  the  spleen,  etc. ,  it  is  best  to 
leave  these  in  Loffler's  methylene  blue  solution  or  in  the  carbol- 
fuchsin  solution  of  Ziehl  for  twelve  hours  or  more ;  or  the  aniline- 
fuchsin  solution  may  be  used.  The  sections  should  be  washed  in 
distilled  water  only,  when  Ziehl's  solution  is  used,  or  with  a  very  di- 
lute solution  of  acetic  acid  when  Ehrlich's  tubercle  stain  is  employed 
(Baumgarten). 

Biological  Characters. — The  typhoid  bacillus  is  a  motile,  aero- 
bic, non-liquefying  bacillus,  which  grows  readily  in  a  variety  of 
culture  media  at  the  "  room  temperature."  Although  it  grows  most 
abundantly  in  the  presence  of  free  oxygen,  it  may  also  develop  in  its 
absence,  and  is  consequently  a  facultative  anaerobic. 


348 


THE  BACILLUS   OF   TYPHOID   FEVER. 


FIG.  111.—  Singlecolony  of  Bacillus 
typhi  abdominalis,  ju  nutrient  gela- 
tin, (x?)  From  a  photograph  by 
Roux. 


•HUH 


In  gelatin  plate  cultures  small,  white  colonies  are  developed  at 
the  end  of  thirty-six  to  forty-eight  hours,  which  under  the  microscope 

are  seen  to  be  somewhat  irregular  in 
outline  and  of  a  spherical,  oval,  or  long- 
oval  form ;  these  have  by  transmitted 
light  a  slightly  granular  appearance  and 
a  yellowish-brown  color.  At  the  end  of 
three  or  four  days  the  colonies  upon  the 
surface  of  the  gelatin  form  a  grayish- 
white  layer  of  one  to  two  millimetres  in 
diameter,  with  more  or  less  irregular 
margins,  and,  when  developed  from  deep 
colonies,  with  an  opaque  central  nucleus. 
These  colonies,  by  transmitted  light, 
have  a  yellowish-brown  color  towards 
the  centre,  where  they  are  thickest, 
while  the  margins  are  colorless  and  transparent ;  the  surface  is  com- 
monly marked  with  a  network  of  lines  and  furrows.  Stick  cultures 
in  ten-per-cent  gelatin,  at  18°  to  20°  C.,  at  the 
end  of  three  days  show  upon  the  surface  a 
whitish,  semi-transparent  layer,  with  sharply 
defined  margins  and  irregular  outline,  which 
has  a  shining,  pearly  lustre ;  and  along  the 
line  of  puncture  a  grayish-white  growth,  made 
up  of  crowded  colonies,  which  are  larger  and 
more  distinct  at  the  bottom  of  the  line  of  growth. 
Upon  nutrient  agar,  at  a  temperature  of  35° 
to  37°  C.,  the  growth  is  more  rapid  and  forms 
a  whitish,  semi-transparent  layer.  The  cul- 
tures give  off  a  faint  putrefactive  odor.  The 
growth  upon  blood  serum  is  rather  scanty,  in 
the  form  of  transparent,  shining  patches  along 
the  line  of  inoculation. 

The  typhoid  bacillus  develops  abundantly 
in  milk,  in  which  fluid  it  produces  an  acid  re- 
action ;  it  also  grows  in  various  vegetable  in- 
fusions and  in  bouillon. 

None  of  the  above  characters  of  growth 
are  distinctive,  as  certain  common  bacilli  found 
in  normal  faeces  present  a  very  similar  appear- 
ance when  cultivated  in  the  same  media. 

The  growth  of  this  bacillus  upon  potato  is 
an  important  character,  as  was  first  pointed  out 
by  Gaffky.  In  the  incubating  oven  at  the  end  of  forty-eight  hours, 


FIG.  112.— Bacillus  typhi 
abdominalis ;  stick  culture 
in  nutrient  gelatin,  eighth 
day  at  16° -20°  C.  (Baum 
garten.) 


THE   BACILLUS    OF   TYPHOID    FEVER.  349 

or  at  the  room  temperature  in  three  or  four  days,  the  surface  of 
the  potato  has  a  moist,  shining  appearance,  but  there  is  no  visible 
growth  such  as  is  produced  by  many  other  bacteria  upon  this  me- 
dium. A  simple  inspection  would  lead  to  the  belief  that  no  growth 
had  occurred;  but  if  with  a  platinum  needle  a  little  material  is 
scraped  from  any  portion  of  the  shining  surface  and  a  stained  pre- 
paration is  made  from  it,  numerous  bacilli  will  be  seen,  some  of 
which  are  likely  to  be  in  the  form  of  quite  long  threads,  while  others 
are  short  and  have  rounded  extremities.  This  "  invisible  growth " 
has  been  shown  by  the  researches  of  Buchner  and  others  to  be  most 
characteristic  upon  potatoes  having  a  decidedly  acid  reaction,  as  is 
usually  the  case.  When  cultivated  upon  potatoes  having  an  alkaline 
reaction  a  thin,  visible  film  of  a  yellowish-brown  color  and  of  limited 
extent  may  be  developed.  Inasmuch  as  several  common  and  widely 
distributed  bacteria  closely  resemble  the  typhoid  bacillus  in  form  and 
in  their  growth  in  nutrient  gelatin,  this  character  of  invisible  growth 
upon  potato  is  very  important  for  its  differentiation,  especially  as  the 
common  bacilli  referred  to — Bacillus  coli  communis,  bacillus  of  Em- 
merich— produce  a  very  distinct  and  rather  thick,  yellowish-white 
mass  upon  the  surface  of  potato.  But  recent  researches  show  that 
this  invisible  growth,  although  not  a  common  character,  does  not 
belong  exclusively  to  the  typhoid  bacillus  (Babes). 

This  bacillus  in  its  development  in  culture  media  produces  acids — 
according  to  Brieger  small  quantities  of  volatile  fat  acids,  and,  in 
presence  of  grape  sugar,  lactic  acid.  It  also  grows  readily  in  a  de- 
cidedly acid  medium,  and  this  character  has  been  employed  as  a  test 
for  differentiating  it  from  other  similar  bacilli ;  but  some  of  these 
also  grow  in  a  decidedly  acid  medium,  and  too  much  reliance  cannot 
be  placed  upon  this  test. 

Brieger  has  shown  that  indol  is  not  produced  in  cultures  of  the 
typhoid  bacillus,  and  Kitasato  has  proposed  to  use  the  indol  test  for 
differentiating  this  from  other  similar  bacilli  which  are  said,  as  a 
rule,  to  give  the  indol  reaction.  This  test  consists  in  the  addition  to 
ten  cubic  centimetres  of  a  bouillon  culture  which  has  been  in  the  in- 
cubating oven  for  twenty-four  hours,  of  one  cubic  centimetre  of  a 
solution  of  sodium  nitrite  (0.02  gramme  to  one  hundred  cubic  centi- 
metres of  distilled  water),  together  with  a  few  drops  of  concentrated 
sulphuric  acid.  If  indol  is  present  a  red  color  is  developed. 

None  of  the  above-mentioned  tests  are  entirely  reliable,  but,  taken 
together  with  the  morphological  and  biological  characters  above  de- 
scribed, they  may  enable  the  bacteriological  expert  to  give  a  tolerably 
confident  opinion  as  to  the  presence  of  this  bacillus  in  a  water  supply 
suspected  of  contamination,  etc.  And  when  a  bacillus  having  these 
characters  is  obtained  in  a  pure  culture  from  the  spleen  of  a  typhoid 


350  THE   BACILLUS   OF  TYPHOID   FEVER. 

cadaver  the  student  may  be  very  sure  that  he  has  the  typhoid  bacillus. 
But  in  the  presence  of  various  similar  bacilli,  as  in  faeces,  very  careful 
comparative  researches  will  be  required  to  determine  in  a  definite 
manner  that  a  non-liquefying  bacillus  obtained  in  pure  cultures  by 
the  plate  method  is  really  the  one  now  under  consideration — espe- 
cially so  as  the  cultures  of  the  typhoid  bacillus  in  the  same  medium 
may  differ  considerably  at  different  times,  and  a  number  of  bacilli 
are  known  which  resemble  it  so  closely  that  it  is  still  uncertain 
whether  they  are  to  be  considered  as  varieties  of  the  typhoid  bacillus 
or  as  distinct  species.  Thus  Babes,  in  an  extended  research,  found  in 
the  organs  of  typhoid  cases,  associated  with  the  true  typhoid  bacillus, 
other  bacilli  or  varieties  very  closely  resembling  it.  He  has  also 
described  three  varieties  (?),  obtained  by  him  from  other  sources, 
which  could  only  be  differentiated  from  the  true  typhoid  bacillus  by 
very  careful  comparison  of  cultures  made  side  by  side  in  various 
media. 

Cassedebat,  also,  in  an  extended  examination  of  the  river  water 
at  Marseilles  with  reference  to  the  presence  of  the  typhoid  bacillus, 
found  three  species  which  very  closely  resembled  it,  but  which  by 
careful  comparison  were  shown  to  present  slight  but  constant  dif- 
ferences in  their  biological  characters.  He  was  not  able  to  find  the 
true  typhoid  bacillus,  and  his  researches,  together  with  those  of  Babes 
and  other  recent  investigators,  make  it  appear  probable  that  numerous 
mistakes  have  been  made  by  bacteriologists  who  have  reported  the 
finding  of  the  typhoid  bacillus  in  river  and  well  water,  in  faeces,  etc., 
and  who  have  depended  mainly  upon  the  character  of  invisible 
growth  upon  potato  in  making  their  diagnosis.  Cassedebat  states 
that  all  three  of  his  pseudo-typhoid  bacilli  corresponded  in  their 
growth  upon  potato  with  the  bacillus  of  Eberth.  They  also  corre- 
sponded in  their  growth  on  gelatin,  agar-agar,  and  blood  serum, 
which,  as  heretofore  remarked,  has  no  characteristic  features.  They 
all  gave  a  negative  indol  reaction.  Like  the  typhoid  bacillus,  they 
grew  in  milk  without  causing  coagulation  of  the  casein,  but  two  of 
them  produced  an  alkaline  reaction  in  this  fluid,  while  the  third  cor- 
responded with  the  typhoid  bacillus  in  producing  a  decided  acid  re- 
action. Differences  were  also  observed  in  bouillon  cultures,  and  in 
bouillon  and  milk  to  which  various  aniline  colors  had  been  added,  as 
recommended  by  Holz. 

Whether  the  typhoid  bacillus,  as  obtained  from  the  spleen  of  a 
typhoid  cadaver,  is  in  truth  specifically  distinct  from  these  similar 
bacilli,  or  whether  they  are  all  varieties  of  the  same  species,  result- 
ing from  modifications  in  their  biological  characters  acquired  during 
their  continuous  development  under  different  conditions,  is  an  un- 
settled question.  But,  in  view  of  the  experimental  evidence  now 


THE   BACILLUS   OF   TYPHOID    FEVER.  351 

available,  there  is  nothing  improbable  in  the  supposition  that  they  are 
simply  varieties,  and  that,  as  the  result  of  a  saprophytic  mode  of 
life,  this  bacillus  may  undergo  more  or  less  permanent  modifications. 
In  the  writer's  experiments  (1887)  the  thermal  death-point  of  the 
typhoid  bacillus  was  found  to  be  56°  C.,  the  time  of  exposure  being 
ten  minutes  ;  and  potato  cultures  containing  the  refractive  granules 
described  by  Gaffky  as  spores  were  found  to  be  infallibly  destroyed 
by  a  temperature  of  60°  C.  This  result  has  been  confirmed  by  Buch- 
ner  (1888)  arid  by  Janowsky  (1890),  and  the  inference  seems  justified 
that  these  granules  are  not  reproductive  bodies,  as  was  at  first  be- 
lieved ;  for  spores  are  distinguished  by  their  great  resistance  to  heat 
and  other  destructive  agencies.  According  to  Buchner,  the  bacilli 
containing  these  refractive  granules  are  even  less  resistant  than  fresh 
cultures  in  which  they  are  not  present,  and  he  is  disposed  to  look 
upon  them  as  representing  a  degeneration  of  the  protoplasm  of  the 
cells.  They  do  not  stain  by  the  methods  which  are  successful  in 
staining  the  spores  of  other  bacilli,  and,  in  short,  present  none  of  the 
characters  which  distinguish  spores,  except  the  form  and  high  re- 
fractive power. 

The  typhoid  bacillus  retains  its  vitality  for  many  months  in  cul- 
tures; the  writer  has  preserved  bouillon  cultures  for  more  than  a  year 
in  hermetically  sealed  tubes,  and  has  found  that  development 
promptly  occurred  in  nutrient  gelatin  inoculated  from  these.  Dried 
upon  a  cover  glass,  it  may  grow  in  a  suitable  medium  after  having 
been  preserved  for  eight  to  ten  weeks  (Pfuhl).  When  added  to 
sterilized  distilled  water  it  may  retain  its  vitality  for  more  than  four 
weeks  (Bolton),  (forty  days  Cassedebat),  and  in  sterilized  sea- water 
for  ten  days  (De  Giaxa).  Added  to  putrefying  faeces  it  may  preserve 
its  vitality  for  several  months  (Ufflemann),  in  typhoid  stools  for  three 
months  (Karlinski),  and  in  earth  upon  which  bouillon  cultures  had 
been  poured  for  five  and  one-half  months  (Grancher  and  Deschamps). 
In  hanging-drop  cultures  this  bacillus  may  be  seen  to  exhibit  very 
active  movements,  the  shorter  rods  rapidly  crossing  the  field  with  a 
darting  or  to-and-fro,  progressive  motion,  while  longer  filaments 
move  in  a  serpentine  manner. 

In  addition  to  the  volatile  fat  acids  which,  according  to  Brieger, 
are  formed  in  small  amounts  in  cultures  of  the  typhoid  bacillus,  and 
to  lactic  acid  formed  in  solutions  containing  grape  sugar,  a  basic 
substance  possessing  toxic  properties  has  been  isolated  by  the  chemist 
named — his  typhotoxine  (C7H17NO2).  Brieger  supposes  that  other 
basic  substances  are  likewise  formed,  but  believes  this  to  be  the  speci- 
fic product  to  which  the  pathogenic  action  of  the  bacillus  is  due.  It 
is  a  strongly  alkaline  base,  which  produces  in  mice  and  guinea-pigs 
salivation,  paralysis,  dilated  pupils,  diarrhoea,  and  death. 


352 


THE  BACILLUS   OF   TYPHOID   FEVER. 


Numerous  experiments  have  been  made  to  determine  the  amounts 
of  various  germicidal  agents  required  to  destroy  the  vitality  of  this 
bacillus,  and  the  action  of  antiseptics  in  restraining  its  development. 
For  the  results  of  these  experiments  the  reader  is  referred  to  the 
sections  in  Part  Second  relating  to  the  action  of  antiseptics  and  disin- 
fectants. 

Pathogenesis. — The  very  numerous  experiments  which  have  been 
made  on  the  lower  animals  have  not  been  successful  in  producing  in 
any  one  of  them  a  typical  typhoid  process.  Nor  is  this  surprising, 
in  view  of  the  fact  that,  so  far  as  is  known,  no  one  of  them  is  liable  to 
contract  the  disease,  as  man  does,  by  the  use  of  infected  food  or 
water. 

The  experiments  of  Frankel  and  Simmonds  show  that  when  con- 
siderable quantities  of  a  pure  culture  of  this  bacillus  are  injected  into 


Fia    113  —Section  through  wall  of  intestine,  showing  invasion  by  typhoid  bacilli,    x  950. 
(Baumgarten.) 

the  circulation  of  rabbits  through  the  ear  vein,  or  into  the  peritoneal 
cavity  of  mice,  a  certain  proportion  of  the  inoculated  animals  die, 
usually  within  forty-eight  hours,  and  that  the  bacillus  may  be  re- 
covered from  the  various  organs,  although  it  is  not  present  in  the 
blood.  But  death  does  not  always  occur  from  intravenous  injections, 
and  subcutaneous  or  intraperitoneal  injections  in  rabbits  are  usually 
without  result.  Subcutaneous  injections  in  mice  proved  to  be  fatal  in 
ten  cases  out  of  sixteen  inoculated  by  A.  Frankel.  Seitz,  by  following 
Koch's  method — i.e.,  by  rendering  the  contents  of  the  stomach  alka- 
line, and  arresting  intestinal  peristalsis  by  the  administration  of 
opium — obtained  a  fatal  result,  in  a  majority  of  the  guinea-pigs  experi- 
mented upon,  from  the  introduction  of  ten  cubic  centimetres  of  a 
bouillon  culture  into  the  stomach  through  a  pharyngeal  catheter. 
We  may  remark,  with  reference  to  these  results,  that  while  they  show 
that  cultures  of  the  typhoid  bacillus  have  a  certain  pathogenic  power. 


THE   BACILLUS   OF   TYPHOID   FEVER.  353 

they  also  show  thai  the  animals  experimented  upon  frequently  re- 
covered after  comparatively  large  doses,  and  that  the  typhoid  bacil- 
lus is  not  pathogenic  in  the  same  sense  as  are  those  microorganisms 
which,  when  introduced  into  the  body  of  a  susceptible  animal  in  very 
minute  amount,  give  rise  to  general  infection  and  death.  On  the 
other  hand,  a  fatal  result  depends  upon  the  quantity  of  the  culture 
introduced  in  the  first  instance,  rather  than  upon  the  multiplication 
of  the  bacillus  in  the  body  of  the  inoculated  animal.  This  view  is 
confirmed  by  the  experiments  of  Sirotinin,  which  show  not  only  that 
a  fatal  result  depends  upon  the  quantity  injected,  but  also  that  a 
similar  result  follows  the  injection  of  cultures  which  have  been  ster- 
ilized by  heat  or  filtration.  The  pathogenic  action,  then,  depends 
upon  the  presence  of  toxic  substances  produced  during  the  growth  of 
the  bacillus  in  artificial  culture  media.  The  researches  of  Brieger, 
heretofore  referred  to,  show  the  presence  in  such  cultures  of  a  toxic 
ptomaine — his  typhotoxine — to  which  the  pathogenic  potency  of  these 
cultures  appears  to  be  due.  White  mice  and  guinea-pigs  usually  die 
in  from  twenty-four  to  forty-eight  hours  when  inoculated  in  the 
cavity  of  the  abdomen  with  a  virulent  culture  of  the  typhoid  bacillus 
— 0. 1  cubic  centimetre  to  0. 5  cubic  centimetre  of  a  bouillon  culture 
three  days  old.  According  to  Kitasato,  the  virulence  of  cultures 
from  different  cases  of  typhoid  fever  varies  considerably. 

Detection  of  the  Typhoid  Bacillus  in  Water. — The  generally 
recognized  fact  that  typhoid  fever  is  usually  contracted  by  drink- 
ing water  contaminated  by  the  typhoid  bacillus  has  led  to  numer- 
ous researches  having  for  their  object  the  discovery  of  a  reliable 
method  of  detecting  this  bacillus  when  present  in  water  in  compara- 
tively small  numbers  in  association  with  the  ordinary  water  bacilli. 
The  use  of  Koch's  plate  method,  as  commonly  employed,  will 
not  suffice,  because  the  water  bacilli  present  grow  more  rapidly 
and  cause  liquefaction  of  the  gelatin  before  visible  colonies  of  the 
typhoid  bacillus  are  formed  ;  and,  owing  to  the  relatively  small 
number  of  typhoid  bacilli,  these  are  likely  to  escape  detection.  The 
aim  of  bacteriologists  has,  therefore,  been  to  restrain  the  growth  of 
these  common  water  bacilli  by  some  agent  which  does  not  at  the 
same  time  prevent  the  development  of  the  typhoid  bacillus.  Chan- 
temesse  and  Widal  were  the  first  to  propose  the  use  of  carbolic  acid 
for  this  purpose.  They  recommended  the  addition  of  0. 25  per  cent 
of  this  agent  to  nutrient  gelatin  ;  but,  according  to  Kitasato,  the  de 
velopment  of  the  typhoid  bacillus  is  restrained  by  an  amount  exceed- 
ing 0.20  per  cent. 

Holz  prepares  an  acid  medium  by  adding  gelatin  (ten  per  cent)  to 
the  juice  of  raw  potatoes,  and  asserts  that  while  the  typhoid  bacillus 
grows  luxuriantly  in  this  medium,  many  other  bacilli  fail  to  develop 
27* 


354  THE   BACILLUS   OP    TYPHOID    FEVER. 

in  it.  The  test  is  said  to  be  still  more  reliable  if  0.05  per  cent  of  car- 
bolic acid  is  added  to  the  "  potato-gelatin."  According  to  Holz,  the 
addition  of  more  than  0. 1  per  cent  of  carbolic  acid  to  nutrient  gelatin 
prevents  the  free  development  of  the  typhoid  bacillus. 

Thoinot  has  claimed  to  be  able  to  obtain  the  typhoid  bacillus  from 
mixed  cultures — as,  for  example,  from  faeces — by  suspending  a  small 
amount  of  material  containing  it  for  several  hours  in  a  solution  con- 
taining 0.25  per  cent  of  carbolic  acid.  While  other  bacilli  are 
destroyed,  the  typhoid  bacillus  is  said  to  survive  such  exposure. 

The  method  of  Parietti  has  recently  been  tested  in  a  practical 
way  by  Kamen,  and  proved  to  be  satisfactory  for  the  detection  of 
the  typhoid  bacillus  in  water  which  was  supposed  to  be  the  source  of 
a  local  epidemic  of  the  disease.  The  following  solution  is  used  : 

Carbolic  acid,        ........        5  grammes. 

Hydrochloric  acid  (pure),        .....  4 

Distilled  water, 100 

Several  test  tubes,  each  of  which  contains  ten  cubic  centimetres 
of  neutral,  sterilized  bouillon,  are  used  in  the  experiment.  From 
three  to  nine  drops  of  the  acid  solution  are  added  to  each  of  these, 
and  the  tubes  are  then  placed  in  an  incubating  oven  for  twenty-four 
hours  to  ascertain  whether  they  are  still  sterile  after  this  addition. 
If  the  bouillon  remains  clear,  from  one  to  ten  drops  of  the  suspected 
water  are  added  to  each  tube  and  they  are  returned  to  the  incubating 
oven.  If  at  the  end  of  twenty-four  hours  the  bouillon  becomes 
clouded,  this  is  due,  according  to  Parietti,  to  the  presence  of  the 
typhoid  bacillus,  which  is  then  to  be  obtained  in  pure  cultures  by  the 
plate  method. 

The  following  method,  recently  suggested  by  Hazen  and  White  ^ 
has  been  tested  with  favorable  results  by  Foote.  This  method  de- 
pends upon  the  fact  that  most  of  the  common  water  bacilli  do  not 
grow  at  a  temperature  of  40°  C. ,  whereas  this  is  a  favorable  tempe- 
rature for  the  development  of  the  typhoid  bacillus.  A  small  quan- 
tity of  the  suspected  water  is  added  to  liquefied  nutrient  agar  in  test 
tubes,  and  plates  are  made.  These  are  placed,  in  an  incubating  oven 
at  40°  C.,  and  the  typhoid  bacillus,  if  present,  will  develop  colonies 
within  two  or  three  days.  At  the  ordinary  room  temperature  the 
more  numerous  water  bacilli  would  develop  upon  the  same  plates  so 
abundantly  that  it  would  be  difficult  to  recognize  colonies  of  the 
typhoid  bacillus. 

Theobald  Smith,  in  a  recent  paper  (Centralbl.  /.  Bakteriol., 
Bd.  xii.,  page  367),  claims  that  the  typhoid  bacillus  may  be  differen- 
tiated from  other  similar  bacilli  (Bacillus  coli  communis,  bacillus  of 
hog  cholera,  etc. )  by  the  fact  that  it  does  not  produce  gas  in  culture 


PLATE    V 
STERN  BERG'S   BACTERIOLOGY. 


Fig.  ;;. 


PATHOGENIC  UACTERIA, 


THE  BACILLUS  OF  TYPHOID  FEVER.  355 

media  containing  sugar — grape  sugar,  cane  sugar,  or  milk  sugar. 
The  medium  recommended  by  Smith  for  making  this  test  is  a  pep- 
tone-bouillon containing  two  per  cent  of  grape  sugar  and  made 
slightly  alkaline  with  carbonate  of  soda.  The  liquid  becomes  clouded 
throughout  at  the  end  of  twenty-four  hours,  but  not  a  trace  of  gas  is 
developed  even  after  several  days.  On  the  other  hand,  the  colon 
bacillus  and  other  bacilli  which  closely  resemble  the  typhoid  bacillus 
cause  an  abundant  development  of  gas  in  this  medium. 


PLATE  V. 

PATHOGENIC   BACTERIA. 

FlG.  1. — Bacillus  authracis  from  cellular  tissue  of  inoculated  mouse. 
Stained  with  gentian  violet,  x  1,000.  Photomicrograph  by  Frankel  and 
Pfeiffer. 

FIG.  2. — Bacillus  anthracis  in  section  of  liver  of  inoculated  rabbit. 
Stained  with  Bismarck  brown,  x  250.  Photomicrograph  by  Sternberg. 

FlG.  3. — Micrococcus  gonorrhceae  in  gonorrhoeal  pus.  Stained  with  gen* 
tiaii  violet,  x  1,000.  Photomicrograph  by  gaslight  (Sternberg). 

FlG.  4. — Anthrax  spores  from  a  bouillon  culture.  Double-stained  prepara- 
tion— with  carbol-fuchsin  and  methylene  blue,  x  1,000.  Photomicrograph 
by  Frankel  and  Pfeiffer. 

FIG.  5. — Spirillum  cholerse  Asiaticae  from  a  culture  upon  starched  linen 
at  end  of  twenty-four  hours  Stained  with  fuchsin.  x  1,000.  Photomi- 
crograph by  Frankel  and  Pfeiffer. 

FIG.  6. — Bacillus  diphtherias  from  colony  upon  an  agar  plate,  twenty- 
four  hours  old.  Stained  with  Loffler's  solution  of  methylene  blue,  x  1,000. 
Photomicrograph  by  Frankel  and  Pfeiffer. 


IX. 
BACTERIA  IN  DIPHTHERIA. 

DIPHTHERIA  is  generally  recognized  by  physicians  as  a  specific 
infectious  disease,  and,  owing  to  its  wide  prevalence  and  fatal  char- 
acter, a  precise  knowledge  of  its  etiology  is  of  the  greatest  import- 
ance. Until,  as  a  result  of  recent  researches,  this  was  determined, 
pathologists  were  in  doubt  as  to  whether  diphtheria  should  be  con- 
sidered as  primarily  a  local  infection,  or  whether  the  local  manifesta- 
tions were  secondary  to  a  general  systemic  infection.  But  this  question 
appears  now  to  be  definitely  settled  in  favor  of  the  former  view.  We 
have  to-day  a  very  precise  knowledge  of  the  specific  infecting  agent, 
arid  have  evidence  that  it  produces  during  its  growth  a  very  potent 
toxic  substance,  the  absorption  of  which  from  the  seat  of  local  infec- 
tion accounts  in  a  satisfactory  manner  for  the  general  symptoms  of 
the  disease,  which  are  due  to  toxaemia  and  not  to  an  invasion  of  the 
blood  and  tissues  by  the  pathogenic  microorganism  producing  it. 

Numerous  researches  by  competent  bacteriologists  have  failed  to 
demonstrate  the  presence  of  bacteria  in  the  blood  of  patients  suffer- 
ing from  diphtheria,  but  a  variety  of  microorganisms  have  been  ob- 
tained in  cultures  from  diphtheritic  pseudo-membranes,  and  may  be 
demonstrated  by  the  microscopical  examination  of  stained  prepara- 
tions. Among  these  are  the  well-known  pus  organisms,  and  espe- 
cially the  Streptococcus  pyogeiies,  which  appears  to  be  very  commonly 
present,  and  is  perhaps  the  active  agent  in  the  production  of  certain 
forms  of  pseudo-diphtheria.  But  the  malignant,  specific  diphtheria, 
so  well  known  in  this  country  and  in  Europe,  has  been  demonstrated 
by  the  recent  researches  of  bacteriologists  to  be  due  to  a  bacillus  first 
recognized  by  Klebs  in  stained  preparations  of  diphtheritic  false 
membranes  (1883),  and  cultivated  and  described  by  Loftier  in  1884. 
In  his  first  publication  Loftier  did  not  claim  to  have  fully  demon- 
strated the  etiological  relation  of  this  bacillus,  but  this  appears  to  be 
f  ully  established  by  subsequent  researches. 

In  his  first  research  Loftier  studied  twenty-five  cases,  and  in  the 
greater  number  of  them  found  in  stained  preparations  the  bacil- 
lus previously  described  by  Klebs.  From  six  of  these  cases  he 


BACTERIA   IN   DIPHTHERIA.  357 

obtained  it  in  pure  cultures,  and  by  inoculations  in  pigeons,  chickens, 
rabbits,  and  guinea-pigs  proved  that  it  gave  rise  to  a  diphtheritic 
inflammation  when  inoculated  into  the  mucous  membrane  of  the 
trachea,  conjunctiva,  pharynx,  or  vagina.  In  a  second  communica- 
tion Loftier  reported  his  success  in  finding  the  same  bacillus  in  ten 
additional  cases,  and  also  that  he  had  isolated  from  the  same  source 
a  non-pathogenic  bacillus  which  resembled  it  very  closely.  This 
pseudo-diphtheria  bacillus  has  since  been  found  by  other  bacteri- 
ologists (Von  Hoffmann,  Roux  and  Yersin),  and  it  is  uncertain 
whether  it  is  to  be  considered  a  distinct  species,  or  a  non-pathogenic 
variety  of  the  diphtheria  bacillus  as  maintained  by  Roux  and  Yersin. 
But  its  occasional  presence  does  not  invalidate  the  very  positive  ex- 
perimental evidence  relating  to  the  specific  pathogenic  power  of  the 
true  diphtheria  bacillus. 

Loffler  has  recently  (1890)  reviewed  the  evidence  upon  which 
this  bacillus  is  now  generally  conceded  by  bacteriologists  to  be  the 
specific  infectious  agent  in  true  diphtheria.  The  following  are  the 
principal  points  in  the  demonstration  : 

FIRST. — It  is  found  in  all  undoubted  cases  of  diphtheria.  In 
support  of  this  we  have  the  results  of  researches  made  by  Loffler, 
Wyssokowitsch,  D'Espine,  Von  Hoffmann,  Ortmann,  Roux  and 
Yersin,  Kolisko  and  Paltauf,  Zarinko  and  Sorensen,  who  in  nearly 
every  case  have  demonstrated  without  difficulty  the  presence  of  this 
bacillus.  On  the  other  hand,  Prudden  failed  to  find  it  in  a  series  of 
twenty -four  cases  studied  by  him ;  but  his  own  account  of  these 
cases  indicates  that  they  were  not  cases  of  true  diphtheria.  He  says 
in  a  subsequent  communication  : 

' '  In  view  of  the  doubt  existing  among  practitioners  as  to  whether  all 
forms  of  pseudo-membranous  inflammation  should  be  called  diphtheria  or 
not,  and  with  the  purpose  of  making  a  wholly  objective  study,  the  writer 
distinctly  stated  at  the  outset  of  that  paper  that  all  the  fatal  cases  of  exten- 
sive pseudo-membranous  laryngitis,  as  well  as  pharyngitis,  should  in  his 
study  be  considered  as  cases  of  diphtheria.  This  left  the  question  as  to  the 
propriety  of  establishing  separate  groups  of  pseudo-membranous  inflamma- 
tion open  and  free  from  bias.  It  was  distinctly  stated,  however,  that  six- 
teen out  of  the  twenty-four  cases  occurred  in  a  large  asylum,  in  which 
measles  and  scarlet  fever  were  prevalent  during  the  period  in  which  these 
studies  were  under  way.  Five  other  cases  in  another  asylum  were  ex- 
posed to  similar  conditions." 

In  a  subsequent  series  of  "  twelve  cases  of  fatal  pseudo-mem- 
braiious  inflammation  occurring  in  two  children's  asylums,  in  which 
for  many  months  there  had  been  no  scarlatina  and  no  measles,  and 
in  which  there  was  no  complicating  suppurative  inflammation  and 
no  erysipelas,"  Prudden  (1890)  obtained  Loffler's  bacillus  in  cultures 
from  eleven,  and  he  says  : 

"We  are  now,  it  would  seem,  justified,  as  it  did  not  appear  to  the  writer 


358  BACTERIA   IN   DIPHTHERIA. 

that  we  were  two  years  ago,  owing  to  the  large  number  of  important  re- 
searches which  have  been  made  in  the  interim,  in  saying  that  the  name 
diphtheria,  or  at  least  primary  diphtheria,  should  be  applied,  and  exclusively 
applied,  to  that  acute  infectious  disease,  usually  associated  with  a  pseudo- 
membranous  inflammation  of  the  mucous  membranes,  which  is  primarily 
caused  %  the  bacillus  called  Bacillus  diphtherias  of  Loffler." 

In  this  country  Welch  and  Abbott  (1891)  have  also  demonstrated 
the  presence  of  the  Klebs-Loffler  bacillus  in  a  series  of  eight  cases 
occurring  in  Baltimore,  and  have  proved  its  specific  pathogenic 
power  by  inoculations  in  animals. 

With  reference  to  the  question  as  to  how  long  after  convalescence 
is  established  the  diphtheria  bacillus  may  be  present  in  the  throat 
of  an  infected  person,  Loffler  has  made  the  following  research  (1890). 
In  a  typical  case  a  bacteriological  examination  was  made  daily  from 
the  commencement  until  fourteen  days  after  its  termination.  Fever 
disappeared  on  the  fifth  day,  and  the  exudation  had  all  disappeared 
on  the  sixteenth  day.  Up  to  this  time  the  bacillus  was  daily  ob- 
tained in  cultures,  and  subsequently  nearly  every  day  up  to  the 
twenty-fifth — that  is,  for  three  weeks  after  the  febrile  symptoms  had 
disappeared.  Roux  and  Yersin  have  also  obtained  the  bacillus  in 
cultures  from  mucus  scraped  from  the  throats  of  convalescents  sev- 
eral days  after  the  disappearance  of  all  evidence  of  the  disease. 

SECOND.  The  Klebs-Loffler  bacillus  is  found  only  in  diph- 
theria.— In  his  earlier  researches  Loffler  obtained  the  bacillus  in  a 
single  instance  from  the  mouth  of  a  healthy  child,  and  this  fact  led 
him  to  hesitate  in  announcing  it  as  his  conviction  that  it  was  the 
true  cause  of  diphtheria.  But  in  extended  researches  made  subse- 
quently he  has  not  again  succeeded  in  finding  it,  except  in  associa- 
tion with  diphtheria,  and  admits  now  that  he  may  have  been  mis- 
taken as  to  the  identity  of  the  bacillus  found.  This  seems  not 
improbable  in  view  of  the  fact  that  very  similar  bacilli  have  been 
found  by  various  bacteriologists.  Thus  Von  Hoffmann  obtained  a 
very  similar  but  non-pathogenic  bacillus  from  the  mucus  of  chronic 
nasal  catarrh  and  from  healthy  mucous  membranes ;  Babes  from 
cases  of  trachoma,  Neisser  from  ulcers,  Zarinko  from  the  surface  of 
various  mucous  membranes.  But  all  of  these  were  shown  to  present 
certain  differences  in  their  biological  characters  by  which  they  could 
be  differentiated  from  the  true  diphtheria  bacillus. 

Welch  and  Abbott  in  their  comparative  studies  did  not  find  the 
Loffler  bacillus,  "or  any  bacillus  that  an  experienced  bacteriologist 
would  be  likely  to  confound  with  it."  They  examined  mucus  from 
the  throats  of  healthy  children,  from  those  suffering  from  simple  in- 
flammation of  the  tonsils  and  pharynx,  and  from  four  cases  of  so- 
called  follicular  tonsillitis.  As  a  result  of  their  investigations  they 
agree  with  Loffler,  and  with  Roux  and  Yersin,  as  to  "  the  great  prac- 


BACTERIA  IN   DIPHTHERIA.  359 

tical  value,  for  diagnostic  purposes,  of  a  bacteriological  examination 
of  cover-glass  specimens  and  by  cultures  "  of  cases  in  which  there  is 
any  doubt  of  the  true  character  of  the  disease.  They  say  further  : 

"The  only  species  of  bacteria  which  we  have  found  constantly  in  the 
cases  of  diphtheria  has  been  the  Loffler  bacillus.  Two  other  species  have 
been  present  in  many  cases,  viz.,  the  well-known  streptococcus,  which  grows 
in  much  smaller  colonies  and  less  rapidly  than  the  Loffler  bacillus,  and  a 
short,  oval,  often  slightly  pointed  bacillus,  growing  in  long  chains  running 
parallel  to  each  other.  There  are  often  marked  irregularities  in  shape  and 
especially  in  size  of  this  bacillus,  even  of  individuals  in  the  same  chain. 
The  colonies  of  this  bacillus  are  grayish-white,  moist,  larger  than  those  of 
the  streptococcus,  but  smaller  than  those  of  the  Loffler  bacillus." 

THIRD.  As  shown  by  Ldffler's  earlier  researches,  pure  cultures 
of  this  bacillus  induce  characteristic  diphtheritic  inflammation 
when  inoculated  into  the  mucous  membranes  of  certain  lower  ani- 
mals. Roux  and  Yersin  have  also  shown  that  local  paralysis  is 
likely  to  occur  in  inoculated  animals,  as  is  the  case  in  diphtheria  in 
man.  In  speaking  of  their  inoculations  into  the  trachea  in  rabbits 
these  investigators  say  : 

"The  affection  which  is  thus  induced  in  the  rabbit  resembles  croup  in 
man.  The  difficulty  which  the  animal  experiences  in  breathing;  the  noise 
made  by  the  air  in  passing  through  the  obstructed  trachea  •  the  aspect  of  the 
trachea,  which  is  congested  and  covered  with  false  membranes;  the  oedema- 
tous  swelling  of  the  tissues  and  glands  of  the  neck,  make  the  resemblance 
absolutely  remarkable." 

Welch  and  Abbott  give  the  following  account  of  the  results  of 
inoculations  into  the  trachea  in  kittens  : 

"A  half -grown  kitten  is  inoculated  into  the  trachea  with  one  platinum 
loop  from  a  pure  culture  of  the  Loffler  bacillus  on  glycerin-agar,  eleven  days 
old,  derived  from  Case  IV.  For  the  inoculation  a  small  median  incision  was 
made  over  the  trachea,  in  which  a  hole  just  large  enough  to  admit  the  plati- 
num loop  was  made.  The  culture  was  rubbed  over  the  mucosa  of  the  trachea 
for  an  extent  about  three  centimetres  in  length,  and  in  this  process  sufficient 
force  was  used  to  abrade  the  mucous  membrane.  On  the  day  following  the 
inoculation  no  special  alteration  in  the  animal  was  observed,  but  on  the 
morning  of  the  second  day  it  was  found  very  weak.  In  the  course  of  this 
day  it  became  so  weak  as  to  lie  completely  motionless,  apparently  uncon- 
scious, with  very  feeble,  shallow  respiration;  several  times  it  was  thought  to 
be  dead,  but  on  careful  examination  proved  still  to  be  breath  ing  feebly.  It 
was  found  dead  on  the  morning  of  the  third  day.  At  the  autopsy  the  wound 
was  found  gaping  and  covered  with  a  grayish,  adherent,  necrotic,  distinctly 
diphtheritic  layer.  For  a  considerable  distance  around  the  wound  the  sub- 
cutaneous tissues  were  very  cedematous,  the  oedema  extending  from  the 
lower  jaw  dow'n  over  the  sternum,  and  to  the  sides  of  the  neck,  and  along 
the  anterior  extremities.  The  lymphatic  glands  at  the  angle  of  the  jaw  were 
markedly  swollen  and  reddened.  The  mucous  membrane  of  the  trachea, 
beginningat  the  larynx  and  extending  down  for  six  centimetres,  wascovered 
with  a  tolerably  firm,  grayish-white,  loosely  attached  pseudo-membrane,  in 
all  respects  identical  with  the  croupous  membranes  observed  in  the  same 
situation  in  cases  of  human  diphtheria." 


360  BACTERIA    IN    DIPHTHERIA. 

47.    BACILLUS   DIPHTHERIA. 

First  observed  by  Klebs  (1883)  in  diphtheritic  false  membranes. 
Isolated  in  pure  cultures  and  pathogenic  power  demonstrated  by 
Loffler  (1884). 

Found  in  diphtheritic  pseudo-membranes,  and  especially  in  the 
deeper  portions,  intermingled  with  numerous  cellular  elements;  while 
the  superficial  layers  of  the  membrane  commonly  contain  but  few 
cells  or  bacilli,  or  are  invaded  by  other  species,  especially  by  Strep- 
tococcus pyogenes.  The  bacilli  are  not  found  in  the  affected  mucous 
membrane,  or  in  sections  from  the  internal  organs  in  fatal  cases  of 
this  disease. 

Morphology.  —  Rods,  straight  or  slightly  curved,  with  rounded 

ends,  having  a  diameter  of  0.5  to  0.8 
jw,  and  from  2  to  3  IJL  in  length.  Ir- 
regular forms  are  very  common,  and, 
indeed,  are  characteristic  of  this  bacil- 
lus. In  the  same  culture,  and  especially 
in  an  unfavorable  culture  medium,  very 
great  differences  in  form  and  dimen- 
sions may  be  observed  ;  one  or  both  ends 
may  appear  swollen,  or  the  central  por- 
tion may  be  notably  thicker  than  the 
extremities,  or  the  rod  may  be  made  up 
FIG.  114.  —  Bacillus  diphtherias,  of  irregular  spherical  or  oval  segments. 
from  a  culture  upon  blood  serum  Multiplication  occurs  by  fission  only, 

From  a  photomicrograph,     x  1,000.  r 

nd  Pfeiffer.)  and  the  bacilli  do  not  grow  out  into  fila- 


ments. 

In  unstained  preparations  certain  portions  of  the  rod,  and  espe- 
cially the  extremities,  are  observed  to  be  more  highly  refractive  than 
the  remaining  portion  ;  and  in  stained  preparations  these  portions 
are  seen  to  be  most  deeply  colored.  The  diphtheria  bacillus  may  be 
stained  by  the  use  of  Loffler's  alkaline  solution  of  methylene  blue, 
but  is  not  so  readily  stained  with  some  of  the  other  aniline  colors 
commonly  employed.  It  stains  also  by  Gram's  method.  For  the 
demonstration  of  the  bacillus  in  sections  of  diphtheritic  membrane 
"  nothing  can  surpass  in  brilliancy  and  sharp  differentiation  sections 
stained  doubly  by  the  modified  Weigert's  fibrin  stain  and  picro-car- 
mine  "  (Welch  and  Abbott). 

Biological  Characters.  —  The  diphtheria  bacillus  is  aerobic,  non- 
motile,  and  non-liquefying;  it  does  not  form  spores.  It  grows  most 
freely  in  the  presence  of  oxygen,  but  is  also  a  facultative  anaerobic. 

Development  occurs  in  various  culture  media  at  a  temperature  of 
from  20°  to  42°  C.,  the  most  favorable  temperature  being  about  35°  C. 


BACTERIA    IN   DIPHTHERIA.  361 

It  grows  readily  in  nutrient  gelatin  having  a  slightly  alkaline  reac- 
tion, in  nutrient  agar,  glycerin-agar,  or  in  alkaline  bouillon,  but  the 
most  favorable  medium  appears  to  be  that  first  recommended  by 
Loffler — viz.,  a  mixture  of  three 
parts  of  blood  serum  with  one  part 
of  bouillon,  containing  one  per  cent 
of  peptone,  one  per  cent  of  grape 
sugar,  and  0. 5  per  cent  of  sodium 
chloride.  This  mixture  is  steril- 
ized and  solidified  at  a  low  tem- 
perature, as  is  usual  with  blood 
serum.  Upon  this  the  develop- 
ment is  SO  rapid  in  the  incubating  FIG.  115.— Colonies  of  Bacillus  diphtherias 
,,  ,\_  i  £  .  in  nutrient  agar,  end  of  twenty-four  hours. 

oven  that,  at  the  end  of  twenty-     x  :0    (Frankei  knd  pfeiffer.) 
four  hours,  the  large,  round,  ele- 
vated colonies,  of  a  grayish-white  color  and  moist  appearance,  may 
be  easily  recognized,  while  other  associated  bacteria  will,  as  a  rule, 
not  yet  have  developed  colonies  large  enough  to  interfere  with  the 
recognition  of  these. 

Upon  nutrient  agar  plates  the  deep-lying  colonies,  when  magni- 
fied about  eighty  diameters,  appear  as  round  or  oval,  coarsely  granu- 
lar discs,  with  rather  ill-defined  margins,  or,  when  several  colonies 
are  in  juxtaposition,  as  figures  of  irregular  form.  The  superficial  col- 
onies are  grayish-yellow  in  color,  have  an  irregular,  not  well-defined 
outline  and  a  rough,  almost  reticulated  surface.  The  growth  upon 
glycerin-agar  is  very  similar.  The  first  inoculations  in  a  plain  nu- 
trient agar  tube  often  give  a  comparatively  feeble  growth,  which  be- 
comes more  abundant  in  subsequent  inoculations  in  the  same  medium. 
In  stick  cultures  in  glycerin — or  plain — agar,  growth  occurs  to  the 
bottom  of  the  line  of  inoculation,  and  also  upon  the  surface,  but  is 
not  at  all  characteristic.  The  same  may  be  said  with  reference  to 
cultures  in  nutrient  gelatin.  Plate  cultures  in  this  medium  contain- 
ing fifteen  per  cent  of  gelatin,  at  24°  C.,  give  rather  small  colonies, 
which  are  white  by  reflected  light  and  under  the  microscope  are  seen 
as  yellowish-brown,  opaque  discs,  having  a  more  or  less  irregular 
outline  and  a  granular  structure.  In  alkaline  bouillon  the  growth  is 
sometimes  in  the  form  of  small,  whitish  masses  along  the  sides  and 
bottom  of  the  tube,  but  at  others  a  diffusely  clouded  growth  occurs 
in  this  medium  ;  after  standing  for  some  time  in  the  incubating  oven 
a  thin,  white  pellicle  may  form  upon  the  surface  of  the  bouillon. 
The  reaction  of  the  bouillon  becomes  at  first  acid,  but  later  it  has  an 
alkaline  reaction  (Welch).  With  reference  to  the  growth  on  potato, 
authors  have  differed,  probably  because  the  growth  is  scarcely  vis- 
ible ;  upon  this  point  we  quote  from  Welch  and  Abbott  : 
28 


362  BACTERIA  IN  DIPHTHERIA. 

"  Our  experience  has  been  that  the  Bacillus  diphtherias  grows  on  ordinary 
steamed  potato  without  any  preliminary  treatment,  but  that  the  growth  is 
usually  entirely  invisible  or  is  indicated  by  a  dry,  thin  glaze  after  several 
days.  Doubtless  the  invisible  character  of  the  growth  has  led  most  observers 
into  the  error  of  supposing  that  no  growth  existed,  whereas  the  microscopi- 
cal examination  reveals  a  tolerably  abundant  growth,  which  on  the  first  po- 
tato is  often  feebler  than  on  succeeding  ones.  Irregular  forms  are  par- 
ticularly numerous  in  potato  cultures,  and  in  general  the  rods  are  thicker 
than  on  other  media.  In  twenty-four  hours,  at  a  temperature  of  35°  C., 
microscopical  examination  shows  distinct  growth.  We  have  cultivated  the 
bacillus  for  many  generations  on  potato." 

Milk  is  a  favorable  medium  for  the  growth  of  this  bacillus,  and, 
as  it  grows  at  a  comparatively  low  temperature  (20°  C.),  it  is  evi- 
dent that  this  fluid  may.  become  a  medium  for  conveying  the  bacillus 
from  an  infected  source  to  the  throats  of  previously  healthy  children. 

Cultures  of  the  diphtheria  bacillus  may  retain  their  vitality  for 
several  months,  and  when  dried  upon  silk  threads  for  several  weeks 
colonies  are  still  developed  in  a  suitable  medium — in  the  room  from 
three  to  four  weeks,  in  an  exsiccator  five  to  ten,  and  in  one  instance 
fourteen  weeks.  In  dried  diphtheritic  membrane,  preserved  in  small 
fragments,  the  bacillus  retained  its  vitality  for  nine  weeks,  and  in 
larger  fragments  for  twelve  to  fourteen  weeks. 

The  thermal  death-point,  as  determined  by  Welch  and  Abbott,  is 
58°  C.,  the  time  of  exposure  being  ten  minutes.  Loftier  had  previ- 
ously found  that  it  did  not  survive  exposure  for  half  an  hour  to  60° 
C.  With  reference  to  the  action  of  germicidal  and  antiseptic  agents, 
we  refer  to  the  sections  in  Part  Second  relating  to  this  subject. 

Pathogenesis. — In  view  of  the  evidence  heretofore  recorded,  it 
may  be  considered  as  demonstrated  that  this  bacillus  gives  rise  to 
the  morbid  phenomena  which  characterize  the  fatal  disease  in  man 
known  as  diphtheria. 

We  have  already  referred  to  the  effects  of  inoculations  into  the 
trachea  in  rabbits  and  cats,  which  give  rise  to  a  characteristic  diph- 
theritic inflammation,  with  general  toxaemia  and  death  from  the 
absorption  of  soluble  toxic  products  formed  at  the  seat  of  local  in- 
fection. This  inference  as  to  the  cause  of  death  seems  justified  by 
the  fact  that  the  pathogenic  bacillus  does  not  invade  the  blood  and 
tissues,  and  is  supported  by  additional  experimental  evidence  which 
we  give  below.  Subcutaneous  inoculations  in  guinea-pigs  of  a  small 
quantity  of  a  pure  culture  of  the  bacillus  (0. 1  to  0. 5  cubic  centime- 
tre of  a  bouillon  culture)  cause  death  in  from  one  to  four  or  five 
days.  The  usual  changes  observed  at  the  autopsy  are  "  an  exten- 
sive local  oedema  with  more  or  less  hypersemia  and  ecchymosis  at 
the  site  of  inoculation,  frequently  swollen  and  reddened  lymphatic 
glands,  increased  serous  fluid  in  the  peritoneum,  pleura,  and  pericar- 
dium, enlarged  and  hsemorrhagic  suprarenal  capsules,  occasionally 


BACTERIA   IN  DIPHTHERIA.  363 

slightly  swollen  spleen,  sometimes  fatty  degenerations  in  the  liver, 
kidney,  and  myocardium.  We  have  always  found  the  Loffler  ba- 
cilli at  the  seat  of  inoculation,  most  abundant  in  a  grayish-white, 
fibrino-purulent  exudate  present  at  the  point  of  inoculation,  and  be- 
coming fewer  at  a  distance  from  this,  so  that  the  more  remote  parts 
of  the  osdematous  fluid  do  not  contain  any  bacilli "  (Welch  and  Ab- 
bott). The  authors  quoted  agree  with  Loffler  and  others  in  stating 
that  the  bacillus  is  only  found  at  the  point  of  inoculation.  In  all 
cases  their  cultures  from  the  blood  and  from  the  various  organs  gave 
a  negative  result. 

Rabbits  are  not  so  susceptible  and  may  recover  after  the  subcu- 
taneous inoculation  of  very  small  doses,  but  usually  die  in  from  four 
to  twenty  days  when  two  to  four  cubic  centimetres  of  a  bouillon 
culture  have  been  introduced  beneath  the  skin.  In  these  animals 
also  there  is  an  extensive  local  oedema,  enlargement  of  the  neigh- 
boring lymphatic  glands,  and  a  fatty  degeneration  of  the  liver. 
Roux  and  Yersin  have  shown  that  in  these  animals,  when  death 
does  not  ensue  too  quickly,  paralysis  of  the  posterior  extremities  fre- 
quently occurs,  thus  completing  the  experimental  proof  of  the  spe- 
cific pathogenic  power  of  pure  cultures  of  this  bacillus. 

Similar  symptoms  are  produced  in  pigeons  by  the  subcutaneous 
inoculation  of  0. 5  cubic  centimetre  or  more,  but  they  commonly  re- 
cover when  the  quantity  is  reduced  to  0.2  cubic  centimetre  (Roux 
and  Yersin). 

The  rat  and  the  mouse  have  a  remarkable  immunity  from  the 
effects  of  this  poison.  Thus,  according  to  Roux  and  Yersin,  a  dose 
of  two  cubic  centimetres,  which  would  kill  in  sixty  hours  a  rabbit 
weighing  three  kilogrammes,  is  without  effect  upon  a  mouse  which 
weighs  only  ten  grammes. 

Old  cultures  are  somewhat  less  virulent  than  fresh  ones,  but  when 
replanted  in  a  fresh  culture  medium  they  manifest  their  original 
virulence.  Thus  a  culture  upon  blood  serum  which  was  five  months 
old  was  found  by  Roux  and  Yersin  to  kill  a  guinea-pig  in  five  days, 
but  when  replanted  it  killed  a  second  animal  of  the  same  species  in 
twenty-four  hours. 

Evidently  a  microorganism  which  destroys  the  life  of  a  suscepti- 
ble animal  when  injected  beneath  its  skin  in  small  quantity,  and 
which  nevertheless  is  only  found  in  the  vicinity  of  the  point  of  in- 
oculation, must  owe  its  pathogenic  power  to  the  formation  of  some 
potent  toxic  substance,  which  being  absorbed  gives  rise  to  toxaemia 
and  death.  This  inference  in  the  case  of  the  diphtheria  bacillus  is 
fully  sustained  by  the  results  of  recent  experimental  investigations. 
Roux  and  Yersin  (1888)  first  demonstrated  the  pathogenic  power  of 
cultures  which  had  been  filtered  through  porous  porcelain.  Old 


364  BACTERIA  IN  DIPHTHERIA. 

cultures  were  found  by  these  experimenters  to  contain  more  of  the 
toxic  substance  than  recent  ones,  and  to  cause  the  death  of  a  guinea- 
pig  in  the  dose  of  two  cubic  centimetres  in  less  than  twenty-four 
hours.  The  filtered  cultures  produced  in  these  animals  the  same 
effects  as  those  containing  the  bacilli — local  oedema,  hsemorrhagic 
congestion  of  the  organs,  effusion  into  the  pleural  cavity.  Some- 
what larger  doses  were  fatal  to  rabbits,  and  a  few  drops  injected 
subcutaneously  sufficed  to  kill  a  small  bird  within  a  few  hours.  In 
their  second  paper  (1889)  the  authors  mentioned  state  that  so  long  as 
the  reaction  of  a  culture  in  bouillon  is  acid  its  toxic  power  is  com- 
paratively slight,  but  that  in  old  cultures  the  reaction  is  alkaline, 
and  in  these  the  toxic  potency  is  greatly  augmented.  With  such  a 
culture,  filtered  after  having  been  kept  for  thirty  days,  a  dose  of 
one-eighth  of  a  cubic  centimetre,  injected  subcutaneously,  sufficed 
to  kill  a  guinea-pig ;  and  in  larger  amounts  it  proved  to  be  fatal 
to  dogs  when  injected  directly  into  the  circulation  through  a  vein. 

The  same  authors,  in  discussing  the  nature  of  the  poison  in  their 
filtered  cultures,  infer  that  it  is  related  to  the  diastases,  and  state 
that  its  toxic  potency  is  very  much  reduced  by  exposure  to  a  com- 
paratively low  temperature — 58°  C.  for  two  hours — and  completely 
destroyed  by  the  boiling  temperature — 100°  for  twenty  minutes.  It 
was  found  to  be  insoluble  in  alcohol,  and  the  precipitate  obtained  by 
adding  alcohol  to  an  old  culture  proved  to  contain  the  toxic  sub- 
stance. Loffler  also  has  obtained,  by  adding  five  volumes  of  alco- 
hol to  one  of  a  pure  culture,  a  white  precipitate,  soluble  in  water, 
which  killed  rabbits  in  the  dose  of  0.1  to  0.2  gramme  when  injected 
beneath  the  skin  of  these  animals.  It  gave  rise  to  a  local  oedema 
and  necrosis  of  the  skin  in  the  vicinity  of  the  point  of  inoculation, 
and  to  hypersemia  of  the  internal  organs.  This  deadly  toxine  appears 
to  be  an  albuminoid  substance,  but  its  exact  chemical  composition 
has  not  yet  been  determined. 

Brieger  and  Frankel  have  succeeded  in  rendering  guinea-pigs 
immune  against  virulent  cultures  of  the  diphtheria  bacillus  by  inject- 
ing bouillon  cultures  three  weeks  old,  which  had  been  sterilized  by 
exposure  for  an  hour  to  60°  to  70°  C. ,  into  the  subcutaneous  tissues 
(ten  to  twenty  cubic  centimetres).  At  first  the  susceptibility  of  the 
animal  is  rather  increased  than  diminished,  but  at  the  end  of  two 
weeks  immunity  is  said  to  be  complete.  Fraiikel  is  of  the  opinion 
that  immunity  results  from  the  introduction  of  a  substance  which  is 
not  identical  with  the  toxic  product  to  which  the  cultures  owe  their 
pathogenic  power.  This  latter  is  destroyed  by  a  temperature  of  55° 
to  60°  C.,  while  the  substance  which  gives  immunity  is  still  present 
in  the  cultures  after  exposure  to  a  temperature  of  60°  to  70°,  as  shown 
by  the  protective  results  of  inoculations  made  with  such  cultures. 


BACTERIA   IN   DIPHTHERIA.  365 

The  recent  researches  of  Behring  show  that  the  blood  of  immune 
animals  contains  some  substance  which  neutralizes  the  toxic  product 
contained  in  virulent  cultures  of  the  diphtheria  bacillus.  This  effect 
is  said  to  be  produced  when  blood  from  such  an  animal  is  added  to  a 
filtered  culture  without  the  body,  as  well  as  when  the  culture  is  in- 
jected into  the  living  animal.  This  remarkable  fact,  if  fully  con- 
firmed by  further  investigations,  opens  up  a  new  field  of  experimen- 
tal research,  and  may  lead  to  important  results  in  the  therapeutics  of 
this  and  other  infectious  diseases. 

According  to  Roux  and  Yersin,  "  attenuated  varieties  "  of  the 
diphtheria  bacillus  maybe  obtained  by  cultivating  it  at  a  temperature 
of  39.5°  to  40°  C.  in  a  current  of  air  ;  and  these  authors  suggest  that 
a  similar  attenuation  of  pathogenic  power  may  occur  in  the  fauces  of 
convalescents  from  the  disease,  and  that  possibly  the  similar  non- 
pathogenic  bacilli  which  have  been  described  by  various  investiga- 
tors have  originated  in  this  way  from  the  true  diphtheria  bacillus. 
These  authors  further  state,  in  favor  of  this  view,  that  from  diphtheri- 
tic false  membrane,  preserved  by  them  in  a  desiccated  condition  for 
five  months,  they  obtained  numerous  colonies  of  the  bacillus  in  ques- 
tion, but  that  the  cultures  were  destitute  of  pathogenic  virulence. 
They  say: 

' '  It  is  then  possible,  by  commencing  with  a  virulent  bacillus  of 
diphtheria,  to  obtain  artificially  a  bacillus  without  virulence,  quite 
similar  to  the  attenuated  bacilli  which  may  be  obtained  from  a  benign 
diphtheritic  angina,  or  even  from  the  mouth  of  certain  persons  in 
good  health.  This  microbe,  obtained  artificially,  resembles  com- 
pletely the  pseudo-diphtheritic  bacillus  ;  like  it,  it  grows  more  abun- 
dantly at  a  low  temperature;  it  renders  bouillon  more  rapidly  alkaline; 
it  grows  with  difficulty  in  the  absence  of  oxygen. " 

48.    PSEUDO-DIPHTHERITIC    BACILLUS. 

Loffler,  Von  Hoffmann,  and  others  have  reported  finding  bacilli 
which  closely  resemble  the  Bacillus  diphtherias,  but  which  differ 
from  it  chiefly  in  being  non-pathogenic.  The  following  account  we 
take  from  the  latest  paper  upon  the  subject  by  Roux  and  Yersin 
(troisieme  memoire,  1890). 

Found  by  Roux  and  Yersin  in  mucus  from  the  pharynx  and  ton- 
sils of  children— from  forty-five  children  in  Paris  hospitals,  suffering 
from  various  affections,  not  diphtheritic,  fifteen  times ;  from  fifty- 
nine  healthy  children  in  a  village  school  on  the  seaboard,  twenty -six 
times.  Of  six  children  with  a  simple  angina  but  two  furnished  cul- 
tures of  this  bacillus,  while  it  was  obtained  in  five  out  of  seven  cases 
of  measles. 


366  BACTERIA   IN   DIPHTHERIA. 

Its  characters  are  given  as  follows  : 

"The  colonies  of  the  pseudo -diphtheritic  bacillus,  cultivated  upon  blood 
serum,  are  identical  with  the  true  diphtheria  bacillus.  At  a  temperature  of 
33°  to  35°  multiplication  is  rapid,  and  it  continues  at  the  ordinary  tempera- 
ture, although  slowly.  Under  the  microscope  the  appearance  of  the  bacillus 
which  forms  these  colonies  is  the  same  as  that  of  Bacillus  diphtherias.  It 
stains  readily  with  Loffler's  solution  of  methylene  blue,  and  intensely  by 
Gram's  method.  Sometimes  it  colors  uniformly,  at  others  it  appears  granu- 
lar. It  grows  in  alkaline  bouillon,  giving  a  deposit  upon  the  walls  of  the 
vessel  containing  the  culture,  and  in  this  medium  often  presents  the  inflated 
forms,  pear-shaped,  or  club-shaped.  It  is  destroyed  in  a  liquid  medium  by  a 
temperature  of  58°  C.  maintained  for  ten  minutes.  All  of  these  characters 
are  common  to  the  pseudo-diphtheritic  bacillus  and  the  true  Bacillus  diphthe- 
riae.  As  a  difference  between  them  we  may  note  that  the  pseudo- diphtheritic 
bacillus  is  of  ten  shorter  in  colonies  grown  upon  blood  serum;  that  its  cultures 
in  bouillon  are  more  abundant ;  that  they  continue  at  a  temperature  of  20°  to 
22°,  at  which  the  true  bacillus  grows  very  slowly.  When  we  make  a  com- 
parison of  cultures  in  bouillon  they  become  acid  and  then  alkaline,  but  the 
change  occurs  much  sooner  in  the  case  of  the  pseudo-diphtheritic  bacillus. 
Like  the  true  bacillus,  the  pseudo- diphtheritic  grows  in  a  vacuum,  but  less 
abundantly  than  the  other. 

"Inoculations  into  animals  of  cultures  of  this  bacillus  have  never  caused 
their  death ;  but  we  may  remark  that  in  some  experiments  a  notable  oedema 
has  been  produced  in  guinea-pigs  at  the  point  of  inoculation,  while  in  others 
there  has  been  no  local  lesion.  The  most  marked  oedema  resulted  from  cul- 
tures obtained  from  cases  of  measles. 

' '  Do  the  facts  which  we  have  reported  explain  the  question  which  occupies 
us  ?  Can  we  conclude  that  there  is  a  relation  between  the  two  bacilli  ?  On 
the  one  side,  the  presence  of  the  pseudo- diphtheritic  bacillus  in  the  mouths  of 
healthy  persons,  and  of  those  who  have  anginas  manifestly  not  diphtheritic, 
seems  to  be  opposed  to  the  idea  of  a  relationship  between  them.  On  the 
other  hand,  when  we  consider  that  the  non-virulent  bacillus  is  very  rare  in 
fatal  diphtheria,  that  it  is  more  abundant  in  benign  diphtheria,  that  it  be- 
comes more  common  in  severe  cases  as  they  progress  towards  recovery,  and. 
finally,  that  they  are  more  numerous  in  persons  who  have  recently  had 
diphtheria  than  in  healthy  persons,  it  is  difficult  to  accept  the  idea  that  the 
two  microbes  are  entirely  distinct.  The  morphological  differences  which 
have  been  referred  to  are  so  slight  that  they  prove  nothing.  The  two  micro- 
organisms can  only  be  distinguished  by  their  action  upon  animals,  but  the 
difference  of  virulence  does  not  at  all  correspond  with  the  difference  of  ori- 
gin. As  regards  the  form  and  the  aspect  of  cultures,  the  true  and  false 
diphtheria  bacilli  differ  less  than  virulent  anthrax  differs  from  a  very  attenu- 
ated anthrax  bacillus,  which,  however,  originate  from  the  same  source. 
Besides,  the  sharp  distinction  which  we  make  between  the  virulent  and  non- 
virulent  bacilli  is  arbitrary ;  it  depends  upon  the  susceptibility  of  guinea- 
pigs.  If  we  inoculate  animals  still  more  susceptible,  there  are  pseudo  diph- 
theritic bacilli  which  we  must  class  as  virulent;  and  if,  on  the  contrary,  we 
substitute  rabbits  for  guinea  pigs  in  our  experiments,  there  are  diphtheritic 
bacilli  which  we  must  call  pseudo-diphtheritic.  In  our  experiments  we  do 
not  simply  encounter  bacilli  which  are  very  virulent  and  bacilli  which  are 
non- virulent;  between  these  two  extremes  there  are  bacilli  of  every  degree 
of  virulence." 

Abbott  has  recently  (1891)  published  the  result  of  his  researches 
with  reference  to  the  presence  of  the  pseudo-diphtheritic  bacillus  in 
benign  throat  affections.  He  made  a  bacteriological  study  of  fifty- 
three  patients,  nine  of  whom  were  suffering  from  acute  pharyngitis, 
fourteen  from  acute  f ollicular  tonsillitis,  eight  from  ordinary  post- 


BACTERIA   IN   DIPHTHERIA.  367 

nasal  catarrh,  two  from  simple  enlarged  tonsils,  fifteen  from  chronic 
pharyngitis,  one  from  subacute  laryngitis,  one  from  chronic  laryngi- 
tis, one  from  rhinitis,  and  two  from  an  affection  of  the  tonsils  and 
pharynx.  In  forty-nine  cases  nothing  of  particular  interest  was  ob- 
served. A  variety  of  microorganisms  were  isolated,  and  of  these 
the  pyogenic  micrococci  were  the  most  common. 

In  four  cases  microorganisms  were  found  which  resembled  the 
Bacillus  diphtherias  of  Loffler  in  their  morphology  and  growth  in  cul- 
ture media,  but  which  proved  not  to  be  pathogenic.  Abbott  says  : 
' '  The  single  point  of  distinction  that  can  be  made  out  between  the 
organisms  obtained  from  Cases  I. ,  III. ,  and  IV.  and  the  true  bacil- 
lus of  diphtheria  is  in  the  absence  of  pathogenic  properties  from  the 
former,  whereas  in  addition  to  this  point  of  distinction  the  organism 
from  Case  II.  gives,  as  has  been  stated,  a  decided  and  distinct 
growth  upon  the  surface  of  sterilized  potato." 

49.    BACILLUS  DIPHTHERIJE  COLUMBRARUM. 

Described  by  Loffler  (1884),  who  obtained  it  from  diphtheritic  pseudo-mem- 
branes in  the  mouths  of  pigeons  dead  from  an  infectious  form  of  diphtheria 
which  prevails  in  some  parts  of  Germany  among  these  birds  and  among 
chickens. 

Reddened  patches  first  appear  upon  the  mucous  membrane  of  the  mouth 
and  fauces,  and  these  are  covered  later  with  a  rather  thick,  yellowish  layer 
of  fibrinous  exudale.  In  pigeons  the  back  part  of  the  tongue,  the  fauces, 
and  the  corners  of  the  mouth  are  especially  affected ;  in  chickens  the  tongue, 
the  gums,  the  nares,  the  larynx,  and  the  conjunctival  mucous  membrane. 
The  disease  is  especially  fatal  among  chickens,  the  young  fowls  and  those  of 
choice  varieties  being  most  susceptible.  It  is  attended  at  the  outset  by  fever, 
and  usually  proves  fatal  within  two  or  three  weeks,  but  may  last  for  several 
months. 

Morphology. — Short  bacilli  with  rounded  ends,  usually  associated  in  ir- 
regular masses,  and  resembling  the  bacilli  of  rabbit  septicaemia  (fowl 
cholera),  but  a  little  longer  and  not  quite  so  broad.  In  sections  from  the 
liver  they  are  seen  in  irregular  groups  in  the  interior  of  the  vessels. 

Biological  Characters. — An  aerobic,  non-motile,  non-liquefying  bacillus. 

Grows  in  nutrient  gelatin  in  the  form  of  spherical,  white  colonies  along- 
the  line  of  puncture,  and  upon  the  surface  as  a  whitish  layer.  Under  the 
microscope  the  colonies  in  gelatin  plates  have  a  yellowish-brown  color  and 
a  slightly  granular  surface.  Upon  blood  serum  the  growth  consists  of  a 
semi-transparent,  grayish- white  layer.  Upon  potato  a  thin  layer  is  formed 
having  a  grayish  tint. 

Pathogenesi*. — Pigeons  inoculated  with  a  pure  culture  in  the  mucous 
membrane  of  the  mouth  are  affected  exactly  as  are  those  which  acquire  the 
disease  naturally.  Subcutaneous  inoculations  in  pigeons  give  rise  to  an  in- 
flammation resulting  in  local  necrotic  changes.  Pathogenic  for  rabbits  and 
for  mice.  Subcutaneous  injections  in  mice  give  rise  toa  fatal  result  in  about 
five  days.  The  bacillus  is  found  in  the  blood  and  in  the  various  organs,  in 
the  interior  of  the  vessels,  and  sometimes  in  the  interior  of  the  leucocytes; 
they  are  especially  numerous  in  the  liver.  The  lungs  are  dotted  with  red 
spots,  the  spleen  is  greatly  enlarged,  and  the  liver  has  a  marbled  appearance 
from  the  presence  of  numerous  irregular  white  masses  scattered  through  the 
pale-red  parenchyma  of  the  organ.  These  white  masses  are  seen,  in  sec- 
tions, to  consist  of  necrotic  liver  tissue,  in.  the  centre  of  which  the  bacilli 


368  BACTERIA   IN   DIPHTHERIA. 

are  found  in  great  numbers,  in  the  interior  of  the  vessels.  This  appearance 
is  so  characteristic  that  Loftier  considers  inoculations  in  mice  to  be  the  most 
reliable  method  of  establishing  the  identity  of  the  bacillus.  Not  pathogenic 
for  chickens,  guinea-pigs,  rats,  or  dogs. 

There  seems  to  be  some  doubt  whether  the  form  of  diphtheria  which  pre- 
vails among  pigeons,  and  which  Loftier  has  shown  to  be  due  to  the  bacillus 
above  described,  is  identical  with  the  diphtheria  of  chickens.  Diphtheria  in 
man  has  been  supposed  by  some  authors  to  be  identical  with  that  which 
prevails  among  fowls,  and  possibly  this  may  be  the  case  under  certain  cir- 
cumstances. But  the  evidence  seems  to  be  convincing  that  there  is  an 
infectious  diphtheria  of  fowls  which  is  peculiar  to  them,  and  which,  under 
ordinary  circumstances,  is  not  communicated  to  man. 

50.    BACILLUS   DIPHTHERIA  VITULORUM. 

Described  by  Loffier  (1884)  and  obtained  by  him  from  the  pseudo-mem- 
branous exudation  in  the  mouths  of  calves  suffering  f rom  an  infectious  form 
of  diphtheria.  The  disease  is  characterized  by  the  appearance  of  yellow 
patches  upon  the  mucous  membrane  of  the  cheeks,  the  gums,  the  tongue, 
and  sometimes  of  the  larynx  and  nares  of  infected  animals.  There  is  a  yel- 
lowish discharge  from  the  nose,  an.  abundant  flow  of  saliva,  occasional  at- 
tacks of  coughing,  and  diarrhoea.  Death  may  occur  at  the  end  of  four  or 
five  days,  but  usually  the  animal  survives  for  several  weeks.  Diphtheritic 
patches  similar  to  those  in  the  mouth  are  also  found  in  the  large  intestine, 
and  scattered  abscesses  in  the  lungs. 

Loffier,  in  a  series  of  seven  cases  examined,  obtained  from  the  deeper  por- 
tions of  the  pseudo-membranous  deposit  a  long  bacillus  which  appears  to  be 
the  cause  of  the  disease. 

Morphology. — Bacilli,  five  to  six  times  as  long  as  broad,  usually  united  in 
long  filaments.  The  diameter  of  the  rods  is  about  half  that  of  the  bacillus 
of  malignant  oedema. 

Biological  Characters.—  Attempts  to  cultivate  this  bacillus  in  nutrient 
gelatin,  blood  serum  from  sheep,  and  various  other  media  were  unsuccessful. 
But  when  fragments  of  tissue  containing  the  bacillus  were  placed  in  blood 
serum  from  the  calf  a  whitish  border,  consisting  of  the  long  bacilli,  was  de- 
veloped. These  could  not,  however,  be  made  to  grow  when  transferred  to 
fresh  blood  serum. 

Pathogenesis. —  Mice  inoculated  subcutaneously  with  the  fresh  diph- 
theritic exudation  died  in  from  seven  to  thirty  days.  The  autopsy  disclosed 
an  extensive  infiltration  of  the  entire  walls  of  the  abdomen,  which  often  pene- 
trated the  peritoneal  cavity  and  enveloped  the  liver,  the  kidneys,  and  the 
intestine  in  a  yellowish  exudate.  ^  The  bacillus  was  found  in  this  exudate, 
and  by  inoculating  a  little  of  it  into  another  animal  of  the  same  species  a 
similar  result  was  obtained.  Not  pathogenic  for  rabbits  or  guinea-pigs. 

51.    BACILLUS   OF   INTESTINAL   DIPHTHERIA   IN   RABBITS. 

Described  by  Bibbert  (1887)  and  obtained  by  him  from  the  organs  of  rab- 
bits which  succumbed  to  an  affection  characterized  by  a  diphtheritic  inflam- 
mation of  the  mucous  membrane  of  the  intestine.  The  autopsy  revealed  also 
swelling  of  the  mesenteric  glands  and  minute  necrotic  foci  in  the  liver  and 
spleen. 

Morphology. — Bacilli  with  slightly  rounded  ends,  from  three  to  four/* 
long  and  1  to  1.4  u  in  diameter;  often  united  in  pairs  or  in  filaments  con- 
taining several  elements. 

Stains  with  the  aniline  colors,  but  not  so  readily  in  sections  as  some 
other  microorganisms.  Ribbert  recommends  staining  with  aniline-water- 
fuchsin  solution,  washing  in  water,  then  placing  the  sections  in  methylene 
blue  solution,  and  decolorizing  in  alcohol.  Does  not  stain  by  Gram's 
method. 


BACTERIA  IN  DIPHTHERIA.  369 

Biological  Characters. — An  aerobic,  non-liquefying  (non-motile  ?)  ba- 
cillus. Upon  gelatin  plates  semi-transparent,  grayish  colonies  are  formed, 
which  later  have  a  brownish  color;  the  surface  of  these  is  finely  granular 
and  of  a  pearly  lustre.  In  stick  cultures  in  nutrient  gelatin  the  growth 
along  the  line  of  puncture  is  very  scanty.  On  potato  a  flat,  whitish  layer  is 
formed,  which  extends  slowty  over  the  surface.  Grows  best  at  a  temperature 
of  30°  to  35°  C. 

Pathogenesis. — Pure  cultures  injected  into  the  peritoneal  cavity  or  sub- 
cutaneously  in  rabbits  caused  the  death  of  these  animals  in  from  three  to 
fourteen  days,  according  to  the  quantity  injected.  At  the  autopsy  necrotic 
foci  are  found  in  the  liver  and  spleen,  and  the  mesenteric  glands  are  en- 
larged, but  the  intestine  presents  a  healthy  appearance.  But  when  cultures 
are  introduced  into  the  alimentary  canal  the  characteristic  diphtheritic  in- 
flammation of  the  mucous  membrane  of  the  intestine  is  induced.  This  re- 
sult was  obtained  both  by  direct  injection  into  the  lumen  of  the  intestine 
and  by  injecting  cultures  into  the  mouth. 


X. 
BACTERIA  IN   INFLUENZA. 

A  NUMBER  of  bacteriologists  have  made  careful  researches  during 
the  recent  extended  epidemic  of  influenza,  and  quite  recently  (1892) 
a  bacillus  has  been  discovered,  both  by  Pfeiffer  and  by  Canon,  of 
Berlin,  which  there  is  good  reason  to  believe  is  the  specific  cause  of 
this  disease.  Before  describing  this  we  shall  refer  briefly  to  previous 
researches. 

Babes  has  described  no  less  than  seventeen  distinct  species  or  varieties 
isolated  by  him,  principally  from  nasal  or  bronchial  mucus.  Among  these 
a  considerable  number  closely  resemble  Streptococcus  pyogenes  or  Micro- 
coccus  pneumoniae  crouposae.  No  one  form  was  found  with  sufficient  con- 
stancy to  justify  the  inference  that  it  was  the  specific  cause  of  the  disease. 

Klebs,  in  examining  blood  drawn  from  the  fingers  of  patients  with  influ- 
enza, observed  an  enormous  number  of  small,  actively  motile,  highly  refrac- 
tive bodies,  which  in  their  size,  form,  and  movements  corresponded  entirely 
with  similar  bodies  previously  observed  by  him  in  the  blood  of  patients  with 
pernicious  anaemia,  but  which  were  far  more  numerous.  These  bodies  are 
believed  by  Klebs  to  be  flagellate  infusoria  ("flagellata").  The  investiga- 
tions of  other  bacteriologists  have  not  thus  far  confirmed  those  of  Klebs  as 
regards  the  presence  of  microorganisms  of  this  class  in  the  blood  of  patients 
with  influenza. 

Kowalski,  who  made  bacteriological  researches  in  sixteen  cases,  was  not 
able  to  find  microorganisms  of  any  kind  in  the  blood,  examined  both  fresh 
and  in  dried  preparations.  In  his  cultures  from  the  nasal,  buccal,  and 
bronchial  secretions  of  the  sick  he  obtained  in  five  cases  Staphylococcus 
pyogenes  aureus,  in  four  Staphylococcus  pyogenes  albus,  in  two  "diplococ- 
cus  pneumoniae,"  in  two  Streptococcus  pyogenes,  in  two  Staphylococcus 
pyogenes  citreus,  in  one  Friedlander's  bacillus,  in  one  Staphylococcus  cereus 
albus,  in  one  Staphylococcus  cereus  flavus.  In  addition  to  these  he  isolated 
three  species  not  previously  described.  One  of  these  he  found  in  seven 
cases  ;  this  grew  upon  the  surface  of  agar  as  small,  transparent  drops,  but 
did  not  grow  upon  potato,  in  sterilized  milk,  or  in  bouillon ;  it  was  a  coccus 
arranged  in  pairs  or  in  chains,  and  is  designated  by  Kowalski  "  Gallertstrep- 
tococcus." 

Prior,  in  a  bacteriological  study  of  fifty- three  cases,  twenty-nine  of  which 
were  without  complication  and  twenty-four  complicated  by  pneumonia, 
found  in  the  sputum  of  uncomplicated  cases,  as  the  most  abundant  and  com- 
mon microorganism  at  the  outset  of  the  attack,  Micrococcus  pneumoniae 
crouposae ;  next  to  this  came  Staphylococcus  pyogenes  aureus  and  Strepto- 
coccus pyogenes ;  when  the  acme  of  the  attack  was  past  the  two  species  first 
named  quickly  diminished  in  numbers,  while  streptococci  were  found  for  a 
longer  time.  In  cases  of  croupous  pneumonia  following  influenza  "  diplo- 
coccus  pneumoniae  "  was  constantly  found  in  great  numbers. 

Fiscnel  (1891)  obtained  in  cultures  from  the  blood  of  two  cases  two  dif- 


BACTERIA  IN   INFLUENZA.  371 

ferentmicrococci,  one  of  which  was  pathogenic  for  dogs  and  horses  and  gave 
rise  to  symptoms  in  these  animals  resembling  those  of  influenza  (see  Micro- 
coccus  No.  II.  of  Fischel,  No.  39,  page  324). 

Kirchner  (1891)  found  constantly  in  the  sputum  of  recent  cases  a  diplo- 
coccus  enclosed  in  a  jelly-like  capsule,  which  differed  in  its  biological  and 
pathological  characters  from  Micrococcus  pneumonias  crouposae  (see  Micro- 
coccus  of  Kirchner,  No.  38,  page  324). 

52.    BACILLUS  OP  INFLUENZA. 

Discovered  by  Pfeiffer  (1892)  in  the  purulent  bronchial  secretion, 
and  by  Canon  in  the  blood  of  patients  suffering  from  epidemic  in- 
fluenza. Pfeiffer  found  the  bacillus  in  thirty-one  cases  examined  by 
him,  and  in  uncomplicated  cases  it  was  present  in  the  purulent  bron- 
chial secretion  in  immense  numbers  and  in  a  pure  culture.  Canon, 
whose  independent  observations  were  published  at  the  same  time, 
examined  the  blood  of  twenty  influenza  patients  in  stained  prepara- 
tions, and  found  the  same  bacillus  in  nearly  all  of  them.  His  method 
of  demonstrating  it  is  as  follows  : 

The  blood  is  spread  upon  clean  glass  covers  in  the  usual  way. 
After  the  preparations  are  thoroughly  dry  they  are  placed  in  abso- 
lute alcohol  for  five  minutes.  They  are  then  transferred  to  the  fol- 
lowing staining  solution  (Czenzynke's) :  concentrated  aqueous  solu- 
tion of  methylene  blue,  forty  grammes  ;  one-half -per-cent  solution  of 
eosin  (dissolved  in  seventy-per-cent  alcohol),  twenty  grammes  ;  dis- 
tilled water,  forty  grammes.  The  cover  glasses  immersed  in  this 
staining  solution  are  placed  in  an  incubating  oven  at  37°  C.  for  from 
three  to  six  hours,  after  which  they  are  washed  with  water,  dried, 
and  mounted  in  balsam.  In  successful  preparations  the  red  blood 
corpuscles  are  stained  red  by  the  eosin,  and  the  leucocytes  blue.  The 
bacillus  is  seen  in  these  as  a  short  rod,  often  resembling  a  diplococcus. 
It  is  sometimes  seen  in  large  numbers,  but  usually  only  a  few  rods 
are  seen  after  a  long  search — four  to  twenty  in  a  single  preparation. 
In  six  cases  it  was  found  in  numerous  aggregations  containing  from 
five  to  fifty  bacilli  each.  In  these  cases  the  blood  was  drawn  during 
a  fall  of  temperature  or  shortly  after. 

Morphology. — Very  small  bacilli,  having  about  the  same  diameter 
as  the  bacillus  of  mouse  septicaemia,  but  only  half  as  long.  Solitary 
or  united  in  chains  of  three  or  four  elements. 

Stains  with  difficulty  with  the  basic  aniline  dyes — best  with 
dilute  ZiehPs  solution,  or  Loffler's  methylene  blue  solution,  with  heat. 
The  two  ends  of  the  bacilli  are  most  deeply  stained,  causing  them  to 
resemble  diplococci.  Pfeiffer  says  :  "  I  am  inclined  to  believe  that 
some  of  the  earlier  observers  also  saw  the  bacilli  described  by  me, 
but  that,  misled  by  their  peculiar  behavior  with  regard  to  staining 
agents,  they  described  them  as  diplococci  or  streptococci."  Do  not 
stain  by  Gram's  method. 


372  BACTERIA   IN   INFLUENZA. 

Biological  Characters. — An  aerobic,  non-motile  bacillus.  Does 
not  grow  in  nutrient  gelatin  at  the  room  temperature.  Spore  forma- 
tion not  observed.  Upon  the  surface  of  glycerin-agar  in  the  incubat- 
ing oven  very  small,  transparent,  drop-like  colonies  are  developed  at 
the  end  of  twenty-four  hours.  These  can  only  be  recognized  by  the 
aid  of  a  lens.  "  A  remarkable  point  about  them  is  that  the  colonies 
always  remain  separate  from  each  other,  and  do  not,  as  all  other 
species  known  to  me  do,  join  together  and  form  a  continuous  row. 
This  feature  is  so  characteristic  that  the  influenza  b'acilli  can  be 
thereby  with  certainty  distinguished  from  other  bacteria  "  (Kitasato). 
On  1.5  per  cent  sugar-agar  the  colonies  appear  as  extremely  small 
droplets,  clear  as  water,  often  only  recognizable  with  a  lens 
(Pfeiffer). 

In  bouillon  a  scanty  development  occurs,  and  at  the  end  of  twen- 
ty-four hours  small,  white  particles  are  seen  upon  the  surface,  which 
subsequently  sink  to  the  bottom,  forming  a  white,  woolly  deposit, 
while  the  bouillon  above  remains  transparent.  This  bacillus  does 
not  grow  at  temperatures  below  28°  C. 

Canon  has  obtained  colonies,  resembling  those  described  by  Kita- 
sato, in  cultures  from  the  blood  of  influenza  patients.  His  cultures 
were  made  upon  glycerin-agar  in  Petri's  dishes.  Ten  or  twelve  drops 
of  blood  from  a  puncture  made  in  the  finger  of  the  patient,  after 
sterilization  of  the  surface,  were  allowed  to  fall  upon  the  agar  medium, 
and  this  was  placed  in  the  incubating  oven.  As  the  number  of  ba- 
cilli in  the  blood  is  small,  a  considerable  quantity  is  used.  The 
colonies  are  visible  at  the  end  of  twenty-four  to  forty-eight  hours. 

The  influenza  bacillus  is  quickly  destroyed  by  desiccation  ;  a 
pure  culture  diluted  with  water  and  dried  is  destroyed  with  cer- 
tainty in  twenty  hours ;  in  dried  sputum  the  vitality  is  retained 
somewhat  longer,  but  no  growth  occurs  after  forty  hours.  The 
thermal  death-point  is  60°  C.  with  five  minutes'  exposure  (Pfeiffer 
and  Beck). 

Pathogenesis. — Pfeiffer  infers  that  this  is  the  specific  cause  of 
influenza  in  man  for  the  following  reasons  : 

1.  They  were  found  in  all  uncomplicated  cases  of  influenza  ex- 
amined, in  the  characteristic  purulent  bronchial  secretion,  often  in 
absolutely  pure  cultures.     They  were  frequently  situated  in  the  pro- 
toplasm of  the  pus  corpuscles  ;   in  fatal  cases  they  were  found  to 
have  penetrated  from  the  bronchial  tubes  into  the  peribronchitic  tis- 
sue, and  even  to  the  surface  of  the  pleura,  where  in  two  cases  they 
were  found  in  pure  cultures  in  the  purulent  exudation. 

2.  They  were  only  found  in  cases  of  influenza.     Numerous  con- 
trol  experiments  proved   their  absence   in   ordinary  bronchial  ca 
tarrh,  etc. 


PLATE    VI 

STERN  BERG'S  BACTERIOLOGY. 


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ff+.fj        •          m.^  *  -  •    ' 


* 


PATHOGENIC  BACTERIA. 


BACTERIA   IN   INFLUENZA.  373 

3.  The  presence  of  the  bacilli  corresponded  with  the  course  of  the 
disease,  and  they  disappeared  with  the  cessation  of  the  purulent 
bronchial  secretion. 

In  his  preliminary  report  of  his  investigations  Pfeiffer  says  : 
"  Numerous  inoculation  experiments  were  made  on  apes,  rabbits, 
guinea-pigs,   rats,   pigeons,  and  mice.     Only  in  apes  and  rabbits 
could  positive  results  be  obtained.     The  other  species  of  animals 
showed  themselves  refractory  to  influenza." 


PLATE  VI. 

PATHOGENIC   BACTERIA. 

FIG.  1.— Bacillus  tuberculosis  in  giant  cell,  x  1,000.  Photomicrograph 
made  at  the  Army  Medical  Museum,  Washington,  by  Gray. 

FIG.  2. — Bacillus  tuberculosis  from  a  culture  011  glycerin-agar.  x  1,000. 
Photomicrograph  by  Frankel  and  Pfeiffer. 

FIG.  3.— Bacillus  tetani  from  an  agar  culture,  x  1.000.  Photomicro- 
graph by  Frankel  and  Pfeiffer. 

FIG.  4. — Micrococcus  pneumonias  crouposae  in  sputum  of  a  patient  with 
pneumonia,  x  1,000.  Stained  by  Gram's  method.  Photomicrograph  by 
Frankel  and  Pfeiffer. 

FIG.  5. — Bacillus  septicsemise  haemorrhagicce  ("bacillus of  fowl  cholera") 
in  blood  from  the  heart  of  an  inoculated  pigeon,  x  1,000.  Photomicro- 
graph by  Frankel  and  Pfeiffer. 

FIG.  6.— Bacillus  of  hog  cholera,  showing  flagella.  Stained  by  Loffler's 
method,  x  1,000.  Photomicrograph  made  at  the  Army  Medical  Museum, 
Washington,  by  Gray. 


XI. 
BACILLI  IN  CHRONIC  INFECTIOUS  DISEASES. 

IN  tuberculosis,  leprosy,  glanders,  and  syphilis  we  have  a  group 
of  infectious  diseases  which  present  many  points  of  resemblance. 
All  run  a  chronic  course  ;  all  may  be  communicated  to  susceptible 
animals  by  inoculation  ;  in  all,  the  lymphatic  glands  in  the  vicinity 
of  the  point  of  inoculation  become  enlarged,  and  new  growths,  con- 
sisting of  various  cellular  elements  of  a  low  grade  of  vitality,  are  de- 
veloped in  the  tissues  which  are  the  point  of  predilection  for  each  ; 
in  all,  these  new  growths  show  a  tendency  to  degenerative  changes, 
as  a  result  of  which  abscesses,  caseous  masses,  or  open  ulcers  are 
formed. 

In  two  of  the  diseases  in  this  group — tuberculosis  and  glan- 
ders— the  infectious  agent  has  been  obtained  in  pure  cultures  and  its 
specific  pathogenic  power  demonstrated  by  inoculations  in  susceptible 
animals;  in  one — leprosy — there  is  but  little  doubt  that  the  bacillus  con- 
stantly found  in  the  new  growths  characteristic  of  the  disease  bears 
an  etiological  relation  to  it,  although  this  has  not  been  demonstrated, 
the  bacillus  not  having  as  yet  been  cultivated  in  artificial  media. 
The  evidence  with  reference  to  the  parasitic  nature  of  the  fourth  dis- 
ease mentioned  as  belonging  to  this  group — syphilis — is  still  unsatis- 
factory, but  there  is  every  reason  to  believe  that  it  will  also  eventu- 
ally be  proved  to  be  due  to  a  parasitic  microorganism. 

The  announcement  of  the  discovery  of  the  tubercle  bacillus  was 
made  by  Koch,  in  March,  1882,  at  a  meeting  of  the  Physiological 
Society  of  Berlin.  At  the  same  time  satisfactory  experimental  evi- 
dence was  presented  as  to  its  etiological  relation  to  tuberculosis  in 
man  and  in  the  susceptible  lower  animals,  and  its  principal  biologi- 
cal characters  were  given. 

This  achievement,  the  result  of  patient  and  intelligent  scientific 
investigation,  will  always  rank  as  one  of  the  most  important  in  the 
history  of  medicine.  The  previous  demonstration  by  Villemin  (1865) 
— confirmed  by  Cohnheim  (1877)  and  others — that  tuberculosis  might 
be  induced  in  healthy  animals  by  inoculations  of  tuberculous  mate- 
rial, had  paved  the  way  for  this  great  discovery,  and  advanced 


BACILLI    IN   CHRONIC    INFECTIOUS   DISEASES.  375 

pathologists  were  quite  prepared  to  accept  it.  The  more  conservative 
have  since  been  obliged  to  yield  to  the  experimental  evidence,  which 
has  received  confirmation  in  all  parts  of  the  world.  To-day  it  is 
generally  recognized  that  tuberculosis  is  a  specific  infectious  disease 
due  to  the  tubercle  bacillus. 

As  evidence  of  the  thorough  nature  of  Koch's  personal  researches 
in  advance  of  his  first  public  announcement,  we  give  the  following 
resume  of  his  investigations  : 

In  nineteen  cases  of  miliary  tuberculosis  the  bacilli  were  found  in 
the  tubercular  nodules  in  every  instance  ;  also  in  twenty-nine  cases 
of  pulmonary  phthisis,  in  the  sputum,  in  fresh  cheesy  masses,  and  in 
the  interior  of  recently  formed  cavities  ;  in  tuberculous  ulcers  of  the 
tongue,  tuberculosis  of  the  uterus,  testicles,  etc.  ;  in  twenty-one  cases 
of  tuberculous — scrofulous — lymphatic  glands ;  in  thirteen  cases  of 
tuberculous  joints  ;  in  ten  cases  of  tubercular  bone  affections  ;  in  four 
cases  of  lupus  ;  in  seventeen  cases  of  Perlsucht  in  cattle.  His  ex- 
perimental inoculations  were  made  upon  two  hundred  and  seventy- 
three  guinea-pigs,  one  hundred  and  five  rabbits,  forty-four  field 
mice,  twenty-eight  white  mice,  nineteen  rats,  thirteen  cats,  and  upon 
dogs,  pigeons,  chickens,  etc.  Very  extensive  comparative  researches 
were  also  made,  which  convinced  him  that  the  bacillus  which  he  had 
been  able  to  demonstrate  in  tuberculous  sputum  and  tissues  by  a  spe- 
cial mode  of  staining  was  not  to  be  found  in  the  sputa  of  healthy 
persons,  or  of  those  suffering  from  non-tubercular  pulmonary  affec- 
tions, or  in  organs  and  tissues  involved  in  morbid  processes  of  a 
different  nature. 

53.    BACILLUS   TUBERCULOSIS. 

Discovered  by  Koch  (first  public  announcement  of  discovery 
March  24th,  1882).  The  bacilli  are  found  in  the  sputum  of  persons 
suffering  from  pulmonary  or  laryngeal  tuberculosis,  either  free  or  in 
the  interior  of  pus  cells  ;  in  miliary  tubercles  and  fresh  caseous 
masses,  in  the  lungs  or  elsewhere  ;  in  recent  tuberculous  cavities  in 
the  lungs ;  in  tuberculous  glands,  joints,  bones,  and  skin  affections 
(lupus)  ;  in  the  lungs  of  cattle  suffering  from  pulmonary  tubercu- 
losis— Perlsucht ;  and  in  tubercular  nodules  generally  in  animals 
which  are  infected  naturally  or  by  experimental  inoculations. 

In  the  giant  cells  of  tubercular  growths  they  have  a  peculiar  and 
characteristic  position,  being  found,  as  a  rule,  upon  the  side  of  the 
cell  opposite  to  the  nuclei,  which  are  crowded  together  in  a  crescentic 
arrangement  at  the  opposite  pole  of  the  cell.  Sometimes  a  single 
bacillus  will  be  found  in  this  position,  or  there  may  be  several. 
Again,  numerous  bacilli  may  be  found  in  giant  cells  in  which  the 
nuclei  are  distributed  around  the  periphery.  They  are  more  numer- 


376 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


Fia.       116.  —  Bacillus      tuberculosis. 
X  1,000.    From  a  photomicrograph. 


ous  in  tuberculous  growths  of  recent  origin,  and  often  cannot  be 
demonstrated,  by  microscopical  examination,  in  caseous  material 
from  the  centre  of  older  nodules.  But  such  material,  when  inocu- 
lated into  susceptible  animals,  gives  rise  to  tuberculosis,  and  the 
usual  inference  is  that  it  contains  spores  of  the  tubercle  bacillus. 

Morphology. — The  tubercle  bacilli  are  rods  with  rounded  ends, 
of  from  1.5  to  3.5  /*  in  length,  and  are  commonly  slightly  curved  or 

bent  at  an  angle ;  the  diameter  is 
about  0. 2  {A.  In  stained  preparations 
unstained  portions  are  frequently 
seen,  which  are  generally  believed  to 
be  spores,  but  this  is  by  no  means 
certain.  From  two  to  six  of  these 
unstained  spaces  may  often  be  seen 
in  a  single  rod,  and  owing  to  this  al- 
ternation of  stained  and  unstained 
portions  the  bacilli  may,  under  a  low 
power,  be  mistaken  for  chains  of  mi- 
crococci  The  rods  are  usually  soli- 
tary, but  may  be  united  in  pairs,  or 
in  short  chains  containing  three  or  four 
elements.  In  old  cultures  irregular 

forms  may  be  observed,  the  rods  being  sometimes  swollen  at  one 
extremity,  or  presenting  the  appearance  of  having  a  lateral  bud -like 
projection — involution  forms. 

The  staining  characters  of  this  bacillus  are  extremely  important 
for  its  differentiation  and  recognition  in  preparations  of  sputum,  etc. 
Unlike  most  microorganisms  of  the  same  class,  it  does  not  readily 
take  up  the  aniline  colors,  and  when  stained  it  is  not  easily  decolorized, 
even  by  the  use  of  strong  acids.  The  failure  to  observe  it  in  tuber- 
culous material,  prior  to  Koch's  discovery,  was  no  doubt  due  to  the 
fact  that  it  does  not  stain  in  the  usual  aqueous  solutions  of  the  aniline 
dyes.  Koch  first  recognized  it  in  preparations  placed  in  a  staining 
fluid  to  which  an  alkali  had  been  added — solution  of  methylene  blue 
with  caustic  potash  ;  but  this  method  was  not  very  satisfactory,  and 
he  promptly  adopted  the  method  devised  by  Ehrlich,  which  consists 
essentially  in  the  use  of  a  solution  of  an  aniline  color — fuchsin  or 
methyl  violet — in  a  saturated  aqueous  solution  of  aniline  oil,  and  de- 
colorization  with  a  solution  of  a  mineral  acid — nitric  acid  one  part  to 
three  parts  of  water. 

The  original  method  of  Ehrlich  gives  very  satisfactory  results, 
but  various  modifications  have  since  been  proposed,  some  of  which 
are  advantageous.  The  carbol-fuchsin  solution  of  Ziehl  is  now 
largely  employed ;  it  has  the  advantage  of  prompt  action  and  of 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  377 

keeping  well.  The  staining  is  effected  more  quickly  if  heat  is  ap- 
plied. The  tubercle  bacilli  stain  by  Gram's  method,  but  this  is  not 
to  be  recommended  for  general  use,  owing  to  the  fact  that  the  pro- 
toplasm of  the  rods  is  frequently  contracted  into  a  series  of  spheri- 
cal, stained  bodies,  which  might  easily  be  mistaken  for  micrococci. 

The  examination  of  sputum  for  the  presence  of  the  tubercle  ba- 
cillus is  recognized  as  a  most  important  procedure  for  the  early  diag- 
nosis of  pulmonary  tuberculosis.  It  is  at- 
tended with  no  special  difficulties,  and  every 
physician  should  be  acquainted  with  the 
technique. 

The  patient  should  be  directed  to  expec- 
torate into  a  clean,  wide-mouthed  bottle  or 
glass-covered  jar  the  material  coughed  up 
from  the  lungs,  and  especially,  in  recent 
cases,  that  which  is  coughed  up  upon  first 
rising  in  the  morning.  This  should  be 
placed  in  the  physician's  hands  as  promptly  FIG.  m.— Bacillus  tubercuio- 

•  ••1  ij-i  -i          -ii  f  sis  in  sputum,   X  1,000.  (Baum- 

as  possible  ;  although  a  delay  of  some  days      garten!) 
does  not  vitiate  the  result,  and  the  tubercle 

bacilli  may  still  be  demonstrated  after  the  sputum  has  undergone  pu- 
trefaction. It  is  well  to  pour  the  specimen  into  a  clean,  shallow  vessel 
having  a  blackened  bottom — a  Petri's  dish  placed  upon  a  piece  of  dead- 
black  paper  will  answer  very  well.  In  tuberculous  sputum  small,  len- 
ticular masses  of  a  yellowish  color  may  usually  be  observed,  and  one 
of  these  should  be  selected  for  microscopical  examination,  by  picking 
it  up  with  a  platinum  needle  and  freeing  it  as  far  as  possible  from 
the  tenacious  mucus  in  which  it  is  embedded.  If  such  masses  are 
not  recognized  take  any  purulent-looking  material  present  in  the 
specimen,  whether  it  be  in  small  specks  distributed  through  the  mu- 
cus, or  in  larger  masses.  A  little  of  the  selected  material  should  be 
placed  in  the  centre  of  a  clean  cover  glass  and  another  thin  glass 
cover  placed  over  it.  By  pressure  and  a  to-and-fro  motion  the  mate- 
rial is  crushed  and  distributed  as  evenly  as  possible  ;  the  glasses  are 
then  separated  by  a  sliding  motion.  The  film  is  permitted  to  dry  by 
exposure  in  the  air.  When  dry  the  cover  glass,  held  in  forceps,  is 
passed  three  times  through  the  flame  of  an  alcohol  lamp  or  Bunsen 
burner  to  fix  the  albuminous  coating.  Too  much  heat  causes  the  film 
to  turn  brown  and  ruins  the  preparation.  The  staining  fluid  (Ziehl's 
carbol-f  uchsin)  may  then  be  poured  upon  the  cover  glass,  or  this  may 
be  floated  upon  the  surface  of  the  fluid  contained  in  a  shallow  watch 
glass.  Heat  is  now  applied  by  bringing  the  cover  glass  over  a 
flame  and  holding  it  there  until  steam  begins  to  be  given  off  from 
the  surface  of  the  staining  fluid ;  it  is  then  withdrawn  and  again 
29 


378  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

gently  heated  at  intervals  for  a  minute  or  two.  The  cover  glass  is 
then  washed  in  water,  and  the  film  will  be  seen  to  have  a  uniform 
deep-red  color.  The  next  step  consists  in  decolorization  in  the  acid 
solution  (twenty-five-per-cent  solution  of  nitric  or  of  sulphuric  acid). 
The  cover  glass  is  gently  moved  about  in  this  solution  for  a  few 
seconds,  and  the  color  will  be  seen  to  quickly  fade  to  a  greenish 
tint.  The  object  is  to  remove  all  color  from  the  cells  and  the  al- 
buminous background,  so  that  the  bacilli,  which  retain  their  color  in 
presence  of  the  acid,  may  be  clearly  seen.  The  preparation  is  next 
washed  in  dilute  alcohol  (sixty  per  cent)  to  remove  the  fuchsin 
which  has  been  set  free  by  the  acid.  If  decolorization  was  not  car- 
ried far  enough  the  film  will  be  seen  to  still  have  a  red  color,  espe- 
cially in  places  where  it  is  thickest,  when  it  is  removed  from  the 
dilute  alcohol  and  washed  out  in  water.  In  this  case  it  will  be 
necessary  to  return  it  to  the  acid  solution  and  again  wash  it  in  the 
dilute  alcohol  and  in  water.  It  may  now  be  placed  in  a  solution 
of  methylene  blue  or  of  vesuvin  for  a  contrast  stain.  The  tubercle 
bacilli  are  distinguished  by  the  fact  that  they  retain  the  red  color 
imparted  to  them  in  the  fuchsin  solution,  while  other  bacteria  pre- 
sent, having  been  decolorized  in  the  acid  solution,  take  the  contrast 
stain  and  appear  blue  or  brown,  according  to  the  color  used.  The 
double-stained  preparation,  after  a  final  washing  in  water,  may  be 
examined  at  once,  or  dried  and  mounted  in  balsam  for  permanent 
preservation. 

Of  the  various  other  methods  which  have  been  proposed,  that  of 
Frankel,  as  modified  by  Gabbett,  appears  to  be  the  most  useful.  This 
consists  in  staining  as  above  directed  with  Ziehl's  carbol-f  uchsin  solu- 
tion, and  in  then  placing  the  cover  glass  directly  in  a  second  solution 
which  contains  both  the  acid  for  decolorizing  and  the  contrast  stain. 
This  second  solution  contains  twenty  parts  of  nitric  acid,  thirty  parts 
of  alcohol,  fifty  parts  of  water,  and  sufficient  methylene  blue  to  make 
a  saturated  solution  (one  to  two  parts  in  one  hundred).  After  re- 
maining in  this  solution  for  a  minute  or  two  the  cover  glass  is  washed 
in  water,  and  upon  microscopical  examination  the  tubercle  bacilli,  if 
present,  will  be  seen  as  red  rods  which  strongly  contrast  with  the 
blue  background. 

The  methods  recommended  for  cover-glass  preparations  may  also 
be  used  for  staining  the  tubercle  bacillus  in  thin  sections  of  tuber- 
culous tissues,  except  that  it  is  best  not  to  employ  heat.  The  sec- 
tions may  be  left  for  an  hour  in  the  carbol-fuchsin  solution,  or  for 
twelve  hours  in  the  Ehrlich-Weigert  tubercle  stain — eleven  cubic 
centimetres  of  saturated  alcoholic  solution  of  methyl  violet,  ten  cubic 
centimetres  of  absolute  alcohol,  one  hundred  cubic  centimetres  of  ani- 
line water.  They  should  then  be  decolorized  by  placing  them  for 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


379 


about  half  a  minute  in  dilute  nitric  acid  (ten  per  cent) ;  then  wash 
out  color  in  sixty-per-cent  alcohol ;  counter-stain  for  two  or  three 
minutes  in  a  saturated  aqueous  solution  of  methylene  blue ;  dehydrate 
with  absolute  alcohol  or  with  aniline  oil ;  clear  up  in  oil  of  cedar, 
and  mount  in  xylol  balsam.  If  the  aniline- water-methyl-violet  solu- 
tion has  been  used  for  staining  the  bacilli  a  saturated  solution  of 
vesuvin  may  be  used  as  a  contrast  stain. 

Biological  Characters. — A  parasitic,  aerobic,  non-motile  ba- 
cillus, which  grows  only  at  a  temperature  of  about  37°  C.  Is  also  a 
facultative  anaerobic  (Frankel). 

The  question  as  to  spore  formation  has  not  been  definitely  deter- 
mined. It  has  been  generally  assumed  that  the  unstained  spaces 
which  are  frequently  seen  in  the  bacilli  are  spores  ;  and  the  fact  that 


FIG.  118.— Section  through  a  tuberculous  nodule  in  the  lung  of  a  cow,  showing  two  giant  cells 
containing  tubercle  bacilli.    X  950.    (Baumgarten.) 

caseous  material  in  which  a  microscopical  examination  has  failed  to 
demonstrate  the  presence  of  bacilli  may  produce  tuberculosis,  with 
bacilli,  when  inoculated  into  guinea-pigs,  has  been  explained  upon  the 
supposition  that  this  material  contained  spores.  But  a  few  bacilli 
present  in  such  caseous  material  might  easily  escape  detection.  As 
pointed  out  by  Frankel,  the  oval  spaces  in  stained  specimens  have 
not  the  sharply  defined  outlines  of  spores.  Moreover,  the  bacilli,  when 
examined  in  unstained  preparations,  do  not  contain  corresponding  re- 
fractive bodies,  recognizable  as  spores.  And  when  the  bacilli  are 
stained  by  Gram's  method  the  protoplasm  is  often  contracted  in  the 
form  of  little,  spherical  stained  masses,  while  the  unstained  spaces 
are  larger  and  no  longer  have  the  oval  form  presented  in  rods  stained 
by  Ehrlich's  method.  The  great  resisting  power  of  the  bacillus  to 
heat  and  to  desiccation  has  been  supposed  to  be  due  to  the  presence 


380  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

of  spores.  But,  so  far  as  resistance  to  heat  is  concerned,  this  is  not 
so  great  as  was  at  one  time  believed.  Schill  and  Fischer  (1884),  as- 
suming that  the  tubercle  bacillus  forms  spores,  made  quite  a  number 
of  experiments  to  determine  its  thermal  death-point.  They  sub- 
jected sputum  containing  the  bacillus  to  a  temperature  of  100°  C.,  and 
tested  the  destruction  of  vitality  by  inoculations  into  guinea-pigs. 
Exposure  to  steam  at  a  temperature  of  100°  C.  for  two  to  five  min- 
utes was  effective  in  every  experiment,  with  one  exception.  One 
guinea-pig  died  tuberculous  after  having  been  inoculated  with 
sputum  exposed  to  this  temperature  for  two  minutes.  This  result 
was  assumed  to  show  that  the  bacillus  would  survive  lower  tempera- 
tures, but  it  is  evident  that  additional  experiments  were  required  to 
establish  this  fact.  In  1887  the  writer  made  a  few  similar  experi- 
ments at  a  lower  temperature,  and  guinea-pigs  inoculated  with  tuber- 
culous sputum  exposed  for  ten  minutes  to  a  temperature  of  90°,  80°, 
and  60°  C.  failed  to  become  tuberculous,  while  another  guinea-pig, 
inoculated  with  the  same  material  after  exposure  to  a  temperature  of 
50°  C.  for  ten  minutes,  died  tuberculous.  These  results  correspond 
with  those  subsequently  (1888)  reported  by  Yersin,  who  tested  the 
thermal  death-point  of  this  bacillus  by  the  culture  method.  This 
author  assumes  that  the  bacilli  form  spores,  but  states  as  a  result  of 
his  experiments  that  "at  the  end  often  days  bacilli  heated  for  ten 
minutes  at  55°  C.  gave  a  culture  in  glycerin-bouillon  ;  those  heated 
to  60°,  at  the  end  of  twenty-two  days;  while  those  heated  to  70°  and 
above  failed  to  grow  in  every  instance.  This  experiment,  repeated  a 
great  number  of  times,  always  gave  the  same  result.  The  tubercle 
bacilli  then  resist  a  temperature  of  60°  C.  for  ten  minutes,  and  it  is 
to  be  remarked  that  the  resistance  of  spores  to  heat  appears  to  be  no 
greater  than  that  of  the  bacilli  themselves."  Yersin  remarks  in  a 
footnote  that  "  the  spores  which  served  for  these  experiments  did 
not  appear  as  more  or  less  irregular  granules  taking  the  coloring 
matter  strongly,  but  as  veritable  spores  with  sharply  defined  outlines, 
to  the  number  of  one  or  two  in  a  bacillus,  or  three  at  the  outside. 
These  spores  are  particularly  clear  in  cultures  upon  glycerin-agar 
several  weeks  old." 

It  may  be  that  bacteriologists  have  been  mistaken  in  the  infer- 
ence that  all  spores  possess  a  greater  resisting  power  for  heat  than 
that  exhibited  by  bacilli  in  the  absence  of  spores.  That  this  is  true 
as  regards  anthrax  spores  and  many  others,  the  thermal  death-point 
of  which  has  been  determined  by  exact  experiments,  does  not  prove 
that  it  is  true  for  all.  And  it  is  known  that  there  are  wide  differ- 
ences in  the  resisting  power  both  of  the  spores  of  different,  species 
and  in  the  vegetating  cells.  To  admit  that  the  tubercle  bacillus  or 
the  typhoid  bacillus,  etc.,  may  form  spores  which  have  no  greater 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  381 

resisting  power  against  heat  than  the  bacilli  themselves,  would  there- 
fore simply  be  an  admission  that  some  bacteriologists  had  made  a 
mistaken  inference  based  upon  incomplete  data.  In  view  of  the 
facts  stated  we  can  simply  repeat  what  was  said  at  the  outset,  viz., 
the  question  as  to  spore  formation  has  not  been  definitely  deter- 
mined. 

The  tubercle  bacillus  is  a  strict  parasite,  and  its  biological  char- 
acters are  such  that  it  could  scarcely  find  natural  conditions,  outside 
of  the  bodies  of  living  animals,  favorable  for  its  multiplication.  It 
therefore  does  not  grow  as  a  saprophyte  under  ordinary  circum- 
stances. But  it  has  been  noted  by  Roux  and  Nbcard  that  when  it 
has  been  cultivated  for  a  time  in  artificial  media  containing  glycerin 
it  may  grow  in  a  plain  bouillon  of  veal  or  chicken,  in  which  media  it 
fails  to  develop  when  introduced  directly  from  a  culture  originating 
from  the  body  of  an  infected  animal.  This  would  indicate  the  pos- 
sibility of  its  acquiring  the  ability  to  grow  as  a  saprophyte  ;  and  we 
can  scarcely  doubt  that  at  some  time  in  the  past  it  was  a  true  sapro- 
phyte. The  experiments  of  Nuttall  indicate  that  the  bacillus  may 
multiply,  under  favorable  temperature  conditions,  in  tuberculous 
sputum  outside  of  the  body.  And  it  is  extremely  probable  that  mul- 
tiplication occurs  in  the  muco-purulent  secretion  which  accumulates 
in  pulmonary  cavities  in  phthisical  patients.  In  these  cavities  its  de- 
velopment may,  in  a  certain  sense,  be  regarded  as  saprophytic,  as  it 
feeds  upon  non-living  organic  material. 

Koch  first  succeeded  in  cultivating  this  bacillus  upon  coagulated 
blood  serum,  prepared  as  directed  in  Section  VIII.,  Part  First,  of  the 
present  volume.  Roux  and  Nocard  have  since  shown  (1888)  that  it 
grows  very  well  on  nutrient  agar  to  which  glycerin  has  been  added 
(six  to  eight  per  cent),  and  also  in  veal  broth  containing  five  per  cent 
of  glycerin.  It  is  difficult  to  obtain  pure  cultures  from  tuberculous 
sputum,  on  account  of  the  presence  of  other  bacteria  which  grow 
much  more  rapidly  and  take  full  possession  of  the  medium  before  the 
tubercle  bacillus  has  had  time  to  form  visible  colonies.  For  this  rea- 
son it  is  best  to  first  inoculate  a  guinea-pig  with  the  tuberculous  spu- 
tum and  to  obtain  cultures  from  it  after  tuberculous  infection  has 
fully  developed.  The  inoculated  animals  usually  die  at  the  end  of 
three  or  four  weeks.  It  is  best  to  kill  one  which  gives  evidence  of 
being  tuberculous,  and  to  remove  one  or  more  nodules  from  the 
lungs  through  an  opening  made  in  the  chest  walls.  The  greatest 
care  will  be  required  to  prevent  contamination  by  other  common 
microorganisms.  The  instruments  used  must  be  sterilized  by  heat, 
and  the  skin  over  the  anterior  thoracic  wall  carefully  turned  back  ; 
then,  after  again  sterilizing  knives  and  scissors,  cut  an  opening  into 
the  chest  cavity,  draw  out  the  root  of  the  lung,  and  take  up  with 


382  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

slender  sterilized  forceps,  or  with  a  strong  platinum  loop,  one  or 
more  well-defined  tubercular  nodules.  These  may  be  conveyed  di- 
rectly to  the  surface  of  the  solid  culture  medium  and  then  broken 
up  and  rubbed  over  the  surface  as  thoroughly  as  possible  ;  or  they 
may  first  be  crushed  between  two  sterilized  glass  slides,  and  then 
transferred  with  the  platinum  loop  and  thoroughly  rubbed  into  the 
surface  of  the  culture  medium. 

This  breaking-up  of  the  tuberculous  nodules  and  distribution  of 
the  bacilli  upon  the  surface  of  the  culture  medium  is  essential  for 
the  success  of  the  experiment.  Instead  of  using  the  tubercular 
nodules  in  the  lungs,  an  enlarged  lymphatic  gland  from  the  axilla  or 
elsewhere  may  be  used,  as  first  recommended  by  Koch.  This  is  to 
be  crushed  in  the  same  way ;  and  it  will  be  best  to  inoculate  a  num- 
ber of  tubes  at  the  same  time,  as  accidental  contamination  or  failure 
to  develop  is  very  liable  to  occur  in  a  certain  number.  Owing  to  the 
liability  of  the  blood  serum  to  become  too  dry  for  the  development  of 
the  bacillus,  it  is  best  to  keep  the  cultures  in  a  moist  atmosphere,  or 
to  prevent  evaporation  by  applying  a  rubber  cap  over  the  open  end 
of  the  test  tube.  This  should  be  sterilized  in  a  solution  of  mercuric 
chloride  (1  : 1,000) ;  and  the  end  of  the  cotton  plug  should  be  burned 
off  just  before  applying  it,  for  the  purpose  of  destroying  the  spores 
of  mould  fungi,  which  in  a  dry  atmosphere  would  be  harmless,  but 
under  the  rubber  cap  are  likely  to  sprout  and  to  send  their  mycelium 
through  the  cotton  plug  to  the  interior  of  the  tube,  thus  destroying 
the  culture. 

Upon  coagulated  blood  serum  the  growth  first  becomes  visible  at 
the  end  of  ten  to  fourteen  days  (at  37°  C.),  and  at  the  end  of  three 
weeks  a  very  distinct  and  characteristic  develop- 
ment has  occurred.  The  first  appearance  is  that  of 
dry-looking,  grayish- white  points  and  scales,  which 
are  without  lustre,  and  are  sometimes  united  to 
form  a  thin,  irregular,  membranous-looking  layer. 
Under  the  microscope,  with  an  amplification  of 
eighty  diameters,  the  early,  thin  surface  growth 
upon  blood  serum  presents  a  characteristic  appear- 
ance. The  bacilli,  arranged  in  parallel  rows,  form 
variously  curved  figures,  of  which  we  may  obtain 
FIG.  no.— Tubercle  impressions  by  carefully  applying  a  dry  cover  glass 

bacilli  from  surf  ace  of  J  J     V  /       &  .         . 

culture  upon  blood  se-  to  the  surface.  Upon  staining  the  preparation  in 
mm.  x  5oo.  (Koch.)  the  usual  way  the  same  arrangement  of  the  bacilli 
which  adhered  to  the  thin  glass  cover  will  be  pre- 
served. The  growth  is  more  abundant  in  subsequent  cultures, 
which  have  been  kept  up  in  Koch's  laboratory  from  his  original 
pure  cultures  up  to  the  present  time  ;  in  these  the  bacillus  still  pre- 


BACILLI   IN    CHRONIC    INFECTIOUS   DISEASES.  383 

serves  its  characters  of  form  and  growth,  and  its  specific  pathogenic 
power. 

Pastor  (1892)  has  succeeded  in  obtaining  pure  cultures  of  the 
tubercle  bacillus  from  sputum  by  the  following  ingenious  method  : 
After  proving  by  microscopic  examination  that  the  sputum  of  a 
tuberculous  individual  contains  numerous  bacilli,  he  has  the  patient 
cleanse  his  mouth  as  thoroughly  as  possible  with  sterilized  water, 
and  then  expectorate  some  material,  coughed  up  from  the  lungs,  into 
a  sterilized  test  tube.  By  shaking  with  sterilized  water  a  fine  emul- 
sion is  made,  and  this  is  filtered  through  fine  gauze.  The  filtrate, 
which  is  nearly  transparent,  contains  numerous  tubercle  bacilli.  A 
few  drops  of  the  emulsion  are  now  added  to  liquefied  gelatin  in  a  test 
tube,  and  a  plate  is  made  in  the  usual  way.  This  is  kept  for  three 
or  four  days  at  the  room  temperature,  during  which  time  the  com- 
mon mouth  bacteria  capable  of  growth  form  visible  colonies.  By 
means  of  a  hand  lens  a  place  is  now  selected  in  which  no  colonies  are 
seen,  and  a  bit  of  gelatin  is  excised  with  a  sterilized  knife.  This 
piece  is  transferred  to  the  surface  of  blood  serum  or  glycerin- agar, 
and  placed  in  the  incubating  oven,  where  in  due  time  colonies  of 
the  tubercle  bacillus  will  usually  be  found  to  develop. 

Another  method  of  accomplishing  the  same  result  has  recently 
been  described  by  Kitasato.  This  is  a  method  devised  by  Koch  some 
time  since  and  successfully  employed  in  his  laboratory.  The  morn- 
ing expectoration  of  a  tuberculous  patient,  raised  from  the  lungs  by 
coughing,  is  received  in  a  Petri's  dish.  A  bit  of  sputum,  such  as 
comes  from  the  tuberculous  cavity  in  the  lungs  of  such  a  patient,  is 
now  isolated  with  sterilized  instruments  and  carefully  washed  in  at 
least  ten  successive  portions  of  sterilized  water.  By  this  procedure 
the  bacteria  accidentally  attached  to  the  viscid  mass  of  sputum  dur- 
ing its  passage  through  the  mouth  are  washed  away.  In  the  last 
bath  the  mass  is  torn  apart  and  a  small  portion  from  the  interior  is 
used  to  make  a  microscopic  preparation,  the  examination  of  which 
shows  whether  only  tubercle  bacilli  are  present.  If  this  be  the  case 
cultures  upon  glycerin-agar  are  started  from  material  obtained  from 
the  interior  of  the  same  mass.  The  colonies  obtained  in  this  way 
appear  in  about  two  weeks  as  round,  white,  opaque,  moist,  and  shin- 
ing masses.  Kitasato's  researches  show  that  the  greater  portion  of 
the  tubercle  bacilli  in  sputum  obtained  in  this  way,  and  in  the  con- 
tents of  lung  cavities,  are  incapable  of  development,  although  this 
fact  cannot  be  recognized  by  a  microscopic  examination  of  stained 
specimens. 

On  account  of  the  greater  facility  of  preparing  and  sterilizing 
glycerin-agar,  and  the  more  rapid  and  abundant  development  upon 
this  medium,  it  is  now  usually  employed  in  preference  to  blood 


384 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


serum.  The  growth  at  the  end  of  fourteen  days  is  more  abundant  than 
upon  blood  serum  at  the  end  of  several  weeks.  When  numerous 
bacilli  have  been  distributed  over  the  surface  of  the  culture  medium 
a  rather  uniform,  thick,  white  layer,  which  subsequently  acquires  a 
yellowish  tint,  is  developed  ;  when  the  bacilli 
are  few  in  number  or  are  associated  in  scattered 
groups  separate  colonies  are  developed,  which 
acquire  considerable  thickness  and  have  more 
or  less  irregular  outlines  ;  they  are  white  at 
first,  then  yellowish- white.  Frankel  describes 
the  tubercle  bacillus  as  a  facultative  anaerobic, 
and  it  would  appear  that  it  must  be  able  to  grow 
in  situations  where  it  can  obtain  very  little  oxy- 
gen from  its  development  in  the  interior  of  tu- 
berculous nodules,  lymphatic  glands,  etc.  But 
in  stick  cultures  in  glycerin-agar  development 
only  occurs  near  the  surface,  and  not  at  all  in 
the  deeper  portion  of  the  medium.  In  view  of 
its  abundant  growth  on  the  surface  it  is  diffi- 
cult to  understand  this  failure  to  grow  along 
the  line  of  puncture,  if  it  is  in  truth  a  faculta- 
tive anaerobic. 

In  peptonized  veal  broth  containing  five  per 
cent  of  glycerin  the  bacillus  develops  at  first  in 
the  form  of  little  flocculi,  which  accumulate  at 
the  bottom  of  the  flask  and  which  by  agitation 
are  easily  broken  up.  At  the  end  of  two  or 
three  weeks  the  bottom  of  the  flask  is  covered 
with  similar  flocculi,  which  form  an  abundant 
deposit. 

Pawlowski  and  others  report  success  in  cul- 
tivating the  tubercle  bacillus  upon  the  surface 
of  cooked  potato  enclosed  in  a  test  tube  after 
the  method  of  Bolton  and  Roux.  The  open  end 
of  the  tube  is  hermetically  sealed  in  a  flame 
after  the  bacilli  have  been  planted  upon  the 

obliquely-cut  surface  of  the  potato ;  this  prevents  drying.  Ac- 
cording to  Pawlowski,  better  results  are  obtained  if  the  surface  of 
the  potato  is  moistened  with  a  five-per-cent  solution  of  glycerin.  The 
growth  is  said  to  be  seen  at  the  end  of  about  twelve  days  as  grayish, 
dry-looking  flakes ;  at  the  end  of  three  or  four  weeks  it  forms  a  dry, 
smooth,  whitish  layer,  and  no  further  development  occurs. 

The  range  of   temperature  at  which  this  bacillus  will  grow  is 
very  restricted  ;  37°  C.  is  usually  given  as  the  most  favorable  point, 


FIG.  120.— Culture  of  tu- 
bercle bacillus  upon  glyce- 
rin-agar.  Photograph  by 
Roux. 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  385 

but  Roux  and  Nocard  say  that  the  most  favorable  temperature  ap- 
pears to  be  39°,  and  that  development  is  slower  at  37°. 

The  experiments  of  Koch,  Schill  and  Fischer,  and  others  show 
that  the  bacilli  retain  their  vitality  in  desiccated  sputum  for  several 
months  (nine  to  ten  months — De  Toma) ;  but  they  are  said  to  undergo 
a  gradual  diminution  in  pathogenic  virulence,  which  is  more  rapid 
when  the  desiccated  material  is  kept  at  a  temperature  of  30°  to  40°  C. 
In  the  experiments  of  Cadeac  and  Malet  portions  of  the  lung  from 
a  tuberculous  cow,  dried  and  pulverized,  produced  tuberculosis  in 
guinea-pigs  at  the  end  of  one  hundred  and  two  days.  They  retain 
their  vitality  for  a  considerable  time  in  putrefying  material  (forty- 
three  days — Schill  and  Fischer  ;  one  hundred  and  twenty  days — Ca- 
deac and  Malet).  The  resisting  power  of  this  bacillus  against  ger- 
micidal  agents  is  also  greater  than  that  of  certain  other  pathogenic 
microorganisms,  but  not  so  great  as  to  justify  the  inference  that  it 
forms  spores.  It  is  not  destroyed  by  the  gastric  juice  in  the  sto- 
mach, as  is  shown  by  successful  infection  experiments  in  suscep- 
tible animals, 'by  mixing  cultures  of  the  bacillus  with  their  food 
(Baumgarten,  Fischer),  and  also  by  experiments  with  an  artificially 
prepared  gastric  juice  (Falk).  They  are  destroyed,  in  sputum,  in 
twenty  hours  by  a  three-per-cent  solution  of  carbolic  acid,  even 
when  they  present  the  appearance  usually  ascribed  to  the  presence 
of  spores  (Cavagnis) ;  also  by  absolute  alcohol,  a  saturated  aqueous 
solution  of  salicylic  acid,  saturated  aniline  water,  etc.  (Schill  and 
Fischer).  The  more  recent  experiments  of  Yersin  upon  pure  cul- 
tures of  the  bacillus  gave  the  following  results  :  "  Tubercle  bacilli, 
containing  spores,  were  killed  1)y  a  five-per-cent  solution  of  carbolic 
acid  in  thirty  seconds,  by  one-per-cent  in  one  minute  ;  absolute  alco- 
hol, five  minutes  ;  iodof orm-ether,  one  per  cent,  five  minutes  ;  ether, 
ten  minutes ;  mercuric  chloride,  1  : 1,000  solution,  ten  minutes  ; 
thymol,  three  hours  ;  salicylic  acid,  2. 5  per  cent,  six  hours. 

The  tubercle  bacillus  appears  to  be  especially  susceptible  to  the 
action  of  light.  In  his  address  before  the  Tenth  International  Medi- 
cal Congress  (Berlin,  1890)  Koch  says  that  when  exposed  to  direct 
sunlight  the  tubercle  bacillus  is  killed  in  from  a  few  minutes  to  sev- 
eral hours,  according  to  the  thickness  of  the  layer ;  it  is  also  de- 
stroyed by  diffuse  daylight  in  from  five  to  seven  days  when  placed 
near  a  window.  This  fact  has  an  important  hygienic  bearing,  espe- 
cially in  view  of  the  fact  that  the  tubercle  bacillus  is  not  readily 
killed  by  desiccation,  putrefaction  of  the  material  containing  it,  etc. 
Tuberculous  sputum  expectorated  upon  sidewalks,  etc.,  being  ex- 
posed to  the  action  of  direct  sunlight,  will  in  many  cases  be  disin- 
fected by  this  agent  by  the  time  complete  desiccation  has  occurred — 
i.  e. ,  before  it  is  in  a  condition  to  be  carried  into  the  air  as  dust. 
30 


386  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

Sawizky  has  recently  (1891)  made  a  series  of  experiments  to  de- 
termine the  length  of  time  during  which  dried  tuberculous  sputum 
retains  its  virulence.  He  arrives  at  the  conclusion  that  virulence  is 
not  suddenly  but  gradually  lost,  and  that  in  an  ordinary  dwelling 
room  dried  sputum  retains  its  specific  infectious  power  for  two  and 
one-half  months. 

Metschnikoff  states  that  when  kept  at  a  temperature  of  42°  C.  for 
some  time  the  tubercle  bacillus  undergoes  a  notable  diminution  in 
its  pathogenic  power,  and  that  when  kept  at  a  temperature  of  43°  to 
44°  it  after  a  time  only  induces  a  local  abscess  when  injected  subcu- 
taneously  into  guinea-pigs.  The  experiments  of  Lote  also  indicate 
that  an  "  attenuation  of  virulence  "  has  occurred  in  the  cultures  pre- 
served in  Koch's  laboratory,  originating  in  1882  from  the  lungs  of  a 
tuberculous  ape.  The  author  named  made  experiments  with  cul- 
tures from  this  source  (ninetieth  to  ninety -fifth  successive  culture), 
and  at  the  same  time  with  a  culture  obtained  from  Roux,  of 
Pasteur's  laboratory.  Rabbits  inoculated  with  cultures  from  the 
last-m.entioned  source  developed  a  hectic  fever  at  the  end  of  two 
weeks,  and  died  tuberculous  at  the  end  of  twenty-one  to  thirty -nine 
days.  Twelve  rabbits  were  inoculated  with  the  cultures  from 
Koch's  laboratory  ;  the  injections  were  made  either  subcutaneously, 
into  a  vein,  into  the  pleural  cavity,  or  into  the  cavity  of  the  abdo- 
men. No  elevation  of  temperature  occurred  in  any  of  the  animals, 
and  they  were  found  at  the  end  of  a  month  to  have  increased  in 
weight.  At  the  end  of  six  weeks  one  of  them  was  killed  and  tuber- 
cular nodules  were  found  in  various  organs.  The  remaining  animals 
were  killed  at  the  end  of  one  hundred  and  forty-four  to  one  hundred 
and  forty-eight  days.  The  two  inoculated  subcutaneously  presented 
no  sign  of  general  tuberculosis,  but  a  small  yellow  nodule  contain- 
ing bacilli  was  found  at  the  point  of  inoculation.  Those  inoculated 
by  injection  into  a  vein  showed  one  or  two  nodules  in  the  lungs  con- 
taining a  few  bacilli.  In  Koch's  original  experiments  rabbits  were 
killed  by  intravenous  inoculation  of  his  cultures  in  from  thirteen  to 
thirty-one  days.  That  this  attenuation  of  virulence  depends  upon  a 
diminished  production  of  a  toxic  product  to  which  the  bacillus  owes 
its  pathogenic  power  appears  to  be  very  certain,  in  view  of  the  fact 
that  the  late  cultures  in  a  series  have  a  more  vigorous  and  abundant 
development  than  the  more  pathogenic  cultures  obtained  directly 
from  the  animal  body. 

The  discovery  by  Koch  of  a  toxine  in  cultures  of  this  bacillus, 
which  is  soluble  in  glycerin,  and  which  in  very  minute  doses  pro- 
duces febrile  reaction  and  other  decided  symptoms  when  injected  sub- 
cutaneously into  tuberculous  animals,  must  rank  as  one  of  the  first 


BACILLI   IN  CHRONIC   INFECTIOUS   DISEASES.  387 

importance  in  scientific  medicine,  whatever  the  final  verdict  may  be 
as  to  its  therapeutic  value  in  tubercular  diseases  in  man. 

The  toxic  substance  contained  in  Koch's  glycerin  extract  from 
cultures  of  the  tubercle  bacillus,  now  generally  known  under  the 
name  of  tuberculin,  is  soluble  in  water,  insoluble  in  alcohol,  and 
passes  readily  through  dialyzing  membranes.  It  is  not  destroyed  by 
the  boiling  temperature.  According  to  the  chemical  examination  of 
Jolles,  the  "  lymph  "  contains  fifty  per  cent  of  water  and  does  not 
contain  alkaloids  or  cyanogen  compounds.  Ib  contains  albuminates, 
which  are  thrown  down  as  a  voluminous  white  precipitate  by  tannic 
acid,  and  are  redissolved  by  hot  water  containing  sodium  chloride 
and  very  diluted  potash  solution.  The  elementary  analysis  gave 
N"  5.90  per  cent,  C  35.19  per  cent,  and  H  7.02  per  cent.  The  re- 
sults obtained  are  believed  to  show  that  the  active  substance  present 
in  the  lymph  is  a  toxalbumin.  In  experiments  made  with  Koch's 
lymph  in  Pasteur's  laboratory  by  Bardach,  a  very  decided  elevation 
of  temperature  was  produced  in  tuberculous  guinea-pigs  by  the  sub- 
cutaneous injection  of  0.1  gramme,  and  a  fatal  result  by  the  injec- 
tion of  0.2  to  0.5  gramme.  In  man  a  decided  febrile  reaction  is  pro- 
duced in  tuberculous  patients  by  very  much  smaller  doses — 0.001 
cubic  centimetre. 

Hammerschlag,  in  his  chemical  researches,  found  that  the  tubercle 
bacillus  yields  a  larger  proportion  of  substances  soluble  in  alcohol 
and  ether  than  any  other  bacilli  tested  (twenty -seven  per  cent).  The 
alcoholic  extract  contains  fat,  lecithin,  and  a  toxic  substance  which 
produces  convulsions  in  rabbits  and  guinea-pigs.  The  portion  in- 
soluble in  alcohol  and  ether  contains  cellulose  and  an  albuminoid 
substance.  No  ptomaines  were  found,  but  a  toxalbumin  was  isolated, 
which  caused  an  elevation  of  temperature  in  rabbits  of  1°  to  2°  C., 
lasting  for  a  day  or  two. 

Hunter  reports  the  following  results  of  his  chemical  examination 
of  tuberculin.  It  contains — 

1.  Albumoses,  chiefly  protoalbumose  and  deuteroalbumose,  along  with 
heteroalbumose,  and  occasionally  a  trace  of  dysalbumose. 

2.  Alkaloidal  substances,  two  of  which  can  be  obtained  in  the  form  of 
the  platinum  compounds  of  their  hydrochlorate  salts. 

3.  Extractives,  small  in  quantity  and  of  unrecognized  nature. 

4.  Mucin. 

5.  Inorganic  salts. 

6.  Glycerin  and  coloring  matter. 

The  following  conclusions  are  reached  with  reference  to  its  toxic 
properties- : 

1.  Tuberculin  owes  its  activity,  not  to  one  principle,  but  to  at  least  three, 
and  probably  more,  different  substances. 

2.  Its  action  in  producing  local  inflammation,  fever,  and  general  consti- 
tutional disturbance  is  not  a  simple  but  an  extremely  complex  one. 


388  BACILLI  IN  CHRONIC   INFECTIOUS  DISEASES. 

3.  Its  active  ingredients  are  of  the  nature  of  albumoses,  alkaloidal  sub- 
stances, and  extractives.     The  action  of  these  is  in  certain  instances  antag- 
onistic. 

4.  Its  remedial  and  inflammatory  actions  are  connected  with  the  presence 
of  certain  of  its  albumoses,  while  its  fever  producing  properties  are  chiefly 
associated  with  substances  of  non-albuminous  nature. 

5.  The  albumoses  are  not  lost  by  dialysis ;  the  latter  are.    By  the  adoption 
of  suitable  methods  it  is  thus  possible  to  remove  the  substances  which  cause 
the  fever,  while  retaining  those  which  are  beneficial  in  their  action. 

6.  The  fever  produced  by  tuberculin  is  thus  absolutely  unessential  to  its 
remedial  action. 

In  a  recent  communication  (October,  1891)  Koch  has  given  a  full 
account  of  his  method  of  preparing  crude  tuberculin,  and  also  the 
process  by  which  he  obtains  from  this  a  tuberculin  which  appears  to 
be  pure,  or  nearly  so.  To  obtain  considerable  quantities  of  the  crude 
product  the  tubercle  bacillus  is  cultivated  in  an  infusion  of  calves' 
flesh  or  of  beef  extract  to  which  one  per  cent  of  peptone  and  four  to 
five  per  cent  of  glycerin  have  been  added.  This  culture  liquid  must 
be  made  slightly  alkaline,  and  it  is  placed  in  flasks  with  a  flat  bottom, 
which  should  not  be  more  than  half -filled — thirty  to  fifty  cubic  centi- 
metres. The  inoculation  is  made  upon  the  surface  with  small  masses 
from  a  culture  upon  blood  serum  or  glycerin-agar.  By  accident 
Koch  discovered  that  these  masses  floating  upon  the  surface  give  rise 
to  an  abundant  development  and  to  the  formation  of  a  tolerably  thick 
and  dry  white  layer,  which  finally  covers  the  entire  surface.  At  the 
end  of  six  to  eight  weeks  development  ceases  and  the  layer  after  a 
time  sinks  to  the  bottom,  breaking  up  meanwhile  into  fragments. 
These  cultures,  after  their  purity  has  been  tested  by  a  microscopical 
examination,  are  poured  into  a  suitable  vessel  and  evaporated  to  one- 
tenth  the  original  volume  over  a  water  bath.  The  liquid  is  then  fil- 
tered through  porcelain.  The  crude  tuberculin  obtained  by  this  pro- 
cess contains  from  forty  to  fifty  per  cent  of  glycerin,  and  consequently 
is  not  a  suitable  medium  for  the  development  of  saprophytic  bacteria, 
if  they  should  by  accident  be  introduced  into  it.  It  keeps  well  and 
preserves  its  activity  indefinitely. 

From  this  crude  tuberculin  Koch  has  obtained  a  white  precipitate, 
with  sixty-per-cent  alcohol,  which  has  the  active  properties  of  the 
crude  tuberculin  as  originally  prepared.  This  is  fatal  to  tuberculous 
guinea-pigs  in  doses  of  two  to  ten  milligrammes.  It  is  soluble  in 
water  and  in  glycerin,  and  has  the  chemical  reactions  of  an  albu- 
minous body.  In  preparing  it  one  and  a  half  volumes  of  absolute 
alcohol  are  added  to  one  volume  of  the  crude  tuberculin,  and,  after 
stirring  it  to  secure  uniform  admixture,  this  is  put  aside  for  twenty-four 
hours.  At  the  end  of  this  time  a  flocculent  deposit  will  be  seen  at  the 
bottom  of  the  vessel.  The  fluid  above  this  is  carefully  poured  off, 
and  an  equal  quantity  of  sixty-per-cent  alcohol  poured  into  the  vessel 


BACILLI   IX   CHRONIC   INFECTIOUS   DISEASES.  389 

for  the  purpose  of  washing  the  precipitate.  This  is  again  allowed  to 
settle  and  the  procedure  is  repeated  three  or  four  times,  after  which 
the  precipitate  is  washed  with  absolute  alcohol.  It  is  then  placed 
upon  a  filter  and  dried  in  a  vacuum  exsiccator. 

An  analysis  of  this  purified  tuberculin  by  Proskauer  gave  18.46 
per  cent  of  ash,  consisting  almost  entirely  of  potassium  and  magne- 
sium phosphate.  The  elementary  analysis  gave  48.13  per  cent  of 
carbon,  7.06  per  cent  of  hydrogen,  14.46  per  cent  of  nitrogen,  and 
1.17  per  cent  of  sulphur. 

Recently  (1892)  Tizzoni  and  Oattani  have  presented  some  ex- 
perimental evidence  which  indicates  that  injections  of  Koch's  tuber- 
culin into  guinea-pigs  may  produce  in  these  animals  a  certain  degree 
of  immunity  against  tuberculosis  ;  and  that  this  immunity  depends 
upon  the  presence  of  an  anti-tuberculin  formed  in  the  body  of  the 
partially  immune  animal. 

Numerous  experiments  made  by  veterinary  surgeons  upon  tuber- 
culous cows  show  that  the  injection  of  Koch's  tuberculin  in  these 
animals,  in  doses  of  thirty  to  forty  centigrammes,  produces  a  rise  of 
temperature  of  from  1°  to  3°  C.  The  febrile  reaction  usually  occurs 
in  from  twelve  to  fifteen  hours  after  the  injection.  Its  duration  and 
intensity  do  not  depend  upon  the  extent  of  the  tuberculous  lesions, 
but  is  even  more  marked  when  these  are  slight  than  in  advanced 
cases.  In  non-tuberculous  animals  no  reaction  occurs,  and  the  ex- 
periments made  justify  the  suspicion  that  tuberculosis  exists  if  an 
elevation  in  temperature  of  a  degree  or  more  occurs  as  a  result  of 
the  subcutaneous  injection  of  the  dose  mentioned. 

When  the  number  of  tubercle  bacilli  in  sputum  is  comparatively 
small  they  may  easily  escape  observation.  Methods  have  therefore 
been  suggested  for  finding  them  under  -these  circumstances.  Ribbert 
(1886)  proposed  the  addition  to  the  sputum  of  a  two-per-cent  solution 
of  caustic  potash,  and  boiling  the  mixture.  The  tenacious  mucus  is 
dissolved,  and  when  the  mixture  is  placed  in  a  conical  glass  vessel 
the  bacilli  are  deposited  at  the  bottom  and  may  easily  be  found  in 
the  sediment  after  removing  the  supernatant  fluid.  The  same  object 
is  accomplished  by  Stroschein  (1889)  by  the  addition  to  sputum  of 
three  times  its  volume  of  a  saturated  solution  of  borax  and  boracic 
acid  in  water. 

A  method  of  estimating  the  number  of  bacilli  in  sputum  has  re- 
cently been  proposed  by  Nuttall,  which  appears  to  give  sufficiently 
accurate  results  and  to  be  useful  in  judging  of  the  progress  of  a 
case  or  of  the  results  of  treatment.  For  the  details  of  this  method 
we  must  refer  to  the  author's  paper  (Johns  Hopkins  Hospital  Bulle- 
tin, vol.  xi.,  No.  13,  1891).  It  consists  essentially  in  first  making 
the  sputum  fluid  by  the  addition  of  a  solution  of  caustic  potash  ;  in 


390 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


then  shaking  it  thoroughly  in  a  bottle  containing  sterilized  gravel 
or  pounded  glass  ;  in  carefully  measuring  the  total  quantity  of  fluid, 
and  in  dropping  upon  glass  slides  uniform  drops  by  means  of  a  grad- 
uated pipette  ;  in  spreading  these  uniformly  by  means  of  a  platinum 
needle  and  a  turn  table ;  in  covering  the  dried  film  with  a  film  of 
blood  serum,  and  coagulating  this  by  heat ;  and,  finally,  in  staining 
and  counting  the  bacilli  in  a  series  of  slides  from  the  same  specimen, 
and  from  the  average  number  found  in  a  single  drop  estimating  the 
total  number  in  the  sputum  for  twenty-four  hours. 

Pathogenesis. — Man,  cattle,  and  monkeys  are  most  subject  to 
contract  the  disease  naturally,  and  it  may  be  communicated  by  in- 
oculation to  many  of  the  lower  animals — guinea-pigs,  field  mice,  rab- 


Fio.  121.— Limited epithelioid  celled  tubercle  of  the  iris,    x  950.    (Baumgarten.) 

bits,  and  cats  are  among  the  most  susceptible  animals  ;  and  in  larger 
doses  dogs,  rats,  white  mice,  and  fowls  may  also  be  infected. 

When  tuberculous  sputum  is  introduced  beneath  the  skin  of  a 
guinea-pig  the  nearest  lymphatic  glands  are  found  to  be  swollen  at 
the  end  of  two  or  three  weeks,  at  the  same  time  there  is  a  thickening 
of  the  tissues  about  the  point  of  inoculation  ;  later  a  dry  crust  forms 
over  the  local  tuberculous  tumefaction,  and  beneath  this  is  a  flattened 
ulcer  covered  with  cheesy  material.  The  animals  become  emaciated 
and  show  difficulty  in  breathing,  and  usually  succumb  to  general 
tuberculosis,  especially  involving  the  lungs,  within  four  to  eight 
weeks,  Injections  of  tuberculous  sputum,  or  of  pure  cultures  of  the 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  391 

bacillus,  into  the  peritoneal  cavity  give  rise  to  extensive  tuberculo- 
sis of  the  liver,  spleen,  and  lungs,  and  to  death,  as  a  rule,  within 
three  or  four  weeks.  Rabbits  are  less  susceptible  to  subcutaneous 
injections,  but  die  within  seventeen  to  twenty  days  when  virulent — 
recent — cultures  are  injected  into  the  circulation.  As  a  result  of 
such  an  inoculation  the  animal  rapidly  loses  flesh  and  has  a  decided 
elevation  of  temperature,  commencing  at  the  end  of  the  first  week 
and  increasing  considerably  during  the  last  days  of  life.  At  the 
autopsy  the  spleen  and  liver  are  found  to  be  greatly  enlarged,  but 
they  do  not  contain  any  tubercles  that  can  be  recognized  by  the  naked 
eye  (Yersin).  They  contain,  however,  great  numbers  of  tubercle' 
bacilli,  both  free  and  in  the  cells.  Injections  of  a  small  quantity  of 
a  pure  culture  into  the  anterior  chamber  of  the  rabbit's  eye  cause 
first  iris-tuberculosis,  followed  by  swelling  and  caseation  of  the  near- 
est lymph  glands,  and  finally  general  infection  and  death ;  when 
larger  quantities  are  injected  general  tuberculosis  is  quickly  devel- 
oped. The  influence  of  quantity — number  of  bacilli — is  also  shown 
in  subcutaneous,  intravenous,  or  intraperitoneal  injections  into  guinea- 
pigs  and  rabbits  (Hirschberger,  Gebhardt,  Wyssokowitsch).  Thus 
rabbits  which  received  less  than  one  hundred  and  fifty  bacilli,  in 
sputum,  in  the  experiments  of  Wyssokowitsch,  did  not  develop  tuber- 
culosis ;  and  in  guinea-pigs  the  smaller  the  number  injected  the  more 
protracted  the  course  of  the  disease  was  found  to  be. 

Tuberculosis  in  man  no  doubt  results,  in  a  large  proportion  of  the 
cases,  from  the  respiration,  by  a  susceptible  individual,  of  air  con- 
taining the  tubercle  bacillus  in  suspension  in  a  desiccated  condition. 
As  already  stated,  it  has  been  demonstrated  by  experiment  that  the 
bacillus  retains  its  vitality  in  desiccated  sputum  for  several  months. 
The  experiments  of  Cornet  have  demonstrated  that  in  the  dust  of 
apartments  occupied  by  tuberculous  patients  tubercle  bacilli  are  very 
commonly  present  in  sufficient  numbers  to  induce  tuberculosis  in 
guinea-pigs  inoculated  in  the  peritoneal  cavity  with  such  dust,  while 
negative  results  were  obtained  from  inoculations  with  dust  from 
other  localities.  In  view  of  these  facts  the  usual  mode  of  infection 
is  apparent.  Infection  may  also  occur  through  an  open  wound  or 
abrasion  of  the  skin,  as  in  the  small,  circumscribed  tumors  which 
sometimes  develop  upon  the  hands  of  pathologists  as  a  result  of 
handling  tuberculous  tissues.  A  few  instances  of  accidental  inocu- 
lation through  wounds  made  by  glass  or  earthen  vessels  containing 
tuberculous  sputum  have  also  been  recorded.  A  more  common  mode 
of  infection,  especially  in  children,  is  probably  by  way  of  the  intesti- 
nal glands,  from  the  ingestion  of  the  milk  of  tuberculous  cows.  That 
infection  may  occur  by  way  of  the  intestine  has  been  proved  by  ex- 
periments upon  rabbits,  which  develop  tuberculosis  when  fed  upon 


392  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

tuberculous  sputum.  And  that  the  tubercle  bacillus  is  frequently,  if 
not  usually,  present  in  the  milk  of  tuberculous  cows  has  been  proved 
by  the  experiments  of  Bellinger,  Hirschberger,  Ernst,  and  others. 
In  Hirschberger's  investigations  milk  from  tuberculous  cows  induced 
tuberculosis  in  guinea-pigs,  when  injected  subcutaneously  or  into 
the  peritoneal  cavity,  in  fifty-five  per  cent  of  the  cases  studied 
(twenty).  The  conclusion  is  reached  that  the  milk  may  contain  tu- 
bercle bacilli  even  when  the  udder  of  the  cow  is  not  involved.  Ernst 
also,  from  an  examination  of  the  milk  from  thirty-six  tuberculous 
cows  in  which  the  udder  was  apparently  not  involved,  found  the 
tubercle  bacillus  by  microscopical  examination  in  five  per  cent  of  the 
samples  examined  (one  hundred  and  fourteen). 

The  prevalence  of  tuberculosis  among  cattle  is  shown  by  numer- 
ous investigations,  and  especially  by  the  official  inspections  of 
slaughtered  animals  made  in  Germany.  Thus  in  Saxony,  in  the 
year  1889,  of  611,511  cattle  examined  6,135  were  found  to  be  tubercu- 
lous (about  one  per  cent) ;  in  Berlin,  1887-1888,  out  of  130,733  ani- 
mals slaughtered  4,300  were  found  to  be  tuberculous  (3.2  per  cent). 
In  view  of  the  facts  stated  the  great  mortality  from  tubercular  dis- 
eases among  children,  many  of  whom  are  removed  from  other  prob- 
able sources  of  infection,  is  not  difficult  to  understand,  and  the 
practical  and  simple  method  of  preventing  infection  in  this  way,  af- 
forded by  the  sterilization  (by  heat)  of  milk  used  as  food  for  infants, 
must  commend  itself  to  all. 

54.    BACILLUS   TUBERCULOSIS   GALLINARUM. 

The  researches  of  Maffucci  (1889)  and  of  Cadiot,  Gilbert,  and 
Roger  (1890)  show  that  the  bacillus  obtained  from  spontaneous  tu- 
berculosis in  chickens,  although  closely  resembling  the  bacillus  of 
human  tuberculosis,  is  not  identical  with  it,  varying  especially  in  its 
pathogenic  power.  This  view  is  sustained  by  the  observations  of 
Koch,  who  says  in  his  address  before  the  Tenth  International  Medi- 
cal Congress  (Berlin,  1890) : 

"The  care  which  it  is  necessary  to  exercise  in  judging  of  the  characters 
which  serve  to  differentiate  bacteria,  even  those  which  are  well  known,  I 
have  learned  in  the  case  of  the  tubercle  bacillus  This  species  is  so  definitely 
characterized  by  its  staining  reactions,  its  growth  in  pure  cultures,  and  its 
pathogenic  qualities,  and  indeed  by  each  of  these  characters,  that  it  seems 
impossible  to  confound  it  with  other  species.  Nevertheless  in  this  case  also 
one  should  not  rely  upon  a  single  one  of  the  characters  mentioned  for  de- 
termining the  species,  but  should  follow  the  safe  rule  that  all  available 
characters  should  be  considered,  and  the  identity  of  a  certain  bacterium 
should  only  be  regarded  as  demonstrated  when  it  has  been  shown  to  corre- 
spond in  all  of  these  particulars  When  I  made  my  first  researches  with 
reference  to  the  tubercle  bacillus  I  was  controlled  by  this  rule,  and  tested 
tubercle  bacilli  from  various  sources,  not  only  with  reference  to  their  stain- 
ing reactions,  but  also  with  reference  to  their  growth  in  culture  media  and 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  393 

pathogenic  characters.  Only  in  the  tuberculosis  of  chickens  I  was  not  able 
to  apply  this  rule,  as  at  that  time  it  was  not  possible  for  me  to  obtain  fresh 
material  from  which  to  make  pure  cultures.  As,  however,  all  other  forms 
of  tuberculosis  had  given  identical  bacilli,  and  the  bacilli  of  chicken  tuber- 
culosis in  their  appearance  and  behavior  towards  the  aniline  colors  entirely 
corresponded  with  these,  I  believed  myself  justified  in  assuming  their  iden- 
tity, notwithstanding  the  incompleteness  of  the  research.  Later  I  received 
pure  cultures  from  various  sources,  which  apparently  originated  from  tuber- 
cle bacilli,  but  in  several  regards  differed  from  these ;  especially  in  the  fact 
that  inoculation  experiments,  made  by  experienced  and  reliable  investigators, 
led  to  dissimilar  results,  which  it  was  necessary  to  regard  as  unexplained  con- 
tradictions. At  first  I  believed  that  these  differences  depended  upon  changes 
such  as  are  frequently  observed  in  pathogenic  bacteria,  when  these  are  culti- 
vated in  pure  cultures  outside  of  the  body  for  a  long  time  under  more  or  less 
unfavorable  conditions.  In  order  to  solve  the  riddle  I  attempted  by  various 
influences  to  change  the  common  tubercle  bacilli  into  the  presumed  variety 
referred  to.  They  were  cultivated  for  several  months  at  so  high  a  tempera- 
ture that  only  a  scanty  growth  was  obtained;  in  other  experiments  still 
higher  temperatures  were  allowed  to  act  repeatedly  for  so  long  a  time  that 
the  cultures  were  brought  as  nearly  as  possible  to  the  point  of  killing  the 
bacilli.  In  a  similar  way  I  subjected  the  cultures  to  the  action  of  chemical 
agents,  of  light,  or  absence  of  moisture ;  they  were  cultivated  for  many  gen- 
erations in  association  with  other  bacteria ;  inoculated  successively  in  ani- 
mals having  but  a  slight  susceptibility.  But,  in  spite  of  all  these  attempts, 
only  slight  variations  were  obtained  in  their  characters — far  less  than  other 
pathogenic  bacteria  undergo  under  similar  circumstances.  Itappears,  there- 
fore, that  the  tubercle  bacilli  retain  their  characters  with  special  obstinacy ; 
this  is  in  accord  with  the  fact  that  pure  cultures  which  have  now  been  cul- 
tivated by  me  in  test  tubes  for  more  than  nine  years,  without  in  the  mean- 
time having  been  in  a  living  body,  are  still  entirely  unchanged  with  the  ex- 
ception of  a  slight  diminution  of  virulence.  ...  It  happened  about  a  year 
ago  that  I  received  a  living  chicken  which,  wassuffering  from  tuberculosis, 
and  I  used  this  opportunity  to  make  cultures  directly  from  the  diseased  or- 
gans of  this  animal,  which  previously  I  had  not  been  able  to  do.  When  the 
cultures  grew  I  saw  to  my  surprise  that  they  had  precisely  the  appearance 
and  all  of  the  characters  possessed  by  the  enigmatical  cultures  resembling 
those  of  the  genuine  tubercle  bacillus.  Later  I  learned  that  these  also  ori- 
ginated from  tuberculosis  in  fowls,  but,  upon  the  assumption  that  all  forms 
of  tuberculosis  are  identical,  had  been  considered  genuine  tubercle  bacilli. 
A  verification  of  my  observations  I  find  in  the  recently  published  researches 
of  Prof.  Maffucci  with  reference  to  tuberculosis  of  fowls." 

According  to  Maffucci,  adult  chickens  are  refractory  against  the 
action  of  the  Bacillus  tuberculosis  from  man,  and  there  are  slight 
morphological  and  biological  differences  in  the  bacilli  from  the  two 
sources. 

Recently  Cadiot,  Gilbert,  and  Roger  have  made  a  series  of  ex- 
periments with  the  bacillus  of  tuberculosis  in  fowls.  They  found 
the  bacilli  to  be  very  numerous  in  the  livers  of  chickens  suffering 
from  spontaneous  tuberculosis,  and  inoculated  with  material  from 
this  source  six  chickens,  five  rabbits,  and  twelve  guinea-pigs.  The 
chickens,  when  inoculated  in  the  cavity  of  the  abdomen  or  by  injec- 
tion into  a  vein,  died  in  from  forty-one  to  ninety-three  days  from 
general  tuberculosis.  Four  of  the  rabbits  died  of  general  tuberculosis, 
presenting  the  same  appearance  as  that  following  inoculation  with 
31 


394  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

bacilli  from  human  tuberculosis.  Of  the  guinea-pigs,  which  were 
inoculated  in  the  cavity  of  the  abdomen,  eleven  remained  in  good 
health  and  one  only  died  of  general  tuberculosis.  These  experi- 
ments show  a  decided  difference  in  the  pathogenic  properties  of 
tubercle  bacilli  from  the  two  sources,  for  the  guinea-pig  is  especially 
susceptible  to  tuberculosis  as  a  result  of  similar  inoculations  with 
bacilli  from  human  tuberculosis.  We  must  therefore  conclude  that 
the  bacillus  found  in  spontaneous  tuberculosis  in  fowls  is  a  distinct 
variety  of  Bacillus  tuberculosis.  Whether  this  variety  would  cause 
tuberculosis  in  man,  if  introduced  into  susceptible  subjects,  has  not 
been  determined ;  and,  as  pointed  out  by  Koch,  this  question  can 
only  be  answered  in  the  affirmative  if  it  should  be  obtained  in  pure 
cultures  from  cases  of  human  tuberculosis. 

Since  the  above  was  written  Maffucci  has  published  (1892)  an 
elaborate  memoir  upon  tuberculosis  of  fowls.  His  conclusions  are 
stated  as  follows : 

"  The  bacillus  cf  tuberculosis  in  fowls  is  distinguished  from  that  of  tuber- 
culosis in  mammals  by  the  following  points  of  difference : 

"1.  It  does  not  induce  tuberculosis  in  guinea-pigs,  and  seldom  causes 
general  tuberculosis  in  rabbits. 

' '  2.  The  cultures  in  various  media  have  a  different  appearance  from  those 
of  the  Bacillus  tuberculosis  of  mammals. 

"  3.  The  temperature  at  which  it  develops  varies  between  35°  arid  45°  C., 
and  the  thermal  death-point  is  70°  C. 

"4.  At  45°  to  50D  C.  the  cultures  show  long,  thick,  and  branched  forms. 

"  5.  The  bacillus  retains  its  vegetative  and  pathogenic  power  at  the  end 
of  two  years. 

"  6.  This  bacillus  produces  a  substance  which  is  toxic  for  guinea-pigs  and 
is  but  slightly  toxic  for  grown  fowls. 

"  7.  The  tuberculosis  produced  in  fowls  by  this  bacillus  is  without  giant 
cells." 

55.    BACILLUS   LEPR^E. 

Discovered  by  Hansen  (1879),  chiefly  in  the  interior  of  the  peculiar 
round  or  oval  cells  found  in  leprous  tubercles.  Discovery  confirmed 
by  Neisser  (1879)  and  by  many  subsequent  observers. 

While  found  chiefly  in  the  leprous  tubercles  of  the  skin  and  mucous 
membranes,  the  bacilli  have  also  been  found  in  the  lymphatic  glands, 
the  liver,  the  spleen,  the  testicles,  and,  in  the  anaesthetic  form  of  the 
disease,  in  the  thickened  portions  of  nerves  involved  in  the  leprous 
process.  Some  observers  have  also  reported  finding  them  in  the 
blood,  but  this  appears  to  be  quite  exceptional.  In  the  leprous  cells 
they  are  commonly  found  in  great  numbers,  and  they  may  also  be 
seen  in  the  lymph  spaces  outside  of  these  cells.  They  are  not  found 
in  the  epidermal  layer  of  the  skin,  but,  according  to  Babes,  they  may 
penetrate  the  hair  follicles. 

Morphology, — The  bacillus  of  leprosy  resembles  the  tubercle  ba- 
cillus in  form,  but  is  of  more  uniform  length  and  not  so  frequently 


BACILLI   IN  CHRONIC   INFECTIOUS   DISEASES. 


395 


FIG.  122.— Section  of  a  recent  lepra  nodule  of 
the  skin.    X  950.    (Baumgarten.) 


bent  or  curved.  The  rods  have  pointed  ends ;  and  in  stained  pre- 
parations unstained  spaces,  similar  to  those  observed  in  the  tubercle 
bacillus  and  generally  assumed  to  be  spores,  are  to  be  seen,  although 
not  quite  so  distinctly  as  in  the  latter.  The  bacilli  are  said  by  Fliigge 
to  be  from  four  to  six  yu  in  length  and  less  than  one  /*  in  width — 
probably  considerably  less,  for  the  same  author  states  that  the  tubercle 
bacillus  has  about  the  diameter 
of  the  bacillus  of  mouse  septi- 
caemia, and  this  is  given  as  0.2  J*. 

This  bacillus  stains  readily 
with  the  aniline  colors  and  also 
by  Grain's  method.  Although  it 
differs  from  the  tubercle  bacillus 
in  the  ease  with  which  it  takes  up 
the  ordinary  aniline  colors,  it  re 
sembles  it  in  retaining  its  color 
when  subset]  uently  treated  with 
strong  solutions  of  the  mineral 
acids.  Double-stained  prepara- 
tions are  therefore  easily  made  by  first  staining  sections  or  cover- 
glass  preparations  in  Ziehl's  carbol-fuchsin  solution  or  in  an  aqueous 
solution  of  methyl  violet,  decolorizing  in  acid,  washing  in  alcohol, 
and  counter-staining  with  methylene  blue — or,  if  methyl  violet  was 
used  in  the  first  instance,  with  vesuvin. 

Biological  Characters. — The  earlier  attempts  to  cultivate  this 
bacillus  were  without  success,  but  recently  Bordoni-Uffreduzzi  has 
obtained  from  the  marrow  of  the  bones  of  a  leper  a  bacillus  which 
he  believes  to  be  the  leprosy  bacillus,  and  which  he  was  able  to  culti- 
vate upon  blood  serum  to  which  a  certain  amount  of  peptone  and  of 
glycerin  had  been  added.  At  first  this  bacillus  only  grew  with  diffi- 
culty and  in  the  incubating  oven  ;  but  after  it  had  been  cultivated 
artificially  through  a  number  of  generations  it  is  said  to  have  grown 
upon  ordinary  nutrient  gelatin  at  the  room  temperature.  The  bacillus 
obtained  in  this  way  is  said  to  have  retained  its  color  when  treated 
with  acids,  after  having  been  stained  with  aniline-f uchsin,  correspond- 
ing in  this  respect  with  the  bacillus  of  leprosy  and  the  tubercle  ba- 
cillus. But  it  differed  considerably  in  its  morphology  from  the  Ba- 
cillus leprse  as  seen  in  the  tissues  of  lepers,  being  considerably  thicker, 
and  it  was  not  so  promptly  stained  by  the  aniline  colors  as  is  the 
bacillus  found  in  the  tissues.  Moreover,  attempts  to  cultivate  the 
same  bacillus  from  leprous  tubercles  of  the  skin  were  unsuccessful, 
as  were  also  inoculation  experiments  into  the  anterior  chamber  of  the 
eye  in  rabbits.  It  is  therefore  a  matter  of  doubt  as  to  whether  the 
bacillus  obtained  by  Bordoni-Uffreduzzi  is  identical  with  that  present 


396  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

in  such  numbers  in  the  cells  of  the  leprous  tubercles,  to  which  the 
name  Bacillus  leprse  has  been  given.  Quite  recently  the  announce- 
ment has  been  made  that  the  "  India  Leprosy  Commission  "  has  suc- 
ceeded in  cultivating  the  leprosy  bacillus  in  blister  serum.  Not  hav- 
ing seen  a  detailed  account  of  the  experiments  of  this  Commission, 
the  writer  is  unable  to  estimate  the  value  of  their  work  and  the  reli- 
ability of  the  alleged  success  in  cultivating  this  bacillus. 

Some  of  the  earlier  observers  described  the  bacillus  of  leprosy  as 
motile,  but  this  assertion  seems  to  have  been  based  upon  some  error 
of  observation,  and  it  is  now  generally  agreed  that,  like  the  tubercle 
bacillus,  it  is  without  proper  movements.  The  question  of  spore  for- 
mation has  not  been  definitely  settled.  As  before  remarked,  un- 
stained portions,  occurring  at  regular  intervals,  are  seen  in  the  rods  in 
stained  preparations  ;  but  no  satisfactory  evidence  has  been  presented 
to  show  that  these  are  truly  reproductive  spores. 

Pathogenesis, — The  inference  that  the  bacillus  above  described 
bears  an  etiological  relation  to  the  disease  with  which  it  is  associated 
is  based  upon  the  demonstration  of  its  constant  presence  in  leprous 
tissues — which  has  now  been  repeatedly  made  in  various  and  distant 
parts  of  the  world — and  of  its  absence  from  the  same  tissues  involved 
in  different  morbid  processes.  As  it  has  not  been  obtained  in  pure 
cultures,  the  final  proof  of  such  etiological  relation  is  still  wanting. 
We  have,  however,  experimental  evidence  to  show  that  leprous  tis- 
sues containing  this  bacillus  are  infectious  and  may  reproduce  the 
disease.  The  experiment  has  been  made  upon  man  by  Arning,  who 
inoculated  a  condemned  criminal  subcutaneously  with  fresh  leprous 
tubercles.  The  experiment  was  made  in  the  Sandwich  Islands,  and 
the  man  was  under  observation  until  his  death  occurred  from  leprosy 
at  the  end  of  about  five  years.  The  first  manifestations  of  the  disease 
became  visible  in  the  vicinity  of  the  point  of  inoculation  several 
months  after  the  experimental  introduction  of  the  infectious  material. 

Positive  results  have  also  been  reported  in  the  lower  animals  by 
Damsch,  by  Vossius,  and  by  Melcher  and  Ortmann.  The  last-named 
investigators  inoculated  rabbits  in  the  anterior  chamber  of  the  eye 
with  portions  of  leprous  tubercles  excised  for  the  purpose  from  a 
leper.  The  animals  died  from  general  infection  at  the  end  of  several 
months,  and  the  characteristic  tubercles  containing  the  bacillus  were 
distributed  through  the  various  organs. 

56.    BACILLUS   MALLEI. 

Synonyms. — The  bacillus  of  glanders;  Der  Rotzbacillus,  Ger.  ; 
Bacille  de  la  morve,  Fr. 

Discovered  by  Loftier  and  Schiitz  (1882),  and  proved  to  be  the 
cause  of  glanders  by  the  successful  inoculation  of  pure  cultures. 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


39? 


Y 


Found  especially  in  the  recent  nodules  in  animals  infected  with 
glanders  ;  also  in  the  same  after  ulceration,  and  in  the  discharge 
from  the  nostrils,  pus  from  the  specific  ulcers,  etc. ;  sometimes  in  the 
blood  of  infected  animals  (Weichselbaum). 

Morphology. — Bacilli  with  rounded  ends,  straight  or  slightly 
curved,  rather  shorter  and  decidedly  thicker  than  the  tubercle  bacil- 
lus ;  usually  solitary,  but  occasionally  united  in 
pairs,  or  in  filaments  containing  several  elements 
(in  potato  cultures).  In  stained  preparations 
unstained  or  feebly  stained  spaces  are  seen  in 
the  rods,  alternating  with  the  deeply  stained 
protoplasm  of  the  cell.  As  in  the  tubercle  bacil- 
lus, which  presents  a  similar  appearance,  these 
spaces  have  been  supposed  by  some  bacteriolo- 
gists to  represent  spores  ;  but  Loftier  believes 
them  to  represent  rather  a  degeneration  of  the 
protoplasm.  Baumgarten  and  Rosenthal  claim 
to  have  demonstrated  the  presence  of  spores  by  the  use  of  Neisser's 
method  of  staining,  but  they  do  not  consider  it  established  that  the 
unstained  spaces  in  the  rods  referred  to  are  of  this  nature. 

The  glanders  bacillus  may  be  stained  with  aqueous  solutions  of 
the  aniline  colors,  but  the  staining  is  more  intense  when  the  solution 


Fia.  123.— Bacillus  mal- 
lei, x  1,000.  From  a  pho- 
tomicrograph. CFrankel 
and  Pfeiffer.) 


FIG.  134.—  Section  of  a  glanders  nodule,    x  700.    (Flugge.) 

is  made  feebly  alkaline.  Add  to  three  cubic  centimetres  of  a  1 : 10,000 
solution  of  caustic  potash,  in  a  watch  glass,  one  cubic  centimetre  of 
a  saturated  alcoholic  solution  of  an  aniline  color  (methylene  blue, 
gentian  violet,  or  fuchsin)  ;  or  the  aniline-water-fuchsin,  or  methyl 
violet  solution  of  Ehrlich  may  be  used,  with  the  addition  just  be- 
fore use  of  an  equal  quantity  of  1  : 10,000  solution  of  caustic  potash. 
Loffler  recommends  that  cover-glass  preparations  be  placed  in  Ehr- 
lich's  solution  and  heated  for  five  minutes;  then  decolorized  in  a  one- 


398  BACILLI   IN   CHRONIC    INFECTIOUS   DISEASES. 

per-cent  solution  of  acetic  acid  to  which  sufficient  tropseolin  has 
been  added  to  give  it  the  yellow  color  of  Rhine  wine  ;  then  quickly 
washed  in  distilled  water.  This  bacillus  presents  the  peculiarity  of 
losing  very  quickly  in  decolorizing  solutions  the  color  imparted  to  it 
by  the  aniline  staining  solutions.  For  this  reason  the  staining  of  the 
bacillus  in  sections  is  attended  with  some  difficulty.  Loffler  recom- 
mends his  alkaline  methylene-blue  solution  for  staining  sections  ;  and 
for  decolorizing,  a  mixture  containing  ten  cubic  centimetres  of  distilled 
water,  two  drops  of  strong  sulphuric  acid,  and  one  drop  of  a  five- 
per-cent  solution  of  oxalic  acid.  Thin  sections  should  be  left  in  this 
acid  solution  about  five  seconds.  The  method  more  recently  recom- 
mended by  Kuhne  also  gives  good  results  in  skilful  hands  (see  p.  34). 

Biological  Characters. — An  aerobic,  non-motile,  parasitic 
bacillus,  which  may  be  cultivated  in  various  artificial  media  at  a 
temperature  of  37°  C.  The  lowest  temperature  at  which  develop- 
ment occurs  (22°  C. — Loffler)  is  a  little  above  that  at  which  nutrient 
gelatin  is  liquefied  ;  the  highest  limit  is  43°  C.  According  to  Frankel, 
the  glanders  bacillus  is  a  facultative  anaerobic.  Baumgarten  and 
Rosenthal  claim  to  have  demonstrated  the  presence  of  spores  by 
Neisser's  method  of  staining.  Loffler  was  led  to  doubt  the  forma- 
tion of  spores  from  the  results  of  his  experiments  upon  the  thermal 
death-point  of  this  bacillus,  and  its  comparatively  slight  resistance 
to  desiccation  and  destructive  chemical  agents.  He  found  that  ex- 
posure for  ten  minutes  to  a  temperature  of  55°  C.,  or  for  five  minutes 
to  a  three-  to  five-per-cent  solution  of  carbolic  acid,  or  for  two  min- 
utes to  a  1  :  5,000  solution  of  mercuric  chloride,  was  effectual  in  de- 
stroying its  vitality.  As  a  rule,  the  bacilli  do  not  grow  after  having 
been  preserved  in  a  desiccated  condition  for  a  few  weeks  ;  and  in  a 
moist  condition  the  cultures  cannot  be  preserved  longer  than  three 
or  four  months — usually  not  so  long  as  this  (Loffler).  The  bacillus 
does  not  grow  in  infusions  of  hay,  straw,  or  horse  manure,  and  it  is 
doubtful  whether  it  finds  conditions  in  nature  favorable  for  its  sap- 
rophytic  existence.  It  grows,  in  the  incubating  oven,  in  neutral 
bouillon,  in  nutrient  gelatin,  or  in  nutrient  agar,  and  still  better  in 
glycerin-agar.  Upon  the  last-mentioned  medium  it  grows,  even  at 
the  room  temperature  (Kranzfeld),  but  better  still  in  the  incubating 
oven,  as  a  pale- white,  transparent  streak  along  the  line  of  inocula- 
tion, which  at  the  end  of  six  or  seven  days  may  have  a  width  of 
seven  to  eight  millimetres.  According  to  Raskina,  nutrient  agar 
made  with  milk  forms  an  extremely  favorable  medium,  upon  which 
a  thick,  pale- white  layer  develops  in  two  or  three  days,  which  on  the 
third  or  fourth  day  acquires  an  amber-yellow  color,  and  the  deeper 
layers  acquire  a  brownish-red  tint. 

The  growth  upon  solidified  blood  serum,  in  the  course  of  three  or 


BACILLI   IN   CHKONIC   INFECTIOUS   DISEASES.  399 

four  days  at  37°  C.,  consists  of  yellowish,  transparent  drops,  which 
later  coalesce  into  a  viscid  layer,  which  has  a  milky  appearance  from 
the  presence  of  numerous  small  crystals  (Baumgarten).  The  growth 
upon  cooked  potato  is  especially  characteristic.  In  the  incubating 
oven,  at  the  end  of  two  or  three  days,  a  rather  thin,  yellowish,  trans- 
parent layer  develops,  which  resembles  a  thin  layer  of  honey.  Later 
this  ceases  to  be  transparent,  and  the  amber  color  changes,  at  the 
end  of  six  to  eight  days,  to  a  reddish-brown  color ;  and  outside  of 
the  reddish-brown  layer,  with  more  or  less  irregular  outlines,  the 
potato  for  a  short  distance  acquires  a  greenish-yellow  tint. 

Pathogenesis. — Glanders  occurs  principally  among  horses  and 
asses,  but  may  be  contracted  by  man  from  contact  with  infected 
animals  ;  it  has  also  been  communicated,  in  one  instance  with  a  fatal 
result,  by  subcutaneous  inoculation,  resulting  accidentally  from  the 
use  of  an  imperfectly  sterilized  hypodermic  syringe  which  had  pre- 
viously been  used  for  injecting  cultures  of  the  bacillus  into  guinea- 
pigs.  The  field  mouse  and  the  guinea-pig  are  especially  susceptible 
to  infection  by  experimental  inoculations  ;  the  cat  and  the  goat  may 
be  infected  in  the  same  way.  Lions  and  tigers  in  menageries  are 
said  to  have  contracted  glanders  from  being  fed  upon  the  flesh  of  in- 
fected animals  (Baumgarten).  Rabbits  have  but  slight  susceptibility, 
and  the  same  is  true  of  sheep  and  dogs  ;  swine,  cattle,  white  mice, 
and  common  house  mice  are  immune. 

The  etiological  relation  of  the  bacillus  is  fully  established  by  the 
experiments  of  Loffler  and  Schutz,  confirmed  by  other  bacteriologists, 
which  show  that  pure  cultures  injected  into  horses,  asses,  and  other 
susceptible  animals,  produce  genuine  glanders.  The  disease  is  char- 
acterized in  the  equine  genus  by  the  formation  of  ulcers  upon  the 
nasal  mucous  membrane,  which  have  irregular,  thickened  margins 
and  secrete  a  thin,  virulent  mucus ;  the  submaxillary  lymphatic 
glands  become  enlarged  and  form  a  tumor  which  is  often  lobulated  ; 
other  lymphatic  glands  become  inflamed,  and  some  of  them  suppurate 
and  open  externally,  leaving  deep,  open  ulcers ;  the  lungs  are  also 
involved  and  the  breathing  becomes  hurried  and  irregular.  In  farcy, 
which  is  a  more  chronic  form  of  the  same  disease,  circumscribed 
swellings,  varying  in  size  from  a  pea  to  a  hazelnut,  appear  on  differ- 
ent parts  of  the  body,  especially  where  the  skin  is  thinnest ;  these 
suppurate  and  leave  angry -looking  ulcers  with  ragged  edges,  from 
which  there  is  an  abundant  purulent  discharge.  The  specific  bacillus 
can  easily  be  obtained  in  pure  cultures  from  the  interior  of  suppurat- 
ing nodules  and  glands  which  have  not  yet  opened  to  the  surface, 
and  the  same  material  will  give  successful  results  when  inoculated 
into  susceptible  animals.  But  the  discharge  from  the  nostrils  or  from 
an  open  ulcer  contains  comparatively  few  bacilli ;  and  as  these  are 


400 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 


associated  with  various  other  bacteria  which  grow  more  readily  in 
our  culture  media,  it  is  not  easy  to  obtain  pure  cultures,  by  the  plate 
method,  from  such  material. 

In  the  guinea-pig  subcutaneous  inoculation  is  followed  in  four  or 
five  days  by  tumefaction  at  the  point  of  inoculation,  and  after  a  time 
a  prominent  tumor  with  caseous  contents  is  developed  ;  ulceration  of 
the  skin  follows,  and  a  chronic,  purulent  ulcer  with  irregular,  indu- 
rated margins  results ;  after  a  time  this  may  cicatrize.  Meanwhile 
the  lymphatic  glands  become  involved,  and  the  symptoms  of  general 


Fio.  125.— Section  through  a  glanders  nodule  in  liver  of  field  mouse.  Tissue  X  250.  Bacilli 
X  500.  (Baumgarten.) 

infection  are  developed  at  the  end  of  four  or  five  weeks ;  the  glands 
suppurate,  and  in  males  the  testicles  are  also  involved  ;  finally  a  dif- 
fuse inflammation  of  the  joints  occurs,  and  death  results  from  ex- 
haustion. In  the  guinea-pig  the  specific  ulcers  upon  the  nasal  mu- 
cous membrane,  which  characterize  the  disease  in  the  horse,  are  rarely 
developed  to  any  great  extent. 

In  field  mice  general  infection  occurs  at  once  as  a  result  of  the 
subcutaneous  injection  of  a  small  quantity  of  a  pure  culture,  and  the 
animal  dies  at  the  end  of  three  or  four  days.  Upon  post-mortem 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  401 

examination  the  principal  changes  are  found  in  the  liver  and  in  the 
greatly  enlarged  spleen.  Scattered  through  these  organs  are  minute 
gray  points  which  are  scarcely  visible  to  the  naked  eye.  In  the 
guinea-pig,  which  succumbs  at  a  later  date,  these  nodules  are  larger 
and  closely  resemble  miliary  tubercles,  both  macroscopically  and 
under  the  microscope,  in  stained  sections  of  the  tissues.  Similar 
nodules  are  also  found  in  the  kidneys  and  in  the  lungs ;  they  have  a 
decided  tendency  to  undergo  purulent  degeneration.  The  bacilli  are 
found  principally  in  these  nodules,  of  recent  formation,  and  are  com- 
monly associated  in  groups,  as  if  they  had  been  enclosed  in  the  inte- 
rior of  a  cell  the  membranous  envelope  of  which  had  undergone 
degeneration  and  disappeared. 

As  before  remarked,  it  is  not  an  easy  matter  to  demonstrate  the 
bacillus  in  sections  of  the  tissues  containing  these  nodules,  owing  to 
the  facility  with  which  they  lose  their  color  in  alcohol  and  other  de- 
colorizing agents.  For  this  reason  it  will  be  best  to  dehydrate  sec- 
tions by  the  use  of  aniline  oil  (Weigert's  method)  or  to  resort  to 
Kiihne's  method  of  staining. 

It  is  also  difficult  to  demonstrate  the  presence  of  the  bacillus  in 
nodules  which  have  undergone  purulent  degeneration,  in  the  secre- 
tions from  the  nostrils  of  horses  suffering  from  glanders,  or  in  the 
pus  from  the  specific  ulcers  and  suppurating  glands  ;  for  they  are 
present  in  comparatively  small  numbers.  But  the  virulent  nature  of 
these  discharges  is  shown  by  inoculations  into  guinea-pigs  or  mice, 
and  it  is  easier  to  obtain  a  pure  culture  from  such  virulent  material 
by  first  inoculating  a  susceptible  animal  than  directly  by  the  plate 
method;  for  the  small  number  of  bacilli  present,  and  their  associa- 
tion with  other  bacteria  which  develop  more  rapidly  in  our  culture 
media,  make  this  a  very  uncertain  procedure.  For  establishing  the 
diagnosis  of  glanders,  therefore,  Loffler  recommends  the  inoculation 
of  guinea-pigs  with  pus  from  a  suppurating  gland  or  ulcer,  or  the 
nasal  discharge  from  a  suspected  animal,  rather  than  a  direct  attempt 
to  demonstrate  the  presence  of  the  bacillus  by  staining  and  culture 
methods. 

The  method  proposed  by  Strauss  gives  more  prompt  results. 
This  consists  in  the  intraperitoneal  injection  of  cultures  or  of  the 
suspected  products  into  the  cavity  of  the  abdomen  of  male  guinea- 
pigs.  If  the  glanders  bacillus  is  present  the  diagnosis  may  be  made 
within  three  or  four  days  from  the  infectious  process  established  in 
the  testicles.  At  the  end  of  this  time  the  scrotum  is  red  and  shining, 
the  epidermis  desquamates,  and  suppuration  occurs,  the  pus  some- 
times perforating  the  integument.  This  pus  is  found  to  contain  the 
glanders  bacillus.  The  animal  usually  dies  in  the  course  of  twelve 
to  fifteen  days.  When  the  animals  are  killed  three  or  four  days 


402  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

after  the  inoculation,  the  two  layers  of  the  tunica  vaginalis  testis 
are  found  to  be  covered  with  a  purulent  exudate  containing  the 
glanders  bacillus  and  to  be  more  or  less  adherent.  Even  as  early 
as  the  second  day  the  tunica  vaginalis  is  seen  to  be  covered  with 
granulations. 

An  attenuation  of  virulence  occurs  in  cultures  whicn  have  been 
kept  for  some  time,  and  inoculations  with  such  cultures  may  give  a 
negative  result ;  or,  when  considerable  quantities  are  injected,  may 
produce  a  fatal  result  at  a  later  date  than  is  usual  when  small 
amounts  of  a  recent  culture  are  injected  into  susceptible  animals. 

Kalning,  Preusse,  and  Pearson  have  obtained  from  cultures  of 
the  glanders  bacillus  a  glycerin  extract  similar  to  the  crude  tubercu- 
lin of  Koch — mallein.  This,  when  injected  into  animals  suffering 
from  glanders,  gives  rise  to  a  considerable  elevation  of  temperature, 
and  it  has  been  proposed  to  use  it  as  a  means  of  diagnosis  in  cases  of 
suspected  infection  in  animals  in  which  the  usual  symptoms  have  not 
yet  manifested  themselves.  The  value  of  the  test  has  already  been 
demonstrated  by  the  experiments  of  Heyne,  Schilling,  and  others. 

57.    BACILLUS   OF    LUSTGARTEN. 

Synonym. — Syphilis  bacillus. 

Found  by  Lustgarten.  (1884)  in  syphilitic  lesions  and  in  secretions  of 
syphilitic  ulcers,  and  believed  by  him  to  be  the  specific  infectious  agent  in 
this  disease.  No  satisfactory  experimental  evidence  that  this  is  the  case  has 
yet  been  obtained. 

Morphology. — Straight  or  curved  bacilli,  which  bear  considerable  resem- 


FIG.  126.  FIG.  127. 

FIG.  126.— Migrating  cell  containing  syphilis  bacilli.    (Lustgarten. ) 
FIG.  127  —Pus  from  hard  chancre  containing  syphilis  bacilli     (Lustgarten.) 

blance  to  tubercle  bacilli,  but  differ  from  them  in  the  staining  reactions. 
They  are  usually  more  or  less  curved,  or  bent  at  a  sharp  angle,  or  S- shaped ; 
the  ends  often  present  slight  knob-like  swellings  ;  the  length  is  from  three 
and  one-half  ft  to  four  and  one-half  /<,  and  the  diameter  is  from  0  25  to  0.3  //. 
With  a  high  power  the  contour  is  seen  to  be  not  quite  regular,  but  wavy  in 
outline,  and  bright,  shining  spaces  in  the  deeply  stained  roda  may  be  ob- 
served ;  these,  from  two  to  four  in  a  single  rod,  are  believed  by  Lustgarten 


BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES.  403 

to  be  spores.  The  bacilli  are  not  found  free  in  the  tissues,  but  are  enclosed 
in  cells  of  a  round-oval  or  polygonal  form,  which  are  said  to  be  about  double 
the  size  of  a  white  blood  corpuscle.  The  bacilli  are  not  numerous,  and  very 
commonly  only  one  or  two  are  found  in  a  single  cell,  but  groups  of  six  or 
eight  may  sometimes  be  seen,  especially  upon  the  margins  of  a  syphilitic 
lesion,  and  in  the  tissues  in  the  immediate  vicinity  of  the  infiltration,  which 
show  but  little  change  or  are  apparently  healthy  (Lustgarten). 

The  presence  of  these  bacilli  in  syphilitic  lesions  was  demonstrated  by 
Lustgarten  by  the  following  staining  method :  The  thin  sections  are  placed 
in  the  Ehrlich-Weigert  gentian-violet  solution  (one  hundred  parts  aniline 
water,  eleven  parts  saturated  alcoholic  solution  of  gentian  violet)  for  from. 
twelve  to  twenty  four  hours  at  the  room  temperature,  and  two  hours  in  the 
incubating  oven  at  40°  C.  The  sections  are  then  thoroughly  washed  in  alco- 
hol and  placed  for  ten  seconds  in  a  1.5-per-cent  solution  of  potassium  per- 
manganate; in  this  solution  a  precipitate  of  peroxide  of  manganese  is 
formed,  which  adheres  to  the  section;  this  is  dissolved  and  washed  off  in  a 
dilute  aqueous  solution  of  pure  sulphuric  acid ;  the  sections  are  then  washed 
in  water,  and,  if  not  completely  decolorized,  are  returned  for  a  few  seconds  to 
the  permanganate  solution  and  again  washed  off  in  the  acid;  it  may  be 
necessary  to  repeat  this  operation  three  or  four  times.  Finally  the  sections 
are  dehydrated  and  mounted  in  balsam  in  the  usual  manner.  Cover-glass 
preparations  are  made  in  the  same  way,  except  that,  after  being-  taken  from 
the  staining  solution,  they  are  washed  off  in  water  instead  of  in  alcohol. 

Another  method  of  staining,  recommended  by  De  Giacoma,  consists  in 
placing  the  sections  for  twenty -four  hours  in  aniline-water-fuchsin  solution 
(cover-glass  preparations  may  be  stained  in  the  same  solution,  hot,  in  a  few 
minutes),  then  washing  them  in  water,  and  decolorizing  in  a  solution  of  per- 
chloride  of  iron — first  in  a  dilute  and  then  in  a  saturated  solution. 

The  method  of  staining  employed  by  Lustgarten  serves  to  differentiate 
his  bacillus  from  many  other  microorganisms,  but  not  from  the  tubercle  ba- 
cillus and  the  bacillus  of  leprosy,  which,  as  he  pointed  out,  may  be  stained 
in  the  same  way.  And  it  has  since  been  shown  by  Alvarez  and  Tavel,  and 
by  Matte rstock,  that  in  smegma  from  the  prepuce  or  the  vulva,  bacilli  are 
found  which  have  the  same  staining-  reaction  and  are  similar  in  their  mor- 
phology to  the  bacillus  of  Lustgarten.  This  by  no  means  proves  that  the 
smegma  bacilli  found  under  the  prepuce  of  healthy  persons  are  identical 
with  the  bacilli  found  by  Lustgarten  and  others  in  sections  of  tissues  involved 
in  syphilomata.  In  the  absence  of  pure  cultures  and  inoculation  experiments 
it  is  impossible  to  establish  identity,  however  similar  may  be  the  characters 
referred  to.  Several  well-known  pathogenic  bacilli  resemble  quite  as  closely 
in  these  particulars  other  bacilli  which  have,  nevertheless,  been  differentiated 
from  them  by  culture  and  inoculation  experiments.  We  may  mention 
especially  in  this  connection  the  bacillus  of  diphtheria,  as  obtained  from  the 
pseudo-membranous  exudation  in  a  genuine  case  of  this  disease,  and  the 
pseudo  diphtheria  bacilli  found  by  Eoux  and  Yersinin  the  fauces  of  healthy 
children.  On  the  other  hand,  since  it  has  been  shown  that  similar  bacilli 
are  common  in  preputial  srnegma,  we  cannot  attach  great  importance  to  the 
finding  of  Lustgarten's  bacillus  in  primary  syphilitic  sores ;  and  it  has  not 
been  found  in  sufficient  numbers,  or  with  sufficient  constancy,  by  those  who 
have  searched  for  it  subsequently  to  the  publication  of  Lustgarten's  inves- 
tigations, to  give  strong  support  to  the  view  that  it  is  the  specific  infectious 
agent  in  syphilis.  Baumgarten,  who  has  searched  in  vain  for  Lustgarten's 
bacillus  in  uncomplicated  visceral  syphilomata,  suggests  that  the  bacilli 
found  occasionally  in  such  lesions  were  perhaps  tubercle  bacilli  and  repre- 
sented a  mixed  infection.  As  the  bacillus  under  consideration  has  not  been 
obtained  in  cultures,  we  have  no  information  as  to  its  biological  characters 
and  pathogenesis. 

THE   SYPHILIS  BACILLUS   OF   EVE   AND   LINGARD. 
Eve  and  Lingard  (1886)  report  that  they  have  obtained  in  cultures  from 


4:04  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

the  blood  and  diseased  tissues  of  syphilitics  who  have  not  undergone  mer- 
curial treatment,  bacilli  which  in  their  form  and  dimensions  resemble  the 
tubercle  bacilli,  but  which  stain  readily  by  the  common  aniline  colors  and 
by  Gram's  method,  and  are  not  stained  by  Lustgarten's  method.  They  grow 
readily  upon  solidified  blood  serum,  forming  a  thin,  pale-yellow  or  brown- 
ish-yellow layer.  Inoculations  of  pure  cultures  into  apes  were  without 
result.  The  negative  results  which  have  attended  the  culture  experiments 
and  microscopical  examinations  of  the  blood  and  diseased*tissues,  made  by 
many  competent  bacteriologists  in  other  parts  of  Europe,  make  it  appear 
probable  that  the  bacilli  described  by  the  English  investigators  named  belong 
to  some  saprophytic  species,  and  that  they  are  not  usually  present  in  syphilo- 
mata  or  the  blood  of  syphilitic  patients. 

MICROCOCCI  OF  DISSE  AND   TAGUCHI.  . 

Disse  and  Taguchi  (1886)  claim  to  have  obtained  from  the  blood  of  syphi- 
litics micrococci  which  they  were  able  to  cultivate  in  artificial  media  at  20 
to  40°  C.,  and  which  formed  on  the  surface  of  such  media  a  grayish- white 
layer  consisting  of  diplococci  which  are  motile  and  of  larger  motion  less  cocci. 
The  diplococci  are  said  to  originate  from  division  of  the  larger  cocci.  Inocu- 
lations into  rabbits,  dogs,  and  sheep  gave  rise  to  chronic  interstitial  inflam- 
matory processes  in  the  lungs  and  liver,  to  granulomata  in  various  organs, 
and  to  fatty  degenerative  changes  in  the  walls  of  the  arteries,  which,  in  the 
opinion  of  the  authors  named,  correspond  with  the  pathological  changes 
produced  by  syphilitic  infection  in  man.  We  remark,  with  reference  to  the 
supposed  etiological  relation  of  this  coccus,  that  bacteriologists  in  Europe 
have  not  confirmed  the  authors  named  as  to  the  presence  of  this  micrococcus 
in  the  blood  of  syphilitics,  and  that  the  micrococcus  of  progressive  granuloma 
formation  described  by  Manfredi  produces  similar  pathological  changes  in 
inoculated  animals ;  also  that  there  is  no  evidence  that  the  animals  experi- 
mented upon  are  subject  to  syphilitic  irifection. 

58.    BACILLUS   OF  RHINOSCLEROMA   (?). 

First  observed  by  Von  Frisch  (1882)  in  the  newly  formed  tubercles  of 
rhinoscleroma.  Cultivated  by  Paltauf  and  Von  Eiselberg  (1886). 

Rhinoscleroma  is  a  chronic  affection  of  the  skin,  and  especially  of  the 
mucous  membrane  of  the  nares,  which  is  characterized  by  the  formation  of 
tubercular  thickenings  of  the  skin  and  tumefaction  of  the  nasal  mucous 
membrane,  followed  sometimes  by  ulceration.  It  prevails  in  Italy,  Austria, 
and  to  a  slight  extent  in  some  parts  of  Germany.  Pathologists  generally 
regard  it  as  an  infectious  process,  although  this  has  not  been  proved. 

The  bacilli,  first  described  by  Von  Frisch,  appear  to  be  constantly  present 
in  the  newly  formed  tubercles.  They  are  commonly  found  in  certain  large 
hyaline  cells  peculiar  to  the  disease,  and  may  also  be  observed  in  the  lym- 
phatic vessels  or  scattered  about  in  the  involved  tissues. 

Morphology. — Short  bacilli  with  rounded  ends,  usually  united  in  pairs, 
and  surrounded  by  a  gelatinous  capsule  resembling  that  of  Friedlander's 
bacillus.  According  to  Eisenberg,  the  bacilli  are  two  to  three  times  as  long 
as  broad,  and  may  grow  out  into  filaments. 

These  bacilli  stain  readily  with  the  aniline  colors  and  by  Gram's  method. 
The  capsule  may  be  demonstrated  by  the  methods  usually  employed  in  stain- 
ing Friedlander's  bacillus,  or  by  the  following  method  which  is  especially 
recommended  by  Alvarez:  The  excised  portions  of  tissue  involved  in  the  dis- 
ease are  placed  for  twenty-four  hours  in  a  one-per-cent  solution  of  osmic 
acid  and  then  in  absolute  alcohol.  When  properly  hardened  thin  sections 
are  made;  these  are  stained  in  a  hot  solution  of  aniline-water-methyl-violet 
for  a  few  minutes,  and  then  decolorized,  by  Gram's  method,  in  iodine  so- 
lution. 

Biological  Characters,— A.n  aerobic,  non-motile,  non-liquefying  bacillus 
(facultative  anaerobic  ?). 


BACILLI  IN  CHRONIC   INFECTIOUS   DISEASES. 


405 


In  gelatin  stick  cultures  the  growth,  resembles  that  of  Friedlander's  ba- 
cillus— i.e.,  a  nail-like  growth,  consisting  of  densely  crowded,  opaque  colonies 
along  the  line  of  puncture,  and  a  heaped-up,  white,  glistening  mass  upon  the 
surface,  hemispherical  in  form  and  viscous  in  consistence.  Upon  gelatin 
plates  yellowish-white,  spherical  colonies  are  developed  within  two  or  three 
days,  which  under  the  microscope  are  seen  to  be  granular.  Upon  potato  a 
cream-like  growth  occurs  along  the  line  of  inoculation,  which  is  white  or 
yellowish-white  in  color,  and  in  which  gas  bubbles  may  be  developed.  De- 
velopment is  most  rapid  at  a  temperature  of  35°  to  38°,  but  also  occurs  at  the 
room  temperature. 

Pathogenesis. — The  etiological  relation  of  this  bacillus  to  the  disease  with 
which  it  is  associated  has  not  been  established.  It  is  pathogenic  for  mice 
and  for  guinea-pigs,  less  so  for  rabbits ;  in  this  regard,  as  in  its  morphology 
and  growth  in  various  culture  media,  it  bears  a  close  resemblance  to  Fried- 
lander's  bacillus,  which  is  also  found  not  infrequently  in  the  nasal  secretions 
of  healthy  persons  and  in  those  suffering  from  chronic  nasal  catarrh  or  ozaena. 

The  principal  points  of  difference,  as  pointed  out  by  Baumgarten,  are  as 
follows :  The  bacillus  of  rhinoscleroma  is  usually  more  decidedly  rod-shaped 


FIG.  128.— Bacillus  of  rhinoscleroma  in  lymphatic  vessels  of  the  superficial  part  of  tumor. 
X  1,200.    (Cornil  and  Babes  ) 

than  Friedlander's  bacillus,  although  both  may  be  of  so  short  an  oval  as  to 
resemble  micrococci.  The  first-mentioned  bacillus  constantly  presents  the 
appearance  of  being  surrounded  by  a  transparent  capsule,  even  in  the  cul- 
tures in  artificial  media,  while  Friedlander's  bacillus  in  such  media  does  not 
usually  present  this  appearance,  unless  as  a  result  of  special  treatment. 
Finally,  the  bacillus  of  rhinoscleroma  may  retain  its  color,  in  part  at  least, 
when  treated  by  Gram's  method,  while  Friedlander's  bacillus  is  completely 
decolorized  when  placed  in  the  iodine  solution  employed  in  this  method. 

Notwithstanding  these  points  of  difference,  Baumgarten  is  not  entirely 
satisfied  that  this  bacillus  is  a  distinct  species,  and  several  bacteriologists 
have  maintained  that  it  is  identical  with  the  bacillus  of  Friedlander. 

59.   BACILLUS    OF    KOUBASOFF. 

Obtained  by  Koubasoff  (1889)  from  new  growths  in  the  stomach  of  a 
person  who  died  of  cancer  of  the  stomach. 

Morphology. — Bacilli  with  round  ends,  or  with  one  end  pointed,  two  or 
three  times  as  long  as  the  tubercle  bacillus  and  three  or  four  times  as  thick. 

Stains  readily  with  the  aniline  colors. 

Biological  Characters. — A.n  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Forms  spores  in  the  centre  of  the  rods.  Grows 
in  the  usual  culture  media  at  the  room  temperature,  more  rapidly  at  36°  C. 


406  BACILLI   IN   CHRONIC   INFECTIOUS   DISEASES. 

In  stick  cultures  in,  glycerin-gelatin,  the  growth  resembles  an  in  verted  stetho- 
scope; at  the  surface  a  circular,  bluish  membrane  is  formed,  which  is  de- 
pressed in  the  form  of  a  funnel,  while  along  the  line  of  puncture  a  slender, 
yellowish,  jagged  column  is  developed.  Upon  agar,  at  36°  C.,  a  bluish- 
white  layer  is  quickly  developed.  Upon  potato  the  growth  resembles  that 
of  the  typhoid  bacillus  at  first;  later  a  granular  membrane  is  formed;  under 
a  low  power  the  granules  appear  to  be  formed  of  intertwined  masses  of  fila- 
ments. The  growth  upon  blood  serum  is  similar  to  that  upon  agar. 

Pathogenesis. — Subcutaneous  injections  in  guinea-pigs  cause  their  death 
in  one  to  two  weeks,  in  rabbits  in  one  to  two  months,  in  cats  and  dogs  in 
two  months  or  more.  Death  occurs  in  a  shorter  time  in  animals  which,  have 
been  fed  upon  cultures  than  as  a  result  of  subcutaneous  injections.  The 
animals  become  very  much  emaciated  and  have  paralysis  of  the  sphincter 
muscles.  At  the  autopsy  flat  or  nodular  elevations,  which  are  often  ulce- 
rated, are  seen  here  and  there  upon  the  mucous  membrane  of  the  stomach 
and  intestine ;  the  mesentery,  especially  of  the  small  intestine,  is  hyperaemic ; 
the  mesenteric  glands  are  swollen,  as  are  also  the  inguinal  glands.  In  the 
liver  and  sometimes  in  the  ovary,  uterus,  and  spleen  larger  or  smaller  nod- 
ules are  seen. 

60.    BACILLUS  OP  NOCARD. 

Obtained  by  Nocard  (1888)  from  pus  collected  from  the  superficial  ab- 
scesses in  cattle  suffering  from  a  chronic  infectious  disease  which  prevails 
especially  upon  the  island  of  Guadaloupe — known  as  "  farcin  du  boeuf"; 
Ger.  "Wurmkrarikheit." 

Morphology. — A  long  and  slender  bacillus,  about  as  thick  as  the  bacillus 
of  rouget  (Bacillus  murisepticus) ;  usually  seen  in  tangled  masses  which 
consist  of  an  opaque  central  portion  surrounded  by  long  filaments,  which 
apparently  give  off  lateral  ramifications.  (This  description  of  the  morphol- 
ogy gives  rise  to  the  suspicion  that  the  microorganism  described  by  Nocard 
is  a  microscopic  fungus  rather  than  a  bacillus.)  According  to  Nocard,  the 
branching  is  more  apparent  than  real,  and  is  in  fact  a  false  dichotomization, 
such  as  is  seen  in  the  genus  Cladothrix. 

Stains  best  by  Weigert's  method ;  is  decolorized  by  Gram's  method.  Does 
not  stain  readily  with  most  aniline  colors. 

Biological  Characters. — An  aerobic,  non-motile  bacillus,  which  does 
not  grow  in  nutrient  gelatin  at  the  room  temperature.  Grows  in  the  usual 
culture  media  at  a  temperature  of  30 3  to  40°  C.  Forms  small  oval  spores. 
Is  destroyed  in  ten  minutes  by  a  temperature  of  70°  C.  Upon  the  surface 
of  agar  it  forms  irregular,  opaque,  yellowish-white  colonies,  which  are 
thickest  at  the  margin,  have  a  dull,  dusty- looking,  mammillated  surface, 
and  after  a  time  become  confluent,  forming  a  thick,  wrinkled,  membranous 
layer.  Upon  potato  development  is  rapid  in  the  form  of  prominent,  dry, 
pale- yellow  plaques.  In  bouillon  whitish  flocculi  are  formed,  most  of  which 
fall  to  the  bottom,  while  some  float  upon  the  surface,  where  they  form  dry, 
dusty-looking,  rounded  pellicles  of  adirty-gray  color  withagreenish  reflection. 
^Pathogenesis. — The  guinea-pig  is  the  most  susceptible  animal.  When 
injected  into  th^  peritoneal  cavity  of  one  of  these  animals  it  produces,  in 
from  nine  to  twenty  days,  lesions  which  closely  resemble  those  of  miliary 
tuberculosis.  At  the  autopsy  the  peritoneu  m  is  found  to  be  covered  with 
nodules,  in  the  centre  of  which  the  bacillus  is  found  in  tangled  masses ;  the 
liver,  spleen,  kidneys,  and  intestine  are  also  studded  with  pseudo-tubercles, 
but  these  are  only  found  in  the  peritoneal  coat  and  not  in  the  parenchyma 
of  the  various  organs,  or  in  the  organs  of  the  thoracic  cavity.  Intravenous 
injections  give  rise  to  lesions  similar  to  those  of  general  miliary  tuberculo- 
sis, the  organs  generally  containing  a  considerable  number  of  nodules,  in 
the  centre  of  which_tufts  of  bacilli  are  found.  In  cattle  and  sheep  similar 
lesions  result  from  intravenous  injections,  but  without  causing  the  death  of 
the  animal.  The  dog,  the  cat,  the  horse,  the  ass,  and  the  rabbit  are  immune. 
Subcutaneous  inoculations  in  guinea  pigs  produce  an  extensive  local  abscess, 
followed  by  a  chronic  induration  of  the  neighboring  lymphatic  glands. 


XII. 

BACILLI  WHICH  PRODUCE  SEPTICAEMIA   IN 
SUSCEPTIBLE  ANIMALS. 

WHEN,  as  a  result  of  accidental  (natural)  or  experimental  inocula 
tion,  a  microorganism  is  introduced  into  the  body  of  a  susceptible 
animal  which  is  able  to  multiply  in  its  blood,  producing  a  general  in- 
fection, we  speak  of  this  general  blood  infection  as  a  septicfemia. 
When  pathogenic  microorganisms  which  are  unable  to  multiply  in 
the  blood  establish  themselves  in  some  particular  locality  in  the  ani- 
mal body  which  is  favorable  for  their  growth,  and  by  the  formation 
of  toxic  products,  which  are  absorbed,  give  rise  to  general  symptoms 
of  poisoning,  we  designate  the  affection  toxcemia.  As  examples  of 
this  mode  of  pathogenic  action  we  may  mention  diphtheria  and 
tetanus.  As  a  rule,  the  various  forms  of  septicaemia  are  quickly 
fatal,  and,  as  the  microorganisms  to  which  they  are  due  multiply  in 
the  blood  of  the  infected  animal,  this  fluid  possesses  infectious  pro- 
perties, and,  when  inoculated  in  the  smallest  quantity  into  another 
susceptible  animal,  reproduces  the  same  morbid  phenomena.  A  typi- 
cal example  of  this  class  of  diseases  is  found  in  anthrax,  to  which 
disease  a  special  section  has  already  been  devoted  (VII.).  But  in 
this  and  other  forms  of  septicaemia  subcutaneous  inoculations  do  not, 
as  a  rule,  result  in  the  immediate  invasion  of  the  blood  by  the  para- 
sitic microorganism.  Often  a  local  inflammatory  process  of  consider- 
able extent  is  first  induced  ;  and  in  some  cases  general  infection  only 
occurs  a  short  time  before  the  death  of  the  animal,  depending,  per- 
haps, upon  a  previous  toxaemia  from  the  absorption  of  toxic  products 
developed  at  the  seat  of  local  infection.  The  pathogenic  action,  then, 
in  acute  forms  of  septicaemia  appears  to  result,  not  alone  from  the 
presence  and  multiplication  of  the  pathogenic  microorganism  in  the 
blood,  but  also  from  the  toxic  action  of  products  evolved  during  its 
growth. 

Some  of  the  pathogenic  bacilli  of  this  class  now  known  to  bac- 
teriologists have  been  discovered  by  studying  the  infectious  diseases 
induced  by  them  in  lower  animals  among  which  these  diseases  pre- 
vail naturally — i.e.,  independently  of  human  interference.  Many 


4:08  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

more  are  known  to  us  from  experiments  made  in  pathological  labora- 
tories, in  testing  by  inoculations  into  animals  bacteria  obtained  from 
various  sources,  with  reference  to  their  pathogenic  power.  We  in- 
clude in  this  group  only  those  bacilli  which  induce  fatal  septicaemia 
in  susceptible  animals  when  injected  into  the  circulation  or  sub- 
cutaneously  in  a  comparatively  small  quantity — e.g.,  less  than  half 
a  cubic  centimetre  of  a  bouillon  culture. 

61.  BACILLUS  SEPTICAEMIA  HJEMORRHAGIC^E. 

Synonyms. — Bacillus  of  fowl  cholera  •  Microbe  du  cholera  des 
poules  (Pasteur) ;  Bacillus  cholerae  gallinarum  (Flugge);  Bacillus  der 
Hiihnercholera ;  Bacillus  of  rabbit  septicaemia  ;  Bacillus  cuniculi- 
cida  (Flugge)  ;  Bacillus  der  Kaninchenseptikamie  (Koch)  ;  Bacillus 
der  Rinderseuche  (Kitt)  ;  Bacillus  der  Schweineseuche  (Loffler  and 
Schiitz)  ;  Bacillus  der  Wildseuche  (Hueppe)  ;  Bacillus  der  Biiffel- 
seuche  (Oreste-Armanni)  ;  (Bacterium  of  Davaine's  septicaemia  ?) 

It  is  now  generally  admitted  by  bacteriologists  that  Koch's  ba- 
cillus of  rabbit  septicaemia  (1881)  is  identical  with  the  bacillus 
("micrococcus")  of  fowl  cholera  previously  described  by  Pasteur 
(1880).  The  similar  bacilli  found  in  the  blood  of  animals  dead  from 
the  infectious  diseases  known  in  Germany  as  Wildseuche  (Hueppe), 
Rinderseuche  (Kitt),  Schweineseuche  (Schiitz),  and  Buffelseuche 
(Oreste-Armanni)  appear  also  to  be  identical  with  the  bacillus  of 
rabbit  septicaemia  and  fowl  cholera.  This  view  is  sustained  by 
Hueppe  and  by  Baumgarten,  and  by  the  recent  comparative  re- 
searches of  Caneva  (1891)  and  of  Bunzl-Federn  (1891). 

This  is  evidently  a  widely  distributed  pathogenic  bacillus  ;  it  was 

obtained  by  Koch  from  rabbits  inoculated  with  pu- 

^  ^  ,-..   •  *   ,0  tref  ying  flesh  infusion,  by  Gaffky  from  impure  river 

*O'»*O**  W  water,  and  by  Pasteur  from  the  blood  of  fowls  suffer- 

'*>rS***\  *r~»*     ing  from  the  infectious  disease  known  in  France  as 

'•»  v40  '  "  O  *    cholera  des  poules.     It  is  not  infrequently  found  in 

t(\J  t/*  •»     •  '  putrefying  blood,    and  its  presence  in  the  salivary 

FIQ  129     Bacillus  secretions  of  man  has  occasionally  been  demonstrated 

septicaemia?   hsemor-    (Baumgarten) . 

rhagic*  in  the  blood         With   reference  to  the  American   swine   plague 

of  a   rabbit.     X  950.  ° 

(Baumgarten.)  described  by  Salmon  and  Smith,  we  are  informed  by 

Smith,  in  his  most  recent  publication  upon  the  subject 
(Zeitschrift  fur  Hygiene,  Band  x.,  page  493),  that  cultures  of  the 
German  Schweineseuche  bacillus,  received  from  the  Berlin  Hygienic 
Institute,  compared  with  his  cultures  from  infected  swine  in  this 
country,  agreed  in  all  particulars,  except  that  the  former  were  de- 
cidedly more  pathogenic  for  swine  and  for  rabbits. 

It  appears  extremely  probable  that  the  form  of  septicaemia  studied 


IN   SUSCEPTIBLE    ANIMALS.  409 

by  Davaine  (1872),  which  he  induced  in  the  first  instance  by  inject- 
ing putrid  ox  blood  into  rabbits,  was  due  to  the  same  pathogenic  ba- 
cillus. The  writer  obtained  this  bacillus  (1887)  in  Cuba  from  the 
blood  of  rabbits  inoculated  with  liver  tissue  taken  from,  a  yellow- 
fever  cadaver  and  kept  for  forty-eight  hours  in  an  antiseptic  wrap- 
ping. The  name  which  we  have  adopted  is  that  proposed  by  Hueppe 
for  the  form  of  septicaemia  to  which  it  gives  rise — "Septikamia 
hamorrhagica. " 

Morphology. — Short  bacilli  with  rounded  ends,  from  0.6  to  0.7 
/*  in  diameter  and  about  1.4  ^  long;  sometimes  united  in  pairs,  or 
in  chains  of  three  or  four  elements.  In  stained  preparations  the  ex- 
tremities are  usually  stained,  while  the  central  portion  of  the  rod 
remains  unstained.  This  "  end  staining"  causes  the  rods  to  present 
the  appearance  of  diplococci  when  examined  with  a  comparatively 
low  power,  and  some  of  the  earlier  observers  described  the  microor- 
ganism under  consideration  as  a  micrococcus.  It  is  quickly  stained 
by  the  aniline  colors  usually  employed,  but  loses  its  color  when 
treated  by  Gram's  method. 

Biological  Characters. — A  non-motile,  aerobic,  non-liquefy- 
ing bacillus.  Does  not  form  spores.  Grows  in  various  culture  media 
at  the  room  temperature,  but  more  rapidly  at  35°  to  37°  C. — the 
lowest  temperature  at  which  development  occurs  is  about  13°  C. 
Although  this  is  an  aerobic  bacillus  and  a  certain  amount  of  oxygen 
is  necessary  for  its  development,  it  appears  to  grow  better  when  the 
amount  is  somewhat  restricted  than  it  does  on  the  surface  of  nutrient 
media. 

Upon  gelatin  plates,  at  the  end  of  two  or  three  days,  small, 
white  colonies  are  developed  upon  or  near  the  surface ;  these  are 
finely  granular  and  spherical,  with  a  more  or  less  irregular  outline, 
and  by  transmitted  light  have  a  yellowish  color  ;  later  the  central 
portion  of  the  colonies  is  of  a  yellowish-brown  color  and  is  sur- 
rounded by  a  transparent  peripheral  zone.  The  superficial  colonies 
are  commonly  smaller  than  those  which  develop  a  little  below  the 
surface  of  the  gelatin.  In  stick  cultures  in  nutrient  gelatin  the 
growth  upon  the  surface  consists  of  a  thin,  whitish  layer  in  the 
vicinity  of  the  point  of  puncture,  having  an  irregular,  jagged  out- 
line— sometimes  there  is  no  development  upon  the  surface  ;  along 
the  line  of  puncture  the  growth  consists  of  rather  transparent,  dis- 
crete or  confluent  colonies.  In  streak  cultures  upon  nutrient  agar, 
or  gelatin,  or  blood  serum  the  growth  is  limited  to  the  immediate 
vicinity  of  the  line  of  inoculation,  and  consists  of  finely  granular, 
semi-transparent  colonies,  which  form  a  thin,  grayish-white  layer 
with  irregular,  somewhat  thickened  margins.  Upon  potato  no  de- 
velopment occurs,  as  a  rule,  at  the  room  temperature,  but  in  the  in- 
33 


410 


BACILLI  WHICH  PRODUCE   SEPTICAEMIA 


cubating  oven  a  rather  thin,  transparent,  grayish-white  or  yellowish, 
waxy  layer  is  developed  hi  the  course  of  a  few  days.  According  to 
Bunzl-Federn,  the  bacillus  of  fowl  cholera  and  that 
yjjtf  Jjy|i||j  of  rabbit  septicaemia  grow  upon  potato,  while  the 
bacillus  of  Wildseuche,  Schweineseuche,  and  Biif- 
felseuche  do  not.  According  to 
Caneva,  none  of  the  bacilli  of  this 
group  grow  upon  potato.  The 
same  author  states  that  the  growth 
in  milk  is  scanty  and  does  not 
produce  coagulation,  while  Bunzl- 
Federn  finds  that  the  bacillus  of 
fowl  cholera  and  of  rabbit  septi- 
caBmia  produce  coagulation  and 
the  others  do  not.  These  differ- 
ences are  not,  however,  consid- 
ered by  the  author  last  named  as 
sufficient  to  establish  the  specific 
difference  of  the  bacilli  from  these 
different  sources.  He  looks  upon 
them  rather  as  varieties  of  the 
same  species.  Bunzl-Federn  has 
also  ascertained  that  when  cul- 
tivated in  a  peptone  solution  all 
of  the  bacilli  of  this  group,  with 
the  exception  of  that  obtained 
from  the  so-called  Buffelseuche, 
give  the  reaction  for  phenol  and 
for  indol — the  bacillus  of  Buffel- 
seuche gives  the  indol  reaction  only.  Development  in  bouillon  is  rapid 
and  causes  a  uniform  turbidity  of  the  fluid.  Cultures  of  this  bacillus 
may  retain  their  vitality  for  three  months  or 
more  when  kept  in  a  moist  condition ;  but 
the  bacillus  usually  fails  to  grow  after  having 
been  kept  for  a  few  days  in  a  desiccated  con- 
dition ;  according  to  Hueppe,  it  may  resist 
desiccation  for  fourteen  days.  The  thermal 
death-point,  as  determined  by  Salmon  for 
the  bacillus  of  fowl  cholera,  is  56°  C. ,  the  time 
of  exposure  being  ten  minutes  (55°  C.  with 
fifteen  minutes'  exposure — Baumgarten).  It 
is  not  readily  destroyed  by  putrefaction  (Kitt). 
A  solution  of  mercuric  chloride  of  1  :5,000 
•destroys  it  in  one  minute,  and  a  three-per-cent  solution  of  carbolic 


FIG.  130.  —  Bacillus 
septicaemias  haemor- 
rhagicse;  stick  culture 
in  nutrient  gelatin, 
end  of  four  days  at  16°- 
18°  C.  (Baumgarten  > 


FIG.  131.— Bacillus 
of  Schweineseuche ; 
old  stick  culture 
in  nutrient  gela- 
tin. (Schutz.) 


FIG.  132.  —  Bacillus  of  swine 
plague;  colonies  on  gelatin 
plate,  end  of  seven  days. 
X  CO.  (Smith.) 


IX   SUSCEPTIBLE   ANIMALS.  411 

acid  in  six  hours  (Hueppe).  Pasteur  (1880)  has  shown  that  when 
cultures  of  this  bacillus  (microbe  of  fowl  cholera)  in  bouillon  are 
kept  for  some  time  they  gradually  lose  their  pathogenic  virulence, 
and  he  has  ascribed  this  "attenuation  of  virulence"  to  the  action  of 
atmospheric  oxygen.  He  also  ascertained  that  the  particular  degree 
of  virulence  manifested  by  the  mother  culture  after  a  certain  interval 
could  be  maintained  in  successive  cultures  made  at  short  intervals. 
He  was  thus  able  to  cultivate  different  pathogenic  varieties,  and  to 
use  these  in  making  protective  inoculations,  by  which  susceptible  ani- 
mals were  preserved  from  the  effects  of  virulent  cultures  injected 
subsequently. 

Attenuated  cultures  recover  their  virulence  when  inoculated  into 
very  susceptible  animals.  Thus  a  culture  which  would  produce  a 
non-fatal  and  protective  attack  in  a  chicken  may,  according  to  Pas- 
teur, kill  a  small  bird,  like  a  sparrow;  and  by  successive  inoculations 
from  one  sparrow  to  another  the  original  degree  of  virulence  may  be 
restored,  so  that  a  minute  quantity  of  a  pure  culture  would  be  fatal 
to  a  chicken. 

Pathogenesis. — Pathogenic  for  chickens,  pigeons,  pheasants, 
sparrows,  and  other  small  birds,  for  rabbits  and  mice,  also  for  swine 
(Schweineseuche),  for  cattle  (Rinderseuche),  and  for  deer  (Wild- 
seuche).  Subcutaneous  injection  of  a  minute  quantity  of  a  virulent 
culture  usually  kills  chickens  within  forty-eight  hours.  Some  time 
before  death  the  fowl  falls  into  a  somnolent  condition,  and,  with 
drooping  wings  and  ruffled  feathers,  remains  standing  in  one  place 
until  it  dies.  Infection  may  also  occur  from  the  ingestion  of  food 
moistened  with  a  culture  of  the  bacillus  or  soiled  with  the  discharges 
from  the  bowels  of  other  infected  fowls.  At  the  autopsy  the  mucous 
membrane  of  the  small  intestine  is  found  to  be  inflamed  and  studded 
with  small  hsemorrhagic  foci,  as  are  also  the  serous  membranes  ;  the 
spleen  is  notably  enlarged.  The  bacilli  are  found  in  great  numbers 
in  the  blood,  in  the  various  organs,  and  in  the  contents  of  the  in- 
testine. In  rabbits  death  commonly  occurs  in  from  sixteen  to  twenty 
hours,  and  is  often  preceded  by  convulsions.  The  temperature  is 
elevated  at  first,  but  shortly  before  death  it  is  reduced  below  the 
normal.  The  post-mortem  appearances  are  :  swelling  of  the  spleen 
and  lymphatic  glands  ;  ecchymoses  or  diffuse  hsemorrhagic  infiltra- 
tions of  the  mucous  membranes  of  the  digestive  and  respiratory  pas- 
sages, and  in  the  muscles  ;  and  at  the  point  of  inoculation  a  slight 
amount  of  inflammatory  oedema.  The  bacilli  are  found  in  consider- 
able numbers  in  the  blood  within  the  vessels,  or  in  that  which  has 
escaped  into  the  tissues  by  the  rupture  of  small  veins.  They  are  not, 
however,  so  numerous  as  in  some  other  forms  of  septicaemia— e.g., 
anthrax,  mouse  septicaemia — when  an  examination  is  made  imme- 


413  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

diately  after  death  ;  later  the  number  may  be  greatly  increased  as  a 
result  of  post-mortem  multiplication  within  the  vessels.  The  rabbit 
is  so  extremely  susceptible  to  infection  by  this  bacillus  that  inocula- 
tion in  the  cornea  by  a  slight  superficial  wound  usually  gives  rise  to 
general  infection  and  death.  This  animal  may  also  be  infected  by 
the  ingestion  of  food  contaminated  with  a  culture  of  the  bacillus.  It 
is  by  this  means  that  Pasteur  proposed  to  destroy  the  rabbits  in  Aus- 
tralia, which  have  multiplied  in  that  country  to  such  an  extent  as  to 
constitute  a  veritable  pest.  Both  in  fowls  and  in  rabbits  the  disease 
may  under  certain  circumstances  run  a  more  protracted  course — e-(J-, 
when  they  are  inoculated  with  a  small  quantity  of  an  attenuated  cul- 
ture. In  less  susceptible  animals — guinea-pigs,  sheep,  dogs,  horses 


•.,-£.,""      .:./••;,  ] 

''"  **£•  »*.* 


I" 

FIG.  133.— Bacillus  of  Schweineseuche,  in  blood  of  rabbit.    (Schutz.) 

— a  local  abscess,  without  general  infection,  may  result  from  the  sub- 
cutaneous injection  of  the  bacillus  ;  but  these  animals  are  not  entirely 
immune.  In  the  infectious  maladies  of  swine,  cattle,  deer,  and  other 
large  animals  to  which  reference  has  been  made,  and  which  are  be- 
lieved to  be  due  to  the  same  bacillus,  the  symptoms  and  pathological 
appearances  do  not  entirely  correspond  with  those  in  the  rabbit  or 
the  fowl;  but  the  bacillus  as  obtained  from  the  blood  of  such  animals 
corresponds  in  its  morphological  and  biological  characters  with  Pas- 
teur's microbe  of  fowl  cholera  and  Koch's  bacillus  of  rabbit  septi- 
caemia, and  pure  cultures  from  the  various  sources  mentioned  are 
equally  fatal  to  rabbits  and  to  fowls.  In  the  larger  animals  pul- 
monary and  intestinal  lesions  are  developed,  and  in  swine  a  diffused 
red  color  of  the  skin,  similar  to  that  observed  in  the  disease  known 
in  Germany  as  Schweinerothlauf  (Fr.  rouget),  is  sometimes  seen. 


IN   SUSCEPTIBLE   ANIMALS.  413 

According  to  Baumgarten,  bacilli  from  Wildseuche  or  from  Rinder- 
seuche  inoculated  into  swine  give  rise  to  fatal  Schweineseuche,  and 
bacilli  from  any  of  these  forms  of  disease,  when  inoculated  into 
pigeons,  produce  characteristic  fowl  cholera  ;  but  the  bacillus  as  ob- 
tained from  Schweineseuche  or  Wildseuche  is  not  fatal  to  chickens, 
and  the  bacillus  from  Schweineseuche  is  fatal  to  guinea-pigs,  which 
have  but  slight  susceptibility  to  the  bacillus  of  rabbit  septicjemia. 
Notwithstanding  these  differences  he  agrees  with  Hueppe  in  the  view 
that  the  bacilli  from  the  various  sources  mentioned  are  specifically 
identical ;  although  evidently,  if  this  view  is  adopted,  we  must 
admit  that  varieties  exist  which  differ  somewhat  in  their  pathogenic 
power. 

The  researches  of  Smith  and  of  Moore  show  that  ' '  an  attenuated 
variety  of  bacteria,  belonging  to  the  group  of  swine-plague  bacteria 
and  not  distinguishable  from  them,  inhabit  the  mouth  and  upper  air 
passages  of  such  domesticated  animals  as  cattle,  dogs,  and  cats  " 
(Smith). 

62.    BACILLUS   OF   CHOLERA   IN   DUCKS. 

Obtained  by  Coruil  and  Toupet  (1888)  from  the  blood  of  ducks,  in  the 
Jardin  d'Acclimation  at  Paris,  which  had  died  of  an  epidemic  disease  charac- 
terized by  diarrhoaa,  feebleness,  and  muscular  tremors,  and  which  resulted 
fatally  in  two  or  three  days. 

Morphology. — Does  not  differ  in  its  morphology  from  the  bacillus  of 
fowl  cholera  (Bacillus  septicaemias  hsemorrhagicae) ;  short  rods  with  rounded 
ends,  from  1  to  1.5  n  in  length  and  0.5  /<  broad. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method ;  the  ends 
stain  more  deeply  than  the  central  portion. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Does  not  form  spores.  Grows  in  the  usual  culture  media  at  the  room  tem- 
perature. In  its  growth  in  various  media,  as  well  as  in  its  morphology,  Cornil 
and  Toupet  found  this  bacillus  to  correspond  with  the  bacillus  of  fowl 
cholera.  In  gelatin  stick  cultures  the  growth  upon  the  surface  consists  of  a 
thin,  grayish  layer,  and  along  the  line  of  puncture  as  small,  semi-transpa- 
rent, slightly  yellowish,  spherical  colonies.  Upon  agar,  in  the  incubating 
oven,  at  the  end  of  twelve  hours  small,  lentil  shaped,  waxy  colonies  are 
formed,  which  later  may  have  a  diameter  of  three  to  four  millimetres. 
Upon  potato  circular,  yellowish  colonies  are  formed,  which  become  con- 
fluent and  form  a  somewhat  depressed,  pale-yellow  layer. 

Pathogenesis. — According  to  Cornil  and  Toupet,  this  bacillus  is  patho- 
genic for  ducks,  but  not  for  chickens  or  pigeons,  and  only  kills  rabbits  when 
injected  in  considerable  quantity.  Ducks  die  in  from  one  to  three  days 
from  subcutaneous  injections,  or  by  the  ingestion.  of  food  to  which  the  bacil- 
lus has  been  added. 

63.  BACILLUS  OF  HOG  CHOLERA  (Salmon  and  Smith). 

Synonyms. — Bacillus  of  swine  plague  (Billings) ;  Bacillus  of  swine- 
pest  (Selander). 

According  to  Smith,  this  bacillus  was  first  described  by  Klein 
(1S84)  ;  it  was  first  obtained  in  pure  cultures  and  its  principal  char- 
acters determined  by  Salmon  and  Smith  (1885),  and  has  since  been 


414  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

studied  in  cultures  and  by  experimental  inoculations  by  Selander, 
Billings,  Frosch,  Welch,  Caneva,  Bunzl-Federn,  and  others. 

The  bacillus  is  found  in  the  blood  and  various  organs  of  hogs 
which  have  succumbed  to  the  infectious  disease  known  in  this  country 
as  hog  cholera ;  and  also  in  the  contents  of  the  intestine,  from  which 
it  may  be  obtained  by  inoculations  into  rabbits,  but  is  not  easily  iso- 
lated by  the  plate  method  owing  to  the  large  number  of  other  bac- 
teria present  (Smith). 

Morphology. — Short  bacilli  with  rounded  ends,  1.2  to  1.5  //in 
length  and  0. 6  to  0. 7  n  in  breadth  ;  usually  united  in  pairs. 

This  bacillus  is  easily  stained  by  the  aniline  colors  usually  em- 
ployed, but  does  not  retain  its  color  when  treated  by  Gram's  method. 
When  the  staining  agent  is  allowed  to  act  for  a  very  short  time  the 


FIG.  131.— Bacillus  of  hog  cholera;  stained  by  Loffler's  method  to  show  flagella.  x  1,000.  From 
a  photomicrograph  made  at  the  Army  Medical  Museum.  (Gray.) 

ends  of  the  rods  may  be  stained  while  the  central  portion  remains 
unstained. 

Biological  Characters. — Anaerobic  (facultative anaerobic),  non- 
liquefying,  actively  motile  bacillus.  In  many  of  its  characters  this 
bacillus  closely  resembles  the  one  last  described  (Bacillus  septicaemias 
hsemorrhagicse),  but  it  is  distinguished  from  it  by  its  active  move- 
ments, which,  according  to  Smith,  may  be  still  observed  in  cultures 
which  have  been  kept  for  weeks  or  months.  Does  not  form  spores. 
Grows  readily  in  various  culture  media  at  the  room  temperature — 
more  rapidly  in  the  incubating  oven.  Upon  gelatin  plates  colonies 
are  developed  in  from  twenty-four  to  forty-eight  hours.  The  deep  colo- 
nies are  spherical  and  homogeneous,  and  have  a  brownish  color  by 
transmitted  light;  they  seldom  exceed  one-half  millimetre  in  diameter. 


IN   SUSCEPTIBLE   ANIMALS.  415 

The  superficial  colonies  may  attain  a  diameter  of  two  millimetres ; 
they  present  no  distinctive  characters.  Upon  agar  plates  the  colonies 
may  have  a  diameter  of  four  millimetres  ;  they  have  a  grayish,  trans- 
parent appearance  and  a  shining  surface.  In  gelatin  stick  cultures 
small,  yellowish-white  colonies  are  developed  along  the  line  of  in- 
oculation, which  may  become  confluent ;  upon  the  surface  a  thin, 
pearly  layer  is  developed  about  the  point  of  inoculation,  which  may 
have  a  diameter  of  six  millimetres  or  more.  Upon  potato  a  straw- 
yellow  layer  is  developed,  which  later  acquires  a  darker  color.  In 
slightly  alkaline  bouillon  a  slight  cloudiness  may  be  observed  at  the 
end  of  twenty-four  hours,  and  at  the  end  of  one  or  two  weeks,  if 
not  disturbed,  a  deposit  is  seen  at  the  bottom  of  the  tube  and  a  thin, 
broken  film  may  form  upon  the  surface.  The  development  of  this 
bacillus  in  milk  produces  a  direct  solution  of  the  casein  without  pre- 
vious coagulation  ;  when  a  solution  of  litmus  has  been  added  to  milk 
it  retains  its  blue  color  in  presence  of  this  bacillus,  while  the  bacillus 
previously  described  causes  it  to  change  to  red.  Neither  phenol 
nor  indol  is  produced  in  solutions  containing  peptone  (Bunzl-Federn) 
— another  distinguishing  character  from  the  Bacillus  septicsemise 
hsemorrhagicse.  This  bacillus  may  be  cultivated  in  slightly  acid 
media,  which  after  a  time  acquire  an  alkaline  reaction. 

In  Smith's  experiments  this  bacillus  was  found  to  resist  desicca- 
tion from  nine  days  to  several  months,  according  to  the  thickness  of 
the  layer  dried  upon  the  cover  glass  ;  bacilli  from  an  agar  culture  in 
some  experiments  failed  to  grow  after  seventeen  days,  and  in  others 
still  gave  cultures  after  four  months.  Bouillon  cultures  are  steril- 
ized in  four  minutes  by  a  temperature  of  70°  C.,  in  fifteen  minutes 
by  58°  C.,  and  in  one  hour  by  54°  C.  (Smith).  Novy  has  isolated 
from  cultures  of  the  hog-cholera  bacillus  a  toxic  basic  substance 
which  he  calls  susotoxin.  This  was  obtained  by  Brieger's  method  ; 
it  is  a  yellowish-brown,  syrup-like  liquid,  which,  when  injected  into 
rats  in  doses  of  0.125  to  0.25  cubic  centimetre,  causes  their  death  in 
less  than  thirty-six  hours.  He  also  obtained  by  precipitation  with 
absolute  alcohol,  from  cultures  concentrated  in  a  vacuum  at  36°  C., 
a  toxalbumin  which  when  dried  was  in  the  form  of  a  white  powder 
easily  soluble  in  water.  Rats  died  in  three  or  four  hours  after  re- 
ceiving subcutaneously  a  dose  of  0. 1  to  0. 5  gramme. 

Pathogenesis. — Pathogenic  for  swine,  rabbits,  guinea-pigs,  mice, 
and  pigeons. 

In  certain  parts  of  the  United  States  the  disease  known  as  ' '  hog 
cholera "  frequently  prevails  among  swine  as  a  fatal  epidemic.  It 
may  occur  as  an  acute  and  quickly  fatal  septicaemia,  or  in  a  more 
chronic  form  lasting  from  two  to  four  weeks  or  even  longer.  In 
the  acute  form  death  may  occur  within  twenty -four  hours,  and  haem- 


416  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

orrhagic  extravasations  are  found  upon  the  mucous  and  serous; 
membranes  and  in  the  parenchyma  of  the  lungs,  kidneys,  and  lym- 
phatic glands.  The  spleen  is  greatly  enlarged,  soft,  and  dark  in 
color.  In  the  chronic  form  of  the  disease  the  most  notable  changes 
are  found  in  the  alimentary  canal.  These  are  most  constant  and 
characteristic  in  the  caecum  and  colon,  which  may  be  studded  with 
spherical,  hard,  necrotic  masses  or  extensive  diphtheritic  patches. 
According  to  Smith,  the  hsemorrhagic  and  necrotic  form  of  the  dis- 
ease may  exist  at  the  same  time  in  different  animals  of  the  same 
herd.  The  bacilli  are  found  in  all  of  the  organs,  and  especially  in 
the  spleen,  where  they  are  associated  in  irregular  colonies  similar 
to  those  of  the  typhoid  bacillus.  Smith  has  demonstrated  their  pre- 
sence in  urine  taken  from  the  bladder  immediately  after  the  death 
of  the  animal,  and  states  that  the  kidneys  are  almost  always  in- 
volved, as  shown  by  the  presence  of  albumin  and  tube  casts  in  the 
urine. 

An  extremely  minute  quantity  of  a  bouillon  culture  injected  be- 
neath the  skin  of  a  rabbit  causes  its  death  in  from  seven  to  twelve 
days  ;  a  larger  quantity  may  produce  a  fatal  result  in  five  days  ;  in- 
travenous injections  of  very  small  amounts  may  be  fatal  within 
forty-eight  hours.  After  a  subcutaneous  injection  the  animal  re- 
mains in  apparent  good  health  for  three  or  four  days,  after  which  it 
loses  its  appetite  and  is  indisposed  to  move  ;  several  days  before 
death  the  temperature  is  suddenly  elevated  from  2°  to  3°  C.,  and  it 
remains  high  until  the  fatal  termination.  At  the  autopsy  the  spleen 
is  found  to  be  enlarged  and  of  a  dark-red  color  ;  the  liver  is  studded 
with  small,  yellowish- white,  necrotic  foci;  the  kidneys  have  under- 
gone parenchymatous  changes  ;  the  heart  is  fatty  ;  and  the  intestinal 
mucous  membrane  is  more  or  less  marked  with  haemorrhagic  extra- 
vasations. The  bacilli  are  found  in  all  of  the  organs.  In  house 
mice  the  results  of  experimental  inoculations  are  similar  to  those  in 
rabbits.  Guinea-pigs  succumb  when  inoculated  subcutaneously  with 
one-tenth  cubic  centimetre ;  pigeons  require  a  still  larger  dose — 
about  three-quarters  of  a  cubic  centimetre.  Swine  are  killed  by  the 
intravenous  injection  of  one  to  two  cubic  centimetres  of  a  recent 
bouillon  culture,  but,  as  a  rule,  do  not  succumb  to  subcutaneous 
injections.  Cultures  recently  obtained  from  diseased  animals  are 
more  virulent  than  those  which  have  been  propagated  for  a  consider- 
able time  in  artificial  media. 

Smith  has  described  a  variety  of  the  hog-cholera  bacillus  obtained  during 
an  epidemic  in  which  the  disease  was  of  longer  duration — about  four  weeks 
— than  is  usual,  and  in  which  there  was  commonly  found  at  the  autopsy  a 
diphtheritic  inflammation  of  the  mucous  membrane  of  the  stomach.  This 
bacillus  differed  from  the  typical  form  by  being  somewhat  larger  and  in 
forming  considerably  larger  colonies  in  gelatin  plates — two  or  three  times 


IN   SUSCEPTIBLE   ANIMALS.  417 

as  large.  It  also  produced  a  greater  opacity  in  peptonized  bouillon,  and  in 
general  showed  a  more  vigorous  growth  in  various  nutrient  media.  It  dif- 
fered also  in  its  pathogenic  power,  as  tested  upon  rabbits,  causing  death  at  a 
later  date  or  not  at  all ;  and  in  fatal  cases  the  swelling  of  the  spleen  and 
necrotic  foci  in  the  liver,  produced  by  the  first-described  species,  were  absent. 

64.  BACILLUS  OF  BELFANTI  AND  PASCAROLA. 

Synonym.  — Impf  tetanusbacillus. 

Obtained  by  Belfanti  and  Pascarola  (1888)  from  the  pus  of  wounds  in  an 
individual  who  succumbed  to  tetanus.  » 

Morphology. — Bacilli  with  rounded  ends,  sometimes  so  short  as  to  resemble 
micrococci;  resemble  the  Bacillus  septicaemias  haemorrhagicae  (fowl  cholera). 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method.  The 
ends  are  commonly  more  deeply  stained  than  the  central  portion. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying^  non-motile  bacillus.  Spore  formation  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  yel- 
lowish-gray, finely  granular,  spherical  colonies  with  smooth  outlines  are 
developed.  In  gelatin  stick  cultures,  at  18°  to  25°  C.,  at  the  end  of  twenty- 
four  hours  small,  spherical  colonies  are  developed  along  the  line  of  punc- 
ture, which  are  isolated  or  closely  crowded ;  upon  the  surface  a  rather  thin, 
shining,  grayish- white,  iridescent,  circular  layer  is  formed ;  gas  is  given  off 
which  has  not  a  disagreeable  odor.  Upon  the  surface  of  agar  elevated, 
shining,  gray  colonies  develop  along  the  impfstrich,  or  a  gray,  shining  band 
is  formed  which  increases  in  thickness  but  not  in  breadth — usually  less  than 
one-half  centimetre  broad.  Old  cultures  give  off  an  acid  odor.  Upon  blood 
serum  a  thin,  white  layer  is  developed  along  the  line  of  inoculation.  Upon 
potato  a  thin,  white,  varnish-like  layer  is  formed. 

Pathogenesis. — Very  pathogenic  for  rabbits,  guinea-pigs,  white  mice,  and 
sparrows.  Not  pathogenic  for  chickens,  pigeons,  or  geese. 

05.    BACILLUS   OF   SWINE   PLAGUE,    MARSEILLES. 

Synonyms. — Bacillus  der  Schweineseuche,  Marseilles  (Rietsch 
and  Jobert)  ;  Bacillus  der  Frettchenseuche — ferret  disease  (Eberth 
and  Schimmelbusch)  ;  Bacillus  der  Amerikanischen  Binderseuche 
(Caneva)  ;  Bacillus  of  spontaneous  rabbit  septicaemia  (Eberth). 

The  recent  researches  of  Caneva  and  of  Bunzl-Federn  agree  as 
to  the  identity  of  the  bacillus  obtained  by  Rietsch  and  Jobert  (1887) 
from  swine  attacked  with  a  fatal  epidemic  disease  in  Marseilles,  and 
the  bacillus  found  by  Eberth  and  Schimmelbusch  (1889)  in  the  blood 
of  ferrets  suffering  from  a  fatal  form  of  septicaemia  studied  by  them. 
The  first-named  bacteriologist  also  identifies  a  bacillus  supposed 
by  Billings  to  be  the  cause  of  "Texas  fever"  in  cattle  ("  Ameri- 
kanische  Rinderseuche  ")  and  the  bacillus  of  swine  plague  (Billings) 
with  the  above.  Bunzl-Federn  obtained  cultures  of  Billings'  swine- 
plague  bacillus  at  two  different  times.  He  identifies  the  one  first  re- 
ceived with  the  bacillus  now  under  consideration,  and  the  other  with 
the  bacillus  of  hog  cholera  (Salmon).1 

1  The  author  named  says  :  '•  With  reference  to  the  bacillus  of  swine  plague 
(Billings),  I  obtained,  as  did  Caneva,  a  decided  production  of  acid  in  the  cultures 

34 


418  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

Morphology. — Bacilli  with  rounded  ends,  about  twice  as  long  as 
broad,  and  one-third  smaller  than  the  bacillus  of  typhoid  fever 
(Eberth  and  Schimmelbusch).  The  bacillus  of  hog  cholera  is  shorter 
and  more  slender  than  the  Marseilles  bacillus,  and  the  bacillus  of 
Loffler  and  Schiitz  (No.  61)  is  still  smaller  (Rietsch  and  Jobert). 

In  stained  preparations  the  extremities  of  the  rods  are  usually 
deeply  stained,  while  the  central  portion  remains  unstained — "polar 
staining. "  By  Loffler's  method  of  staining  the  presence  of  flagella 
may  be  demonstrated  (Frosch). 

Stains  readily  with  the  aniline  dyes  usually  employed,  but  does 
not  retain  its  color  when  treated  by  Gram's  method. 

Biological  Characters. — An  aerobic  (facultative  anaerobic), 
non-liquefying,  actively  motile  bacillus.  Grows  readily  at  the 
room  temperature,  and  is  distinguished  from  the  bacillus  of  septi- 
caemia hsemorrhagica  by  its  active  movements  and  more  rapid  and 
abundant  development  in  the  various  culture  media  usually  em- 
ployed. It  is  distinguished  from  the  bacillus  of  hog  cholera  (No.  63) 
by  producing  phenol  and  indol  in  solutions  containing  peptone,  by 
causing  coagulation  of  milk,  and  by  producing  an  acid  reaction  in 
this  fluid.  Grows  in  culture  media  having  an  acid  reaction. 

Rietsch  and  Jobert  give  the  following  account  of  the  characters 
of  growth  in  various  culture  media,  as  compared  with  the  bacillus  of 
hog  cholera  and  the  bacillus  of  Schweineseuche  (Loffler,  Schiitz), 
No.  61  : 

Gelatin  streak  cultures.  At  the  end  of  twenty-four  hours  this 
bacillus  had  developed  considerably,  while  the  growth  of  the  hog- 
cholera  bacillus  was  scarcely  to  be  discerned  with  the  naked  eye,  and 
the  bacillus  of  Schweineseuche  did  not  form  a  visible  growth  until 
the  end  of  forty-eight  hours.  After  several  days  the  bacillus  of 
swine  plague  (Marseilles)  formed  an  opaque,  yellowish-white  streak, 
which,  when  examined  with  a  low-power  lens,  had  a  brown  color  by 
transmitted  light  and  a  bluish-white  color  by  reflected  light.  The 
streak  of  the  Loffler-Schiitz  bacillus  was  not  so  thick  and  not  so 
opaque,  and  was  made  up  of  small,  nearly  transparent  colonies  ;  the 
hog-cholera  bacillus  came  between  the  other  two.  Upon  blood 
serum,  agar,  and  glycerin-agar  the  Marseilles  bacillus  grew  more 
rapidly  than  the  other  two,  forming  a  layer  which  was  opaque  and 
of  a  white  color,  with  bluish  and  reddish  reflections.  \Jponpotato 
it  formed  a  thick,  opaque,  yellowish  layer,  while  the  growth  of  the 
hog-cholera  bacillus  was  much  thinner  and  that  of  the  Loffler-Schiitz 
bacillus  scarcely  to  be  seen.  In  bouillon  the  Loffler-Schiitz  bacillus, 

first  sent  by  Billings  ;  but  upon  testing  later  cultures  received  directly  from  Bil- 
lings and  from  other  sources,  the  result  was  exactly  the  opposite — viz.,  a  decided 
production  of  alkali  in  milk  and  identity  with  the  hog-cholera  bacillus  of  Salmon." 


IX   SUSCEPTIBLE   ANIMALS.  419 

at  the  end  of  three  days  at  37°  C.,  had  not  produced  any  perceptible 
cloudiness,  while  the  Marseilles  bacillus  at  the  end  of  twenty-four 
hours  had  caused  the  fluid  to  be  clouded,  a  film  of  bacteria  had 
formed  upon  the  surface  and  a  deposit  at  the  bottom  of  the  tube  ;  the 
hog-cholera  bacillus  produced  a  less  degree  of  opacity  in  the  bouillon. 

Pathogenesis. — This  bacillus  is  pathogenic  for  sparrows  and 
other  small  birds  when  injected  beneath  the  skin  in  small  amounts, 
and  also  for  pigeons  in  a  longer  time — five  to  fourteen  days.  Frosch 
reports  a  negative  result  from  subcutaneous  injections  into  rabbits, 
guinea-pigs,  mice,  and  pigeons,  but  his  cultures  appear  to  have  be- 
come attenuated,  as  the  recent  cultures  of  Eberth  and  Schimmelbusch 
were  fatal  to  pigeons  in  four  out  of  five  experiments.  Two  rabbits 
were  inoculated  subcutaneously  by  Rietsch  and  Jobert  with  half  a 
Pravaz  syringef ul  of  a  pure  culture  of  the  Marseilles  bacillus  ;  one  of 
these  died  on  the  sixth  day  and  the  other  survived. 

In  sparrows,  which  succumb  in  from  twenty-four  to  thirty-six 
hours  after  receiving  a  small  amount  of  a  pure  culture  in  the  breast 
muscle,  the  bacillus  is  present  in  the  blood  in  large  numbers,  and  a 
purulent  pleuritis  and  pericarditis  is  found  at  the  autopsy.  In  the 
ferrets  from  which  Eberth  and  Schimmelbusch  obtained  their  cultures 
the  bacillus  was  not  present  in  the  blood  in  sufficient  numbers  to  be 
readily  demonstrated  by  microscopical  examination,  but  it  was  ob- 
tained in  pure  cultures  from  the  liver,  spleen,  and  lungs.  The  prin- 
cipal pathological  appearances  noted  were  enlargement  of  the  spleen 
and  pneumonia.  Caneva  reports  that  the  Marseilles  bacillus  injected 
into  white  mice  gives  rise  to  an  extensive  abscess  at  the  point  of  in- 
oculation, but  does  not  kill  adult  animals.  In  a  young  mouse  which 
succumbed  to  such  an  injection  the  bacilli  were  not  generally  dis- 
tributed in  the  tissues,  but  were  found  as  emboli  in  the  smaller  capil- 
laries. This  bacillus,  then,  is  distinguished  from  the  similar  bacilli 
previously  described  (Nos.  61  and  63)  by  its  comparatively  slight 
pathogenic  power,  as  well  as  by  its  more  vigorous  growth  in  culture 
media,  and  the  other  characters  heretofore  mentioned. 

66.    BACILLUS   SEPTICUS   AGRIGENUS. 

Obtained  by  Nicolaier  from  soil  which  bad  been  manured. 

Morphology. — Resembles  the  bacillus  of  fowl  cholera  and  of  rabbit  sep- 
ticaemia, of  which  it  is  perhaps  a  variety,  but  is  usually  somewhat  longer. 
It  also  sometimes  shows  the  end-staining  characteristic  of  Bacillus  septicae- 
miae  hsemorrhagicae,  but  not  so  constantly  and  not  so  sharply  denned. 

Biological  Characters. — An  aerobic,  (non-liquefying  f),  non- motile  ba- 
cillus. Does  not  form  spores. 

In  gelatin  plate  cultures  spherical,  finely  granular  colonies  are  developed 
having  a  yellowish-brown  central  portion,  which  is  separated  by  a  dark 
ring  from  a  grayish-brown  marginal  zone ;  later  this  difference  in  color  dis- 
appears and  the  colonies  become  more  decidedly  granular.  In  stick  cultures 
the  growth  consists  of  a  thin  layer  which  is  not  at  all  characteristic. 


420  BACILLI  WHICH   PRODUCE   SEPTICJ3MIA 

Pathogenesis. — Small  quantities  of  a  pure  culture  injected  into  the  ear 
vein  of  a  rabbit  cause  its  death  in  from  twenty-four  to  thirty-six  hours; 
pathogenic  also  for  house  mice  and  for  field  mice.  At  the  autopsy  no  notable 
pathological  changes  are  observed.  The  bacilli  are  found  in  blood  from  the 
heart  and  in  the  capillaries  of  the  various  organs,  but  are  not  so  numerous 
as  in  rabbit  septicaemia;  they  show  a  special  inclination  to  adhere  to  the 
margins  of  the  red  blood  corpuscles. 

67.    BACILLUS   ERYSIPELATOS   SUIS. 

Synonyms. — Bacillus  of  hog  erysipelas;  Bacillus  des  Schweine- 
rothlauf  (Loffler,  Schutz)  ;  Bacille  du  rouget  du  pore  (Pasteur)  ;  Ba- 
cillus of  mouse  septicaemia;  Bacillus  murisepticus  (Fliigge)  ;  Bacil- 
lus des  Mauseseptikamie  (Koch). 

The  bacillus  of  mouse  septicaemia,  first  described  by  Koch  (1878), 
resembles  so  closely  in  its  morphology,  characters  of  growth,  and 
pathogenic  power  the  bacillus  of   Schweinerothlauf  of  Loffler  and 
Schutz  (1885)  that  they  can  scarcely  be  considered  as  distinct  spe- 
cies, although,  from  slight  differences  which  have  been  observed,  they 
are  perhaps  entitled  to  separate  consideration  as  varieties  of   the 
same  species.    Fliigge,  Eisenberg,  Frankel,  and  other  authors,  while 
recognizing  the  fact  that  the  bacilli  from  the  two 
sources  closely  resemble  each  other,  apparently  do 
not  consider  them  identical   and  describe  them 
separately.      Baumgarten,  on  the  other  hand,  de- 
scribes them  under  one  heading  and  considers  it 
highly  probable  that  they  are  identical,  although 
he  also  admits  slight  differences  in  the  morpho- 
logical characters  and  growth  in  culture  media. 
These  differences  are,  however,  no  greater  than 

FIG.  135.-Bacillus  of  ,  .  .,.    .          '  ,  .°..  . 

mouse  septicaemia  in    we  have  in  artificially  produced  varieties  or  other 
leucocytes  from  blood    well-known  microorganisms,  and  we  think  it  best 

of  mouse.  X  700.  (Koch.)  e   11          T»  j  •!_•          .LI  j 

to  follow  Baumgarten  in  describing  them  under  a 
single  heading. 

Koch  first  obtained  this  bacillus  by  injecting  putrefying  blood  or 
flesh  infusion,  during  the  first  days  of  putrefactive  change,  beneath 
the  skin  of  mice.  A  certain  proportion  of  the  animals  experimented 
upon  contracted  a  fatal  form  of  septicaemia,  and  the  bacillus  under 
consideration  was  found  in  their  blood.  The  bacillus  of  Schweine- 
rothlauf was  obtained  by  Loffler  and  by  Schutz  from  the  blood  and 
various  organs  of  swine  which  had  succumbed  to  the  infectious 
malady  known  in  Germany  as  rothlauf  and  in  France  as  rouget. 

Morphology. — Extremely  minute  bacilli,  about  1  p  in  length  and 
0.2  /^  in  diameter.  The  Schweinerothlauf  bacilli  are  described  as 
somewhat  thicker  and  longer  by  Fliigge,  by  Frankel,  and  by  Eisen- 
berg, but  Baumgarten  states  that  they  are  somewhat  more  slender  and 


SUSCEPTIBLE  ANIMALS. 


421 


on  the  average  shorter  than  the  bacillus  of  mouse  septicaemia.     The 

bacilli  are  solitary,  or  in  pairs  the  elements  of  which  are  often  united 

at  an  angle  ;  occasionally  a  chain 

of  three  or  four  elements  may  be 

observed,  and  in  old  cultures  the 

bacilli  may  grow  out  into  short 

threads  which  are  straight  or  more 

or  less  curved  and  twisted.     Small 

refractive  bodies  may  sometimes 

be  distinguished  in  the  rods,  and 

these  have  been  supposed  by  some 

authors  to  be  spores,  but  this  has 

not  been  demonstrated. 

This  bacillus  stains  readily 
with  the  ordinary  aniline  staining 
agents  and  also  by  Gram's  method. 

Bioloqical         Characters. — A         FlQ-  Ise.-Bacillus  of  rouget,  from  a  pure 
,.    ,  f  7  .  7 .  culture.    X  1,000.    From  a  photomicrograph. 

facultative  anaerobic,  non-hque-    (Roux.) 
fying     bacillus.       According    to 

Schottelius,  the  rothlauf  bacilli  are  sometimes  mo- 
^utf^^M         tile,  but  Fliigge  states  that  other  observers  have 

oo 

not  seen  them  in  active  motion.  Frankel  says 
they  have  the  power  of  voluntary  motion.  Eisen- 
berg  says  that  the  bacillus  of  mouse  septicaemia  is 
motionless,  and  Frankel  says  "  they  seem  to  be  in- 
capable of  voluntary  motion/'  Baumgarten  re- 
marks :  "Whether  the  bacilli  exhibit  voluntary 
movements  has  not  been  determined/'  Although 
this  bacillus  is  not  strictly  anaerobic,  it  grows 
better  in  the  absence  of  oxygen  than  in  its  pre- 
sence. Development  occurs  in  various  culture  me- 
dia at  the  room  temperature,  but  is  more  rapid  in 
the  culture  oven.  In  gelatin  stick  cultures  no 
development  occurs  upon  the  surface,  but  the 
growth  along  the  line  of  puncture  is  very  charac- 
teristic; this  consists  of  a  delicate,  cloud-like,  ra- 
diating growth,  which  extends,  in  the  course  of  a 
few  days,  almost  to  the  walls  of  the  test  tube. 
The  rothlauf  bacillus  does  not  extend  so  rapidly 
through  the  gelatin,  and  the  branching,  cloud-like 
growth  is  not  as  delicate;  Fliigge  compares  it  to 
the  brush  of  bristles  used  for  cleansing  test  tubes. 
In  old  cultures  in  nutrient  gelatin  a  slight  soften- 
ing of  the  gelatin  occurs  along  the  line  of  growth,  and  as  a  result  of 


FIG.  137.— Bacillus  of 
mouse  septicaemia ; 
culture  in  nutrient  gela- 
tin, end  of  four  days  at 
18°  C.  (Baumgarten.) 


422  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

evaporation  and  desiccation  a  funnel-shaped  cavity  is  formed  in  the 
culture  medium  in  the  course  of  two  or  three  weeks.  In  gelatin 
plates  colonies  are  developed  in  the  course  of  two  or  three  days  in  the 
deeper  layers  of  the  gelatin,  but  not  upon  the  surface  ;  these  are  ne- 
bulous, grayish-blue,  radiating  masses,  which  are  so  delicate  as  to  be 
scarcely  visible  without  the  aid  of  a  lens  or  a  dark  background. 
Under  a  low  power  they  appear  as  branching,  feathery  masses,  which 
have  been  compared  by  Fliigge  to  the  radiating  growth  of  "  bone 
corpuscles."  In  older  cultures  they  coalesce  and 
cause  a  nebulous  opacity  of  the  whole  plate,  which  has 
a  bluish-gray  lustre. 

Upon  the  surface  of  nutrient  agar  or  blood  serum 
a  very  scanty  development  occurs  along  the  line  of 
inoculation.      No  growth  occurs  upon  potato.      In 
bouillon  the  bacilli  cause  a  slight  cloudiness  at  the 
mia;  single  colony    outset,  and  later  a  scanty,  grayish- white  deposit  upon 

x  80Utr(Fmg|otm'  tnebottom  of  the  test  tube  ;  no  film  is  formed  upon 
the  surface. 

The  thermal  death-point  of  this  bacillus,  as  determined  by  the 
writer  (1887),  is  58°  C.,  the  time  of  exposure  being  ten  minutes.  In 
the  experiments  of  Bolton  it  was  destroyed  in  two  hours  by  mercuric 
chloride  solution  in  the  proportion  of  1  : 10,000  ;  by  carbolic  acid  and 
by  sulphate  of  copper  in  one-per-cent  solution.  These  results  are 
opposed  to  the  view  that  the  minute  refractive  granules  which  may 
sometimes  be  seen  in  the  interior  of  the  rods  are  reproductive  spores, 
for  all  known  spores  have  a  much  greater  resisting  power  to  heat 
and  the  chemical  agents  named. 

PatTiogenesis. — Pathogenic  for  swine,  rabbits,  white  mice,  house 
mice,  pigeons,  and  sparrows.  Field  mice,  guinea-pigs,  and  chickens 
are  immune. 

Swine  may  be  infected  by  the  ingestion  of  food  containing  the 
rothlauf  bacillus,  as  has  been  demonstrated  by  allowing  them  to  eat 
the  intestine  of  an  animal  which  had  recently  succumbed  to  the  dis- 
ease, and  also  by  the  subcutaneous  injection  of  pure  cultures.  The 
disease  usually  terminates  fatally  within  three  or  four  days,  and 
sometimes  in  less  than  twenty -four  hours.  It  is  characterized  by 
fever,  debility,  loss  of  appetite,  and  by  the  appearance  upon  the  sur- 
face of  the  body  of  red  patches,  which  gradually  extend  and  become 
confluent,  producing  after  a  time  a  uniform  dark-red  or  brown  color 
of  the  entire  surface.  The  discharges  from  the  bowels  frequently 
contain  bloody  mucus.  At  the  autopsy,  in  acute  cases,  the  spleen  is 
notably  enlarged,  and  the  liver  and  kidneys  are  likely  to  be  more  or 
less  swollen,  as  are  also  the  lymphatic  glands,  especially  those  of 
the  mesentery;  the  gastric  and  intestinal  mucous  membranes  are 


IN   SUSCEPTIBLE   ANIMALS.  423 

usually  inflamed  and  spotted  with  haemorrhagic  extravasations  ;  the 
serous  membranes  also  may  be  inflamed,  and  the  cavities  of  the 
pleurae,  pericardium,  and  peritoneum  usually  contain  more  or  less 
fluid.  The  bacilli  are  found  in  the  blood  vessels  throughout  the 
body,  and  are  especially  numerous  in  the  interior  of  the  leucocytes. 
Cornevin  and  Kitt  have  shown  that  the  contents  of  the  intestine 
also  contain  the  bacilli  in  large  numbers,  and  the  disease  appears  to 
be  propagated  among  swine  principally  by  the  contamination  of  their 
food  with  the  alvine  discharges  of  diseased  animals. 

Pigeons  are  very  susceptible  to  the  pathogenic  action  of  this  ba- 
cillus, and  usually  die  within  three  or  four  days  after  inoculation 
with  a  pure  culture.  Rabbits  are  not  so  susceptible,  although  a 
certain  proportion  die  from  general  infection  after  being  inoculated 
in  the  ear.  The  first  effect  of  such  an  inoculation  is  to  produce  an 
erysipelatous  inflammation.  When  the  animal  recovers  it  is  subse- 
quently immune. 

White  mice  and  house  mice  are  extremely  susceptible,  but  field 


FIG.  139.— Section  of  diaphragm  of  a  mouse  dead  from  mouse  septicaemia,  showing  bacilli  in 
a  capillary  blood  vessel.    (Baumgarten.) 

mice  are  immune.  This  remarkable  fact  was  first  ascertained  by 
Koch  by  experiments  with  his  bacillus  of  mouse  septicaemia.  House 
mice  which  have  been  inoculated  with  a  minute  quantity  of  a  pure 
culture  of  the  rothlauf ,  or  mouse  septicaemia,  bacillus,  die  in  from 
forty  to  sixty  hours.  The  animal  is  usually  found  dead  in  a  sitting 
position,  with  its  back  strongly  curved,  and  for  many  hours  before 
death  it  remains  quietly  sitting  in  the  same  position  ;  the  eyes  are 
glued  together  by  a  sticky  secretion  from  the  conjunctival  mucous 
membrane.  At  the  autopsy  the  spleen  is  found  to  be  very  much  en- 
larged, and  there  may  be  a  slight  amount  of  oedema  at  the  point  of 
inoculation. 


4:24  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

The  bacilli  are  found  in  the  blood  vessels  generally,  and  are  very 
numerous  in  the  interior  of  the  leucocytes,  which  are  sometimes  com- 
pletely filled  with  them. 

Pasteur's  first  studies  relating  to  the  etiology  of  "  rouget "  were 
made,  in  collaboration  with  Chamberlain,  Roux,  and  Thuillier,  in 
1882.  His  description  of  the  microorganism  to  which  he  attributed 
the  disease  does  not  correspond  with  that  subsequently  isolated  by 
Loffler  and  by  Schiitz  ;  but  the  last-named  bacteriologists,  and  Schot- 
telius  also,  found  the  characteristic  rothlauf  bacillus  in  cultures  from 
his  laboratory  which  had  been  prepared  for  the  protective  inoculation 
of  swine — "  vaccins."  Pasteur  found,  by  experimental  inoculations 
of  his  bacillus  of  rouget  into  pigeons,  that  the  virulence  of  his  cul- 
tures was  increased  by  successive  inoculations  through  a  series  of 
these  birds,  as  shown  by  the  occurrence  of  death  at  an  earlier  date, 
and  also  by  the  fact  that'  blood  taken  from  the  last  pigeon  in  a  series 
was  more  virulent  for  swine  than  that  from  the  first  or  from  an  in- 
fected pig.  On  the  other  hand,  the  virulence  was  diminished  by  in- 
oculations into  rabbits  ;  and,  by  passing  the  bacillus  through  a  series 
of  these  animals,  a  vaccine  was  obtained  which  produced  a  com- 
paratively mild  and  non-fatal  attack  in  swine.  In  practice  the  use 
of  two  different  vaccines  is  recommended,  a  mild — "attenuated" 
— virus  being  first  inoculated,  and,  after  an  interval  of  twelve  days, 
a  second  vaccine  having  greater  pathogenic  potency.  These  inocula- 
tions have  been  extensively  practised  in  France,  and  that  immunity 
from  the  disease  may  be  secured  in  this  way  is  well  established,  hav- 
ing been  confirmed  in  Germany  by  Schiitz,  by  Lydtin,  and  by  Schot- 
telius.  There  is,  however,  some  doubt  as  to  the  practical  value  of 
the  method,  inasmuch  as  a  certain  number  of  the  inoculated  animals 
die,  and  there  appears  to  be  danger  that  the  disease  may  be  spread 
by  the  alvine  discharges  of  inoculated  animals.  In  a  region  where 
the  annual  losses  from  the  disease  are  considerable,  and  where  the 
soil  is,  perhaps,  thoroughly  infected  with  rothlauf  bacilli,  protective 
inoculations  probably  afford  the  best  security  against  loss.  But 
under  other  circumstances  the  quarantine  of  infected  animals  and 
thorough  disinfection  of  the  localities  in  which  cases  have  occurred 
will  probably  prove  a  better  mode  of  procedure. 

68.    BACILLUS  COPROGENES   PARVUS. 

Synonym. — Mauseseptikamieahnlicher  Bacillus  (Eisenberg). 

Obtained  by  Bienstock  from  human  faeces. 

Morphology. — A  very  minute  bacillus,  which  is  but  little  longer  than  it 
is  broad,  and  might  easily  be  mistaken  for  a  micrococcus. 

Biological  Characters. — Grows  very  slowly  on  nutrient  gelatin,  forming 
a  scarcely  visible  film  along  the  line  of  inoculation,  which  at  the  end  of 
several  weeks  is  scarcely  one  millimetre  wide.  Is  not  motile. 

Pathogenesis. — In  white  mice  an  extensive  oedema  is  developed  at  the 


IN  SUSCEPTIBLE  ANIMALS.  425 

point  of  inoculation  at  the  end  of  ten  or  twelve  hours,  and  the  animal  dies 
within  thirty-six  hours.  The  bacilli  are  found  in  great  numbers  in  the 
effused  serum  at  the  point  of  inoculation  and  in  comparatively  small  num- 
bers in  the  blood.  A  rabbit  inoculated  with  a  pure  culture  obtained  from  a 
mouse  died  at  the  end  of  eight  days.  The  inoculation,  which  was  made  in 
the  ear,  gave  rise  to  a  local  erysipelatous  inflammation. 

69.   BACILLUS  CAVICIDA. 

Synonym. — Brieger's  bacillus.  Probably  identical  with  Bacterium  coli 
commune  of  Escherich. 

Obtained  by  Brieger  (1884)  from  human  faeces. 

Morphology. — Small  bacilli,  about  twice  as  long  as  broad,  which  closely 
resemble  the  colon  bacillus  of  Escherich  (Bacterium  coli  commune). 

Biological  Characters. — An  aerobic  (facultative  anaerobic),  non-liquefy- 
ing bacillus. 

The  growth  in  gelatin  plate  cultures  is  said  to  be  very  characteristic,  the 
colonies  being  "  in  the  form  of  very  beautifully  grouped,  whitish,  concentric 
rings,  which  are  arranged  like  the  ccales  upon  the  back  of  a  turtle."  (Eisen- 
berg).  The  writer  has  studied  cultures  of  this  bacillus  brought  from  the 
bacteriological  laboratories  of  Germany,  side  by  side  with  cultures  of  the 
Bacterium  coli  commune  of  Escherich,  and  has  found  no  appreciable  differ- 
ences in  the  colonies  in  gelatin  plates,  or  in  the  growth  in  various  culture 
media.  Upon  potato  it  grows  rapidly  in  the  incubating  oven,  forming  a 
dirty-yellow,  moist  layer. 

Pathogenesis. — -This  bacillus,  as  first  obtained  by  Brieger,  was  character- 
ized by  being  very  pathogenic  for  guinea-pigs,  which  were  invariably  killed, 
within  seventy-two  hours,  by  the  subcutaneous  injection  of  a  minute  quan- 
tity of  a  pure  culture.  The  bacillus  was  found  in  great  numbers  in  the 
blood  of  animals  which  succumbed  to  an  experimental  inoculation.  The 
writer's  experiments  with  this  bacillus,  made  in  1889,  indicate  that  its  patho- 
genic power  had  become  attenuated,  inasmuch  as  considerable  quantities  of 
a  pure  culture  injected  into  guinea-pigs  did  not  cause  the  death  of  the  ani- 
mals— culture  used  came  originally  from  Germany.  Not  pathogenic  for 
rabbits  or  for  mice. 

70.   BACILLUS  CAVICIDA  HAVANIENSIS. 

This  bacillus  was  obtained  by  the  writer  from  the  contents  of  the  intestine 
of  a  yel  low-fever  cadaver,  in  Havana,  1889,  through  inoculated  guinea-pigs. 

Morphology. — A  bacillus  with  rounded  ends, 
from  tiro  to  three  ft  long  and  about  0.7  ju  broad, 
frequently  united  in  pairs. 

Stains  readily  with  the  ordinary  aniline  colors. 

Biological  Characters.— An  aerobic  and  fac- 
ultative anaerobic,  non  -liquefying,  actively  mo- 
tile bacillus. 

In  gelatin  stick  cultures  the  growth  upon  the 
surface : 3  very  scanty  and  thin,  not  extending  far 
from  tb  3  point  of  puncture  ;  along  the  line  of 
puncture  are  developed  small,  translucent,  pearl- 
like,  sph  irical  colonies,  which  later  become  opaque 
and  sometimes  granular.     In  gelatin  roll  tubes, 
at    the  end  of    twenty- four    hours    at    22°    C.,         FIG.  140.— Bacillus  cavicida 
the  deep  colonies  are  very  small  spheres,  of  a  pale      Havaniensis;  from   a  potato 
straw  col  )r ;  later  they  become  opaque,  light  brown      culture,    x  1,000.  From  a  pho- 
spheres,  or  may  have  a  dark  central  mass  sur-      tomicrograph.   (Sternberg.) 
rounded  by  a  transparent  zone.     The  superficial 

colonies  it  the  end  of  five  days  are  small,  translucent  masses  of  a  pale  straw 
color  tow  ards  the  centre,  with  thin  and  irregular  margins,  sometimes  with 
35 


426 


BACILLI  WHICH  PRODUCE   SEPTICAEMIA 


a  central  light-brown  nucleus ;  at  the  end  of  ten  days  the  deep  colonies  are 
still  quite  small,  of  a  brown  color,  and  opaque. 

In  glycerin-agar  roll  tubes,  at  the  end  of  twenty-four  hours,  the  deep  colo- 
nies are  in  the  form  of  a  biconvex  lens,  and  "appear  spherical  when  viewed 
in  face  and  biconvex  when  seen  from  the  side;  they  have  a  straw  color 
by  transmitted  light  and  are  bluish- white  by  reflected  light ;  the  superficial 
colonies  are  translucent,  with  a  bluish- white  lustre. 

On  potato,  at  22°  C.,  at  the  end  of  forty  eight  hours  there  is  a  thin,  dirty- 
yellow  growth  of  limited  extent;  at  the  end  of  ten  days  there  is  a  thin, 
gamboge-yellow  layer  and  little  masses  of  the  same  color;  the  growth  is 
quite  thin,  with  irregular  outlines,  and  is  confined  to  the  vicinity  of  the 
impfstrich. 

Grows  in  nutrient  agar  containing  0.2  per  cent  of  hydrochloric  acid. 
Thermal  death-point  55°  C.  Grows  in  agua  coco  without  forming  gas,  arid 
causes  this  liquid  and  bouillon  to  become  slightly  translucent — not  milky. 

Pathogenesis. — Pathogenic  for  guinea-pigs,  less  so  for  rabbits.  Guinea- 
pigs  inoculated  subcutaneously  with  a  few  drops  of  a  pure  culture  die  in  ten 
or  twelve  hours  from  general  infection.  There  is  usually  a  considerable 
effusion  of  bloody  serum  in  the  vicinity  of  the  point  of  inoculation,  and  the 
spleen  is  more  or  less  enlarged. 

71.   BACILLUS  CRASSUS  SPUTIGENUS. 

Obtained  by  Kreibohm  (1886)  from  the  sputum  of  two  individuals,  and 
once  in  scrapings  from  the  tongue. 

Morphology.— -Short,  thick  bacilli,  of  oblong  form,  with  rounded  corners, 
often  bent  or  twisted — "sausage-shaped."  Immediately  after  division  the 
bacilli  are  about  one-half  longer  than  they  are  broad,  but  before  dividing 


sC%z^*2»£ilJ?i5;r  <*•'•  »-H 

o.'-v:--;  •>'•••  r)  ->vC:;vV;^  /r  -  •'•;{«Ci 

S^p^S-P^ 

%^v,.;:^,;;;:^-v^.-: 

"'?l^iift 


?*•. 

%V<' 


FIG.  141.— Bacillus  crassus  sputigenus,  from  blood  of  mouse.    X  700.    (Flug^e.) 

again  they  may  attain  a  length  of  three  to  four  times  the  breadth.  Irregular 
forms  with  swollen  ends  or  uneven  contour  are  frequently  seen. 

This  bacillus  is  quickly  stained  by  the  ordinary  aniline  colors  and  also 
by  Gram's  method. 

Biological  Characters. — An  aerobic,  non-liquefying  (non-motile  ?)  ba- 
cillus. Grows  in  various  culture  media  at  the  room  temperature— more 
rapidly  in  the  incubating  oven.  "Appears  to  form  spores  at  35°  C." 
(Fliigge). 

In  gelatin  plates,  at  the  end  of  thirty-six  hours,  grayish- white  colonies  are 
developed,  which  soon  reach  the  surface  of  the  gelatin  and  spread  out  as 


IN   SUSCEPTIBLE  ANIMALS.  427 

round,  viscid,  grayish  white  drops,  which  project  considerably  above  the 
surface  of  the  culture  medium.  Under  a  low  magnifying  power  recent  colo- 
nies appear  as  spherical,  grayish -brown  discs,  the  surface  of  which  is  marked 
with  dark  points  or  lines.  The  superficial  colonies  are  more  transparent, 
have  irregular  outlines,  and  the  surface,  especially  near  the  margins,  is 
coarsely  granular.  The  development  in  stick  cultures  is  very  rapid  and  re- 
sembles that  of  Friedlander's  bacillus — "  nail-shaped  "  growth.  Upon  potato 
the  growth  is  also  similar  to  that  of  Friedlander's  bacillus,  and  consists  of  a 
thick,  grayish-white,  moist,  and  shining  layer. 

Pathogenesis. — Mice  inoculated  with  a  small  quantity  of  a  pure  culture 
die  from  acute  septicaemia  in  about  forty-eight  hours.  The  bacilli  are  found 
in  blood  from  the  heart  and  from  the  various  organs — most  numerous  in 
the  liver.  Rabbits  are  killed  within  forty  eight  hours  by  intravenous  injec- 
tion of  a  small  quantity,  and  the  blood  contains  the  bacillus  in  great  num- 
bers. Larger  amounts  injected  into  the  circulation  of  rabbits  or  dogs  cause 
death  in  a  few  hours  (three  to  ten),  preceded  by  diarrhoea,  and  in  some  in- 
stances bloody  discharges  from  the  bowels.  At  the  autopsy  an  acute  gastro- 
enteritis is  found. 

72.    BACILLUS  PYOGENES  FCETIDUS. 

Obtained  by  Passet  (1885)  from  an  abscess  of  the  anus. 

Morphology.— Short  bacilli  with  rounded  ends,  1.45  /*  long  and  0.58  u 
broad ;  usually  associated  in  pairs  or  in  short  chains. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Grows  rapidly  in  the  usual  culture  media  at  the  room  temperature.  In  the 
interior  of  the  rods,  in  stained  preparations,  one  or  two  unstained,  spherical 
places  may  sometimes  be  seen,  which  have  been  supposed  to  be  spores  (?). 
The  independent  motion  exhibited  by  this  bacillus  is  not  very  active.  In 
gelatin  plates  white  colonies  are  developed  at  the  end  of  twenty-four  hours, 
which  upon  the  surface  spread  out  as  grayish-white  plaques,  having  a  dia- 
meter sometimes  of  one  centimetre ;  these  are  thickest  in  the  centre  and  of 
a  whitish  color ;  the  colonies  may  become  confluent.  In  gelatin  stick  cul- 
tures the  growth  upon  the  surface,  at  the  end  of  twenty-four  hours,  consists 
of  a  thin,  grayish-  white  layer  with  rather  thick,  irregular  margins ;  along  the 
line  of  puncture  more  or  less  crowded  colonies.  Upon  potato  the  bacillus 
forms  an  abundant,  shining,  pale-brown  layer.  The  cultures  give  off  a  dis- 
agreeable putrefactive  odor. 

According  to  Eisenberg,  mice  and  guinea-pigs  are  killed  in  twenty-four 
hours  by  injections  beneath  the  skin  or  into  the  cavity  of  the  abdomen,  anu 
numerous  bacilli  are  found  in  the  blood. 

73.  PROTEUS  HOMINIS  CAPSULATUS. 

Obtained  by  Bordoni-Uffreduzzi  (1887)  from  two  cadavers  presenting  the 
pathological  appearances  of  the  so-called  "  Hadernkrankheit. 

Morphology. — Bacilli,  varying  considerably  in  dimensions;  somewhat 
thicker  than  the  anthrax  bacillus ;  often  swollen  in  the  middle  or  at  the  ex- 
tremities ;  more  or  less  curved ;  isolated,  united  in  pairs  or  in  long  filaments ; 
in  stained  preparations  from  agar  cultures  or  from  blood  the  bacilli  are  sur- 
rounded by  a  "  capsule. " 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  (facultative  anaerobic  ?),  non-lique- 
fying, non-motile  bacillus.  Formation  of  spores  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  At  a  temperature  of  15°  to 
17°  C.  long  filaments  are  formed,  in  which  the  bacilli  are  surrounded  with  a 
capsule ;  at  22°  to  24°  C.  the  bacilli  are  for  the  most  part  isolated,  but  few  fila- 
ments being  formed  ;  at  32°  to  37°  C.  the  bacilli  are  so  short  as  to  resemble 
micrococci ;  development  ceases  at  a  temperature  of  8°  and  is  very  slow  at 
15°  C. 


428 


BACILLI  WHICH  PRODUCE  SEPTICAEMIA 


FIG.  142,— Proteus  hominis  capsulatus,  from 
liver  of  mouse.  X  1,000.  (Bordoni-Uffre 
duzzi.) 


This  bacillus  grows  as  well  in  an  acid  medium  as  in  one  which  is  slightly 
alkaline.  In  gelatin  plates,  at  the  end  of  eighteen  to  twenty-four  hours, 
colonies  are  formed  which  under  a  low  power  are  seen  to  be  spherical  and 
to  contain  a  quantity  of  shining  granules;  the  following  day,  at  a  tempera- 
ture of  15°  to  17°  C.,  the  colonies  may  be  as  large  as  a  pin's  head  and  still 

remain  spherical  or  slightly  oval,  but 

,-  -"-" -^~^~  -.-^  the  outline  is  no  longer  so  uniform, 

and  between  the  shining  points  in  the 
interior  a  confused  network  may  be 
seen ;  as  the  colony  becomes  larger  it 
is  raised  above  the  surface  of  the  gela- 
tin, becomes  opaque,  and  has  a  pearly 
lustre  like  that  of  Friedlander's  bacil- 
lus. In  gelatin  stick  cultures  the 
growth  resembles  that  of  Friedlan- 
der's bacillus — "  nail-shaped  growth." 
Upon  the  surface  of  nutrient  agar  a 
rapidly  extending,  semi-transparent 
layer  is  formed.  Upon  potato,  at  15° 
to  17°  C.,  at  the  end  of  twenty-four 
hours  transparent  drops  are  seen  in 
the  vicinity  of  the  point  of  inocula- 
tion, and  later  a  moist,  shining,  color- 
less layer,  of  tough  consistence,  is 
formed,  which  gradually  extends  over 
the  surface.  The  growth  upon  blood 
serum  resembles  that  upon  nutrient 
agar,  and  the  blood  serum  is  not  liquefied.  In  liquid  blood  serum  or  in 
bouillon  the  bacilli  are  isolated — not  in  filaments ;  they  cause  a  clouding  of 
the  liquid,  and  an  abundant  deposit  accumulates  at  the  bottom  of  the  tube, 
while  a  film  of  bacilli  forms  upon  the  surface.  The  cultures  never  give  off 
a  putrefactive  odor. 

Pathogenesis. — Pathogenic  for  dogs  and  for  mice,  less  so  for  rabbits  and 
for  guinea-pigs.  Agar  cultures  grown  in  the  incubating  oven  at  32°  to  37 
C.  are  more  pathogenic  than  cultures  in  gelatin  at  the  room  temperature. 
A  small  quantity  of  a  recent  culture  injected  subcutaneously  in  mice  causes 
their  death  in  from  one  to  four  days,  according  to  the  quantity  and  age  of 
the  culture;  the  recent  cultures  are  most  virulent.  When  the  animal  lives 
more  than  twenty -four  hours  it  has  a  mucous  diarrhoea.  At  the  autopsy  the 
spleen  is  found  to  be  much  enlarged  and  dark  in  color  ;  the  lymphatic 
glands  are  also  swollen  and  haemorrhagic,  the  liver  and  kidneys  hyperaemic ; 
m  the  vicinity  of  the  point  of  inoculation  is  a  subcutaneous  oedema  of  jelly- 
like  appearance  and  numerous  punctiform  haemorrhages  are  seen.  The  ba- 
cillus is  found  in  great  numbers  in  the  effused  serum  from  the  subcutaneous 
tissues,  in  the  blood,  the  contents  of  the  intestine,  and  in  the  parenchyma  of 
the  various  organs.  When  examined  at  once  the  bacilli  in  the  subcutaneous 
oedema  and  in  the  lymphatic  glands  are  usually  quite  short,  and  even  spherical, 
while  in  the  blood  they  are  somewhat  longer  and  may  appear  as  short  fila- 
ments with  swollen  ends,  surrounded  by  a  capsule.  When  the  examination 
is  made  some  time  after  the  death  of  the  animal  longer  filaments  are  quite 
numerous.  Rabbits  and  guinea-pigs  are  killed  by  the  intravenous  injection 
of  comparatively  small  amounts  of  a  recent  culture,  but  quite  large  doses 
are  required  to  produce  a  fatal  result  when  the  injection  is  made  beneath 
the  skin.  From  two  to  three  cubic  centimetres  of  a  recent  culture  injected 
into  the  circulation  of  a  dog  give  rise  to  symptoms  of  toxaemia,  and  the  ani- 
mal usually  dies  on  the  second  day.  At  the  autopsy  the  abdominal  organs 
are  found  to  be  hyperaemic,  the  mucous  membrane  of  the  intestine  swollen, 
red  in  color,  and  covered  with  bloody  mucus.  The  bacillus  is  found  in  the 
blood  and  in  the  various  organs.  When  smaller  doses  are  injected  into  a 
vein  (a  few  drops)  the  animal,  after  a  few  hours,  has  a  mucous  diarrhoea  and 


IN  SUSCEPTIBLE  ANIMALS.  429 

vomiting,  or  efforts  to  vomit.  Death  usually  occurs  at  the  end  of  two  or 
three  days.  At  the  autopsy  the  spleen  is  found  to  be  normal,  the  other  or- 
gans slightly  hyperaemic,  and  the  intestinal  mucous  membrane  in  a  state  of 
catarrhal  inflammation.  The  bacilli  are  found  in  the  blood  and  in  the  vari- 
ous organs  in  considerable  numbers. 

74.    PROTEUS   CAPSULATUS   SEPTICUS. 

Obtained  by  Banti  (1888)  from  a  case  of  "  acute  hasmorrhagic  infection." 
According  to  Banti,  this  is  possibly  identical  with  the  preceding  species — 

Proteus  hominis  capsulatus — but  in  some  respects  more  nearly  resembles 

Friedlander's  bacillus. 

75.    BACILLUS  ENTERITIDIS. 

Obtained  by  Gartner  (1888)  from  the  tissues  of  a  cow  which  was  killed  in 
consequence  of  an  attack  characterized  by  a  mucous  diarrhoea,  and  also  from 
the  spleen  of  a  man  who  died  twelve  hours  after  eating  the  flesh  of  this 
animal. 

Morphology. — Short  bacilli,  about  twice  as  long  as  broad,  frequently  united 
in  pairs;  chains  of  four  to  six  elements  are  sometimes  seen. 

Stains  with  the  usual  aniline  colors,  and  presents  the  peculiarity  of 
staining  deeply  at  one  end  while  the  remainder  of  the  rod  is  but  slightly 
stained.  When  two  bacilli  are  united  the  deeply  stained  ends  are  in  apposi- 
tion. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  determined.  Grows  in  the  usual  culture  media  at  the 
room  temperature.  Upon  gelatin  plates  pale-gray,  superficial  colonies  are 
formed  at  the  end  of  twenty-four  hours ;  under  a  low  power  these  are  seen 
to  be  coarsely  granular  and  transparent ;  the  central  portion  usually  pre- 
sents a  greenish  color  ;  deep  colonies  are  spherical,  indistinctly  granular, 
and  of  a  brownish  color  ;  in  older  colonies  a  marginal  transparent  zone  is 
seen  which  appears  to  be  made  up  of  minute  fragments  of  glass  of  a  pale- 
brown  color.  In  gelatin  stick  cultures  but  slight  development  occurs  along 
the  line  of  puncture  ;  upon  the  surface  a  thick,  grayish-white  layer  is 
formed,  which  after  a  time  becomes  very  much  wrinkled.  Upon  the  surface 
of  agar,  at  37°  C.,  at  the  end  of  eighteen  to  twenty  hours  a  grayish-yellow 
layer  has  formed.  Upon  potato  a  moist,  shining,  yellowish-gray  layer  is 
developed.  The  growth  upon  blood  serum  is  rapid  in  the  form  of  a  gray 
layer  along  the  line  of  inoculation. 

Pathogenesis. — White  mice  and  house  mice  usually  die  in  from  one  to 
three  days  when  fed  with  a  pure  culture  of  this  bacillus.  Rabbits  and  gui- 
nea-pigs die  in  from  two  to  five  days  from  subcutaneous  injections—less 
pathogenic  for  pigeons  and  canary  birds.  Dogs,  cats,  chickens,  and  sparrows 
are  immune.  A  goat  died  in  twenty  hours  after  receiving  an  intravenous 
injection  of  two  cubic  centimetres  of  a  culture  in  blood  serum.  The  princi- 
pal pathological  appearance  consists  in  an  intense  inflammation  of  the  in- 
testinal mucous  membrane.  The  bacilli  are  found  in  blood  from  the  heart 
and  also  in  the  contents  of  the  stomach. 

76.   BACILLUS  OF  GROUSE  DISEASE. 

Obtained  by  Klein  (1889)  from  the  lungs  and  liver  of  grouse  which  had 
succumbed  to  an  epidemic  disease. 

Morphology. — Bacilli  with  rounded  ends,  from  0.8  to  1.6>ulong;  may 
also  be  seen  as  spherical  or  oval  cells  0. 6  /*  long  and  0.4  /*  thick ;  solitary,  in 
pairs,  or  in  chains  of  three  to  four  elements. 

Stains  best  with  Weigert's  solution  of  methylene  blue  in  aniline  water. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at  the 


430  BACILLI   WHICH   PRODUCE   SEPTICAEMIA 

room  temperature — better  in  the  incubating1  oven.  Upon  gelatin  plates,  at 
20°  C.,  at  the  end  of  twenty-four  hours  small,  angular,  transparent  scales 
may  be  seen  upon  the  surface  with  a  low-power  lens;  at  the  end  of  three  or 
four  days  these  form  flat,  more  or  less  irregular,  shining,  gray  colonies,  with 
thin  and  of  ten  dentate  margins ;  these  colonies  may  become  confluent  and 
form  a  dry,  scaly  layer  which  by  reflected  light  has  a  peculiar,  fatty  lustre 
In  gelatin  stick  cultures  the  superficial  growth  is  in  the  form  of  a  trans- 
parent, dry,  grayish  layer  with  dentate  margins,  not  more  than  three  to  five 
millimetres  in  diameter.  Upon  agar,  at  36°  to  37°  C.,  a  thin,  whitish-gray, 
dry  layer  is  formed. 

Pathogenesis. — Pathogenic  for  mice,  for  guinea-pigs,  for  linnets,  and  for 
green-finches;  less  so  for  sparrows.  Chickens,  pigeons,  and  rabbits,  accord- 
ing to- Klein,  are  immune.  Of  eight  mice  inoculated  subcutaneously  with 
one  or  two  drops  of  a  bouillon  culture,  six  died  within  forty-eight  hours 
and  two  recovered.  Out  of  eight  guinea-pigs  inoculated  in  the  same  way 
four  died  in  forty-eight  hours  and  two  recovered.  At  the  autopsy  the 
lungs  and'  liver  were  found  to  be  hyperaemic,  the  spleen  not  enlarged.  The 
bacilli  were  present  in  large  numbers  in  blood  from  the  heart  and  in  the 
lungs. 

77.   BACILLUS   GALLINARUM. 

Obtained  by  Klein  (1889)  from  the  blood  of  chickens  which  succumbed 
to  an  epidemic  disease  resembling  "fowl  cholera."  The  bacillus  is  believed 
by  Klein  not  to  be  identical  with  Pasteur's  bacillus  of  fowl  cholera,  and  is 
said  not  to  be  pathogenic  for  rabbits,  which  would  seem  to  differentiate  it 
from  this  bacillus  (Bacillus  septicaemias  haemorrhagicae). 

Morphology. — Bacilli  with  rounded  ends,  from  0.8  to  2  ft  long  and 
0.3  to  0.4  U  thick ;  often  in  pairs. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Does  not  form  spores.  G-rows  in  the  usual  culture  media  at  the  room  tem- 
perature— better  in  the  incubating  oven.  Upon  gelatin  plates  forms  grayish- 
white,  superficial  colonies,  which  later  present  the  appearance  of  flat,  homo- 
geneous, whitish  discs  with  thin  edges  and  irregular  margins,  and  by 
transmitted  light  have  a  brownish  color.  The  deep  colonies  are  small  and 
spherical,  and  have  a  brownish  color  by  transmitted  light.  In  gelatin  stick 
cultures  a  thin,  gray  layer  with  irregular  margins  and  of  limited  extent 
forms  upon  the  surface,  and  a  scanty  growth  occurs  along  the  line  of  punc- 
ture in  the  form  of  a  grayish-white  line.  Upon  the  surface  of  agar,  at 
37°  C.,  a  thin,  gray  layer  with  irregular  margins  has  developed  at  the  end  of 
twenty-four  hours ;  later  this  extends  over  the  entire  surface  as  a  thin,  gray- 
ish-white layer.  No  growth  occurs  upon  potato  at  37°  C.  In  bouillon,  at  37° 
C.,  development  occurs,  with  clouding  of  the  bouillon,  within  twenty -four 
hours ;  later  a  deposit  consisting  of  bacilli  is  seen  at  the  bottom  of  the  tube, 
but  no  film  forms  upon  the  surface. 

Pathogenesis.  —Chickens  inoculated  subcutaneously  with  a  pure  culture 
die  in  from  twenty-four  hours  to  eight  or  nine  days.  Pigeons  and  rabbits 
are  immune. 

78.   BACILLUS   SMARAGDINUS  FCETIDUS. 

Obtained  by  Reimann  (1887)  from  the  nasal  secretions  in  a  case  of 
ozaena. 

Morphology. — Small,  slender,  slightly  curved  bacilli,  about  half  as  large 
as  the  tubercle  bacilli;  usually  arranged  in  parallel  groups. 

Biological  Characters. — Anaerobic  and  facultative  anaerobic,  liquefying 
bacillus.  Spore  formation  not  observed.  Grows  slowly  at  the  room  tem- 
perature in  the  usual  culture  media— more  rapidly  at  37°  C.  In  gelatin  stick 
cultures  development  occurs  along1  the  line  of  puncture,  and  at  the  end  of 
forty-eight  hours  a  slight  liquefaction,  in  form  of  a  funnel,  occurs  near  the 


IN   SUSCEPTIBLE   ANIMALS.  431 

surface ;  after  the  eighth  day  liquefaction  progresses  more  rapidly.  About 
the  sixth  day  a  bright-green  color  is  recognized  in  the  upper  part  of  the  tube 
by  reflected  light.  Upon  agar  plates,  at  37°  0. ,  at  the  end  of  forty-eight 
hours  minute  colonies  are  formed,  of  irregular  form,  which  have  a  white 
color  with  a  shade  of  green ;  in  older  colonies  the  central  portion  may  be 
finely  granular  and  brownish  yellow  in  color,  while  the  marginal  zone  is 
more  transparent ;  the  agar  has  by  reflected  light  a  deep  emerald  green  color. 
In  agar  stick  cultures,  at  the  end  of  twenty  hours,  an  abundant  development 
has  occurred  without  color ;  at  the  end  of  forty-eight  hours  the  culture  me- 
dium is  of  a  bright  green  color  throughout ;  later  the  color  changes  to  brown. 
A  dirty-yellow  layer  forms  upon  the  surface  of  the  agar.  Upon  potato,  at 
37°  C.,  a  dark-brown  layer  forms  in  the  vicinity  of  the  line  of  inoculation; 
later  this  is  chocolate  brown. 

The  cultures  in  gelatin  and  agar  give  off  a  peculiar,  penetrating  odor 
similar  to  that  of  jasmin. 

Pathogenesis. — Pathogenic  for  rabbits  when  injected  into  a  vein  or  sub- 
cutaneously.  Death  occurs  in  from  thirty- six  to  forty- eight  hours.  At  the 
autopsy  haemorrhagic  extravasations  are  found  beneath  the  pericardium  and 
the  pleuras ;  abscesses  in  the  lungs  and  liver.  The  bacilli  are  found  in  the 
blood  and  in  the  various  organs  in  large  numbers. 

79.   BACILLUS  PNEUMOSEPTICUS. 

Obtained  by  Babes  (1889)  from  the  blood  and  tissues  of  an  individual  who 
died  of  septic  pneumonia. 

Morphology. — Small,  straight  bacilli  about  0.2  n  thick. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters.—  An  aerobic  and  facultative  anaerobic,  non-lique- 
fying, non-motile  bacillus.  Spore  formation  not  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  superfi- 
cial colonies  are  formed  which  are  flat,  irregular  in  outline,  whitish,  shining, 
and  semi  transparent ;  under  a  low  power  finger- like  offshoots  are  seen  about 
the  periphery.  In  gelatin  stick  cultures  an  abundant  development  occurs 
along  the  line  of  puncture;  the  colonies  give  off  a  strong  sperm-like  odor. 
Upon  the  surface  of  agar  small,  whitish,  flat,  shining  colonies  with  ill  de- 
fined outlines  are  formed,  which  soon  become  confluent  and  cover  the  sur- 
face ;  an  abundant  white  deposit  is  seen  in  the  condensation  water.  Upoti 
potato  a  moist,  white  layer  is  formed.  Upon  blood  serum  circular,  whitish, 
transparent  colonies  are  formed  along  the  line  of  inoculation,  which  soon 
coalesce. 

Pathogenesis. — Very  pathogenic  for  rabbits,  guinea-pigs,  and  mice  when 
injected  subcutaneously  in  small  amount.  The  animals  die  in  from  two  to 
three  days  without  any  noticeable  local  inflammation  and  with  symptoms  of 
septicaemia.  The  lungs  and  spleen  are  found  to  be  hyperaamic.  The  bacilli 
are  found  in  the  blood  free,  or  sometimes  enclosed  in  the  leucocytes ;  they 
are  only  found  in  small  numbers  in  the  capillaries  of  the  internal  organs. 
Cultures  gradually  lose  their  virulence  when  propagated  ia  artificial  media. 

80.   BACILLUS  CAPSULATUS. 

Obtained  by  Pfeiffer  (1889)  from  the  blood  of  a  guinea-pig  which  died 
spontaneously. 

Morphology. — Thick  bacilli  with  rounded  ends,  usually  two  or  three 
times  as  long  as  broad;  often  united  in  chains  of  two  or  three  elements;  may 
grow  out  into  homogeneous  filaments.  Stained  preparations  show  the  ba- 
cilli to  be  enveloped  in  an  oval  capsule  which  may  be  considerably  broader 
than  the  bacilli  themselves — two  to  five  times  as  broad ;  where  several  ba- 
cilli are  united  they  are  surrounded  by  a  single  capsular  envelope. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method.  In  pre- 
parations which  are  deeply  stained  with  hot  fuchsin  or  gentian  violet  solu- 


432 


BACILLI  WHICH  PRODUCE   SEPTICAEMIA 


FXG  143.— Bacillus  capsulatus,  from  peritoneal 
exudate  of  an  inoculated  guinea-pig.  X  1,000. 
From  a  photomicrograph.  (Ffeiffer.) 


tion  the  capsule  is  so  deeply  stained  that  the  bacillus  is  hidden;  by  careful 
treatment  with  a  weak  solution  of  acetic  acid  the  capsule  may  be  differen- 
tiated as  a  pale- red  or  violet  envelope  surrounding  the  deeply  stained  bacilli. 

Biological  Characters. — An  aer- 
obic and  facultative  anaerobic, 
non  liquefying,  non-motile  bacillus. 
Spore  formation  not  observed. 
Grows  in  the  usual  culture  media 
at  the  room  temperature.  The  cul- 
tures in  agar or  upon  potato  are  very 
viscid  and  draw  out  into  long 
threads  when  touched  with  the  pla- 
tinum needle ;  the  blood  of  an  ani- 
mal killed  by  inoculation  with  this 
bacillus  has  the  same  viscid  charac- 
ter. Upon  gelatin  plates  minute 
colonies  are  first  visible  at  the  end 
of  twenty  four  to  thirty-six  hours; 
later  the  deep  colonies  are  white, 
oval  masses  the  size  of  a  pin's  head ; 
the  superficial  colonies  attain  the 
size  of  a  lentil,  and  are  flattened, 
hemispherical  masses  with  a  porcQ- 
lain-white  color.  In  gelatin  stick 
cultures  growth  occurs  to  the  bot- 
tom of  the  line  of  puncture,  and  on 
the  surface  a  shining  white,  circular, 
arched  mass  forms  around  the  point  of  puncture,  resembling  the  growth  of 
Friedlander's  bacillus.  Upon  the  surface  of  agar,  at  37°  C  ,  at  the  end  of 
twenty-four  hours  a  thick,  soft  layer  of  a  pure  white  color  is  formed,  which 
is  very  viscid  and  resembles  the  growth  of  Micrococcus  tetragenus  upon  the 
same  medium.  Upon  potato  an  abundant  and  viscid,  shining,  yellowish- 
white  layer  is  quickly  developed. 

Pathogenesis. — Pathogenic  for  white  mice  and  for  house  mice,  which  die 
at  the  end  of  two  or  three  days  after  being  inoculated  at  the  root  of  the  tail 
with  a  small  quantity  of  a  pure  culture.  Inoculation  from  mouse  to  mouse 
increases  the  virulence  of  the  cultures.  At  the  autopsy  the  superficial  veins 
are  distended  with  blood,  the  inguinal  glands  enlarged,  the  spleen  consid- 
erably enlarged,  the  liver  and  kidneys  hyperaemic,  the  intestine  pale,  the 
heart  distended  with  blood,  which  usually  is  very  viscid  and  is  drawn  out 
into  threads  when  touched  with  the  platinum  needle.  The  bacilli  are  found 
in  the  blood  and  in  all  of  the  organs,  in  the  contents  of  the  peritoneum  and 
pleurae,  and  in  the  exudate  in  the  vicinity  of  the  point  of  inoculation. 
Pathogenic  also  for  guinea  pigs  and  for  pigeons;  guinea-pigs  are  infallibly 
killed  within  thirty-six  hours  by  the  injection  of  a  single  drop  of  a  bouillon 
culture,  twenty-four  hours  old,  into  the  cavity  of  the  abdomen ;  the  blood 
contains  the  bacillus  in  enormous  numbers,  as  does  the  viscid  fluid  found  in 
the  peritoneal  cavity.  Rabbits  do  not  succumb  to  intraperitoneal  or  subcu- 
taneous inoculations,  but  are  killed  by  the  intravenous  injection  of  one 
cubic  centimetre  of  a  recent  bouillon  culture.  Putrefactive  changes  occur 
very  quickly  in  animals  killed  by  inoculation  with  this  bacillus. 

81.   BACILLUS  HYDROPHILUS  FUSCUS. 

Obtained  by  Sanarelli  (1891)  from  the  lymph  of  frogs  suffering  from  a 
fatal  infectious  disease. 

Morphology. — Bacilli  with  rounded  ends,  usually  from  1  to  3  ju  in  length ; 
often  short  oval;  may  grow  out  into  filaments  of  12  to  20  //  in  length. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  In  gelatin  stick  cul- 


IN   SUSCEPTIBLE   ANIMALS. 


433 


tures,  at  18°  to  203  C.,  liquefaction  has  already  commenced  along  the  line  of 
puncture  at  the  end  of  twelve  hours,  and  at  the  end  of  thirty-six  to  forty- 
eight  hours  half  of  the  gelatin  is  liquefied  in  funnel  shape ;  on  the  third  or 
fourth  day  the  gelatin  is  completely  lique- 
fied, and  a  thick,  white,  flocculent  deposit 
is  seen  at  bottom  of  the  tube.  In  glycerin- 
agar,  at  37°  C.,  a  slight,  bluish,  diffuse 
fluorescence  is  seen  upon  the  surface  at  the 
end  of  twelve  hours,  and  soon  after  a  luxu- 
riant growth,  which  soon  covers  the  entire 
surface,  is  developed ;  at  the  end  of  twenty- 
four  to  thirty-six  hours  large  gas  bubbles 
begin  to  form  in  the  agar;  gradually  the 
fluorescence  disappears,  the  surface  growth 
becomes  thicker  and  has  a  dirty -gray  color 
which  changes  later  to  brownish.  Blood 
serum  is  a  favorable  medium  and  is  rapidly 
liquefied  by  this  bacillus.  Upon  potato  the 
growth  is  most  characteristic.  At  the  end 

of  twelve  hours  a  thin  straw-yellow  layer        FlG  144._Baciiius  hydrophiius  fus- 
is    developed    along   the   impfstrich;    this     cus,  in  blood  of  triton.   (Sanareiiu 
gradually  becomes  yellow,  and  at  the  end 

of  four  to  five  days  has  a  brown  color,  resembling  that  of  the  glanders  bacil- 
lus upon  potato. 

Pathogenesis. — Pathogenic  for  frogs,  toads,  lizards,   and  oth      "cold- 
^^  blooded"   animals;  also  for  guinea-pigs,    rabbits,   dogs, 

cats,  mice,  chickens,  and  pigeons.  When  a  few  drops  of 
a  bouillon  culture  are  injected  into  the  muscles  of  the 
thigh,  swelling  and  redness  at  the  point  of  inoculation 
are  quickly  developed,  and  death  usually  occurs  in  eight 
to  ten  hours.  The  bacilli  are  found  in  great  numbers  in 
the  blood  and  in  all  of  the  organs.  Guinea  pigs  die  from 
general  infection  within  twelve  hours  after  receiving  a 
subcutaneous  injection  of  a  small  amount  of  a  pure  cul- 
ture ;  the  spleen  is  enlarged  and  the  liver  and  spleen  hy- 
persemic ;  an  extensive  inflammatory  oedema  in  the  vicin- 
ity of  the  inoculation  wound  is  frequently  observed;  the 
bacilli  are  very  numerous  in  the  blood  and  in  all  the  or- 
gans. Rabbits  die  in  five  to  six  hours  from  an  intravenous 
injection.  Adult  dogs  are  immune,  but  new-born  dogs 
(three  to  four  days  old)  die  infallibly,  after  receiving  a 
subcutaneous  injection  of  a  small  quantity  of  a  pure  cul- 
ture, in  twelve  to  thirty -six  hours.  Young  cats  also  suc- 
cumb to  similar  inoculations.  Chickens  and  pigeons  die 
within  five  to  seven  hours  after  receiving  an  intravenous 
injection,  but  resist  subcutaneous  injections. 


82.    BACILLUS  TENUIS   SPUTIGENUS. 

Obtained  by  Pansini  (1890)  from  sputum. 
Morphology.     Short   bacilli,  usually  in  pairs  and  sur- 
FIG.  i45.-Baciiius      rounded  by  a  capsule, 
hydrophiius  fuscus;  Stains  by  Gram's  method. 

culture  in  nutrient  Biological  Characters. — An  aerobic,  non-liquefying, 

gelatin,  end  of  six-  non- motile  bacillus.  Grows  in  nutrient  gelatin  at  the 
teen  hours.  (Sana-  room  temperature.  Develops  abundantly  on  potato. 
reiii.)  Coagulates  milk  and  produces  an  acid  reaction  in  this 

medium. 

Pathogenesis.  —Pathogenic  for  rabbits  and  white  rats;  not  for  guinea- 
pigs  or  for  Avhite  mice  (in  small  doses). 
36 


434  BACILLI   WHICH    PRODUCE   SEPTICAEMIA 

83.    BACILLUS   OF   LASER. 

Obtained  by  Laser  (1892)  from  mice  which  succumbed  to  an  epidemic  dis- 
ease in  Frankel's  laboratory  at  Konigsberg. 

In  its  characters  this  bacillus  closely  resembles  the  bacillus  of  swine 
plague  (No.  65),  and  is  perhaps  identical  with  it. 

Morphology. — A  small  bacillus,  with  rounded  ends,  about  twice  as  long 
as  broad.  Has  flagella  both  at  the  extremities  and  sides. 

Stains  by  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Spore  formation  not  observed.  Grows 
either  in  the  incubating  oven  or  at  the  room  temperature.  Thermal  death - 
point  65°  to  70°  C. — ten  minutes'  exposure.  Upon  gelatin  plates,  at  the  end 
oftwo  days,  the  deep  colonies  are  spherical,  finely  granular,  and  brownish 
in  color;  the  superficial  are  transparent,  fiuely  granular,  and  leaf -like. 
In  gelatin  stick  cultures  growth  occurs  along  the  entire  line  of  puncture  as 
well  as  upon  the  surface.  At  the  end  of  three  days  a  considerable  evolution 
of  gas  is  usually  observed.  In  agar  an  abundant  development  is  seen  at  the 
end  of  twenty- four  hours  in  the  incubating  oven;  upon  the  surface  a  gray- 
ish-white, shining  layer  with  dentate  margins  is  formed  along  the  track  of 
the  needle.  In  bouillon,  at  37D  C.,  development  is  abundant  and  rapid;  a 
thin  film  is  formed  on  the  surface  at  the  end  of  the  second  day.  Upon  potato 
a  brownish  layer  is  formed  at  the  end  of  twenty-four  hours.  In  milk  an 
acid  reaction  is  produced. 

Pathogenesis. — Pathogenic  for  field  mice,  guinea-pigs,  rabbits,  and 
pigeons.  The  bacillus  is  found  in  the  blood  and  various  organs  of  infected 
mice.  The  spleen  is  found  to  be  greatly  enlarged. 

84.    BACILLUS   TYPHI   MURIUM    (Loffler). 

Obtained  by  Loffler  (1889)  from  mice  which  died  in  his  laboratory  from 
an  epidemic  disease  due  to  this  bacillus. 

Morphology. — Short  bacilli,  resembling  the  bacillus  of  diphtheria  in 
pigeons,  and  varying  considerably  in  dimensions— like  the  bacillus  of 
typhoid  fever;  grows  out  into  flexible  filaments. 

Stains  with  the  aniline  colors — best  with  Loffler's  solution  of  methylene 
blue. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  determined.  Has  flagella 
around  the  periphery  of  the  cells,  like  those  of  the  typhoid  bacillus,  and  ex- 
hibits similar  active  movements.  In  gelatin  stick  cultures,  at  the  room 
temperature,  growth  occurs  upon  the  surface,  at  the  end  of  forty-eight  hours, 
in  the  form  of  a  flat,  grayish- white,  round,  semi-transparent  mass  the  size  of 
a  pin's  head ;  later  the  surface  colony  increases  in  extent  and  has  more  or 
less  irregular  margins.  In  gelatin  plate  cultures  the  deep  colonies  are  at 
first  round,  slightly  granular,  transparent,  and  grayish;  later  they  are  of  a 
yellowish-brown  color  arid  decidedly  granular.  The  superficial  colonies  are 
very  granular  and  marked  by  delicate  lines — similar  to  colonies  of  the 
typhoid  bacillus.  Upon  agar  a  grayish- white  layer  is  developed  which  is 
not  at  all  characteristic.  Upon  potato  a  rather  thin,  whitish  layer  is  formed, 
and  around  this  the  potato  acquires  a  dirty  bluish-gray  color.  In  milk  an 
abundant  development  occurs,  and  a  decidedly  acid  reaction  is  produced 
withoiit  causing  any  perceptible  change  in  the  appearance  of  the  fluid. 

Pathogenesis. — Pathogenic  for  white  mice,  which  die  in  from  one  to  two 
weeks  after  infection  ;  also  to  field  mice,  which  succumb  to  subcutaneous  in- 
jections of  a  pure  culture,  and  also,  in  from  eight  to  twelve  days,  when  fed 
upon  potato  cultures  or  bread  moistened  with  a  small  quantity  of  a  bouillon 
culture.  Loffler  believes  that  this  bacillus  may  be  used  for  the  destruction 
of  field  mice  in  grain  fields,  inasmuch  as  they  invariably  die  after  ingesting 
food  which  has  been  contaminated  with  it,  and  also  from  eating  the  bodies 


IN   SUSCEPTIBLE   ANIMALS.  435 

of  other  mice  which  have  died  as  a  result  of  infection.  House  mice  are  also 
susceptible.  Rabbits,  guineapigs,  pigeons,  and  chickens  were  found  by 
Loffler  not  to  be  susceptible  to  infection  by  feeding. 

85.  BACILLUS  OP  CAZAL  AND  VAILLARD. 

Obtained  by  Cazal  and  Vaillard  (1891)  from  cheesy  nodules  upon  the 
peritoneum  and  in  the  pancreas  of  an  individual  who  died  in  the  hospital 
at  Val  de  Grace. 

Morphology. — Bacilli  with  rounded  ends,  but  little  longer  than  they  are 
broad ;  solitary,  in  pairs,  or  in  chains  of  ten  to  fifteen  or  more  elements. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method ;  the 
extremities  of  the  rods  are  more  deeply  stained  than  the  central  portion — 
"  polar  staining." 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Does  not  form  spores.  Grows  in  the  usual  culture  media 
at  the  room  temperature — more  rapidly  in  the  incubating  oyen  at  37°  C.  In 
gelatin  stick  cultures,  at  the  end  of  twenty-four  hours,  a  series  of  puncti- 
form,  white  colonies  is  developed  along  the  line  of  puncture ;  upon  the  sur- 
face development  is  more  abundant,  and  at  the  end  of  forty-eight  hours 
liquefaction  commences  ;  this  progresses  slowly  from  above  downward, 
and  a  white,  flocculent  deposit  accumulates  at  the  bottom  of  the  liquefied 

gelatin.  Upon  the  surface  of  agar,  at  the  end  of  twenty-four  hours  at  37° 
.,  a  moist,  transparent,  opalescent  layer  is  developed,  which  rapidly  ex- 
tends over  the  entire  surface  ;  later  this  layer  becomes  somewhat  thicker, 
whitish,  and  cream- like  in  consistence,  without  losing  its  transparency. 
Upon  potato  a  thick,  prominent,  moist,  and  slightly  viscid  layer  is  devel- 
oped, which  at  first  has  a  pale-yellow  and  later  a  yellowish-brown  color. 
In  bouillon  development  is  abundant,  producing  a  milky  opacity  of  the 
liquid;  a  thick,  flocculent  deposit  accumulates  at  the  bottom  of  the  tube  ; 
the  reaction  of  the  culture  liquid  becomes  very  alkaline.  All  of  the  cultures 
give  off  a  peculiar  odor,  slightly  ammoniacal  and  resembling  that  of  putrid 
urine.  The  cultures  retain  their  vitality  for  several  months — in  a  closed 
tube  for  more  than  a  year.  The  thermal  death-point  is  60°  C.  with  fifteen 
minutes'  exposure. 

Pathogenesis. — Pathogenic  for  rabbits  and  mice,  but  not  for  guinea-pigs. 
In  mice  death  occurs  from  general  infection,  at  the  end  of  forty -eight  to 
sixty  hours,  from  the  subcutaneous  injection  of  one  eighth  cubic  centimetre 
of  a  recent  bouillon  culture.  In  rabbits  injection  of  one  cubic  centimetre 
into  the  circulation  causes  the  death  of  the  animal  in  thirty-six  to  fifty 
hours.  The  symptoms  induced  are  a  foetid  diarrhoea  and  paralysis  of  the 
extremities.  When  smaller  doses  are  injected  (0.5  cubic  centimetre)  a 
chronic  malady  is  developed,  characterized  at  the  outset  by  diarrhoea  and 
emaciation,  then  by  the  development  of  tumors  which  resemble  those  found 
in  the  man  from  whom  the  cultures  were  first  obtained.  These  tumors  are 
for  the  most  part  located  in  the  subcutaneous  connective  tissue ;  after  a  time 
they  attain  the  size  of  a  chestnut  and  ulcerate,  allowing  the  escape  of  a 
semi-fluid,  purulent  material.  The  animals  usually  recover.  Similar  tumors 
are  developed  as  a  result  of  subcutaneous  injections  of  one  to  three  cubic 
centimetres  of  a  recent  bouillon  culture. 

86.  BACILLUS  OF  BABES  AND  OPRESCU. 

Obtained  by  Babes  and  Oprescu  (1891)  from  a  case  of  septicaemia  haemor- 
rhagica  presenting  some  resemblance  to  exanthematic  typhus. 

Morphology.  —  In  agar  cultures  the  bacilli  are  from  0. 4  to  0. 5  ju.  thick,  and 
are  frequently  united  in  pairs ;  associated  with  these  rod -shaped  bacteria  are 
forms  which  are  of  a  short  oval.  In  gelatin  cultures  oval  forms  are  more 
numerous  ;  they  have  a  diameter  of  0.3  to  0.4  ju,  and  often  appear  to  be 
surrounded  by  a  capsule.  In  fresh  cultures  the  bacilli  are  often  in  form  of 


43G  BACILLI  WHICH   PRODUCE   SEPTICAEMIA 

a  figure  8,  and  are  only  stained  at  the  point  of  contact  of  the  two  segments. 
In  potato  cultures  they  are  sometimes  elongated  and  swollen  at  one  ex- 
tremity. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non-lique- 
fying, actively  motile  bacillus.  Spore  formation  not  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature — more  rapidly  at  37°  C.  In 
gelatin  stick  cultures  yellowish- white  colonies  are  developed  along  the  line 
of  puncture ;  at  the  bottom  these  may  have  a  diameter  of  one  to  two  millime- 
tres, and  they  have  a  brown  color.  Upon  the  surface  an  irregular,  lobulated, 
whitish,  translucent,  paraffin  like  layer  is  developed.  At  the  end  of  eight 
days  the  surface  growth  consists  of  large,  confluent,  transparent  plaques, 
with  irregular  outlines  and  crenated,  elevated  margins  ;  along  the  line  of 
puncture  large,  separate,  lenticular  or  spherical  colonies  are  seen  ;  these 
have  a  brownish-white  color.  At  the  end  of  two  months  the  surface  growth 
is  concentric  and  still  more  transparent,  while  the  colonies  near  the  surface 
have  become  almost  brown.  Upon  the  surface  of  agar,  at  37°  C.,  a  narrow 
band  is  developed  along  the  line  of  inoculation ;  above,  this  is  composed  of 
transparent,  shining,  flat,  round  colonies  having  a  diameter  of  one  milli- 
metre or  more ;  below,  the  colonies  are  confluent  and  form  a  transparent, 
whitish  layer.  In  glycerin-agar  development  is  still  more  abundant,  and 
may  already  be  perceived  at  the  end  of  twelve  hours.  Crystals  are  seen 
below  the  surface  in  agar  cultures  and  about  the  superficial  colonies  in  gela- 
tin. Upon  potato  a  uniform,  thin,  grayish,  very  transparent  layer  is  de- 
veloped, which  sometimes  has  a  brownish-gray  tint.  At  the  end  of  a  few 
days  the  potato  acquires  a  brownish  color.  In  bouillon  cloudiness  of  the 
medium  is  apparent  at  the  end  of  ten  hours  ;  twenty-four  hours  later  a 
whitish  precipitate  is  seen  at  the  bottom  of  the  tube,  which  is  more  abun 
dant  when  the  culture  medium  contains  glucose;  later  a  thin  pellicle  is 
seen  upon  the  surface  and  the  bouillon  acquires  a  yellowish  color. 

Pathogenesis. — Recent  cultures  are  pathogenic  for  rabbits,  guinea-pigs, 
pigeons,  and  mice,  which  die  from  general  infection  in  from  two  to  four 
days.  Old  cultures  are  less  virulent. 

87.    BACILLUS   OF   LUCET. 

Obtained  by  Lucet  (1891)  from  chickens  and  turkeys  suffering  from  an 
infectious  form  of  septicaemia  characterized  by  dysenteric  discharges — ;i  Dy- 
senterie  epizootique  des  poules  et  des  dindes." 

Resembles  Bacillus  gallinarum  of  Klein,  and  is  perhaps  identical  with 
this  microorganism. 

Morphology. — Short  bacilli,  from  1.2  to  1.8  n  long,  usually  in  pairs. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  an  d  facultative  anaerobic,  non-lique- 
fying, non-motile  bacillus.  Spore  formation  not  observed.  Grows  slowly  in 
the  usual  culture  media  at  the  room  temperature — more  rapidly  at  37°  C. 

In  gelatin  plates  small,  shining,  moist,  white,  circular  colonies  are  devel- 
oped, which  look  like  little  drops  of  wax;  later  these  increase  in  size,  and 
especially  in  thickness,  forming  hemispherical  masses.  In  gelatin  stick  cul- 
tures grayish,  punctiform  colonies  are  developed  along  the  line  of  puncture, 
and  upon  the  surface  a  circular,  prominent,  whitish  plaque.  Streak  cultures 
upon  the  surface  of  gelatin  are  in  the  form  of  a  dirty- white  or  grayish- white, 
moist  streak,  with  regular  margins,  limited  to  the  line  of  inoculation,  but 
increasing  in  thickness  until  it  breaks  loose  and  slips  down  the  oblique  sur- 
face of  the  culture  medium.  The  deposit  which  collects  in  this  way  acquires, 
as  it  becomes  old,  in  the  deepest  portion  a  reddish  color.  Upon  agar  it  forms 
a  thick,  yellowish-white,  mucus-like  layer  with  straight  or  slightly  dentate 
margins.  In  bouillon  it  produces  a  decided  clouding  of  the  liquid,  and  an 
abundant  grayish,  pulverulent  sediment  accumulates  at  the  bottom  of  the 
tube;  the  bouillon  after  a  time  becomes  transparent  above  this  sediment  and 


RNBERG'S  BACTERIOLOGY. 


Plate  VII. 


V* 

Y> 


l  $VS^ 

W&K 


.2. 


Fig. I. 


Fig  3. 


BACILLUS  OF  GLANDERS  (LOEFFLER) 


IN   SUSCEPTIBLE  ANIMALS.  437 

is  viscid,  drawing  out  into  threads.  In  the  absence  of  oxygen  the  characters 
of  growth  are  the  same  as  in  its  presence.  The  cultures  acquire  an  alkaline 
reaction;  they  are  sterilized  by  exposure  for  ten  minutes  to  a  temperature  of 
60°  C.  Does  not  grow  upon  potato. 

Pathogenesis. — Pathogenic  for  chickens  and  turkeys.  Not  pathogenic  for 
pigeons,  guinea-pigs,  or  rabbits  when  injected  subcutaneously  or  into  the 
peritoneal  cavity,  but  kills  rabbits  when  injected  into  a  vein.  In  the  in- 
fected fowls  the  bacilli  are  found  in  small  numbers  in  the  blood,  more  nu- 
merous in  the  kidneys  and  liver,  still  more  numerous  in  the  spleen,  and  in 
enormous  numbers  in  the  intestinal  mucus,  where  in  acute  cases  it  is  found 
almost  in  a  pure  culture.  Fowls  do  not  contract  the  disease  as  a  result  of 
the  ingestion  of  grains  soiled  with  cultures  of  the  bacillus,  but  become  in- 
fected when  fed  with  animal  food  to  which  a  pure  culture  has  been  added. 

88.   CAPSULE  BACILLUS  OP  LOEB. 

Obtained  from  a  case  of  keratomalacia  infantum  by  inoculating  culture 
media  with  a  little  of  the  softened  exudate  in  the  cornea. 

Morphology. — Resembles  Bacillus  capsulatus  of  Pfeiffer,  but  this  is  said 
to  be  somewhat  larger  and  thicker.  In  the  blood  of  mice,  however,  both 
bacilli  vary  considerably  in  size,  and  according  to  Loeb  it  was  not  possible 
to  determine  with  certainty  that  one  bacillus  was,  on  the  average,  larger 
than  the  other. 

In  staining  reactions,  also,  no  difference  was  observed — both  bacilli  stain 
with  the  usual  aniline  colors,  and  under  certain  circumstances  the  centre  of 
the  rods  is  less  deeply  stained  than  the  extremities. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non-lique- 
fying, non-motile  bacillus.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  In  its  growth  in  culture  media  it  closely  resembles  Bacillus 
capsulatus  of  Pfeiffer  (No.  80). 

Pathogenesis. — Pathogenic  for  mice  and  for  guinea-pigs,  but  not  for  rab- 
bits and  pigeons ;  Pfeiff er's  bacillus  is  pathogenic  for  these  animals. 


PLATE  VII. 

BACILLUS  OF  GLANDERS. 

FlG.  1. — Bacillus  mallei  from  the  liver  of  a  field  mouse,  cover-glass  pre- 
paration. (Loftier.) 

FIG.  2. — Bacillus  mallei  from  a  recent  culture  upon  blood  serum-  (Lof- 
fler.) 

FIG.  3. — Bacillus  mallei  in  section  of  spleen  of  a  field  mouse  dead  from 
glanders.  (Loffler.) 

FlG.  4. — -Culture  of  glanders  bacillus  upon  cooked  potato.     (Loffler.) 
37 


XIII. 

PATHOGENIC   AEROBIC   BACILLI    NOT  DESCRIBED   IN 
PREVIOUS   SECTIONS. 

A  CONSIDERABLE  number  of  saprophytic  bacilli  are  pathogenic  for 
small  animals  when  injected  into  the  circulation,  or  subcutaneously, 
or  into  a  serous  cavity  in  considerable  quantity — one  to  five  cubic 
centimetres  or  more — but  fail  to  produce  any  appreciable  effect 
when  introduced  into  the  bodies  of  these  animals  in  minute  doses, 
and  do  not  multiply  in  the  blood  to  any  considerable  extent,  al- 
though in  fatal  cases  they  may  usually  be  recovered  in  cultures  from 
the  blood  and  tissues.  These  bacilli  are  pathogenic  by  reason  of  the 
toxic  ptomaines  produced  by  them,  or  because  of  local  inflammatory 
processes  which  they  induce,  or  for  both  of  these  reasons  combined. 
Some  of  them  may  also,  under  certain  circumstances,  multiply  in 
the  blood  and  thus  give  rise  to  septicaemia  as  well  as  to  toxaemia  ; 
this  is  the  case,  for  example,  with  the  "  colon  bacillus  "  of  Escher- 
ich.  When  injected  in  considerable  quantity  into  the  circulation 
of  a  guinea-pig  it  causes  the  death  of  the  animal  within  twenty-four 
hours,  and  the  bacillus  is  found  in  the  blood  in  great  numbers  ;  but 
minute  amounts  injected  into  a  vein,  or  larger  amounts  injected 
subcutaneously,  do  not  usually  produce  general  infection.  It  is, 
therefore,  not  included  among  the  "  bacilli  which  produce  septi- 
caemia in  susceptible  animals. "  There  is  reason  to  believe,  however, 
that  under  certain  circumstances  this  bacillus  may  have  sufficient 
pathogenic  potency  to  produce  a  genuine  septicaemia  in  guinea-pigs. 
Thus  the  original  cultures  of  Brieger's  bacillus,  which  appears  to  be 
a  variety  of  the  colon  bacillus,  are  reported  to  have  produced  fatal 
septicaemia  in  guinea-pigs  when  injected  subcutaneously  in  small 
amounts.  A  strict  division  into  pathogenic  bacilli  which  produce 
general  blood  infection — septicaemia — and  those  which  produce  a 
fatal  result  owing  to  the  production  of  toxic  chemical  substances  is 
not  possible;  for  many  pathogenic  bacteria  produce  general  infection 
when  injected  in  comparatively  large  doses,  and  at  the  same  time 
give  rise  to  symptoms  of  toxaemia  ;  or  general  infection  may  occur 
in  animals  of  one  species,  and  fatal  toxaemia  without  septicaemia  in 


PATHOGENC  AEROBIC  BACILLI   NOT  BEFORE   DESCRIBED.       439 

those  of  another  species.  Many  of  the  bacilli  described  in  the  pre- 
sent section  are  common  saprophytes,  which  have  been  shown  by 
laboratory  experiments  to  be  pathogenic  for  certain  animals  when 
introduced  into  their  bodies  in  a  certain  amount,  which  differs  greatly 
for  different  bacteria  and  for  different  species  of  animals.  The  ex- 
periments of  Cheyne  and  others  show  how  largely  the  pathogenic 
power  of  saprophytic  bacteria  depends  upon  the  quantity  of  a  cul- 
ture which  is  injected,  as  well  as  upon  the  age  of  the  culture  and 
the  seat  of  the  inoculation — in  the  blood,  the  abdominal  cavity,  the 
subcutaneous  tissues,  or  the  muscles.  And  the  bacteriologist  named 
has  also  shown  that  pathogenic  power  depends,  in  some  instances  at 
least,  upon  the  combined  action  of  the  toxic  substances  introduced 
in  the  first  instance  and  of  the  living  bacteria.  Thus  Cheyne  found 
that  one-tenth  of  a  cubic  centimetre  of  a  bouillon  culture  of  Proteus 
vulgaris  injected  into  the  dorsal  muscles  of  a  rabbit  infallibly  caused 
its  death  within  forty -eight  hours,  but  when  the  dose  was  reduced 
to  one-fortieth  cubic  centimetre  the  animal  recovered.  But  if  to 
this  amount  (one-fortieth  cubic  centimetre)  he  added  one  cubic  cen- 
timetre of  a  sterilized  (by  heat)  culture  of  the  same  bacillus  instead 
of  diluting  with  distilled  water,  and  injected  the  mixture  into  the 
dorsal  muscles  of  a  rabbit,  death  occurred  in  every  experiment 
within  fort}T-eight  hours.  The  sterilized  culture  injected  by  itself 
produced  no  effect  in  this  dose  (one  cubic  centimetre),  and  Cheyne 
believes  that  the  fatal  result  in  these  experiments  was  due  to  the 
fact  that  the  toxic  products  present  in  the  sterilized  culture  over- 
came the  natural  resisting  powers  of  the  tissues  and  enabled  the 
bacillus  to  multiply  over  a  larger  area  than  would  otherwise  have 
been  the  case.  As  a  result  of  this,  toxic  substances  were  produced  in 
the  body  of  the  animal  in  sufficient  quantity  to  cause  general  toxae- 
mia and  death  ;  whereas  the  bacilli  alone,  in  the  dose  mentioned, 
were  not  able  to  invade  the  tissues  in  the  vicinity  of  the  point  of 
inoculation,  and  gave  rise  to  a  local  abscess  only.  The  same  ex- 
planation is  probably  true  for  very  many  of  the  saprophytic  bacteria 
which  have  been  shown  to  possess  pathogenic  power  ;  and  it  is  prob- 
able that  many  of  those  which  are  now  classed  by  bacteriologists  as 
non-pathogenic  would  prove  to  be  pathogenic  in  the  same  way  if 
thoroughly  tested  upon  various  species  of  animals,  although  it  might 
be  necessary  to  use  unusually  large  doses  to  accomplish  the  same 
result. 

89.    BACILLUS   COLI   COMMUNIS. 

Synonyms. — Bacterium  coli  commune  (Escherich) ;  Colon  bacillus 
of  Escherich  ;  Emmerich's  bacillus  (Bacillus  Neapolitanus).  Prob- 
ably identical  with  Bacillus  cavicida  (Brieger's  bacillus). 


440  PATHOGENIC   AEROBIC   BACILLI 

Obtained  by  Emmerich  (1885)  from  the  blood,  various  organs,  and 
the  alvine  discharges  of  cholera  patients  at  Naples  ;  by  Weisser 
(1886)  from  normal  and  abnormal  human  faeces,  from  the  air,  and 
from  putrefying  infusions  ;  by  Escherich  (1886)  from  the  faeces  of 
healthy  children  ;  since  shown  to  be  constantly  present  in  the  alvine 
discharges  of  healthy  men,  and  probably  of  many  of  the  lower  ani- 
mals. Found  by  the  writer'in  the  blood  and  various  organs  of  yellow- 
fever  cadavers,  in  Havana  (1888  and  1889). 

Numerous  varieties  have  been  cultivated  by  different  bacteriolo- 
gists, which  vary  in  pathogenic  power  and  to  some  extent  in  their 
growth  in  various  culture  media  ;  but  the  differences  described  are 
not  sufficiently  characteristic  or  constant  to  justify  us  in  considering 
them  as  distinct  species. 

Morphology.  —  Differs  considerably  in  its  morphology  as  obtained 
from  different  sources  and  in  various  culture  media.     The  typical 
form  is  that  of  short  rods  with  rounded  ends,  from  two  to  three  /*  in 
length  and  0.4  to  0.6  /*  broad  ;  but  under  certain  cir- 
.        cumstances  the  length  does  not  exceed  the  breadth  — 
»  .     about  0.5  j.i  —  and  it  might  be  mistaken  for  a  micrococ- 
i'>        cus  ;  again  the  prevailing  form  in  a  culture  is  a  short 
^  oval  ;  filaments  of  five  jj.  or  more  in  length  are  often 

FIG.  146.  —  Ba-  observed  in  cultures,  associated  with  short  rods  or  oval 
C°x  i°ooo~  cells.     The  bacilli  are  frequently  united  in  pairs.     The 


(Escherich.)  presence  of  spores  has  not  been  demonstrated.  In  un- 
favorable culture  media  the  bacilli,  in  stained  prepara- 
tions, may  present  unstained  places,  which  are  supposed  by  Escherich 
to  be  due  to  degenerative  changes  in  the  protoplasm.  Under  certain 
circumstances  some  of  the  rods  in  a  pure  culture  have  been  observed 
by  Escherich  to  present  spherical,  unstained  portions  at  one  or  both 
extremities,  which  closely  resemble  spores,  but  which  he  was  not  able 
to  stain  by  the  methods  usually  employed  for  staining  spores,  and 
which  he  is  inclined  to  regard  as  "  involution  forms." 

This  bacillus  stains  readily  with  the  aniline  colors  usually  em- 
ployed by  bacteriologists,  but  quickly  parts  with  its  color  when 
treated  with  iodine  solution  —  Gram's  method  —  or  with  diluted  al- 
cohol. 

Biological  Characters.  —  An  aerobic  and  facultative  anaerobic, 
non-liquefying  bacillus.  Sometimes  exhibits  independent  move- 
ments, which  are  not  very  active.  One  rod  of  a  pair,  in  a  hanging- 
drop  culture,  may  advance  slowly  with  a  to-and-fro  movement, 
while  the  other  follows  as  if  attached  to  it  by  an  invisible  band 
(Escherich).  The  writer's  personal  observations  lead  him  to  believe 
that,  as  a  rule,  this  bacillus  does  not  exhibit  independent  movements. 
Does  not  form  spores.  Grows  in  various  culture  media  at  the  room 


NOT   DESCRIBED    IN   PREVIOUS   SECTIONS.  441 

temperature — more  rapidly  in  the  incubating  oven.     Grows  in  a  de- 
cidedly acid  medium. 

In  gelatin  plates  colonies  are  developed  in  from  twenty-four  to 
forty-eight  hours,  which  vary  considerably  in  their  appearance  ac- 
cording to  their  age,  and  in  different  cultures  in  the  same  medium. 
The  deep  colonies  are  usually  spherical  and  at  first  are  transparent, 
homogeneous,  and  of  a  pale-straw  or  amber .  color  by  transmitted 
light ;  later  they  frequently  have  a  dark-brown,  opaque  central  por- 
tion surrounded  by  a  more  transparent  peripheral  zone  ;  or  they  may 
be  coarsely  granular  and  opaque ;  sometimes  they  have  a  long-oval 
or  "  whetstone  "  form.  The  superficial  colonies  differ  still  more  in 
appearance  ;  very  young  colonies  by  transmitted  light  often  resemble 
little  drops  of  water  or  fragments  of  broken  glass  ;  when  they  have 
sufficient  space  for  their  development  they  quickly  increase  in  size, 
and  may  attain  a  diameter  of  three  to  four  centimetres  ;  the  central 
portion  is  thickest,  and  is  often  marked  by  a  spherical  nucleus  of  a 
dark-brown  color  when  the  colony  has  started  below  the  surface  of 
the  gelatin  ;  the  margins  are  thin  and  transparent,  the  thickness 
gradually  increasing  to  wards  the  centre,  as  does  also  the  color,  which 
by  transmitted  light  varies  from  light  straw  color  or  amber  to  a  dark 
brown.  The  outlines  of  superficial  colonies  are  more  or  less  irregular, 
and  the  surface  may  be  marked  by  ridges,  fissures,  or  concentric 
rings,  or  may  be  granular.  The  writer  has  observed  colonies  re- 
sembling a  rosette,  or  a  daisy  with  expanded  petals.  Escherich 
speaks  of  colonies  which  present  star-shaped  figures  surrounded  by 
concentric  rings. 

In  gelatin  stick  cultures  the  growth  upon  the  surface  is  rather 
dry,  and  may  be  quite  thin,  extending  over  the  entire  surface  of  the 
gelatin,  or  it  may  be  thicker  with  irregular,  leaf -like  outlines  and 
Nvith  superficial  incrustations  or  concentric  annular  markings.  An 
abundant  development  occurs  all  along  the  line  of  puncture,  which 
in  the  deeper  portion  of  the  gelatin  is  made  up  of  more  or  less  closely 
crowded  colonies  ;  these  are  white  by  reflected  light,  and  of  an  am- 
ber or  light-brown  color  by  transmitted  light  ;  later  they  may  become 
granular  and  opaque.  Frequently  a  diffused  cloudy  appearance  is 
observed  near  the  surface  of  the  gelatin,  and  under  certain  circum- 
stances branching,  moss-like  tufts  develop  at  intervals  along  the  line 
of  growth.  One  or  more  gas  bubbles  may  often  be  seen  in  recent 
stick  cultures  in  gelatin. 

Upon  nutrient  agar  and  blood  serum,  in  the  incubating  oven,  an 
abundant,  soft,  white  layer  is  quickly  developed.  Upon  potato  an 
abundant,  soft,  shining  layer  of  a  brownish-yellow  color  is  developed. 
The  growth  upon  potato  differs  considerably,  according  to  the  age  of 
the  potato.  According  to  Escherich,  upon  old  potatoes  there  may 


442 


PATHOGENIC   AEROBIC   BACILLI 


be  no  growth,  or  it  may  be  scanty  and  of  a  white  color.  In  milk,  at 
37°  C.,  an  acid  reaction  and  coagulation  of  the  casein  are  produced  at 
the  end  of  eight  or  ten  days.  In  the  absence  of  oxygen  this  bacillus 
is  able  to  grow  in  solutions  containing  grape  sugar  (Escherich).  In 
bouillon  it  grows  rapidly,  producing  a  milky  opacity  of  the  culture 
liquid.  The  thermal  death-point  of  Emmerich's  bacillus,  and  of  the 
colon  bacillus  from  faeces,  was  found  by  Weisser  to  be  60°  C. ,  the 
time  of  exposure  being  ten  minutes.  The  writer  has  obtained  corre- 
sponding results.  Weisser  found  that  when  the  bacilli  from  a  bouil- 
lon culture  were  dried  upon  thin  glass  covers  they  failed  to  grow 


FIQ.  147. 


FIG.  148. 


FIG.  147. — Bacillus  coli  communis  in  nutrient  gelatin  containing  twenty  per  cent  of  gelatin,  end 
of  two  weeks,  showing  moss-like  tufts  along  the  line  of  growth.  (Sternberg.) 

FIG.  148.— A  portion  of  the  growth  shown  in  Fig  147,  at  a,  magnified  about  six  diameters. 
From  a  photograph.  (Sternberg.) 

after  twenty-four  hours.     These  results  give  confirmation  to    the 
view  that  the  bacillus  under  consideration  does  not  form  spores. 

Pathogenesis. — Comparatively  small  amounts  of  a  pure  culture 
of  the  colon  bacillus  injected  into  the  circulation  of  a  guinea-pig 
usually  cause  the  death  of  the  animal  in  from  one  to  three  days,  and 
the  bacillus  is  found  in  considerable  numbers  in  its  blood.  But  when 
injected  subcutaneously  or  into  the  peritoneal  cavity  of  rabbits  or 
guinea-pigs,  a  fatal  termination  depends  largely  on  the  quantity  in- 
jected ;  and  although  the  bacillus  may  be  obtained  in  cultures  from 
the  blood  and  the  parenchyma  of  the  various  organs,  it  is  not  present 


NOT   DESCRIBED    IX   PREVIOUS   SECTIONS.  443 

in  large  numbers,  and  death  appears  to  be  due  to  toxaemia  rather  than 
to  septicaemia.  Mice  are  not  susceptible  to  infection  by  subcutaneous 
injections.  Small  quantities  injected  beneath  the  skin  of  guinea-pigs 
usually  produce  a  local  abscess  only  ;  larger  amounts — two  to  five 
cubic  centimetres — frequently  produce  a  fatal  result,  with  symptoms 
and  pathological  appearances  corresponding  with  those  resulting 
from  intravenous  injection.  These  are  fever,  developed  soon  after 
the  injection,  diarrhoea,  and  symptoms  of  collapse  appearing  shortly 
before  death.  At  the  autopsy  the  liver  and  spleen  appear  normal,  or 
nearly  so ;  the  kidneys  are  congested  and  may  present  scattered 
purictiform  ecchymoses  (Weisser).  According  to  Escherich,  the 
spleen  is  often  somewhat  enlarged.  The  small  intestine  is  hyper- 
aemic,  especially  in  its  upper  portion,  and  the  peritoneal  layer  pre- 
sents a  rosy  color ;  the  mucous  membrane  gives  evidence  of  more 
or  less  intense  catarrhal  inflammation,  and  contains  mucus,  often 
slightly  mixed  with  blood.  In  rabbits  death  occurs  at  a  somewhat 
later  date,  and  diarrhoea  is  a  common  symptom.  In  dogs  the  subcu- 
taneous injection  of  a  considerable  quantity  of  a  pure  culture  may 
give  rise  to  an  extensive  local  abscess. 

Varieties. — Booker,  in  his  extended  studies  relating  to  the  bac- 
teria present  in  the  faeces  of  infants  suffering  from  summer  diarrhoea, 
has  isolated  seven  varieties  "which  closely  resemble  Bacterium  coli 
commune  in  morphology  and  growth  in  agar,  neutral  gelatin,  and 
potato,  but  by  means  of  other  tests  a  distinction  can  be  made  between 
them."  These  are  described  as  follows  : 

BACILLUS   d  OF   BOOKER. 

' '  Found  in  two  cases  of  cholera  inf antum  and  the  predominating1  form  in 
one  serious  case  of  catarrhal  enteritis. 

"  Morphology. — Resembles  Bacterium  coli  commune. 

' '  Growth  in  Colonies. — Gelatin :  Colonies  grow  luxuriantly  in  gelatin, and 
thrive  in  acid  and  sugar  gelatin  equally  as  well  as  in  neutral  gelatin.  In 
the  latter  the  colonies  closely  resemble,  but  are  not  identical  with,  the  Bac- 
terium coli  commune.  In  acid  gelatin  they  differ  very  much  from  Bacterium 
coli  commune.  The  colonies  spread  extensively  and  are  bluish-white  with 
concentric  rings.  Slightly  magnified,  they  have  a  large,  uniform,  yellow 
central  zone  surrounded  by  a  border  composed  of  perpendicular  threads 
placed  thickly  together.  Sometimes  a  series  of  these  rings  appear  with  inter- 
vening yellow  rings. 

"Agar:  The  colonies  are  round,  spread  out,  and  blue  or  bluish- white. 
Slightly  magnified,  they  have  a  pale-yellow  color. 

'•  Stab  Cultures — Gelatin:  In  sugar  gelatin  the  surface  growth  has  a 
nearly  colorless  centre  surrounded  by  a  thick  border  with  an  outer  edge  of 
fine,  hair-like  fringe ;  the  growth  along  the  line  of  inoculation  is  fine  and  deli- 
cate. In  neutral  gelatin  the  growth  is  not  so  luxuriant  as  on  sugar  gelatin ; 
on  the  surface  it  is  thick  and  white,  with  a  delicate  stalk  in  the  depth. 

"  Agar :  Thick  white  surface  growth  with  a  well -developed  stalk  in  the 
depth. 

"Potato:  Luxuriant  yellow,  glistening,  moist,  and  slightly  raised  sur- 
face, with  well-defined  borders. 


444  PATHOGENIC   AEROBIC   BACILLI 

"  Action  on  Milk. — Coagulated  into  a  gelatinous  coagulum  in  twenty- four 
hours  at  38°  C.,  and  into  a  solid  clot  in  two  days. 

"  Milk  Litmus  Reaction. — Milk  colored  blue  with  litmus  is  changed  to 
light  pink  in  twenty-four  hours  at  38°  C.  The  pink  color  gradually  fades, 
and  by  the  second  or  third  day  is  white  or  cream  color  with  a  thin  layer*  of 
pink  on  top.  The  pink  color  extends  in  a  few  days  about  one-half  down  the 
clot. 

"  Temperature. — Grows  best  about  38°  C. 

' '  Spores  have  not  been  observed. 

"  Gas  Production. — Gas  bubbles  are  produced  in  milk ;  not  observed  on 
potato. " 

BACILLUS   6   OF   BOOKER. 

' '  Found  as  the  predominating  form  in  two  cases  of  dysentery  one  of 
which  was  fatal  and  the  other  a  mild  case. 

"  Morphology. — Resembles  Bacterium  coli  commune. 

"  Growth  in  Colonies. — Gelatin  :  The  colony  growth  varies  considerably 
with  slight  difference  in  the  gelatin.  In  ten-per-cent  neural  gelatin  the  colo- 
nies resemble  those  of  Bacterium  coli  commune.  On  the  second  or  third 
day,  when  the  colonies  have  just  broken  through  the  surface  and  are  spread 
out,  it  is  impossible  to  distinguish  one  variety  from  the  other,  but  as  the 
colonies  grow  older  a  difference  can  generally  be  recognized.  In  sugar  and 
acid  gelatin  the  colonies  have  a  clear  centre  with  white  border ;  slightly 
magnified,  a  uniform  brown  centre  surrounded  by  a  brown  zone  composed 
of  fine,  needle-like  rays  perpendicular  to  the  border.  After  cultivating  for  a 
few  generations  on  acid  and  sugar  gelatin  the  colonies  cease  to  develop,  and 
either  grow  in  very  small  colonies  or  do  not  grow  at  all.  The  activity  is  re- 
gained if  cultivated  on  neutral  gelatin. 

' '  Agar :  Colonies  are  large,  round,  and  have  a  mother-of-pearl  appearance. 
Slightly  magnified,  a  uniform  yellow  color. 

"  Stab  Cultures. — Agar:  Luxuriant,  nearly  colorless  surf  ace  growth,  with 
well-developed  stalk  along  the  line  of  inoculation  in  the  depth. 

'"Potato:  Golden- yellow,  glistening,  slightly  raised  surface  with  well-de- 
fined borders. 

' '  Action  on  Milk. — Milk  becomes  gelatinous  in  twenty-four  hours  at  38°  C. , 
and  in  a  few  days  a  solid  coagulum  is  formed.  Milk  colored  blue  with  lit- 
mus is  reduced  to  white  or  cream  color  in  twenty-four  to  forty -eight  hours 
at  38°  C.,  with  a  thin  layer  of  pink  at  the  top  of  the  culture.  The  pink  color 
gradually  extends  lower  in  the  coagulum. 

'  Temperature.—  Thrives  best  at  about  38°  C. 
'  Spores  have  not  been  observed. 

'  Gas  Production. — Occurs  in  milk,  but  not  seen  in  potato  cultures. 
'  Relation  to  Gelatin. — Does  not  liquefy  gelatin. 

'  Resemblance. — Resembles  Bacterium  coli  commune  and  bacillus  d ;  dif- 
fering from  the  former  in  the  character  of  the  colony  growth  on  acid  and 
sugar  gelatin,  and  in  ceasing  to  develop  in  these  media  after  several  genera- 
tions. It  differs  from  bacillus  d  in  this  latter  respect." 

BACILLUS  /  OF   BOOKER. 

"  Found  in  one  case  of  cholera  infantum  and  one  case  of  catarrhal  ente- 
ritis. 

"Morphology. — Resembles  Bacterium  coli  commune. 

"  Growth  in  Colonies.—  Gelatin:  It  is  difficult  to  distinguish  the  colony 
growth  from  the  Bacterium  coli  commune.  There  is  often  a  difference  in  the 
colonies  planted  at  the  same  time  and  kept  under  similar  conditions,  but  it 
is  not  very  marked  nor  always  the  same  kind  of  difference.  The  tendency 
to  concentric  rings  is  greater  in  this  variety.  The  colonies  develop  some- 
what better  on  neutral  and  sugar  gelatin  than  on  acid  gelatin. 


NOT   DESCRIBED   IX   PREVIOUS   SECTIONS.  445 

"Agar:  The  colonies  are  large,  round,  and  bluish- white.  Slightly  magni- 
fied, a  light-yellow  color. 

' '  Stab  Cultures. — Gelatin :  The  culture  is  spread  over  the  surface  and  has 
a  mist-like  appearance ;  in  the  depth  along  the  line  of  inoculation  is  a  deli- 
cate stalk. 

"Agar:  Thick,  luxuriant,  white  surface  growth,  with  a  well-developed 
stalk  along  the  line  of  inoculation  in  the  depth. 

"  Potato:  Bright-yellow,  glistening,  moist  surface  with  well-defined  bor- 
ders, and  but  slightly  raised  above  the  surrounding  potato. 

"  Action  on  Milk  and  Litmus  Reaction. — Milk  is  coagulated  into  a  solid 
clot  in  twenty-four  hours  at  38°  C.  Milk  colored  blue  with  litmus  is  changed 
to  pink  in  twenty-four  hours  at  38°  C.,  and  in  forty-eight  hours  is  reduced  to 
white  or  cream  color  with  a  thin  pink  layer  on  top. 

"  Gas  Production. — Gas  bubbles  arise  in  milk  cultures,  but  they  have  not 
l>een  observed  on  potato  cultures. 

'  Temperature. — Grows  better  at  38°  C. 
'  Spores  have  not  been  observed. 
'  Relation  to  Gelatin. — Does  not  liquefy  gelatin. 

'Resemblance. — It  closely  resembles  Bacterium  coli  commune  and  Brie- 
ger  s  bacillus  in  the  character  of  its  growth  upon  different  media,  but  is  readily 
distinguished  from  both,  as  is  also  Brieger's  bacillus  from  the  Bacterium  coli 
commune,  by  the  following  differential  test  recently  made  known  by  Dr. 
Mall.  Yellow  elastic  tissue  from  the  ligamentum  nuchae  of  an  ox  is  cut  into 
fine  bits  and  placed  in  test  tubes  containing  water  with  ten-per-cent  bouillon 
and  one-per-cent  sugar,  and  sterilized  from  one  and  one-half  to  two 
hours  at  a  time  for  three  consecutive  days.  Into  this  is  inoculated  two 
species  of  bacteria,  one  of  which  is  the  bacterium  under  observation, 
the  other  a  bacillus  found  in  garden  earth.  The  latter  bacillus  is  anaerobic, 
grows  in  hydrogen,  nitrogen,  and  ordinary  illuminating  gas,  in  the  bottom 
of  bouillon,  in  the  depth  but  not  on  the  surface  of  agar  stab  cultures,  and 
not  at  all  in  gelatin  stab  cultures.  It  has  a  spoi-e  in  one  end  making  a  knob 
bacillus.  Different  species  of  bacteria — Streptococcus  Indicus,  tetragenus, 
cholera,  swine  plague.  Bacterium  lactis  aerogenes,  Bacterium  coli  commune, 
Brieger's  bacillus,  and  a  number  of  varieties  of  bacteria  which  I  have  iso- 
lated from  the  faeces — were  inoculated  with  the  head  bacillus  into  the  above- 
described  elastic- tissue  tubes.  The  tubes  inoculated  with  Brieger's  bacillus 
developed  a  beautiful  purple  tint,  which  started  as  a  narrow  ring  at  the  top 
of  the  culture,  gradually  extending  downward  and  deepening  in  color  until 
the  whole  tube  had  a  dark-purple  color.  This  color  reaction  began  in  five  to 
fourteen  days,  and  was  constantly  present  in  a  large  number  of  tests.  Tubes 
inoculated  with  bacillus  /  gave  a  much  fainter  purple  color,  which  was 
longer  in  appearing  and  never  became  so  dark  as  with  Brieger's  bacillus. 

'  'Tubes  inoculated  with  the  other  species  of  bacteria  above  mentioned  gave 
no  color  change  and  remained  similar  to  control.  Bacillus  /also  shows  a 
slight  difference  from  Bacterium  coli  commune  in  coagulating  milk  and  re- 
ducing litmus  more  rapidly,  and  appears  to  produce  more  active  fermentation 
in  milk.  Like  Brieger's  bacillus,  the  gelatin  colonies  more  frequently  show 
a  concentric  arrangement  than  those  of  the  Bacterium  coli  commune." 

BACILLUS  g  OF  BOOKER. 

"  Found  in  one  case  of  serious  gastro-enteric  catarrh.  It  was  not  in  large 
quantity. 

"  Morphology  and  Biological  Characters. — In  morphology,  character  of 
growth  on  agar,  gelatin,  and  potato,  it  resembles  Bacterium  coli  commune. 

"  Action  on  Milk  and  Litmus  Reaction. — Milk  is  not  coagulated,  and  milk 
colored  blue  with  litnms  is  changed  to  pink  in  a  few  days,  and  holds  this 
color.  These  characteristics  distinguish  it  from  the  Bacterium  coli  com- 
mune. 

"  Gas  Production. — Not  observed  in  milk  or  potato  cultures. 

''Relation  to  Gelatin. — Does  not  liquefy  gelatin." 


44(>  PATHOGENIC   AEROBIC   BACILLI 

BACILLUS  h   OF  BOOKER. 

' '  Found  in  one  case  of  mild  dysentery,  not  in  large  quantity. 

"  Morphology. — Resembles  Bacterium  coli  commune. 

"  Growth  in  Colonies. — Gelatin:  In  plain  neutral  gelatin  the  colonies  re- 
semble those  of  Bacterium  coli  commune.  In  sugar  gelatin  the  colonies  are 
white  and  spread  exten'sively.  Slightly  magnified,  they  have  a  round,  dark 
centre  surrounded  by  a  yellow,  loose  zone  with  an  outer  white  rim  ;  later 
the  whole  colony  has  a  uniform  yellow  color  and  is  not  compact. 

' '  Agar  :  Colonies  are  white,  round,  and  large.  Slightly  magnified,  they 
are  brownish-yellow. 

"  Stab  Cultures. — Nothing  characteristic  in  gelatin  and  agar. 

"Potato  culture  is  yellow,  dry,  and  slightly  raised,  with  well-defined  bor- 
ders. 

"  Action  on  Milk  and  Litmus  Reaction. — Milk  is  coagulated  into  a  solid 
clot  in  two  days  at  38°  C.  Milk  colored  blue  with  litmus  is  changed  to  pink 
in  twenty-four  hours. 

"  Gas  Production. — Occurs  in  milk;  not  observed  on  potato. 

"Relation  to  Gelatin. — Does  not  liquefy  gelatin." 

BACILLUS  k  OF  BOOKER, 

"  Found  in  two  cases  of  cholera  infantum  and  one  of  catarrhal  enteritis. 

"  Morphology. — Resembles  Bacterium  coli  commune. 

' '  Growth  in  Colonies. — Gelatin :  In  neutral  gelatin  the  colonies  cannot  be 
distinguished  from  those  of  Bacterium  coli  commune.  In  acid  gelatin  the 
colonies  do  not  spread  so  extensively  as  those  of  Bacterium  coli  commune, 
and  they  have  a  decided  concentric  arrangement,  a  wide  white  centre  sur- 
rounded by  a  narrow,  transparent  blue  ring,  and  outside  of  this  a  white  bor- 
der. Slightly  magnified,  the  colonies  have  an  irregular,  yellowish-brown 
centre  mottled  over  with  dark  spots  and  surrounded  by  a  light-yellow  ring 
bordered  by  a  brownish-yellow  wreath. 

"Agar:  Colonies  are  large,round,  and  bluish-white.  Slightly  magnified, 
a  light  brownish-yellow  color. 

"  Stab  Cultures. — Gelatin:  In  sugar  gelatin  the  surface  growth  is  exten- 
sive, nearly  colorless,  and  has  a  rough,  misty  appearance.  In  the  depth  if  a 
delicate  growth.  In  plain  neutral  gelatin  the  surface  growth  is  bluish -white, 
thick,  and  not  so  extensively  spread ;  the  growth  in  the  depth  is  also  thicker. 

' '  Potato  culture  is  moist,  dirty-cream  color,  has  raised  surface  and  defined 
border. 

"  Action  on  Milk. — Milk  becomes  gelatinous  in  twenty-four  hours  at  38° 
C.,  and  a  solid  clot  in  two  days.  Milk  colored  blue  with  litmus  is  changed  to 
pink  in  twenty- four  hours,  and  reduced  to  white  with  a  pink  layer  on  top  in 
two  days," 

BACILLUS  H  OF  BOOKER, 

' '  Found  in  large  quantity,  but  not  the  predominating  form,  in  one  case 
of  chronic  gastro-enteric  catarrh —extremely  emaciated. 

"  Morphology.—  Resembles  Bacterium  coli  commune. 

"  Growth  in  Colonies. — Gelatin :  In  neutral  gelatin  the  colonies  are  spread 
out  and  have  a  frosty  or  ground-glass  appearance.  The  centre  is  blue  and 
border  white,  but  both  have  the  ground-glass  appearance.  Slightly  magni- 
fied, the  central  part  is  light  yellow  and  the  border  brown  with  a  rough,  fur- 
rowed surface.  In  acid  gelatin  the  white  border  is  wider  and  the  surface  is 
rougher. 

'*  Agar:  Colonies  are  round,  blue,  or  bluish- white,  and  spread  out.  Under 
the  microscope  they  have  a  light-yellow  color. 

"Stab  Cultures. — Gelatin:  Has  a  rough,  nearly  colorless  surface  growth, 
and  a  thick  stalk  in  the  depth  along  the  line  of  inoculation. 

' '  Agar :  Thick  white  surface  growth  with  well-developed  stalk  in  the  depth. 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS.  447 

"  Action  on  Milk  and  Litmus  Reaction, — Milk  remains  liquid,  and  milk 
colored  blue  with  litmus  is  changed  to  pink. 

"  Gas  Production. — Not  observed  in  milk  or  potato  cultures. 
"  Relation  to  Gelatin. — Does  not  liquefy  gelatin. 
"Spores  have  not  been  noticed." 

Bacillus  Coli  Communis  in  Peritonitis. — The  researches  of  A. 
Frankel  show  that  Bacillus  coli  communis  may  be  obtained  in  pure 
cultures  from  the  exudate  into  the  peritoneal  cavity  in  a  considerable 
proportion  of  the  cases  of  peritonitis,  and  there  is  good  reason  for 
believing  that  in  these  cases  it  was  the  causs  of  the  inflammatory 
process.  Thirty-one  cases  were  examined  by  Frankel,  with  the  fol- 
lowing result:  Pure  cultures  of  Bacillus  coli  communis  were  obtained 
in  nine  cases ;  of  Streptococcus  (pyogenes  ?)  in  seven ;  of  Bacillus 
lactis  aerogenes  in  two  ;  of  "  diplococcus  pneumonise  "  in  one  ;  of 
Staphylococcus  pyogenes  aureus  in  one.  Of  the  remaining  eleven 
cases,  seven  gave  mixed  cultures,  and  in  three  of  these  Bacillus  coli 
communis  was  the  most  abundant  species.  The  author  referred  to 
has  also  shown  that  pure  cultures  of  Bacillus  coli  communis  injected 
into  the  cavity  of  the  abdomen  of  rabbits  cause  a  typical  peritonitis. 
The  present  writer  has  frequently  obtained  the  same  result  in  experi- 
ments made  with  this  bacillus.  It  would  appear,  therefore,  that  the 
peritonitis  which  so  constantly  results  from  wounds  of  the  intestine 
is  probably  due,  to  a  considerable  extent,  to  the  introduction  of  this 
microorganism  from  the  lumen  of  the  intestine,  where  it  is  con- 
stantly found,  into  the  peritoneal  cavity,  where  the  conditions  are 
favorable  for  its  rapid  development. 

90.    BACILLUS   LACTIS   AEROGENES. 

Synonym  — Bacillus  lactis  aerogenes  (Escherich). 

Obtained  by  Escherich  (1886)  from  the  contents  of  the  small  intestine  of 
children  and  animals  fed  upon  milk  ;  in  smaller  numbers  from  the  faeces  of 
milk-fed  children,  and  in  one  instance  from  uncooked  cow's 
milk. 

Morphology. — Short  rods  with  rounded  ends,  from  1  to  ^ 

2  n  in  length  and  from  0.1  to  0.5  V-  broad;   short  oval  and  e£t    %/ 

spherical  forms  are  also  frequently  observed,  and,  under  99 

certain  circumstances,  longer  rods  — 3  fi — may  be  developed :  $"*  /  g 

usually  united  in  pairs,  and  occasionally  in  chains  contain- 
ing several  elements.     In  some  of  the  larger  cells  Escherich 
lias  observed  unstained  spaces,  but  was  not  able  to  obtain        FlG< 
any  evidence  that  these  represent  spores. 

This  bacillus  stains  readily  with  the  ordinary  aniline      Si*-*?1 
colors,  but  does  .not  retain  its  color  when  treated  by  Gram's 
method. 

Biological  Characters. — An  aerobic  (facultative  anaerobic),  non-liquefy- 
ing, non  motile  bacillus.  Does  not  form  spores.  Grows  in  various  culture 
media  at  the  room  temperature — more  rapidly  in  the  incubating  oven. 
Upon  gelatin  plates,  at  the  end  of  twenty-four  hours,  small  white  colonies 
are  developed.  Upon  the  surface  these  form  hemispherical,  soft,  shining 
masses  which,  examined  under  the  microscope,  are  found  to  be  homogeneous 


448  PATHOGENIC   AEROBIC   BACILLI 

and  opaque,  with  a  whitish  lustre  by  reflected  light.  The  deep  colonies  are 
spherical  and  opaque  and  attain  a  considerable  size.  In  gelatin  stick  cul- 
tures the  growth  resembles  that  of  Friedlander's  bacillus — i.e.-,  an  abundant 
growth  along  the  line  of  puncture  and  a  rounded  mass  upon  the  surface, 
forming  a  "  nail-shaped"  growth.  In  old  cultures  the  upper  portion  of  the 
gelatin  is  sometimes  clouded,  and  numerous  gas  bubbles  may  form  in  the 
gelatin.  Upon  the  surface  of  nutrient  agar  an  abundant,  soft,  white  layer- 
is  developed.  Upon  old  potatoes,  in  the  incubating  oven,  at  the  end  of 
twenty-four  hours  a  yellowish-white  layer,  several  millimetres  thick,  is 
developed,  which  is  of  paste-like  consistence  and  contains  about  the  peri- 
phery a  considerable  number  of  small  gas  bubbles ;  this  layer  increases  in 
dimensions,  has  an  irregular  outline,  and  larger  and  more  numerous  gas 
bubbles  are  developed  about  the  periphery,  some  the  size  of  a  pea ;  later  the 
whole  surface  of  the  potato  is  covered  with  a  creamy,  semi-fluid  mass  filled 
with  gas  bubbles.  On  young  potatoes  the  development  is  different ;  a  rather 
luxuriant,  thick,  white  or  pale-yellow  layer  is  formed,  which  is  tolerably 
dry  and  has  irregular  margins;  the  surface  is  smooth  and  shining,  and  a 
few  minute  gas  bubbles  only  are  formed  after  several  days. 

Pathogenesis. — Injections  of  a  considerable  quantity  of  a  pure  culture 
into  the  circulation  of  rabbits  and  of  guinea-pigs  give  rise  to  a  fatal  result 
within  forty -eight  hours. 

In  his  first  publication  relating  to  "  the  bacteria  found  in  the  dejecta  of 
infants  afflicted  with  summer  diarrhoea,"  Booker  has  described  a  bacillus 
which  he  designates  by  the  letter  B,  which  closely  resembles  Bacillus  lactis 
aerogenes  and  is  probably  identical  with  it.  He  says : 

"  Summary  of  Bacillus  B. — Found  nearly  constantly  in  cholera  infan- 
tum  and  catarrhal  enteritis,  and  generally  the  predominating  form.  It 
appeared  in  larger  quantities  in  the  more  serious  cases.  It  was  not  found 
in  the  dysenteric  or  healthy  fasces.  It  resembles  the  description  of  the  Ba- 
cillus lactis  aerogenes,  but  the  resemblance  does  not  appear  sufficient  to  con- 
stitute an  identity,  and,  in  the  absence  of  a  culture  of  the  latter  for  com- 
parison, it  is  considered  a  distinct  variety  for  the  following  reasons :  Bacillus 
B  is  uniformly  larger,  its  ends  are  not  so  sharply  rounded,  and  in  all  culture 
media  long,  thick  filaments  are  seen,  and  many  of  the  bacilli  have  the  pro- 
toplasm gathered  in  the  centre,  leaving  the  poles  clear.  ~~  There  is  some 
difference  in  their  colony  growth  on  gelatin,  and  in  gelatin  stick  cultures 
bacillus  B  does  not  show  the  nail- form  growth  with  marked  end  swelling  in 
the  depth.  In  potato  cultures  the  Bacillus  lactis  aerogenes  shows  a  differ- 
ence between  old  and  new  potatoes,  while  bacillus  B  does  not  show  any 
difference. 

"  Bacillus  B  possesses  decided  pathogenic  properties,  which  was  shown 
both  by  hypodermic  injections  and  feeding  with  milk  cultures." 

91.    BACILLUS    C   OF    BOOKER. 

Found  by  Booker  (1889)  in  a  case  of  cholera  infaiitum. 

Morphology. — Resembles  Bacillus  lactis  aerogenes  of  Escherich. 

Biological  Characters . — Resembles  Bacillus  lactis  aerogenes,  but  differs 
from  it  in  not  coagulating  milk;  the  growth  on  potato  also  is  more  luxuri- 
ant and  the  surface  is  more  thickly  covered  with  gas  bubbles. 

BACILLI   OF   JEFFRIES. 

Jeffries,  in  a  study  of  the  alvine  discharges  of  children  suffering  from 
summer  diarrhoea,  isolated  a  number  of  bacilli  resembling  Bacillus  coli 
conimunis  and  Bacillus  lactis  aerogenes  of  Escherich.  He  says: 

"  While  Brieger's  bacillus  and  the  lactic  acid  bacillus  of  Escherich  were 
not  found,  a  whole  group  of  species  in  growth,  form,  and  general  physiology 
closely  resembling  them  have  been  isolated.  This  group  is  represented  by 
bacilli  A,  G,  J,  K,  P,  S,  Z ;  they  seem  to  form  a  genus  ;  the  form  is  very 


NOT   DESCRIBED   IN  PREVIOUS   SECTIONS.  449 

much  alike.  All  are  good  anaerobic  growers ;  all  form  gas ;  all  turn  milk 
distinctly  acid ;  and  all  closely  resemble  one  another  in  pure  cultures.  Many 
would  doubtless  class  these  altogether  as  one  species ;  but  if  species  are  to 
be  recognized  at  all,  we  must  come  to  recognizing  every  fixed  difference  as 
constituting  a  species. 

"  This  group  occurred — always  very  abundantly — in  eighteen  out  of  the 
twenty- two  cases  of  summer  diarrhoea,  and  is  also  well  represented  among 
the  kittens.  They  are,  however,  so  much  like  the  harmless  forms  found  by 
Escherich  that  they  may  for  the  present  be  laid  aside  as  of  no  specific  sig- 
nificance. They  are  also  almost  the  only  forms  tested  which  failed  to  pro- 
duce intestinal  troubles  in  kittens.  Excluding  these,  there  is  no  species,  or 
group  of  species,  left  either  generally  occurring  or  in  sufficient  numbers  to 
be  regarded  as  the  specific  pathogenic  plant  of  summer  diarrhoaa." 

92.    BACILLUS   ACIDIFORMANS. 

Obtained  by  the  writer  (1888)  from  a  fragment  of  yellow-fever  liver  pre- 
served for  forty-eight  hours  in  an  antiseptic  wrapping ;  since  obtained  from 


FIG.  150.  FIG.  151. 

Fi».  150.— Bacillus  acidiformans,  from  a  potato  culture.  X  1,000.  From  a  photomicrograph* 
(Sternberg.) 

FIG.  151.— Culture  of  Bacillus  acidiformans  in  nutrient  gelatin,  end  ofjfour  days  at  22°  C. 
From  a  photograph.  (Sternberg.) 

liver  preserved  in  the  same  way  from  two  comparative  autopsies — i.e.,  not 
cases  of  yellow  fever. 

Morphology. — A  short  bacillus  with  rounded  corners,  sometimes  short 
oval  in  form ;  from  li  to  3  y"  in  length  and  about  1.2  #  in  breadth ;  may  grow 
out  into  filaments  of  5  to  10  jj. ,  or  more,  in  length ;  in  some  cultures  the  short 
oval  form  predominates. 

Stains  readily  with  the  aniline  colors  usually  employed,  and  by  Gram's 
method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Does  not  form  spores.  Grows  rapidly  at 
the  room  temperature  in  the  usual  culture  media.  Grows  in  decidedly  acid 
media;  in  culture  media  containing  glycerin  or  glucose  it  produces  an  abun- 
dant evolution  of  carbon  dioxide,  and  a  volatile  acid  is  formed. 

It  does  not  liquefy  gelatin,  and  in  stick  cultures  grows  abundantly  both 
on  the  surface  and  along  the  line  of  puncture.  At  the  end  of  twenty-four 
hours,  at  22°  C.,  a  rounded  white  mass  is  formed  upon  the  surface,  resembling 


450 


PATHOGENIC  AEROBIC   BACILLI 


the  growth  of  Friedlander's  bacillus ;  at  the  bottom  of  the  line  of  puncture 
the  separate  colonies  are  spherical,  opaque,  and  pearl-like  by  reflected  light. 
Gas  bubbles  are  formed  in  the  gelatin.  At  the  end  of  a  week  the  surface  is 
•covered  with  a  thick,  white,  semi-fluid  mass. 

In  gelatin  roll  tubes  the  superficial  colonies  are  translucent  or  opaque, 
and  circular  or  somewhat  irregular  in  outline ;  by  reflected  light  they  are 
slightly  iridescent  ;  the  deep  colonies  are  spherical,  opaque,  and  homo- 
geneous. 

The  growth  upon  the  surface  of  nutrient  agar  is  abundant  and  rapid,  of 
a  shining  milk-white  color,  and  cream-like  in  consistence.  An  abundant 
development  forms  along  the  line  of  puncture  and  the  culture  medium  is 
split  up  by  gas  bubbles.  In  glycerin-agar  the  evolution  of  gas  is  very  abun- 
dant and  the  culture  medium  acquires  an  intensely  acid  reaction. 

On  potato  the  growth  is  abundant  and  rapid  at  a  temperature  of  20°  to 
30°  C.,  forming  a  thick,  semi-fluid  mass  of  a  milk-white  color. 

I  have  not  obtained  any  evidence  that  this  bacillus  forms  spores;  the 
cultures  are  sterilized  by  ten  minutes'  exposure  to  a  temperature  of  160°  F. 

When  cultivated  in  bouillon  to  which  five  per  cent  of  glycerin  has  been 
added  the  culture  medium  acquires  a  milky  opacity,  and  there  is  a  copious 
precipitate,  of  a  viscid  consistence,  consisting  of  bacilli ;  during  the  period 
of  active  development  the  surface  is  covered  with  gas  bubbles,  as  in  a  sac- 
charine liquid  undergoing  alcoholic  fermentation,  and  the  liquid  has  a  de- 
cidedly acid  reaction. 

Pathogenesis. — Pathogenic  for  rabbits  and  for  guinea-pigs  when  injected 
into  the  cavity  of  the  abdomen — one  to  two  cubic  centimetres  of  a  culture  in 
bouillon.  The  animal  usually  dies  in  less  than  twenty-four  hours.  The 
bacilli  are  found  in  the  blood  in  rather  small  numbers,  and  are  frequently 
seen  in  the  interior  of  the  leucocytes.  The  spleen  is  enlarged,  the  liver 
normal,  the  intestine  usually  hyperaemic. 


93.    BACILLUS   CUNICULICIDA  HAVAXIENSIS. 

Obtained  by  the  writer  (1889)  from  the  contents  of  the  intestine  of  yellow- 
fever  cadavers,  and  also  from  fragments  of  yellow-fever  liver  preserved  for 

forty -eight  hours  in  an  antiseptic  wrap- 
ping— my  bacillus  x,  Havana,  1889. 

Morphology. — Thisbacillusresembles 
the  colon  bacillus  in  form,  but  is  some- 
what larger,  from  2  to  4  n  in  length  and 
from  0.8  to  1  /<  in  diameter  ;  sometimes 
associated  in  pairs ;  may  grow  out  into 
short  filaments — not  common.  The  ends 
of  the  rods  are  rounded,  and  under  cer- 
tain circumstances  vacuoles  are  seen  at 
the  extremities,  especially  in  potato  cul* 
tures. 

Stains  quickly  with  the  aniline  colors 
usually  employed,  and  also  by  Gram's 
method. 

Biological  Characters. — An  aerobic 
m  .and  facultative    anaerobic,    non-lique- 
'  'fying  bacillus.     Under  certain  circum- 
stances may  exhibit  active  movements, 
but  is  usually  motionless. 

A  very  curious  thing  with  reference 
to  this  bacillus  is  that  it  presented  ac- 
tive movements  in  my  cultures  made  directly  from  yellow-fever  cadavers, 
but  that  these  movements  were  not  constant,  and  that  since  my  return  to 
Baltimore  I  have  not,  as  a  rule,  observed  active  movements  in  cultures  from 
the  same  stock,  which,  however,  preserved  their  pathogenic  power  and  other 


FIG.  152.— Bacillus  cuniculicida  Havani- 
ensis,  from  a  single  colony  in  nutrient  gela- 
tin, x  1,000.  From  a  photomicrograph. 
(Sternberg.) 


NOT   DESCRIBED   IX   PREVIOUS   SECTIONS. 


451 


•chai-acters.  In  Havana  these  movements  were  usually  not  observed  in  all 
the  bacilli  in  a  field  under  observation,  but  one  and  another  would  start  from 
a  quiescent  condition  on  an  active  and  erratic  course ;  sometimes  spinning 
actively  upon  its  axis,  and  again  shooting  across  the  field  as  if  propelled  by 
a  flagellum. 

My  notes  indicate  that  cultures  passed  through  the  guinea-pig  are  more 
apt  to  be  motile. 

In  gelatin  stick  cultures  the  growth  of  bacillus  x  resembles  that  of  the 
colon  bacillus,  but  the  colonies  at  the  bottom  of  the  line  of  puncture  are 
more  opaque  and  not  of  a  clear  amber  color  like  that  of  colonies  of  the  colon 
bacillus.  Upon  the  surface  the  growth  is  thicker  than  that  of  the  colon 
bacillus,  and  forms  a  milk-white,  soft  mass. 

The  colonies  in  gelatin  Esmarch  roll  tubes  vary  considerably  at  different 
times.  Deep  colonies  are  usually  spherical,  homogeneous,  light  brown  in 
color,  and  more  opaque  than  the  similar  colonies  of  the  colon  bacillus.  At 
the  end  of  a  few  days  the  deep  colonies  become  quite  opaque,  and  may  be 
lobate,  like  a  mulberry,  or  coarsely  granular;  sometimes  the  deep  colonies 
have  an  opaque  central  portion  surrounded  by  a  transparent  marginal  zone. 

In  old  gelatin  roll  tubes  these  deep  colonies  form  opaque  white  hemi- 


Fio.  153.  FIG.  154. 

Fig.  153.— Bacillus  cuniculicida  Havaniensis;  colonies  in  gelatin  roll  tube,  third  day  at  20°  C. 
X  6.  From  a  photograph.  (Sternberg.) 

FIG.  154.— Bacillus  cuniculicida  Havaniensis ;  colonies  in  gelatin  roll  tube,  end  of  forty-eight 
hours.  X  10.  From  a  photograph.  (Sternberg.) 


spheres  projecting  from  the  surface  of  the  dried  culture  medium,  and  little 
tufts  of  acicular  crystals  are  sometimes  observed  to  project  from  the  side  of 
such  old  colonies. 

The  superficial  colonies  are  circular  or  irregular  in  outline,  with  trans- 
parent margins  and  an  opaque  central  portion,  sometimes  corrugated.  They 
are  finely  granular  and  iridescent  by  reflected  light,  and  of  a  milk-white 
color ;  by  transmitted  light  they  have  a  brownish  color.  Young  colonies 
closely  resemble  those  of  the  colon  bacillus.  This  bacillus  grows  well  at  a 
temperature  of  20°  0.  (68°  F.),  but  more  rapidly  and  luxuriantly  at  a  higher 
temperature — 30°  to  35°  C. 

It  grows  well  in  agar  cultures,  and  especially  in  glycerin-agar,  in  which 
it  produces  some  gas  and  an  acid  reaction.  The  growth  on  the  surface 
of  glycerin-agar  cultures  is  white,  cream-like  in  consistence,  and  quite  abun- 
dant. 

It  grows  well  in  an  agar  or  gelatin  medium  made  acid  by  the  addition  of 
0.2  per  cent  (1:  500)  of  hydrochloric  acid. 


453  PATHOGENIC   AEROBIC   BACILLI 

In  cocoanut  water  it  multiplies  rapidly,  producing-  a  milky  opacity  of  the 
previously  transparent  fluid,  an  acid  reaction,  and  an  evolution  of  carbon 
dioxide. 

On  potato  it  produces  a  thick  layer,  which  may  cover  the  entire  surface 
in  three  or  four  days,  and  which  has  a  dirty-white,  cream-white,  or  pinkish- 
white  color  and  cream-like  consistence.  The  growth  upon  potato  varies  at 
different  times,  evidently  owing1  to  differences  in  the  potato. 

When  stained  preparations  are  examined  with  the  full  light  of  the  Abbe 
condenser  the  ends  of  some  of  the  rods  appear  to  be  cut  away,  leaving  a  con- 
cave extremity;  but  by  using  a  small  diaphragm  to  obtain  definition  it  will 
be  seen  that  the  cell  wall  extends  beyond  the  stained  portion  of  the  rod  and 
includes  what  appears  to  be  a  vacuole.  There  is  no  reason,  to  believe  that 
this  appearance  is  due  to  the  presence  of  an  end  spore,  for  the  supposed 
vacuole  is  not  refractive,  as  a  spore  would  be,  and  my  experiments  on  the 
thermal  death-point  of  this  bacillus  indicate  that  it  does  not  form  spores. 
Cultures  are  sterilized  by  exposure  for  ten  minutes  to  a  temperature  of  160° 
F.  (71.2°  C.). 

Pathogenesis. — Very  pathogenic  for  rabbits  when  injected  into  the  cavity 
of  the  abdomen.  Injections  of  a  small  quantity  of  a  pure  culture  into  the 
ear  vein  or  subcutaneously  generally  give  a  negative  result.  Injections  of 
from  one  to  five  cubic  centimetres  of  a  culture  in  bouillon,  blood  serum,  or 
agua  coco,  into  the  cavity  of  the  abdomen,  frequently  prove  fatal  to  rabbits 
in  a  few  hours — t\vo  to  six. 

The  negative  results  obtained  in  injecting  cultures  beneath  the  skin  or 
into  the  ear  vein  of  rabbits  show  that  this  bacillus  does  not  induce  a  fatal 
septicaemia  in  these  animals,  and  the  fatal  result  when  injections  are  made 
into  the  peritoneal  cavity  does  not  appear  to  be  due  to  an  invasion  of  the 
blood,  but  rather  to  the  local  effect  upon  the  peritoneum,  together  with  the 
toxic  action  of  the  chemical  products  resulting  from  its  growth. 

It  is  true  that  I  have  always  been  able  to  recover  the  bacillus  from  the 
liver,  or  from  blood  obtained  from  one  of  the  cavities  of  the  heart,  even  in 
animals  which  succumb  within  a  few  hours  to  an  injection  made  into  the 
cavity  of  the  abdomen.  But  the  direct  examination  of  the  blood  shows  that 
the  bacilli  are  present  in  very  small  numbers,  and  leads  me  to  believe  that 
the  bacillus  does  not  multiply,  to  any  considerable  extent  at  least,  in  the 
circulating  fluid. 

The  spleen  is  not  enlarged,  as  is  the  case  in  anthrax,  rabbit  septicaemia, 
and  other  diseases  in  which  the  pathogenic  microorganism  multiplies  abun- 
dantly in  the  blood. 

On  the  other  hand,  there  is  evidence  of  local  inflammation  in  the  peri- 
toneal cavity.  When  death  occurs  within  a  few  hours  the  peritoneum  is 
more  or  less  hyperaemic  and  there  is  a  considerable  quantity  of  straw-colored 
fluid  in  the  cavity  of  the  abdomen.  When  the  animal  lives  for  twenty 
hours  or  more  there  is  a  decided  peritonitis  with  a  fibrinous  exudation  upon 
the  surface  of  the  liver  and  intestine.  Usually  the  liver,  in  animals  which 
die  within  twenty-four  hours,  is  full  of  blood,  rather  soft,  and  dark  in  color. 
In  a  single  instance  I  found  the  liver  to  be  of  a  light  color  and  loaded  with 
fat. 

The  rapidly  fatal  effect  in  those  cases  in  which  I  have  injected  two  or 
more  cubic  centimetres  of  a  culture  into  the  cavity  of  the  abdomen  has  led 
me  to  suppose  that  death  results  from  the  toxic  effects  of  a  ptomaine  con- 
tained in  the  culture  at  the  time  of  injection.  The  symptoms  also  give  sup- 
port to  this  supposition.  The  animal  quickly  becomes  feeble  and  indisposed 
to  move,  and  some  time  before  death  lies  helpless  upon  its  side,  breathing 
regularly,  but  is  too  feeble  to  get  up  on  its  feet  when  disturbed.  Death  some- 
times occurs  in  convulsions,  but  more  frequently  without— apparently  from 
heart  failure. 

Pathogenic  also  for  guinea-pigs  when  injected  into  the  cavity  of  the 
abdomen,  but  death  does  not  occur  in  so  short  a  time — eighteen  to  twenty 
hours.  Subcutaneous  injections  of  one-half  to  one  cubic  centimetre  gave  a 


NOT   DESCRIBED    IX   PREVIOUS   SECTIONS.  453 

negative  result  in  eleven  out  of  thirteen  guinea-pigs  inoculated — two  died 
within  twenty -four  hours. 

94.    BACILLUS   LEPORIS   LETHALIS. 

Obtained  by  Dr.  Paul  Gibier  (1888)  from  the  contents  of  the  intestine  of 
yellow-fever  patients;  also  by  the  writer  from  the  same  source  (1888,  1889) 
in  exceptional  cases  and  in  comparatively  small  numbers.  Named  and  de- 
scribed by  present  writer. 

Morphology. — Bacilli  with  rounded  ends,  from  1  to  3  ft  in  length  and 
about  0.5  H  in  breadth.  The  length  may  vary  in  the  same  culture  from  a 
short  oval  to  rods  which  are  two  or  three  times  as  long  as  broad,  or  it  may 
grow  out  into  flexible  filaments  of  considerable  length.  In  recent  cultures 
the  bacilli  are  frequently  united  in  pairs. 

Stains  readily  with  the  aniline  colors  usually  employed.  In  cultures 
which  are  several  days  old,  or  in  recent  cultures  when  the  stained  prepara- 
tion is  washed  in  alcohol,  the  ends  of  the  rods  are  commonly  more  deeply 
stained  than  the  centi'al  portion — "  end  staining" ;  and  in  old  cultures  some 
of  the  bacilli  are  very  faintly  stained. 

Biological  Characters. — Anaerobic,  liquefying,  actively  motile  bacillus. 
Does  not  form  spores.  . 

In  gelatin  stick  cultures,  at  the  end  of  twenty-four  hours  at  a  tempe- 
rature of  20°  to  22°  C.,  there  is  an  abundant  development  along  the  line  of 
puncture  and  commencing  liquefaction  at  the  surface.  Later, the  liquefaction 
is  funnel-shaped,  and  there  is  an  opaque  white  central  core  along  the  line 
of  puncture,  with  liquefied  gelatin  around  it.  Liquefaction  progresses  most 
rapidly  at  the  surface,  and  in  the  course  of  three  or  four  days  the  upper  por- 
tion of  the  gelatin  for  a  distance  of  half  an  inch  or  more  is  completely  lique- 
fied, and  an  opaque  white  mass,  composed  of  bacilli,  rests  upon  the  surface 
of  the  unliquefied  portion. 

In  gelatin  roll  tubes  the  young  colonies  upon  the  surface  are  transparent 
and  resemble  somewhat  small  fragments  of  broken  glass;  later  liquefaction 
occurs  rapidly.  Deep  colonies  in  gelatin  roll  tubes,  or  at  the  bottom  of  stick 
cultures,  are  spherical,  translucent,  and  of  a  pale  straw  color. 

Upon  the  surface  of  nutrient  agar  it  grows  rapidly,  forming  a  rather  thin, 
translucent,  shining,  white  layer,  which  covers  the  entire  surface  at  the  end 
of  two  or  three  days  at  a  temperature  of  20°  C. 

Upon  potato  the  growth  is  rapid  and  thin,  covering  the  entire  surface, 
and  is  of  a  pale-yellow  color. 

This  bacillus  grows  at  a  comparatively  low  temperature,  and  its  vitality 
is  not  destroyed  by  exposure  for  an  hour  and  a  half  in  a  freezing  mixture  at 
15°  C.  below  zero  (5°  F.). 

Decided  growth  occurred  in  a  stick  culture  in  gelatin  exposed  in  Balti- 
more during  the  month  of  January  in  an  attic  room.  During  the  twenty- 
two  days  of  exposure  the  highest  temperature,  taken  at  9  A.M.  each  day, 
was  11°  C.,  and  the  lowest  2°  C.  At  a  temperature  of  16°  to  20°  C.  develop- 
ment in  a  favorable  cultui-e  medium  is  rapid. 

There  is  no  evidence  that  this  bacillus  forms  spores ;  cultures  are  sterilized 
by  exposure  to  a  temperature  of  60°  C.  for  ten  minutes. 

Coagulated  blood  serum  is  liquefied  by  this  bacillus.  It  retains  its  vitality 
for  a  long  time  in  old  cultures,  having  grown  freely  when  replanted  at  the 
end  of  a  year  from  a  hermetically  sealed  tube  containing  a  pure  culture  in 
blood  serum. 

Pathogenesis. — This  bacillus  is  very  pathogenic  for  rabbits  when  injected 
into  the  cavity  of  the  abdomen  in  quantities  of  one  cubic  centimetre  or  more ; 
it  is  less  pathogenic  for  guinea-pigs,  and  is  not  pathogenic  for  white  rats 
when  injected  subcutaneously.  Gelatin  cultures  seem  to  possess  more  in- 
tense pathogenic  power  than  bouillon  cultures,  and  cultures  from  the  blood 
of  an  animal  recently  dead  as  the  result  of  an  inoculation  are  more  potent 

38 


454  PATHOGENIC   AEROBIC   BACILLI 

than  those  from  my  original  stock  which  had  not  been  passed  through  a 
susceptible  animal. 

The  mode  of  death  in  rabbits  is  quite  characteristic.  A  couple  of  hours 
after  receiving  in  the  cavity  of  the  abdomen  two  or  three  cubic  centimetres 
of  a  liquefied  gelatin  culture  the  animal  becomes  quiet  and  indisposed  to  eat 
or  move  about.  Soon  after  it  becomes  somnolent,  the  head  drooping  for- 
ward and  after  a  time  resting  between  the  front  legs,  with  the  nose  on  the 
floor  of  its  cage.  It  can  be  roused  from  this  condition,  and  raises  its  head  in 
an  indifferent  and  stupid  way  when  pushed  or  shaken,  but  soon  drops  off 
again  into  a  profound  sleep.  Frequently  the  animals  die  in  a  sitting  posi- 
tion, with  their  nose  resting  upon  the  floor  of  the  cage  between  the  front 
legs.  I  have  not  seen  this  lethargic  condition  produced  by  inoculations  with 
any  other  microorganism.  Convulsions  sometimes  occur  at  the  moment  of 
death. 

The  time  of  death  depends  upon  the  potency  of  the  culture  and  its  quan- 
tity as  compared  with  the  size  of  the  animal.  From  three  to  four  cubic 
centimetres  of  a  liquefied  gelatin  culture  usually  kill  a  rabbit  in  from  three 
to  seven  hours. 

The  rapidity  with  which  death  occurs  when  a  considerable  quantity  of  a 
liquefied  gelatin  culture  is  injected  into  the  cavity  of  the  abdomen,  and  the 
somnolence  which  precedes  death,  give  rise  to  the  supposition  that  the  lethal 
effect  is  due  to  the  presence  of  a  toxic  chemical  substance  rather  than  to  a 
multiplication  of  the  bacillus  in  the  body  of  the  animal.  And  this  view  is 
supported  by  the  fact  that  animals  frequently  recover  when  the  dose  admin- 
istered is  comparatively  small  and  especially  when  it  is  injected  subcuta- 
neously. 

In  all  cases  in  which  death  occurs,  even  when  but  a  few  hours  have 
elapsed  since  the  inoculation  was  made,  I  have  recovered  the  bacillus  in 
cultures  made  from  blood  obtained  from  the  heart  or  the  interior  of  the 
liver,  and,  as  stated,  these  cultures  appear  to  have  a  greater  virulence  than 
those  not  passed  through  the  rabbit. 

In  sections  of  the  liver  and  kidney  stained  with  Loffler's  solution  of 
methylene  blue  the  bacilli  are  seen,  and  are  often  in  rather  long-jointed  fil- 
aments. 

95.    BACILLUS   PYOCYANUS. 

Synonyms. — Bacillus  of  green  pus  ;  Microbe  du  pus  bleu;  Bacil- 
len  des  griinblauen  Eiters ;  Bacterium  aeruginosum. 

Obtained  by  Gessard  (1882)  from  pus  having  a  green  or  blue 
color,  and  since  carefully  studied  by  Gessard,  Charrin,  and  others. 
This  bacillus  appears  to  be  a  widely  distributed 
saprophyte,  which  is  found  occasionally  in  the 
purulent  discharges  from  open  wounds,  and  some- 
times in  perspiration  and  serous  wound  secretions 
(Gessard) .    The  writer  obtained  it,  in  one  instance, 
FIG.    155.  —  Bacillus     in  cultures  from  the  liver  of  a  yellow-fever  cada- 
ver  (Havana,  1888). 

Morphology. — A  slender  bacillus  with  rounded 
ends,  somewhat  thicker  than  the  Bacillus  murisepticus  and  of  about 
the  same  length  (Fliigge) ;  frequently  united  in  pairs,  or  chains  of  four 
to  six  elements;  occasionally  grows  out  into  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacil- 
lus. Grows  readily  in  various  culture  media  at  the  room  tempera- 


NOT   DESCRIBED    IN   PREVIOUS    SECTIONS.  455 

ture — more  rapidly  in  the  incubating  oven.  Is  a  facultative  anae- 
robic (Frankel).  Does  not  form  spores.  The  thermal  death-point, 
as  determined  by  the  writer,  is  56°  C.,  the  time  of  exposure  being  ten 
minutes.  In  gelatin  plate  cultures  colonies  are  quickly  developed, 
which  give  to  the  medium  a  fluorescent  green  color  ;  at  the  end  of 
two  or  three  days  liquefaction  commences  around  each  colony,  and 
usually  the  gelatin  is  completely  liquefied  by  the  fifth  day.  Before 
liquefaction  commences  the  deep  colonies,  under  a  low  power,  appear 
as  spherical,  granular  masses,  with  a  serrated  margin,  and  have  a 
yellowish-green  color ;  the  superficial  colonies  are  quite  thin  and 
finely  granular  ;  at  the  centre,  where  they  are  thickest,  they  have  a 
greenish  color,  which  fades  out  towards  the  periphery. 

In  stick  cultures  in  nutrient  gelatin  development  is  most  abun- 
dant near  the  surface,  and  causes  at  first  liquefaction  in  the  form 
of  a  shallow  funnel ;  later  the  liquefied  gelatin  is  separated  from 
that  which  is  not  liquefied  by  a  horizontal  plane,  and  a  viscid,  yel- 
lowish-white mass,  composed  of  bacilli,  accumulates  upon  this  sur- 
face, which  gradually  has  a  lower  level  as  liquefaction  progresses  ; 
the  transparent,  liquefied  gelatin  above  is  covered  with  a  delicate, 
yellowish-green  film,  and  the  entire  medium  has  a  fluorescent  green 
color.  Upon  nutrient  agar  a  rather  abundant,  moist,  greenish-white 
layer  is  developed,  and  the  medium  acquires  a  bright  green-color, 
which  subsequently  changes  to  olive  green.  Upon  potato  a  viscid 
or  rather  dry,  yellowish-green  or  brown  layer  is  formed,  and  the 
potato  beneath  and  immediately  around  the  growth  has  a  green  color 
when  freely  exposed  to  the  air  or  to  the  vapors  of  ammonia.  In  milk 
the  casein  is  first  precipitated  and  then  gradually  dissolved,  while  at 
the  same  time  ammonia  is  developed.  The  green  pigment  is  formed 
only  in  the  presence  of  oxygen;  it  is  soluble  in  chloroform  and  may 
be  obtained  from  a  pure  solution  in  long,  blue  needles  ;  acids  change 
the  blue  color  to  red,  and  reducing  substances  to  yellow.  According 
to  Ledderhose,  it  is  an  aromatic  compound  resembling  anthracene, 
and  is  not  toxic.  According  to  Gessard's  latest  researches  (1890),  two 
different  pigments  are  produced  by  this  bacillus,  one  of  a  fluorescent 
green  and  the  other — pyocyanin — of  a  blue  color.  Cultivated  in  egg 
albumin  the  fluorescent  green  pigment,  which  changes  to  brown 
with  time,  is  alone  produced.  In  bouillon  and  in  media  containing 
peptone  or  gelatin  both  pigments  are  formed,  and  the  pyocyanin 
may  be  obtained  separately  by  dissolving  it  in  chloroform.  In  an 
alkaline  solution  of  peptone  (two  per  cent)  to  which  five  per  cent  of 
glycerin  has  been  added  the  blue  pigment  alone  is  formed. 

Pathogenesis. — The  experiments  of  Ledderhose,  Bouchard,  and 
others  show  that  this  bacillus  is  pathogenic  for  guinea-pigs  and  rab- 
bits. Subcutaneous  or  intraperitoneal  injections  of  recent  cultures — 


PATHOGENIC   AEROBIC   BACILLI 

one  cubic  centimetre  or  more  of  a  culture  in  bouillon — usually  cause 
the  death  of  the  animal  in  from  twelve  to  thirty-six  hours.  An  ex- 
tensive inflammatory  oedema  and  purulent  infiltration  of  the  tissues 
result  from  subcutaneous  inoculations,  and  a  sero-fibrinous  or  puru- 
lent peritonitis  is  induced  by  the  introduction  of  the  bacillus  into  the 
peritoneal  cavity.  The  bacillus  is  found  in  the  serous  or  purulent 
fluid  in  the  subcutaneous  tissues  or  abdominal  cavity,  and  also  in  the 
blood  and  various  organs,  from  which  it  can  be  recovered  in  pure 
cultures,  although  not  present  in  great  numbers,  as  is  the  case  in 
the  various  forms  of  septicaemia  heretofore  described.  When  smaller 
amounts  are  injected  subcutaneously  the  animal  usually  recovers 
after  the  formation  of  a  local  abscess,  and  it  is  subsequently  immune 
when  inoculated  with  doses  which  would  be  fatal  to  an  unprotected 
animal.  Immunity  may  also  be  secured  by  the  injection  of  a  con- 
siderable quantity  of  a  sterilized  culture.  Bouchard  has  also  pro- 
duced immunity  in  rabbits  by  injecting  into  them  the  filtered  urine 
of  other  rabbits  which  had  been  inoculated  with  a  virulent  culture  of 
the  bacillus.  It  has  been  shown  by  Bouchard,  and  by  Charrin  and 
Guignard,  that  in  rabbits  which  have  been  inoculated  with  a  culture 
of  the  anthrax  bacillus  a  fatal  result  may  be  prevented  by  soon  after 
inoculating  the  same  animals  with  a  pure  culture  of  the  Bacillus 
pyocyanus.  The  experiments  of  Woodhead  and  Wood  indicate  that 
the  antidotal  effect  is  due  to  chemical  products  of  the  growth  of  the 
bacillus,  and  not  to  an  antagonism  of  the  living  bacterial  cells.  They 
were  able  to  obtain  similar  results  by  the  injection  of  sterilized  cul- 
tures of  the  Bacillus  pyocyanus,  made  soon  after  infection  with  the 
anthrax  bacillus. 

96.    BACILLUS  OP  FIOCCA. 

Found  by  Fiocca  in  the  saliva  of  cats  and  dogs. 

Closely  resembles  the  influenza  bacillus  of  Pfeiffer  and  of  Canon. 

Morphology. — Resembles  the  bacillus  of  rabbit  septicaemia,  but  is  only 
half  as  large — from  0.2  to  0.33  /*  in  breadth.  The  length  is  but  little  greater 
than  the  breadth.  Usually  seen  in  pairs,  closely  resembling  diplococci. 
When  cultivated  on  potato  it  appears  to  be  a  micrococcus,  but  in  the  blood 
of  infected  animals  and  in  bouillon  cultures  it  is  seen  to  be  a  short  bacillus. 

Stains  with  difficulty  with  the  usual  aniline  colors,  but  is  readily  stained 
by  Ehrlich's  method  or  with  Ziehl's  solution. 

Biological  Characters.— An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Spore  formation  not  observed.  Grows  best 
at  37°  C.  and  does  not  develop  at  temperatures  below  15°  C.  In  agar  plates, 
at  37°  C.,  small,  punctiform  colonies  are  developed  at  the  end  of  twenty -four 
hours;  these  do  not  increase  in  size  later;  under  the  microscope  the  deep 
colonies  are  seen  to  be  spherical,  granular,  and  dark  yellow  in  color ;  the 
superficial  colonies  are  more  or  less  round,  with  irregular  outlines,  trans- 
parent, slightly  granular,  and  often  have  a  shining  nucleus  at  the  centre. 
Upon  gelatin  plates  the  colonies  have  a  similar  appearance,  but  are  not  vis- 
ible in  less  than  four  or  five  days.  In  streak  cultures  upon  the  surface  of 
agar  small,  punctiform  colonies  are  seen  along  the  track  of  the  needle  at  the 
end  of  twenty-four  hours,  resembling  fine  dewdrops;  the  following  day 


NOT   DESCRIBED   IN  PREVIOUS   SECTIONS. 


457 


these  colonies  are  a  little  larger  and  less  transparent;  they  remain  distinct, 
especially  along1  the  margins  of  the  line  of  growth.  Upon  potato  a  very 
thin,  transparent  layer  is  developed,  which  does  not  change  the  appearance 
of  the  surface  of  the  potato,  but  slightly  increases  its  resistance  to  the  plati- 
num needle.  In  bouillon  small  flocculi.  suspended  in  the  clear  liquid,  are 
developed  within  twenty-four  hours ;  these  subsequently  sink  to  the  bottom. 

Milk  is  not  coagulated  by  this  bacillus,  and  no  gas  is  produced  in  media 
containing-  sugar. 

Pathogenesis. — Pathogenic  for  rabbits,  guinea-pigs,  young  rats,  and  mice, 
in  which  animals  it  produces  general  infection,  and  death- in  rabbits — at 
the  end  of  twenty-four  hours.  The  bacillus  is  found  in  tne  blood  in  great 
numbers. 

97.    PROTEUS  VULGARIS. 

Obtained  by  Hauser  (1885)  from  putrefying  animal  substances, 
and  since  shown  to  be  one  of  the  most  common  and  widely  distrib- 
uted putrefactive  bacteria.  This  and  the  other  species  of  Proteus 


Fia.  156.— Proteus  vulgaris;  "  swarming  islands  "  from  a  gelatin  culture,    x  285.    (Kauser.y 

described  by  the  same  bacteriologist  (Proteus  mirabilis,  Proteus  Zen- 
keri)  have  no  doubt  frequently  been  encountered  by  previous  observ- 
ers, and  are  among  the  species  formerly  included  under  the  name 
"  Bacterium  termo,"  which  was  applied  to  any  minute  motile  bacilli 
found  in  putrefying  infusions. 

Morphology. — Bacilli  with  rounded  ends,  about  0.6  /u  broad,  and 
varying  greatly  in  length,  being  sometimes  short  oval,  and  at  others 
from  1.25  to  3.75  /*  in  length  ;  also  grow  out  into  flexible  filaments, 
which  may  be  more  or  less  wavy  or  spiral  in  form.  The  short  rods 
are  commonly  seen  in  pairs  ;  they  have  terminal  flagella  ;  involution 
forms  are  frequently  seen,  the  most  common  being  spherical  bodies 
about  1.6  /u  in  diameter.  In  old  cultures  in  bouillon,  or  in  cultures 
made  in  meat  infusion  in  the  incubating  oven,  the  short  oval  forms 
greatly  predominate,  but  in  recent  cultures  in  nutrient  gelatin  fila- 


458  PATHOGENIC   AEROBIC   BACILLI 

ments  of  considerable  length  are  encountered  in  association  with 
shorter  rods. 

Stains  readily  with  fuchsin  or  gentian  violet — not  so  well  with 
the  brown  aniline  colors  ;  does  not  stain  by  Gram's  method  (Cheyne). 

Biological  Characters. — An  aerobic  and  facultative  anaerobic, 
liquefying,  motile  bacillus.  Grows  rapidly  in  the  usual  culture 
media  at  the  room  temperature. 

The  growth  upon  gelatin  plates  (five  per  cent  of  gelatin)  at  the 
room  temperature  is  very  characteristic  ;  at  the  end  of  six  or  eight 
hours  small  depressions  in  the  gelatin  are  observed,  which  contain 
liquefied  gelatin  and  grayish-white  masses  of  bacilli.  Under  a  low 
power  these  depressions  are  seen  to  be  surrounded  by  a  marginal 
zone  consisting  of  two  or  three  layers,  outside  of  which  is  a  zone  of  a 
single  layer,  from  which  amoeba-like  processes  extend  upon  the  sur- 
face of  the  gelatin.  These  processes  are  constantly  undergoing 
changes  in  their  form  and  position,  and  may  become  separated  from 
the  mother  colony,  or  remain  temporarily  attached  to  it  by  a  narrow 
thread  consisting  of  bacilli ;  after  a  time  the  entire  surface  of  the 
gelatin  is  covered  with  wandering,  amoeba-like  colonies ;  these 
rapidly  cause  liquefaction,  which  by  the  end  of  twenty-four  to  forty- 
eight  hours  has  reached  a  depth  of  one  millimetre  or  more  over  the 
entire  surface.  The  deep  colonies  also  are  surrounded  by  processes 
projecting  into  the  gelatin,  which  may  be  observed  to  suddenly  ad- 
vance and  again  to  be  retracted  towards  the  central  zoogloea-like 
mass.  Liquefaction  around  the  colony  rapidly  progresses,  and 
actively  motile  rods  and  spiral  filaments  may  be  seen  about  the  peri- 
phery of  this  liquefied  gelatin,  while  about  it  is  a  radiating  crown  of 
irregular  processes,  some  of  which  may  be  screw-like  or  corkscrew- 
formed.  In  ten-per-cent  gelatin  the  migration  of  surface  colonies, 
above  described,  is  not  observed.  In  gelatin  stick  cultures  liquefac- 
tion occurs  along  the  entire  line  of  puncture,  and  soon  the  contents 
of  the  tube  are  completely  liquefied  ;  near  the  surface  of  the  liquefied 
gelatin  the  growing  bacilli  form  a  grayish-white  cloudiness,  and  at 
the  bottom  of  the  tube  an  abundant  flocculent  deposit  is  formed. 
Upon  the  surface  of  nutrient  agar  a  rapidly  extending,  moist,  thin, 
grayish-white  layer  is  formed.  Upon  potato  this  bacillus  produces  a 
dirty-white,  moist  layer.  The  cultures  in  media  containing  albumin 
or  gelatin  have  a  putrefactive  odor  and  acquire  a  strongly  alkaline 
reaction.  A  temperature  of  20°  to  24°  C.  is  most  favorable  for  the 
growth  of  this  bacillus.  It  is  a  facultative  anaerobic  and  grows  in 
an  atmosphere  of  hydrogen  or  of  carbon  dioxide,  although  not  so 
rapidly  as  in  the  presence  of  oxygen.  The  movements  are  often  ex- 
tremely active  and  difficult  to  follow  under  the  microscope  ;  again 
they  may  be  quite  deliberate,  or  the  bacilli  may  remain  motionless 


NOT   DESCRIBED    IN   PREVIOUS    SECTIONS.  459 

for  a  time  and  again  dart  off  in  active  motion.  The  long  terminal 
flagella  may  sometimes  be  discerned  by  means  of  a  good  objective 
and  careful  manipulation  of  the  light. 

Pathogenesis. — Pathogenic  for  rabbits  and  for  guinea-pigs  when 
injected  into  the  circulation,  into  the  cavity  of  the  abdomen,  or  sub- 
cutaneously  in  considerable  quantity.  Cultures  in  nutrient  gelatin 
are  said  by  Cheyne  to  be  more  pathogenic  (toxic)  than  those  in  bouil- 
lon. When  injected  into  the  muscles  of  rabbits  a  much  smaller 
dose  produces  a  fatal  result  than  when  injected  subcutaneously. 
In  Cheyne's  experiments,  made  in  London  (1886),  one-tenth  cubic 
centimetre  of  a  liquefied  gelatin  culture,  injected  into  the  dorsal 
muscles,  was  invariably  fatal  in  from  twenty-four  to  thirty-six  hours; 
a  dose  of  one-twentieth  cubic  centimetre,  injected  in  the  same  way, 
usually  caused  death;  while  one -fortieth  cubic  centimetre  gave  rise  to 
an  extensive  local  abscess,  and  the  animals  died  at  the  end  of  six  or 
eight  weeks.  Doses  of  less  than  one-five-hundredth  cubic  centimetre 
produced  no  effect.  Cheyne  estimates  that  one  cubic  centimetre  of  a 
culture  in  nutrient  gelatin  contains  4,500,000,000  bacilli,  and,  conse- 
quently, that  a  smaller  number  than  9,000,000  produced  no  effect  when 
injected  into  the  muscular  tissue  of  rabbits.  Injections  into  the  sub- 
cutaneous connective  tissues  of  a  dose  twice  as  large  as  that  which  in- 
variably proved  fatal  when  injected  into  the  muscles  usually  caused 
an  extensive  abscess,  but  did  not  kill  the  animal ;  and,  after  re- 
covery from  the  effects  of  such  an  injection,  the  rabbit  was  found  to 
be  immune  against  a  similar  dose  injected  into  the  muscles.  Foa 
and  Bonome  have  succeeded  in  producing  immunity  against  the 
effects  of  virulent  cultures  of  this  bacillus  by  inoculating  rabbits  with 
filtered  cultures,  and  also  by  injecting  beneath  the  skin  of  these  ani- 
mals a  solution  of  neurin,  which  they  believe  to  be  the  principal 
toxic  product  present  in  the  cultures. 

Proteus  Vulgaris  in  Cholera  Infantum. — The  extended  re- 
searches of  Booker  have  led  him  to  the  conclusion  that  this  bacillus 
plays  an  important  part  in  the  production  of  the  morbid  symptoms 
which  characterize  cholera  infantum.  Proteus  vulgaris  was  found 
in  the  alvine  discharges  in  a  considerable  proportion  of  the  cases  ex- 
amined, but  was  not  found  in  the  faeces  of  healthy  infants.  "  The 
prominent  symptoms  in  the  cases  of  cholera  infantum  in  which  the 
proteus  bacteria  were  found  were  drowsiness,  stupor,  emaciation 
and  great  reduction  in  flesh,  more  or  less  collapse,  frequent  vomiting 
and  purging,  with  watery  and  generally  offensive  stools." 

Another  bacillus  found  by  Booker  in  a  considerable  number  of  his 
cases  he  has  designated  by  the  letter  A  (No.  103). 


•±60  PATHOGENIC   AEROBIC   BACILLI 

98.    PROTEUS   OF   KARLINSKI. 

Synonym. — Bacillus  murisepticus  pleomorphus  (Karlinski).  Probably 
identical  with  Proteus  vulgaris  of  Hauser. 

Obtained  by  Karlinski  (1889)  from  a  fibro-purulent  uterine  discharge,  and 
from  abscesses  in  the  uterus  and  its  appendages  in  a  puerperal  woman. 

Morphology.  —Resembles  Proteus  vulgaris  of  Hauser  in  its  morphology, 
and  presents  various  forms  under  different  circumstances  relating  to  the 
culture  medium,  the  temperature,  age  of  culture,  etc. — sometimes  as  spheri 
cal  or  short  oval  cells,  at  others  as  longer  or  shorter  rods  or  spiral  filaments ; 
usually  as  bacilli  with  round  ends  two  and  a  half  times  as  long  as  thick,' 
often  united  in  pairs. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  not  observed.  Grows  rapidly  in  the 
usual  culture  media  at  the  room  temperature.  In  gelatin  plate  cultures,  at 
the  end  of  ten  hours,  small  colonies  are  developed  which  have  well-defined 
outlines,  are  oval  or  whetstone-shaped,  of  a  light-brown  color  by  transmitted 
light  and  white  by  reflected  light,  with  a  somewhat  darker  margin  and  a 
smooth  surface,  sometimes  marked  by  shallow  clefts ;  at  the  end  of  twenty 
hours  the  colonies  commence  to  have  irregular  margins,  and  the  surface  of 
the  gelatin  above  them  is  marked  by  concentric  rings.  At  the  end  of  thirty 
hours  the  colonies  have  formed  a  bulb-shaped  liquefaction  of  the  gelatin, 
and  delicate,  ray-like  offshoots  are  seen  around  the  margin.  At  the  end  of 
two  days  the  bulbous  cavities  are  aboutone  and  a  half  millimetres  in  diameter 
and  contain  a  cloudy,  grayish-white  liquid ;  they  are  surrounded  by  a  moist- 
looking,  gray,  irregular  marginal  zone.  In  gelatin  stick  cultures,  at  the  end 
of  twenty -four  hours,  a  funnel-shaped  liquefaction  of  the  gelatin  occurs  near 
the  surface,  and  a  grayish-white,  cloudy  mass  is  developed  along  the  line  of 
puncture;  at  the  end  of  forty- eight  hours  a  sac-like  pouch  of  liquefied  gela- 
tin has  formed,  and  in  the  course  of  four  or  five  days  the  gelatin  is  entirely 
liquefied.  Upon  agar  plates  the  colonies  are  at  first  oval  in  form  and  white 
by  reflected  light,  or  pale  brown  by  transmitted  light  ;  at  the  end  of  thirty 
hours  the  surface  becomes  wrinkled  or  folded  and  is  surrounded  by  radiat- 
ing, delicately  twisted  offshoots.  Upon  the  surface  of  agar  a  white  layer 
is  developed.  Upon  potato  a  whitish-gray,  soft,  homogeneous  layer,  which 
after  standing  along  time  has  a  darker  color.  Upon  blood  serum  a  thin, 
grayish-white  layer  is  formed  and  the  serum  is  rapidly  liquefied.  Gelatin 
cultures  acquire  a  strongly  alkaline  reaction  and  give  off  a  disagreeable 
odor  resembling  that  of  butyric  acid. 

Pathogenesis. — White  mice  inoculated  at  the  root  of  the  tail  die  in  from 
twenty-two  to  twenty-four  hours  ;  the  spleen  is  greatly  enlarged;  the  bacilli 
are  found  in  blood  from  the  various  organs — less  numerous  in  blood  from 
the  heart.  Field  mice  and  house  mice  are  less  susceptible.  Subcutaneous 
injections  in  rabbits  may  give  rise  to  local  inflammation  and  also  to  general 
infection.  In  white  rats  and  guinea-pigs  a  local  abscess  may  result  from  a 
subcutaneous  inoculation. 

99.    PROTEUS   MIRABILIS. 

Obtained  by  Hauser  (1885)  from  putrefying  animal  substances. 

Morphology. — Bacilli  resembling  very  closely  the  preceding  species  (Pro- 
teus vulgaris),  but  presenting  more  numerous  involution  forms,  which  may 
be  spherical,  pear-shaped,  or  spermatozoa-like,  etc.  The  bacilli  are  about 
0.6  n  in  diameter  and  vary  greatly  in  length,  being  sometimes  nearly  spheri- 
cal, or  forming  rods  of  2  to  3.75  /*  in  length,  or  long  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  has  not  been  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Does  not  liquefy  gelatin  as 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS.  401 

rapidly  as  Proteus  vulgaris.  Upon  gelatin  plates,  at  the  end  of  twelve 
hours,  superficial  colonies  of  two  to  three  millimetres  in  diameter  are  formed ; 
under  a  low  power  these  appear  finely  granular  and  brownish  in  color,  and 
have  an  irregular  outline;  outgrowths  from  the  margin  extend  in  varkms 
directions  and  form  new  colonies,  which  may  be  attached  for  a  time  by  a 
long  and  slender  thread  consisting  of  bacilli.  The  movement  of  these  new 
colonies  is  not  as  pronounced  as  in  the  case  of  the  preceding  species,  and 


FIG.  157. — "  Swarming  islands  "  of  Proteus  mirabilis,  from  a  gelatin  culture,    x  285.    (Hauser.) 

they  are  characterized  by  the  presence  of  numerous  distorted  bacilli — invo- 
lution forms.    The  deep  colonies  form  spiral  zoogloea  masses. 

In  gelatin  stick  cultures  the  whole  surface  is  first  covered  with  threads 
and  islands  of  bacilli,  which  after  a  time  form  an  anastomosing  network,  and 
finally  a  confluent  layer  which  at  the  end  of  forty-eight  hours  is  rather  thick, 


FIG.  157.— Spiral  zoogloea  from  a  culture  of  Proteus  mirabilis.    X  95.    (Hauser.) 

with  a  moist,  shining  surface  and  grayish  color,  and  appears  to  be  perforated 
with  numerous  small,  sieve-like  openings.  These  thinner  and  transparent 
places  disappear  after  a  time,  and  at  the  end  of  two  or  three  days  liquefac- 
tion of  the  gelatin  commences;  complete  liquefaction  does  not  occur  until 
the  fifth  or  sixth  day,  or  even  later.  Along  the  line  of  puncture  finely  gran- 
ular colonies  are  first  formed,  from  which  long  threads  are  given  off,  which 
form  after  a  short  time  a  tolerably  broad  zone  of  threads  and  spiral  zoogloea 


masses. 


39 


463  PATHOGENIC   AEROBIC   BACILLI 

Pathogenesis. — In  Hauser's  experiments  filtered  cultures  (two  to  six  cubic 
centimetres),  injected  into  the  circulation  or  into  the  cavity  of  the  abdomen 
in  rabbits,  caused  fatal  toxemia. 

100.  PROTEUS  ZENKERI. 

Obtained  by  Hauser  (1885)  from  putrefying  animal  substances. 

Morphology. — Bacilli  which  vary  greatly  in  length — average  about  1. 65  /*, 
and  about  0.4  ju.  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Upon  the  surface  of  nutrient 
gelatin  a  laminated  mass  forms  about  the  point  of  puncture,  from  the  peri- 
phery of  which  offshoots  are  given  off,  at  the  extremities  of  which  colonies 
are  formed,  as  in  the  case  of  Proteus  mirabilis.  Gi'adually  a  rather  thick, 
grayish- white,  opaque  layer  is  formed,  which  covers  the  entire  surface  of  the 
gelatin  and  is  easily  detached  from  it.  This  species  is  distinguished  from 
the  two  preceding  by  the  fact  that  it  does  not  liquefy  gelatin  or  blood  serum 
and  does  not  give  off  a  decided  putrefactive  odor  when  cultivated  in  these 
media. 

Pathogenesis. — Considerable  quantities  injected  into  small  animals  give 
rise  to  local  abscesses  and  to  symptoms  of  toxaemia. 

101.  PROTEUS   SEPTICUS. 

Obtained  by  Babes  (1889)  from  the  mucous  membrane  of  the  intestine  and 
the  various  organs  of  a  boy  who  died  of  septicaemia. 

Morphology. — Bacilli  about  0. 4  /j.  broad  and  varying  greatly  in  length; 
slightly  curved  rods  or  flexible  filaments,  often  associated  in  loose  chains. 

Stains  by  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  In  gelatin  plates  centres  of  liquefaction  are  quickly  formed 
and  rapidly  extend.  The  spherical,  liquefied  places  have  at  first  a  wavy  or 
dentate  outline,  and  are  surrounded  by  a  branching,  transparent,  granular 
margin  which  rapidly  extends  in  advance  of  the  liquefaction.  In  stick  cul- 
tures in  nutrient  gelatin  liquefaction  of  the  entire  contents  of  the  tube  may 
take  place  within  twenty-four  hours,  or  a  broad,  liquefied  sac  is  formed 
along  the  line  of  puncture.  Gelatin  cultures  give  off  a  very  disagreeable 
odor.  Upon  the  surface  of  nutrient  agar,  at  37°  C.,  a  peculiar,  thick  net- 
work extends  over  the  surface  in  the  course  of  a  few  hours.  Upon  potato  an 
elevated,  brownish-white,  shining  layer  is  formed.  Blood  serum  is  lique- 
fied by  this  bacillus. 

Pathogenesis. — Pathogenic  for  mice,  less  so  for  rabbits.  In  mice  death 
occurs  in  from  one  to  three  days  after  the  subcutaneous  injection  of  a  small 
quantity  of  a  pure  culture  ;  the  bacilli  are  present  in  the  blood  in  small 
numbers. 

102.    PROTEUS   LETHALIS. 

Synonym. — Proteus  bei  Lungengangran  des  Menschen  (Babes). 

Obtained  by  Babes  (1889)  from  the  spleen  and  gangrenous  portions  of  the 
lung  of  a  man  who  died  of  septicaemia. 

Morphology. — Short  rods  with  round  ends,  from  0.8  to  1.5  ju.  thick  ;  often 
swollen  in  the  middle,  like  a  lemon  or  a  flask  ;  forms  short,  flexible  filaments 
which  also  present  similar  swellings.  f 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Not  observed  to  form  spores.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  In  gelatin  plates  forms  hemi- 
spherical, elevated,  whitish,  translucent  colonies,  which  later  send  out 


NOT    DESCRIBED    IN    PREVIOUS    SECTIONS.  463 

coarse  branches  which  ramify  over  the  surface  of  the  gelatin.  A  similar 
growth  is  observed  upon  the  surface  of  gelatin  stick  cultures,  and  an  abun- 
dant development  takes  place  along  the  line  of  puncture.  Upon  nutrient 
cigar  a  thick,  opaque,  slightly  yellowish  layer  is  formed.  Upon  potato  a 
moist,  shining,  brownish  layer  is  developed,  and  the  potato  acquires  a 
brownish  color.  Upon  blood  serum  the  growth  is  less  abundant  than  on 
agar;  the  blood  serum  is  not  liquefied.  This  bacillus  grows  rapidly  at  the 
room  temperature;  it  is  destroyed  by  a  temperature  of  80°  C.,  and  presum- 
ably does  not  form  spores. 

Pathogenesis. — Recent  cultures  are  very  pathogenic  for  mice  and  for 
rabbits,  less  so  for  guinea-pigs.  The  subcutaneous  injection  of  a  small 
quantity  of  a  pure  culture  kills  susceptible  animals  in  two  or  three  days. 
More  or  less  cedema  is  found  at  the  point  of  inoculation.  Injections  into  the 
rectum  of  rabbits  gave  rise  to  hsemorrhagic  enteritis,  peritonitis,  and  death 
at  the  end  of  four  days. 

103.    BACILLUS   A   OF  BOOKER. 

Obtained  by  Booker  (1889)  from  the  al vine  discharges  of  children  suffer- 
ing from  cholera  infantum. 

Morphology. — Bacilli  with  round  ends,  varying  greatly  in  length,  usually 
three  to  four  n  long  and  0.7  ju  broad  (in  recent  agar  cultures).  In  older  cul- 
tures the  bacilli  are  shorter  and  smaller. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, motile  bacillus.  Grows  at  the  room  temperature  in  the  usual  culture 
media.  In  gelatin  plates  colonies  are  visible  at  the  end  of  twenty-four 
hours;  under  the  microscope  these  are  nearly  colorless,  and  liquefaction 
soon  occurs  around  them.  In  gelatin  stick  cultures  complete  liquefaction 
occurs  in  three  or  four  days.  Upon  agar  a  colorless  layer  covering  the  entire 
surface  is  developed  in  three  or  four  days,  and  an  abundant  development 
occurs  along  the  line  of  puncture.  Agar  colonies  have  a  bluish  look,  and 
are  surrounded  by  an  indistinct  halo  which  shades  off  gi'adually  into  the 
surrounding  agar  ;  under  a  low  power  the  colonies  are  light-brown  and  the 
borders  indistinct ;  the  surface  has  a  delicate,  wavy  appearance.  Upon  po- 
tato the  growth  is  luxuriant  and  of  a  dirty-brown  color.  Blood  serum  is 
liquefied  by  this  bacillus. 

Milk  is  coagulated  into  a  gelatinous  mass  having  an  alkaline  reaction ; 
later  the  coagulum  is  dissolved. 

Pathogenesis. — Mice  and  guinea-pigs  fed  with  cultures  in  milk  die  in  from 
one  to  eight  days. 

104.    BACILLUS  ENDOCARDITIDIS   GRISEUS. 

Obtained  by  Weichselbaum  (1888)  from  the  affected  valves  in  a  case  of 
endocarditis  recurrens  ulcerosa. 

Morphology. — Short  rods  with  rounded  or  somewhat  pointed  ends,  about 
two  to  three  times  as  long  as  broad — of  about  the  same  dimensions  as  the 
bacillus  of  typhoid  fever. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method;  the 
longer  rods  from  old  cultures  are  irregularly  stained. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Refractive  bodies  may  be  seen  in  some  of  the  rods,  which  resemble  spores  and 
are  stained  by  the  method  of  Ernst,  but  they  do  not  show  the  resistance  of 
known  spores  to  physical  and  chemical  agents.  Grows  well  in  the  usual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates  colonies  are 
formed  which  resemble  those  of  Friedlander's  bacillus,  but  which  gradually 
acquire  a  gray  or  grayish- white  color.  The  prominent,  convex,  superficial 
colonies  under  a  low  power  are  finely  granular  and  grayish-brown  in  color; 
the  deep  colonies  are  yellowish-brown  in  color,  have  slightly  notched  mar- 
gins, and  the  surface  is  covered  with  minute  projections.  In  stick  cultures 


464  PATHOGENIC   AEROBIC   BACILLI 

a  rather  thin,  circular  layer  forms  about  the  point  of  puncture ;  this  has  the 
appearance  of  stearin ;  later  it  becomes  grayish- white  and  the  margins  are 
marked  by  radiating  lines.  Upon  the  surface  of  nutrient  agar  a  similar 
growth  occurs  which  has  a  pale-brown  or  reddish-gray  color.  Upon  potato 
in  the  incubating  oven  an  abundant  development  occurs,  forming  a  dry- 
looking  layer  of  a  grayish-brown  color  and  having  irregularly  notched  mar- 
gins. Upon  blood  serum  an  abundant,  grayish- white  growth  of  cream-like 
consistence  forms  along  the  impfstrich;  later  this  has  a  reddish  gray  color. 
This  bacillus  grows  to  the  bottom  of  the  line  of  puncture  in  stick  cultures, 
and  is  no  doubt  a  facultative  anaerobic. 

Pathogenesis. — Pathogenic  for  white  mice  and  for  guinea-pigs. 

105.    BACILLUS   ENDOCARDITIDIS   CAPSULATUS. 

Obtained  by  Weichselbaum  (1888)  from  thrombi  and  embolic  infarctions 
in  the  spleen  and  kidneys  of  a  man  who  died  from  endocarditis  with  forma- 
tion of  thrombi. 

Morphology. — Resembles  Friedlander's  bacillus,  and  is  frequently  sur- 
rounded by  a  capsule,  which  may  be  stained ;  also  forms  long,  curved  fila- 
ments, in  the  protoplasm  of  which  vacuoles  may  be  observed  in  stained  pre- 
parations. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method ;  by 
staining  with  fuchsin  and  carefully  decolorizing  with  diluted  alcohol  the 
presence  of  a  capsule  may  be  demonstrated. 

Biological  Characters. — Anaerobic,  non-liquefying  bacillus.  Grows  in 
the  usual  culture  media  at  the  room  temperature. 

In  gelatin  stick  cultures  development  occurs  along  the  line  of  puncture, 
and  on  the  surface  as  a  rather  thin,  white,  dry  layer  which  resembles  stearin. 
In  agar  plates  the  superficial  colonies  are  thin,  about  two  millimetres  in 
diameter  and  gray  in  color  ;  under  a  low  power  the  margins  are  trans- 
parent and  colorless,  and  the  centre  resembles  the  deep  colonies;  these  are 
very  small  and  grayish-white  in  color  ;  under  a  low  power  the  surface  is 
seen  to  be  covered  with  tooth-like,  projecting  masses,  the  margin  is  dentate 
and  has  a  pale-yellow  color,  while  the  centre  is  yellowish- brown. 

Pathogenesis. — Rabbits  are  killed  by  the  injection  of  a  considerable  quan- 
tity of  a  pure  culture  into  the  cavity  of  the  abdomen  or  subcutaneously. 

10G.    BACILLUS   OF   LESAGE. 

Obtained  by  Lesage  (1887)  from  the  green-colored  discharges  of  infants 
suffering  from  "  green  diarrhoea,"  and  supposed  to  be  the  cause  of  this  com- 
plaint (?)•  According  to  Baumgarten,  this  bacillus  is  probably  identical 
with  a  well-known  pigment-producing  saprophyte — the  Bacillus  fluorescens 
non-liquefaciens. 

Morphology. — Small  bacilli  with  round  ends,  about  2.4  ju  long  and  0.75  to 
1 H  broad ;  in  old  cultures  may  grow  out  into  long  filaments. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic,  non-liquefying  (slight  liquefaction 
in  old  cultures),  motile  bacillus.  Forms  spores.  Grows  slowly  at  the  room 
temperature  in  the  usual  culture  media,  more  rapidly  at  25°  to  35°  C.  Upon 
gelatin  plates  superficial  colonies  are  formed  which  have  irregularly  dentate, 
leaf-like  margins  and  a  smooth  surface ;  they  produce  a  greenish  color  in  the 
gelatin.  In  gelatin  stick  cultures  a  thin,  smooth,  transparent,  greenish 
layer  forms  upon  the  surface,  and  in  the  course  of  four  or  five  days  the  gela- 
tin has  acquired  throughout  a  bright-green  color.  Upon  potato  a  dark- 
green  layer  is  formed.  The  cultures  have  the  odor  of  old  urine. 

Pathogenesis. — The  injection  of  a  considerable  quantity  of  a  pure  culture 
•into  the  ear  vein  of  a  rabbit  is  said  to  have  produced  green  diarrhoea,  and 
the  same  result  was  obtained  by  mixing  cultures  with  the  food  of  these  ani- 
mals. These  results  have  not  yet  been  confirmed  by  other  investigators. 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS.  405 

107.    BACILLUS   OF   DEMME. 

Obtained  by  Demme  (1888)  from  the  fluid  contents  of  the  tumors  and 
pustules  of  erythema  nodosum,  and  also  from  the  blood  of  the  affected  indi- 
vidual. 

Morphology. — Bacilli  with  round  ends,  from  2.2  to  2.5  jj.  long-  and  0.5  to 
0.7  >u  broad;  usually  collected  in  smaller  or  larger  groups. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic  (facultative  anaerobic?)  bacillus, 
which  does  not  grow  in  nutrient  gelatin  at  the  room  temperature.  Grows 
in  nutrient  agar  at  35°  to  37°  C.  Forms  spores.  In  agar plates,  at  35°  to  37° 
C.,  smooth,  spherical,  shining  white  colonies  are  formedin  from  forty-eight 
to  sixty  hours,  which  at  the  end  of  six  or  seven  days  may  have  the  size  of  a 
small  coin — five  centimes;  these  are  marked  by  lines  radiating  from  the 
centre,  which  are  slightly  elevated  above  the  surface  of  the  colony  and  have 
a  silvery  lustre  by  obliquely  reflected  light;  the  margins  of  the  colony  are 
fringe-like,  and  after  ten  or  twelve  days  conical  offshoots  are  given  off  from 
this  thready  margin.  In  agar  stick  cultures  growth  occurs  along  the  line 
of  puncture  in  the  form  of  a  thorny  column  which  has  a  paraffin-like 
lustre. 

Pathogenesis. — According  to  Demme,  when  injected  subcutaneously  into 
guinea-pigs,  or  by  rubbing  pure  cultures  into  the  scarified  skin,  an  eruption 
occurs  which  resembles  that  of  erythema  nodosum  and  is  followed  by  a 
gangrenous  condition  of  the  skin.  Rabbits,  dogs,  and  goats  proved  to  be 
refractory. 

108.    BACILLUS   CEDEMATIS  AEROBICUS. 

Synonym. — A  new  bacillus  of  malignant  oedema  (Klein). 

Obtained  from  garden  earth  by  inoculation  in  guinea-pigs. 

Morphology. — Bacilli  from  0.8  to  2.4  /win  length  and  0.7  u  thick;  grow 
out  into  long  filaments. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non-lique- 
fying, motile  bacillus.  Does  not  form  spores.  Grows  at  the  room  tempera- 
ture in  the  usual  culture  media.  Upon  gelatin  plates,  at  the  end  of  twenty- 
four  hours,  small,  gray,  punctiform  colonies  are  developed ;  at  the  end  of 
forty-eight  hours  the  superficial  colonies  are  seen  as  flat,  grayish,  transparent 
plaques,  the  margins  of  which  are  thin  and  irregularly  notched ;  these  attain 
a  diameter  of  several  millimetres  in  the  course  of  a  few  days.  The  deep  colo- 
nies do  not  exceed  the  diameter  of  a  pin's  head;  they  remain  spherical,  and 
by  transmitted  light  have  a  brownish  color.  In  gelatin  stick  cultures  a 
white  line  of  growth  is  developed  along  the  track  of  the  inoculating  needle, 
and  at  the  bottom  of  this  isolated,  punctiform  colonies  are  seen ;  upon  the 
surface  a  flat,  thin,  transparent,  grayish  layer  with  a  dentate  margin  is 
developed.  Upon  the  surface  of  agar  a  smeary,  grayish-white  stripe  is  de- 
veloped along  the  impfstrich.  Alkaline  bouillon,  at  the  end  of  twenty-four 
hours  at  37J  C.,  is  densely  clouded,  and  later  contains  numerous  flocculi,  but 
no  pellicle  upon  the  surface ;  at  the  end  of  twenty -four  hours  the  reaction 
becomes  strongly  alkaline.  Upon  potato  a  viscid,  yellowish  stripe  is  devel- 
oped along  the  line  of  inoculation.  In  deep  cultures  in  nutrient  gelatin  gas 
bubbles  are  developed  in  from  twenty- four  to  forty-eight  hours ;  these  are 
attached  to  the  isolated  colonies. 

Pathogenic  for  guinea-pigs,  rabbits,  and  white  mice.  The  animals  die 
within  twenty-four  hours — when  very  small  quantities  are  injected  subcu- 
taneously into  guinea-pigs  they  may  live  for  two  or  three  days  and  sometimes 
recover.  The  lethal  dose  of  a  bouillon  culture  is  from  one-fourth  to  one- 
half  cubic  centimetre,  but  one  drop  of  the  cedematous  fluid  from  the  subcu- 
taneous connective  tissue  of  an  inoculated  animal  is  infallibly  fatal.  In 
guinea-pigs  an  extensive  inflammatory  cedema  is  produced  by  subcutaneous 
inoculations ;  the  spleen  is  but  slightly  enlarged.  In  rabbits  but  slight  oedema 


466  PATHOGENIC   AEROBIC   BACILLI 

and  a  small  spleen.  In  mice  no  oedema  and  a  slightly  enlarged  spleen.  The 
bacilli  are  found  in  the  blood  of  the  heart  in  small  numbers,  and  are  some- 
what more  numerous  in  the  spleen,  especially  in  mice. 

109.    BACILLUS   OF   LETZERICH. 

Obtained  by  Letzerich  (1887)  from  the  urine  of  children  suffering  from 
"nephritis  interstitialis  primaria."  Etiological  relation  not  satisfactorily 
demonstrated. 

Morphology. — Bacilli  with  round  ends,  straight  or  slightly  curved,  often 
forming  filaments. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters.— An  aerobic,  liquefying  bacillus.  Forms  spores. 
Grows  rapidly  in  nutrient  gelatin  at  a  comparatively  low  temperature — best 
at  14°  C.  Upon  gelatin  plates,  at  14°  C.,  complete  liquefaction  has  occurred 
in  from  thirty-six  to  forty-eight  hours,  and  a  thin,  white  film  covers  the 
surface  of  the  liquefied  gelatin;  the  same  in  gelatin  stick  cultures. 

Pathogenesis. — Rabbits  injected  in  the  cavity  of  the  abdomen  are  said  to 
die  in  about  fourteen  days.  The  autopsy  shows  an  extensive  abscess,  en- 
largement and  congestion  of  the  kidneys,  enlarged  spleen,  etc.  The  bacilli 
are  found  in  great  numbers  in  all  of  the  organs. 

110.    BACILLUS  OF  SCHIMMELBUSCH. 

Obtained  by  Schimmelbusch  (1889)  from  the  necrotic  tissues  at  the  boun- 
dary line  of  the  still  living  tissues  in  cancrum  oris,  or  noma.  Etiological 
relation  not  proved. 

Morphology. — Small  bacilli  with  round  ends;  often  united  in  pairs; 
may  grow  out  into  long  filaments. 

Stains  best  with  an  aqueous  solution  of  gentian  violet ;  does  not  stain  by 
Gram's  method. 

Biological  Characters. — An  aerobic,  non- liquefy  ing  bacillus.  Grows  in 
the  usual  culture  media  at  the  room  temperature — better  in  the  incubating 
oven  at  30°  to  37°  C.  Upon  gelatin  plates  forms  below  the  surface  spheri- 
cal, finely  granular,  grayish- white  colonies,  which  come  to  the  surface  and 
form  elevated  masses  with  slightly  dentate  margins  and  an  irregularly  cleft 
surface.  In  gelatin  stick  cultures  the  growth  along  the  line  of  inoculation 
is  coarsely  granular ;  upon  the  surface  a  broad,  flat  layer.  Upon  the  sur- 
face of  agar,  in  twenty -four  hours  at  37°  C.,  a  grayish- white  layer  along  the 
line  of  inoculation,  which  is  smooth  and  about  three  millimetres  in  breadth. 
Upon  potato,  at  the  end  of  two  weeks,  a  broad,  moist,  grayish- white  layer 
from  two  to  three  millimetres  wide.  Upon  coagulated  ascitic  fluid,  at  the 
end  of  twenty-four  hours,  a  thin  layer  along  the  impfstrich,  from,  which 
lateral  offshoots  are  given  off. 

Pathogenesis. — Cultures  injected  subcutaneously  into  rabbits  produced 
local  abscesses  only ;  not  pathogenic  for  mice  or  pigeons. 

111.    BACILLUS   FCETIDUS   OZJENM. 

Obtained  by  Hajek  (1888)  from  the  nasal  secretions  of  patients  with  ozae- 
na.  Etiological  relation  not  proved. 

Morphology. — Short  bacilli,  but  little  longer  than  broad;  usually  in  pairs, 
or  in  chains  of  six  to  ten  elements. 

Stains  with  Loffler's  solution  of  methylene  blue  or  solutions  of  aniline 
colors  in  aniline  water — not  so  well  in  aqueous  solutions ;  does  not  stain  by 
Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  not  observed.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates  the  colonies, 
at  the  end  of  thirty-six  hours,  are  scarcely  visible,  with  well-defined  but 


NOT   DESCRIBED    IN   PREVIOUS   SECTIONS.  467 

somewhat  irregular  outlines;  later  liquefaction  commences  and  crater-like 
depressions  in  the  gelatin  ai'e  formed,  in  which  a  gas  bubble  is  seen ;  com- 
plete liquefaction  occurs  in  the  course  of  a  few  days.  In  gelatin  stick  cul- 
tures liquefaction  occurs  all  along  the  line  of  inoculation,  and  is  complete 
at  the  end  of  from  eight  to  fourteen  days.  Upon  agar  plates  the  colonies 
are  granular  in  the  centre,  and  the  margins,  under  a  low  power,  are  seen  to 
be  fringed.  Upon  the  surface  of  agar  a  moist,  slimy  layer  is  formed  along 
the  impfstrich.  Upon  potato,  at  the  end  of  twenty-four  hours,  a  yellowish- 
brown  layer  is  formed.  Upon  blood  serum  development  is  rapid  in  the  form 
of  a  whitish  layer,  which  extends  over  the  whole  surface.  The  cultures, 
and  especially  those  kept  in  the  incubating  oven,  give  off  a  disagreeable 
putrefactive  odor,  which  is  most  intense  in  the  blood-serum  cultures. 

Pathogenesis. — Pathogenic  for  mice.  When  injected  subcutaneously 
into  rabbits  it  gives  rise  to  intense  local  inflammation  and  progressive  gan- 
grene of  the  connective  tissue. 

112.  BACILLUS  OF  LUMNITZER. 

Obtained  by  Lumnitzer  (1888)  from  the  bronchial  secretions  of  persons 
suffering  from  "putrid  bronchitis."  Etiological  relation  not  demonstrated. 

Morphology. — Bacilli  with  round  ends,  from  1.5  to  2  n  long,  somewhat 
curved. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  motile  bacillus.  Does  not  grow  in 
nutrient  gelatin  at  the  room  temperature.  Grows  slowly  upon  agar  and 
more  rapidly  upon  blood  serum  at  36°  to  38°  C.  Forms  spores.  Upon  agar 
plates,  at  37°  C.,  small,  grayish-white  colonies  are  formed  in  two  or  three 
days;  upon  the  surface  these  form  hemispherical  masses  which  slowly  in- 
crease in  size.  At  the  end  of  six  or  seven  days  the  cultures  give  off  a  dis- 
agreeable odor,  quite  like  that  given  off  by  the  sputum  of  the  cases  of  putrid 
bronchitis  from  which  the  bacillus  was  obtained.  Upon  the  surface  of 
blood  serum  the  growth  is  rapid  and  forms  grayish-white,  shining  colonies, 
of  about  one  millimetre  in  diameter,  which  become  confluent  at  the  end  of 
about  four  days,  and  cover  the  entire  surface  in  eight  or  nine  days. 

Pathogenesis. — Causes  a  purulent  inflammation  when  injected  into  the 
lungs  of  rabbits,  which  involves  the  bronchial  tubes,  the  blood  vessels,  and 
the  pulmonary  alveoli ;  when  injected  subcutaneously  produces  inflamma- 
tion and  necrosis  of  the  tissues. 

113.  BACILLUS  OP  TOMMASOLI. 

Obtained  by  Tommasoli  (1889)  from  the  hairs  of  the  head  of  a  patient  suf- 
fering from  a  form  of  sycosis  supposed  to  be  due  to  the  presence  of  this 
parasite  (?). 

Morphology. — Short,  straight  bacilli,  with  round  ends,  from  1  to  1.8  // 
long  and  from  0.25  to  0.3  /*  broad  ;  often  united  in  chains  containing  four 
to  six  elements. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Does  not  form  spores.  Grows  slowly  at  the  room  temperature  in  the 
usual  culture  media.  Upon  gelatin  plates,  at  the  end  of  four  days,  the  deep 
colonies  are  seen  as  small,  white  points,  the  superficial  colonies  as  smooth 
discs  of  a  grayish  color.  At  the  end  of  a  month  the  deep  colonies  may  be  as 
large  as  a  mustard  seed;  the  superficial  are  thin,  shining,  and  slimy,  and 
have  a  diameter  of  one  to  two  millimetres.  In  gelatin  stick  cultures  a  con- 
vex, shining,  white  mass  is  developed  at  the  point  of  inoculation,  and  along 
the  line  of  puncture  in  the  course  of  five  or  six  days  a  white  line  of  growth 
is  seen  which  consists  of  closely  crowded,  small  colonies.  Upon  agar  the 
development  is  very  slow,  and  forms  at  first  thin,  slimy,  grayish-white 
patches  which  are  distributed  along  the  impfstrich ;  later  these  become  con- 


408  PATHOGENIC   AEROBIC   BACILLI 

fluent  and  form  shining,  wavy  stripes.  Upon  potato  the  development  is 
more  rapid  and  forms  elevated,  sharply  denned  colonies,  of  granular  ap- 
pearance and  of  a  chamois-yellowish-white  color ;  later  these  become  conflu- 
ent ;  the  potato  acquires  a  dark-gray  color  and  the  culture  gives  off  an  in- 
tensely disagreeable  odor. 

Pathogenesis. — Pure  cultures  rubbed  into  the  skin  of  man  produce,  at 
the  end  of  twenty-four  hours,  intense  itching,  redness,  and  a  vesicular  erup- 
tion about  the  hairs ;  at  the  end  of  three  days  small  pustules  are  formed, 
from  which  pure  cultures  may  be  recovered  (Tommasoli) .  Subcutaneous  in- 
jection into  a  rabbit  produced  no  other  result  than  the  formation  of  a  small 
abscess. 

114.    BACILLUS   OF  SCHOU. 

Obtained  by  Schou  (1885)  in  rabbits  suffering  from  vagus  pneumonia 
resulting  from  section  of  the  vagi ;  found  also  in  the  buccal  secretions  of  a 
healthy  rabbit — one  out  of  twenty-five  examined. 

Morphology. — Described  as  elliptical  cocci,  or  diplococci,  or  as  short, 
thick  bacilli. 

Stains  with  the  aniline  colors  usually  employed,  but  not  by  Gram's 
method. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  In  gelatin  plates 
forms  spherical,  opaque,  granular  colonies  having  a  slightly  rough  surface. 
At  the  end  of  twenty -four  hours,  under  the  microscope,  active  movements 
are  observed  in  these  colonies,  which  are  surrounded  by  a  zone  of  diverging 
rays.  Iri  gelatin  stick  cultures  liquefaction  quickly  occurs,  and  a  copious 
white  deposit,  consisting  of  bacilli,  is  seen  at  the  bottom  of  the  tube. 

Pathogenesis. — Pure  cultures  injected  into  the  trachea,  the  pleura! 
cavity,  or  the  lungs  are  said  to  have  produced  fatal  pneumonia  in  rabbits ;  a 
similar  result  was  obtained  from  inhalation  experiments. 

115.    BACILLUS  NECROPHORUS. 

Obtained  by  Loftier  (1884)  from  rabbits  which  had  been  inoculated  in  the 
anterior  chamber  of  the  eye  with  small  fragments  of  a  broad  condyloma. 

Morphology. — Bacilli  of  various  lengths,  often  forming  long,  slender, 
wavy  filaments. 

Biological  Characters. — Does  not  grow  in  the  ordinary  culture  media, 
but  may  be  cultivated  in  neutral  rabbit  bouillon ;  a  less  favorable  medium  is 
blood  serum  from  the  horse.  When  small  fragments  of  the  organs  of  an 
infected  animal  are  placed  in  rabbit  bouillon  they  become  enveloped,  in  the 
course  of  three  or  four  days,  in  a  cotton-like  mass  of  filaments ;  later  white 
flocculi  are  distributed  through  the  medium,  which  consist  of  similar  fila- 
ments loosely  interlaced.  The  filaments  may  present  swellings  here  and 
there,  which  are  supposed  to  represent  involution  forms. 

Pathogenesis. — Rabbits  inoculated  in  the  ear  or  in  the  anterior  chamber 
of  the  eye  with  the  flocculi  from  a  bouillon  culture,  or  with  a  small  frag- 
ment of  one  of  the  organs  of  an  infected  animal,  usually  die  at  the  end  of 
eight  days.  At  the  autopsy  a  necrotic,  cheesy  process  is  found  at  the  point 
of  inoculation,  and  purulent  foci,  surrounded  by  inflamed  or  necrotic  areas, 
in  the  lungs ;  also  purulent  collections  in  the  myocardium ;  these  were  the 
principal  pathological  changes,  but  sometimes  nodules  were  found  in  the 
abdominal  viscera.  The  slender  bacilli  described  were  found  in  all  of  these 
localized  centres  of  infection.  Pathogenic  also  for  white  mice,  which  usually 
died  in  six  days  after  being  inoculated  subcutaneously. 

116.   BACILLUS  COPROGENES  FCETIDUS. 

Synonym. — Darmbacillus  of  Schottelius. 

Obtained  by  Schottelius  (1885)  from  the  intestinal  contents  of  pigs  which 
had  died  of  Schweinerothlauf  (rouget). 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS  469 

Morphology.  —Resembles  Bacillus  subtilis,  but  is  shorter,  with  rounded 
ends. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Forms  spores  in  presence  of  oxygen  in  the  course  of  three  or  four  days  at 
the  room  temperature ;  these  are  oval  in  form  and  are  arranged  in  rows; 
when  they  germinate  this  occurs  in  a  direction  perpendicular  to  their  long 
axis  and  to  that  of  the  filament  in  which  they  developed  ;  as  a  result  of 
this  the  newly  formed  rods  lie  parallel  to  each  other.  In  gelatin  stick  cul- 
tures the  growth  upon  the  surface  consists  of  a  thin,  transparent,  grayish 
layer;  along  the  line  of  puncture  crowded,  pale-yellow  colonies  are  de- 
veloped. The  cultures  give  off  an  intense  putrefactive  odor.  \Jponpotato 
a  dry,  grayish  layer  is  formed,  which  may  be  about  0.5  millimetre  in  thick- 
ness. 

Pathogenesis. — Not  pathogenic  for  mice  or  for  rabbits  when  injected  in 
small  amounts,  but  in  considerable  quantities  causes  fatal  toxaemia  in  rabbits. 

117.    BACILLUS   OXYTOCUS   PERNICIOSUS. 

Obtained  by  Wyssokowitsch  from  milk  which  had  been  standing  for  a 
long  time. 

Morphology. — Short  bacilli  with  rounded  ends,  somewhat  thicker  and 
shorter  than  the  lactic  acid  bacillus. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  In  gela- 
tin plates  the  deep  colonies  are  small,  spherical,  finely  granular,  and  of  a 
yellowish  or  brownish-yellow  color.  The  superficial  colonies  are  hemi- 
spherical masses  of  a  grayish-white  color— by  transmitted  light,  light-brown. 
They  may  have  a  diameter  of  one  and  one-half  millimetres. 

In  gelatin  stick  cultures  the  growth  is  at  first  "nail-like"  ;  later  it  ex- 
tends over  the  entire  surface  of  the  gelatin.  It  causes  coagulation  of  milk, 
with  a  sour  reaction,  within  twenty-four  hours.  The  cultures  are  without 
odor. 

Pathogenesis. — Small  closes  are  not  pathogenic  for  mice  or  for  rabbits,  but 
considerable  quantities  injected  into  the  circulation  of  rabbits  cause  their 
death  in  from  three  to  twenty-two  hours.  Soon  after  the  injection  an  abun- 
dant diarrhoea  is  developed.  At  the  autopsy  a  haemorrhagic  inflammation 
of  the  intestinal  mucous  membrane  is  the  principal  pathological  appearance 
observed. 

118.    BACILLUS  SAPROGENES  II. 

Obtained  by  Rosenbach  (1884)  from  the  perspiration  of  foul-smelling  feet. 

Morphology. — Short  bacilli  with  rounded  ends. 

Biological  Characters.  —Aerobic  and  facultative  anaerobic.  Characters 
of  growth  in  gelatin,  motility,  etc.,  not  given. 

Streak  cultures  upon  the  surface  of  nutrient  agar,  at  the  end  of  twenty- 
four  hours,  cause  the  entire  surface  to  be  covered  with  minute,  transparent 
colonies,  which  later  become  confluent  and  gradually  somewhat  opaque, 
forming  a  viscid,  whitish  gray  layer.  The  odor  of  cultures  resembles  that  of 
perspiring  feet.  Causes  putrefaction  of  albuminous  substances  in  the  pre- 
sence of  oxygen,  with  evolution  of  stinking  gases.  In  the  absence  of  oxygen 
putrefactive  changes  also  occurred,  but  less  rapidly. 

Pathogenesis. — When  injected  in  considerable  quantity  into  the  knee 
joint  or  into  the  pleural  cavity  of  rabbits,  the  animals  succumb  in  from  three 
to  five  days. 

119.    BACILLUS  OF  AFANASSIEW. 

Obtained  by  Afanassiew  (1887)  from  mucus  and  masses  of  pus  coughed 
up  by  patients  suffering  from  whooping  cough.  Etiological  relation  not 
demonstrated. 

Morphology.—  Bacilli  from  0.6  to  2.2  /*  long;  solitary,  in  pairs,  or  in 
short  chains. 

40 


470  PATHOGENIC   AEROBIC   BACILLI 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Forms  spores.  Grows  at  the  room  temperature  in.  the  usual  culture  media. 
Upon  gelatin  plates  the  colonies  are  spherical  or  oval  and  of  a  li^ht-brown 
color;  under  a  low  power  they  are  seen  to  be  finely  granular,  and  later  have 
a  dark-brown  color.  Upon  the  surface  of  gelatin  stick  cultures  a  grayish- 
white  layer  is  formed ;  but  slight  development  occurs  along  the  line  of  punc- 
ture. Upon  the  surface  of  agar  a  thick,  gray  layer  forms  along  the  line  of 
inoculation.  Upon  potato  yellowish,  glistening,  dew-like  drops  are  first 
formed  along  the  line  of  inoculation,  and  later  a  rather  thick,  brownish 
layer  is  formed  which  extends  rapidly  over  the  surface.  Development  is 
most  rapid  in  the  incubating  oven. 

Pathogenesis. — According  to  Afanassiew,  pure  cultures  injected  into  the 
air  passages  or  pulmonary  parenchyma,  in  young  dogs  or  in  rabbits,  produce 
bronchial  catarrh,  broncho-pneumonia,  and  attacks  of  spasmodic  coughing 
resembling  those  of  whooping1  cough.  Death  sometimes  occurs.  At  the 
autopsy  the  bacillus  is  found  in  great  numbers  in  the  bronchial  and  nasal 
mucus. 

120.    PNEUMOBACILLUS   LIQUEFACIENS   BOVIS. 

Obtained  by  Arloing  from  the  lung  of  an  ox  which  succumbed  to  an  in- 
fectious form  of  pneumonia. 

Morphology. — Slender,  short  bacilli,  which  rather  resemble  micrococci 
when  cultivated  in  gelatin. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, non-motile  bacillus.  Spore  formation  not  observed ;  is  killed  by  ex- 
posure for  fifteen  to  twenty  minutes  to  a  temperature  of  55°  C.  Grows  in 
the  usual  culture  media  at  the  room  temperature — better  at  35°  C.  Forms 
white  colonies  in  gelatin  plates,  and  causes  rapid  liquefaction  of  the  gelatin. 
Upon  potato  grows  very  rapidly  as  a  white  layer,  which  later  has  a  brownish 
color. 

Pathogenesis. — From  one-half  to  one  cubic  centimetre  of  a  pure  culture 
injected  beneath  the  skin  of  an  ox,  where  the  connective  tissue  is  loose, 
causes  the  development  of  an  acute  abscess  the  size  of  a  man's  hand  ;  after 
extending  for  two  or  three  days  this  gradually  becomes  smaller  and  recovery 
occurs.  When  larger  quantities  are  injected  a  fatal  termination  may  result. 
Guinea-pigs  and  rabbits  are  less  susceptible,  and  dogs  are  said  to  be  immune. 

121.   BACILLUS  PSEUDOTUBERCULOSIS. 

Obtained  by  Pfeiffer  (1889)  from  the  organs  of  a  horse  suspected  of  hav- 
ing glanders  and  killed. 

Morphology. — Rather  thick  bacilli  with  round  ends ;  vary  considerably 
in  length — usually  three  to  five  times  as  long  as  broad. 

Stains  with  f  uchsin  and  Lofner's  solution  of  inethyleiie  blue ;  does  not 
stain  by  Gram's  method. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin  plates,  at  the  end  of  twenty-four 
hours,  the  superficial  colonies  are  small,  yellowish-brown  plates,  which  in- 
crease rapidly  in  diameter ;  under  a  low  power  a  central  papilla  is  observed, 
around  which  the  colony  extends  as  a  pale-yellow,  peculiarly  marbled,  crys- 
talline disc  ;  the  deep  colonies  are  at  first  transparent,  sharply  defined  spheres ; 
on  the  third  day,  under  a  low  power,  they  are  seen  to  have  a  dark,  finely 
granular  central  portion  surrounded  by  a  transparent  zone  ;  when  not 
crowded  upon  the  plate  they  may  appear  as  yellowish-brown,  finely  granu- 
lar, pear-shaped  or  lemon-shaped  colonies.  In  gelatin  stick  cultures  growth 
occurs  along  the  line  of  puncture  in  the  form  of  grayish-white,  spherical 
colonies,  more  or  less  crowded  above,  and  often  isolated  below,  where  by 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS.  471 

transmitted  light  they  are  seen  to  have  a  brownish  color  ;  upon  the  surface 
a  grayish-white,  concentric  layer  is  formed  about  the  point  of  inoculation  in 
the  course  of  five  or  six  days,  which  later  forms  a  disc  with  thickened  mar- 
gins. Upon  the  surface  of  agar  the  growth  along  the  line  of  inoculation  is 
abundant  and  viscid.  Does  not  grow  well  upon  potato.  Upon  blood  serum 
forms  transparent,  drop-like  colonies  which  have  an  opalescent  appearance. 

Pathogenesis. — Pathogenic  for  rabbits,  guinea-pigs,  hares,  white  mice, 
and  house  mice.  Death  occurs  in  from  six  to  twenty  days.  At  the  autopsy 
the  lymphatic  glands  ai'e  found  to  be  enlarged  and  to  have  undergone  case- 
ation  ;  the  liver  and  spleen  are  enlarged,  the  lungs  cedematous  and  occasion- 
ally contain  tuberculous-looking  nodules.  An  abscess  forms  at  the  point  of 
inoculation.  Bacilli  are  found  in  the  blood,  the  lymphatic  glands,  and  the 
various  organs. 

122.  BACILLUS   GINGIVJE   PYOGENES. 

Synonym. — Bacterium  gingivse  ^yogenes  (Miller"). 

Obtained  by  Miller  from  an  alveolar  abscess  and  from  deposit  around  the 
teeth  "  in  a  filthy  mouth." 

Morphology. — Short  and  thick  bacilli  with  rounded  ends,  one  to  four 
times  as  long  as  broad ;  occur  singly  or  in  pairs. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing bacillus.  Grows  rapidly  in  the  usual  culture  media.  Upon  gelatin 
plates  it  forms  spherical  colonies  at  the  end  of  twenty-four  hours,  which 
have  a  yellowish  color  and  well-defined  margin ;  at  the  end  of  forty-eight 
hours  liquefaction  has  progressed  so  far  that  the  colonies  have  become  con- 
fluent. In  gelatin  stick  cultures  liquefaction  occurs  rapidly  in  the  form  of  a 
funnel,  at  the  bottom  of  which  a  white  deposit  is  formed.  Upon  the  surface 
of  agar  a  thick,  moist  growth  occurs  along  the  line  of  inoculation,  which 
under  the  microscope  has  a  slightly  greenish-yellow  tint  and  a  fibrillated 
structure. 

Pathogenesis. — Pathogenic  for  rabbits,  guinea-pigs,  and  for  white  mice, 
when  injected  into  the  cavity  of  the  abdomen  in  comparatively  small 
amounts  (0.25  cubic  centimetre).  At  the  autopsy  peritonitis,  sometimes 
purulent,  is  observed.  Death  occurs  in  from  ten  to  twenty-four  hours.  The 
bacilli  are  found  in  the  blood  in  small  numbers.  Subcutaneous  injections  in 
the  animals  mentioned  produce  a  local  abscess  only. 

123.  BACILLUS   DENTALIS   VIRIDANS. 

Found  by  Miller  in  the  superficial  layers  of  carious  dentine. 

Morphology. — Slightly  curved  bacilli  with  pointed  ends;  solitary  or  in 
paii-s. 

Biological  CJiaracters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  bacillus.  Spore  formation  not  observed.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  In  gelatin  plates  the  colonies  are 
spherical,  and  under  a  low  power  are  colorless  or  have  a  slightly  yellow  tint ; 
when  not  crowded  they  may  present  two  or  three  concentric  rings.  In  gela- 
tin stick  cultures  growth  occurs  both  upon  the  surface  and  along  the  line  of 
puncture.  Gelatin  cultures  acquire  an  opalescent-green  color.  Upon  the 
surface  of  agar  a  thin  growth  with  irregular  margins  occurs  along  the  impf- 
strich ;  this  is  bluish  by  transmitted  light  and  greenish-gray  by  reflected  light 
— colorless  under  the  microscope. 

Pathogenesis. — Injections  into  the  cavity  of  the  abdomen  of  white  mice 
or  of  guinea-pigs  usually  cause  fatal  peritonitis  in  from  one  to  six  days ;  the 
bacilli  are  only  found  in  the  blood  in  small  numbers,  by  the  culture  method. 
Subcutaneous  injections  in  the  animals  mentioned  produce  severe  local  in- 
flammation and  suppuration. 

124.   BACILLUS   PULP.E  PYOGENES. 
Obtained  by  Miller  from  .gangrenous  tooth  pulp. 


472  PATHOGENIC  AEROBIC   BACILLI 

Morphology. — Slightly  curved  bacilli  with  pointed  ends;  solitary  or  in 
pairs,  or  in  chains  of  four  to  eight  elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing bacillus.  Spore  formation  not  observed.  Grows  in  the  usual  culture 
media  at  the  room  temperature.  In  gelatin  plates  large,  spherical,  opaque, 
yellowish-brown  colonies  are  formed.  In  gelatin  stick  cultures  liquefaction 
occurs  in  the  upper  part  of  the  tube  and  gradually  extends  downward,  the 
liquefied  gelatin  being  separated  from  the  non-liquefied  by  a  horizontal 
plane. 

Pathogenesis. — Small  quantities  of  a  pure  culture  injected  into  the  abdo- 
minal cavity  of  white  mice  proved  fatal  to  these  animals  in  from  eighteen  to 
thirty  hours. 

125.    BACILLUS   SEPTICUS   KERATOMALACOS. 

Obtained  by  Babes  (1889)  from  the  broken-down  corneal  tissues  and  from 
the  various  organs  of  a  child  which  died  of  septicaemia  following  keratoma- 
lacia. 

Stains  with  the  usual  aniline  colors ;  deeply  colored  granules  may  often 
be  seen  at  the  extremities  of  the  rods,  or  in  the  middle,  in  preparations 
stained  with  Loffler's  solution. 

Morphology. — Short,  thick  bacilli,  thinning  out  at  the  ends;  often  united 
in  pairs ;  may  be  surrounded  by  a  capsule. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  bacillus.  Spore  formation  not  observed.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates  forms  white, 
slightly  elevated,  flat  colonies  with  finely  dentate  margins.  In  gelatin  stick 
cultures  the  growth  is  abundant  both  on  the  surface  and  along  the  line  of 
puncture ;  gas  bubbles  are  formed  in  the  gelatin.  Upon  the  surface  of  agar 
the  growth  along  the  line  of  inoculation  is  leaf-like,  finely  dentate,  some- 
what opalescent,  and  the  culture  has  a  slightly  ammoniacal  odor.  Upon 
blood  serum  a  semi-transparent,  glistening  film  is  formed,  which  has  dentate 
margins. 

Pathogenesis. — Pathogenic  for  rabbits  and  mice,  less  so  for  birds;  not 
pathogenic  for  guinea-pigs.  The  animals  die  in  from  three  to  seven  days. 
Inoculated  into  the  cornea  it  causes  a  purulent  keratitis. 

126.    BACILLUS   SEPTICUS  ACUMINATUS. 

Obtained  by  Babes  (1889)  from  the  blood,  the  umbilical  stump,  and  the 
various  organs  of  a  child  which  died  five  days  after  birth,  apparently  from 
septic  infection. 

Morphology.  — Bacilli  with  lancet-shaped  ends,  somewhat  resembling  the 
bacillus  of  mouse  septicaemia,  but  thicker.  Often  shows  unstained  places  in 
the  middle  of  the  rods  in  stained  preparations. 

Stains  readily  with  the  usual  aniline  colors.  - 

Biological  Characters. — An  aerobic  bacillus;  does  not  grow  in  gelatin  at 
the  room  temperature.  Spore  formation  not  observed.  Grows  upon  blood 
serum  and  upon  nutrient  agar  at  37°  C.,  in  form  of  small,  flat,  circular, 
transparent,  shining  colonies,  which  become  confluent  and  later  form  a  yel- 
lowish layer.  Blood  serum  is  the  most  favorable  medium. 

Pathogenesis. — Pathogenic  for  rabbits  and  guinea-pigs,  not  for  mice. 
The  animals  die  in  from  two  to  six  days,  and  the  bacilli  are  found  in  their 
blood  and  in  the  various  organs. 

127.   BACILLUS  SEPTICUS  ULCERIS  GANGRJENOSI. 

Obtained  by  Babes  (1889)  from  the  blood  and  various  organs  of  a  boy  who 
died  from  septicaemia  following  gangrene  of  the  skin,  etc. 

Morphology. — Bacilli  with  round  ends,  oval  or  rod-shaped,  about  0.5  to 
0.6  u  thick. 


NOT  DESCRIBED    IN   PREVIOUS   SECTIONS.  473 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Does 
not  form  spores.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
In  gelatin  stick  cultures  a  sac-formed  liquefaction  occurs  and  a  yellow  de- 
posit is  seen  at  the  bottom  of  the  liquefied  gelatin ;  gas  bubbles  are  given  off 
from  the  culture.  Upon  the  surface  of  agar  development  occurs  along  the 
line  of  inoculation  in  the  form  of  flat,  grayish-yellow,  transparent,  varnish- 
like  plaques.  Upon  potato,  after  several  days,  a  brownish,  shining,  moist, 
transparent  film  is  formed.  Upon  the  surface  of  blood  serum  smooth, 
yellowish,  transparent  colonies  are  formed,  under  which  the  blood  serum  is 
softened,  allowing  these  to  sink  below  the  surface. 

Pathogenesis. — Pathogenic  for  mice  and  for  guinea-pigs,  which  die  in 
from  one  to  two  days.  An  abscess  forms  at  the  point  of  inoculation,  which 
is  covered  with  a  dry,  retracted  crust. 

128.    BACILLUS  OF  TRICOMI. 

Obtained  by  Tricomi  (1886)  from  a  case  of  senile  gangrene. 

Morphology. — Bacilli  with  round  ends,  about  three  ju  long  and  one  « 
thick,  solitary  o-  in  pairs ;  sometimes  one  end  of  a  rod  shows  a  club-shaped 
thickening. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile  bacillus. 
Forms  spores.  Grows  in  the  usual  culture  media  at  the  room  temperature — 
better  at  37°  C. 

Upon  gelatin  plates,  at  the  end  of  twenty-four  hours,  the  colonies  are 
spherical,  finely  granular,  and  of  a  dirty-yellow  color  ;  after  from  thirty-six 
to  forty-eight  hours  liquefaction  of  the  surrounding  gelatin  occurs.  In  gela- 
tin stick  cultures  closely  crowded,  small,  white  colonies  are  formed  along 
the  line  of  puncture  ;  at  the  end  of  forty-eight  hours  liquefaction  com- 
mences in  funnel  form,  with  formation  of  an  air  bubble  above — like  the 
cholera  spirillum;  later  the  entire  gelatin  is  liquefied  and  becomes  trans- 
parent, while  a  dirty-white  collection  of  bacilli  is  seen  at  the  bottom  of  the 
tube.  Upon  the  surface  of  agar  a  white  layer  with  irregular  margins  is 
formed,  which  later  extends  over  the  entire  surface  as  a  homogeneous,  rather 
thin  membranous  film.  ~Upon potato,  at  37°  C.,  dirty-white,  milky  colonies 
are  formed,  which  later  become  confluent.  Upon  blood  serum  the  growth  is 
similar  to  that  upon  agar. 

Pathogenesis. — The  subcutaneous  injection  of  one-half  to  one  cubic  centi- 
metre of  a  gelatin  culture  is  said  by  Tricomi  to  produce  in  rabbits  and  in 
guinea-pigs  a  gangrenous  process  resembling  senile  gangrene  in  man.  The 
subcutaneous  connective  tissue  is  infiltrated  with  a  foul-smelling  serum,  the 
muscles  are  soft  and  gray,  and  a  portion  of  the  skin  has  a  mummified  ap- 
pearance. The  gangrene  extends  over  the  abdomen,  and  death  occurs  in 
guinea-pigs  in  two  to  three  days,  in  rabbits  after  four  days,  in  house  mice 
at  the  end  of  twenty-four  hours ;  white  mice  are  said  to  be  immune. 

129.    BACILLUS  ALBUS   CADAVERIS. 

Obtained  by  Strassmann  and  Strieker  (1888)  from  the  blood  of  two  cada- 
vers four  days  after  death. 

Morphology. — Bacilli  about  two  and  one-half  >"  long  and  0.75  ft  broad; 
also  grow  out  into  filaments  of  six  ft  or  longer. 

Stains  with  the  usual  aniline  colors  andby  Gram's  method. 

Biological  Characters.— An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  in  the  usual  culture  media  at  the  room  tem- 
perature. In  gelatin  plates  small,  spherical,  yellowish  colonies  are  formed 
during  the  first  twenty-four  hours ;  later  a  radiating  outgrowth  occurs  from 
the  periphery,  and  liquefaction  of  the  gelatin  takes  place.  In  gelatin  stick 
cultures  liquefaction  begins  within  forty-eight  hours,  and  forms  a  long  fun- 
nel, at  the  opening  of  which  is  a  cavity  containing  air  ;  the  liquefied  gela- 


474  PATHOGENIC   AEROBIC   BACILLI 

tin  is  transparent,  and  a  deposit  of  thick,  granular  masses  accumulates  at  the 
bottom  of  the  tube.  Upon  the  surface  of  agar  a  thick,  white  layer  is  formed, 
which  later  is  wrinkled  and  after  a  time  gives  off  a  putrefactive  odor.  Gela- 
tin cultures  give  off  an  odor  of  sulphuretted  hydrogen.  Upon  potato  a  soft, 
white  or  pale-yellow  layer  is  formed,  which  in  places  is  made  up  of  small 
granules.  The  potato  around  the  growth  has  a  bluish-brown  color. 

Pathogenesis. — Subcutaneous  injection  of  a  small  quantity  (0.1  cubic 
centimetre)  of  a  liquefied  gelatin  culture  is  fatal  to  mice  in  about  six  hours ; 
the  animals  become  comatose  before  death,  and  at  the  autopsy  putrefactive 
changes  are  already  observed ;  the  bacillus  can  be  recovered  from  the  blood 
in  cultures.  Sterilized  cultures  also  prove  fatal  to  mice.  Pathogenic  also 
for  guinea-pigs,  which  die  in  about  twenty  hours  after  receiving  a  subcuta- 
neous inoculation. 

130.    BACILLUS   VARICOSUS   CONJUNCTIVE. 

Obtained  by  Gombert  (1889)  from  the  healthy  conjunctiva!  sac  of  man. 

Morphology. — Large  bacilli  with  round  ends,  from  two  to  eight  n  long 
and  about  one  n  broad;  the  shorter  bacilli  are  often  constricted  in  the 
middle. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, non-motile  bacillus.  Grows  very  slowly  in  nutrient  gelatin  at  22°  C. ; 
rapidly  in  agar  and  upon  potato  at  87°  C.  In  gelatin  stick  cultures,  at  the 
end  of  twenty-four  hours,  a  circular  layer  haying  a  grayish- white  centre  is 
developed  upon  the  surface,  and  a  scarcely  visible  grayish- white  thread  along 
the  line  of  puncture.  Liquefaction  extends  gradually  from  the  surface 
without  clouding  or  changing  the  gelatin,  so  that  at  the  end  of  two  weeks 
the  gelatin  is  entirely  liquefied  without  giving  any  other  evidence  of  the  pre- 
sence of  the  microorganism.  Upon  agar  plates,  at  37°  C.,  the  deep  colonies 
have  a  diameter  of  about  four  millimetres  by  the  end  of  the  fourth  day; 
under  a  low  power  they  are  seen  to  be  covered  with  minute,  irregular,  thorn- 
like  projections,  which  subsequently  increase  in  size ;  the  centre  of  the  colony 
is  granular  and  opaque.  The  superficial  colonies,  under  a  low  power,  are  seen 
to  have  an  opaque  central  micleus  surrounded  by  a  yellowish,  finely  granu- 
lar, transparent  peripheral  zone;  later  the  central  portion  is  irregular  and 
semi-opaque,  surrounded  by  a  broad  marginal  zone  which  consists  of  twisted 
and  bent  tapering  offshoots  having  a  dark  contovir.  Upon  the  surface  of 
agar  a  thin,  white,  dry,  very  adherent  film  is  formed ;  a  thick,  white  film 
forms  upon  the  surface  of  the  condensation  water.  Upon  potato  develop- 
ment is  rapid  at  37°  C.,  forming  at  first  a  dry,  white  layer,  which  at  the  end 
of  ten  days  covers  the  entire  surface ;  it  then  has  an  irregular  surface  and 
fringed  margins,  is  smooth,  dry,  and  after  a  time  has  a  reddish-brown  color. 

Pathogenesis. — When  inoculated  into  the  cornea  of  rabbits  a  grayish- 
white  cloudiness  is  developed  in  twenty-four  hours,  around  which  the  cornea 
is  highly  vascular;  the  animal  recovers  without  the  formation  of  an  abscess. 
Injected  into  the  conjunctiva  it  causes  an  intense  hyperaemia. 

131.    BACILLUS   MENINGITIDIS   PURULENTJE. 

Obtained  by  Neumann  and  Schaffer  (1887)  from  pus  from  beneath  the  pia 
mater  in  an  individual  who  died  of  purulent  meningitis. 

Morphology. — Bacilli  about  two  u  long  and  0.6  to  0.7/*  broad;  often 
grow  out  into  long  filaments,  especially  in  gelatin  cultures. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Does  not  form  spores.  Grows  in  the  usual 
culture  media  at  the  room  temperature — better  in  the  incubating  oven.  Upon 
gelatin  plates  the  deep  colonies,  under  a  low  power,  are  homogeneous,  round 
or  oval,  pale  brown,  and  with  a  smooth  contour;  the  superficial  colonies  are 


NOT   DESCRIBED    IN    PREVIOUS    SECTIONS.  475 

thin,  moist,  and  transparent  in  appearance ;  later  they  have  a  grayish  color, 
a  coarsely  granular  surface,  and  are  made  up  of  Hap-like  layers.  In  gelatin 
stick  cultures  the  superficial  growth  consists  of  broad,  grayish  layers,  and  a 
grayish-yellow  growth  is  seen  along  the  line  of  puncture,  made  up  of  crowded 
colonies.  Upon  agar  plates,  at  the  end  of  twenty-four  hours  at  37°  C., 
thin  colonies  are  developed,  which  have  a  granular  surface,  a  smooth,  more 
or  less  irregular  outline,  and  a  pale-brown  color  in  the  centre.  Upon  potato 
a  scanty,  moist,  white  layer  develops  along  the  line  of  inoculation.  Upon 
blood  serum,  at  37°  C. ,  at  the  end  of  twenty-four  hours  a  moist,  shining  layer 
about  four  millimetres  broad  is  developed  along  the  impfstrich ;  this  is  gra- 
nular at  the  margins,  and  later  more  or  less  fissured. 

Pathogenesis. — Subcutaneous  injection  produces  in  dogs,  rabbits,  guinea- 
pigs,  and  white  mice  a  purulent  inflammation  in  the  vicinity  of  the  point  of 
inoculation. 

132.    BACILLUS   SEPTICUS   VESICLE. 

Obtained  by  Clado  (1887)  from  the  urine  of  a  person  suffering  from  cys- 
titis. 

Morphology. — Bacilli  with  round  ends,  1.6  to  2  /J.  long  and  0.5 /^  thick; 
never  united  in  pairs  or  chains. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters.—  An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Forms  spores.  Grows  in  the  usual  culture 
media  at  the  room  temperature.  Upon  gelatin  plates  small,  spherical  or 
oval  colonies  are  developed  throughout  the  gelatin,  which  rarely  exceed  the 
size  of  a  pin's  head  ;  these  are  transparent,  and  yellowish-white  in  color  ; 
under  a  low  poAver  the  centre  is  seen  to  be  dark  gray  and  is  surrounded  by  a 
well-defined  marginal  zone  of  a  pale-yellow  color.  In  gelatin  stick  cultures 
the  growth  along  the  line  of  puncture  is  first  seen  as  a  delicate,  whitish 
thread  ;  at  the  end  of  six  or  seven  days  it  is  made  up  of  lenticular  colonies, 
one-third  as  large  as  a  pin's  head,  arranged  in  two  lines  like  piles  of  coin. 
Upon  the  surface  the  growth  is  scanty  and  consists  of  a  thin  layer  around  the 
point  of  inoculation,  which  has  a  jagged  contour.  Upon  the  surface  of  agar 
development  is  slow  and  forms  a  grayish- white  stripe  along  the  impfstrich. 
Upon  potato  a  flat,  dry,  chestnut-brown  layer  is  formed. 

Pathogenesis. — Pathogenic  for  rabbits,  guinea-pigs,  and  mice.  Death 
appears  to  result  from  the  toxic  products  formed,  as  well  as  from  the  multi- 
plication of  the  bacilli  in.  the  inoculated  animals. 

133.    BACILLUS   OF   GESSNER. 

Synonym. — Bacterium  tholoideum  (Gessner). 

Obtained  by  Gessner  from  the  contents  of  the  intestine  of  healthy  persons. 
Resembles  in  its  morphology  and  in  its  growth  in  culture  media  Bacillus 
lactis  aerogenes  of  Escherich. 

Pathogenic  for  mice  and  for  guinea-pigs. 

134.    BACILLUS  CHROMO-AROMATICUS. 

Obtained  by  Galtier  (1888)  from  a  pig  which  died  from  a  general  infec- 
tious malady  characterized  by  broncho-pneumonia,  pleuritis,  enteritis,  and 
swelling  of  the  lymphatic  glands. 

Morphology. — Bacilli  of  medium  size  with  rounded  ends. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Not  observed  to  form  spores.  Grows  in  the  usual  cul- 
ture media  at  the  room  temperature — better  in  the  incubating  oven.  The 
cultures  all  produce  a  green  or  brown  pigment  and  have  an  aromatic  odor. 
In  gelatin  stick  cultures  a  yellowish- white  layer  is  formed  upon  the  surface 
of  the  liquefied  gelatin,  which  has  a  bright-green  color  ;  a  yellowish- white 


470  PATHOGENIC   AEROBIC   BACILLI 

deposit  accumulates  at  the  bottom  of  the  tube.  Upon  the  surface  of  agar 
whitish  colonies  are  formed,  which  coalesce  to  form  a  thin  layer.  Upon 
potato  a  tolerably  thick,  somewhat  iridescent,  brown  layer  is  formed,  which 
extends  over  the  entire  surface.  In  bouillon,  at  the  end  of  twenty-four  to 
forty-eight  hours  at  37°  C.,  a  greenish-yellow  color  is  developed,  first  near 
the  surface  and  later  extending  throughout  the  fluid,  which  acquires  the  color 
of  a  dilute  solution  of  sulphate  of  copper  ;  a  whitish  film  forms  upon  the 
surface.  In  anaerobic  cultures  the  color  is  a  pale  brown  instead  of  green. 

Pathogenesis. — Rabbits  die  at  the  end  of  two  to  three  weeks  after  receiv- 
ing an  intravenous  injection.  At  the  autopsy  they  are  found  to  have  pneu- 
monia with  pleuritis  and  pericarditis. 

135.   BACILLUS  CANALIS  CAPSULATUS. 

Obtained  by  Mori  (1888)  from  sewer  water. 

Morphology. — Bacilli  with  round  ends,  elliptical  or  rod-shape  in  form, 
and  from  0.9  to  1.6  /j.  thick  ;  often  surrounded  with  a  broad  capsule,  which 
is  always  seen  in  preparations  from  the  blood  or  tissues  of  an  infected  ani- 
mal ;  sometimes  in  pairs  with  the  acute  ends  of  the  rods  in  apposition,  and 
surrounded  by  a  single  capsule. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Spore  formation  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
hemispherical,  porcelain-white,  sharply  defined  colonies,  resembling  those  of 
Friedlander's  bacillus,  are  developed  at  the  end  of  twenty -four  hours.  In 
gelatin  stick  cultures  development  occurs  along  the  line  of  puncture  and 
upon  the  surface,  forming  a  "  nail-shaped  "  growth  similar  to  that  of  Fried- 
lander's  bacillus  (Bacillus  pneumonias)  in  the  same  medium.  Upon  agar 
a  viscid  and  abundant  growth  is  formed  in  the  incubating  oven  at  37°  C. 
Upon  potato  an  abundant  development  in  the  form  of  a  yellowish,  moist,  vis- 
cid layer,  with  irregular  outlines.  In  bouillon,  at  the  end  of  three  or  four 
days,  a  white  film  forms  on  the  surface,  especially  in  contact  with  the  test 
tube. 

Pathogenesis. — Mice  die  in  two  to  three  days  after  receiving  a  subcutane- 
ous injection.  Guinea-pigs  and  rabbits  are  immune. 

136.   BACILLUS  CANALIS  PARVUS. 

Obtained  by  Mori  (1888)  from  sewer  water. 

Morphology. — Bacilli  with  round  ends,  from  2  to  5  u.  long  and  0.8  to  1  /* 
broad. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method  ;  the 
ends  of  the  rods  are  more  deeply  stained  than  the  central  portion. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Not  observed  to  form  spores.  Grows  very  slowly  at  the  room  tempera- 
ture— more  rapidly  at  37°  C.  Upon  gelatin  plates,  at  the  end  of  two  to  three 
weeks,  extremely  minute,  homogeneous,  pale-yellow  colonies  are  developed. 
In  gelatin  stick  cultures  a  thin,  yellowish  layer  forms  upon  the  surface  at 
the  end  of  three  weeks.  Upon  the  surface  of  agar,  at  37°  C. ,  a  dry,  yellow- 
ish layer  with  jagged  outlines  is  developed  in  two  or  three  days.  No  growth 
occurs  upon  potato.  Upon  blood  serum  a  thin,  pale-green,  dry  layer  is 
formed. 

Pathogenesis. — Mice  die  in  from  sixteen  to  thirty  hours  after  receiving  a 
subcutaneous  inoculation,  guinea-pigs  in  about  two  days. 

137.    BACILLUS  INDIGOGENUS. 

Obtained  by  Alvarez  (1887)  from  an  infusion  of  the  leaves  of  the  indigo 
plant. 

Morphology. — Bacilli  with  round  ends,  about  3  n  long  and  1. 5 /z  thick, 


NOT  DESCRIBED   IN  PREVIOUS   SECTIONS.  477 

often  united  in  chains  of  six  to  eight  elements.  The  cells  are  surrounded  by 
a  transparent  capsule  resembling  that  of  Friedlaiider's  bacillus. 

Biological  Characters. — An  aerobic,  motile  bacillus.  Upon  agar,  at 
37°  C.,  a  yellowish- white  layer  is  quickly  developed  and  there  is  production 
of  gas.  According  to  Alvarez,  this  bacillus  develops  an  indigo-blue  color  in 
a  sterilized  infusion  of  the  leaves  of  the  indigo  plant. 

Pathogenesis. — Guinea  pigs  die  in  from  three  to  twelve  hours  from  the 
intravenous  injection  of  a  pure  culture. 

138.   BACILLUS  OF  KARTULIS. 

Obtained  by  Koch  (1883)  and  by  Kartulis  from  the  conjunctival  secre- 
tions of  persons  suffering  from  a  form  of  infectious  catarrhal  conjunctivitis 
which  prevails  in  Egypt. 

Morphology. — Resembles  the  bacillus  of  mouse  septicaemia  (Bacillus  mu- 
risepticus)  in  its  form  and  dimensions.  * 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic  bacillus.  Does  not  grow  in  nutri- 
ent gelatin  at  the  room  temperature.  Upon  the  surface  of  nutrient  agar,  at 
28°  to  30°  C.,  at  the  end  of  thirty  to  forty  hours  small,  grayish-white  points 
are  developed  along  the  impfstrich  ;  later  these  become  confluent  and  form 
an  elevated,  shining,  dark-colored  layer  with  irregular  and  often  jagged 
margins. 

Pathogenesis. — Out  of  six  experimental  inoculations,  with  pure  cultures, 
made  by  Kartulis  in  the  eyes  of  healthy  individuals,  four  gave  a  negative 
result,  one  produced  a  catarrhal  inflammation  lasting  for  a  week,  in  an  eye 
which  was  blind  from  a  previous  attack  of  sclerochoroiditis,  and  one  a  con- 
junctivitis lasting  for  ten  days  in  a  perfectly  healthy  eye. 

139.   BACILLUS  OF  UTPADEL. 

Obtained  by  Utpadel  (1887)  from  the  wards  of  a  military  hospital  at  Augs- 
burg— in  the  "  Zwischendeckenfullung  " ;  also  by  Gessner  from  the  contents 
of  the  small  intestine  in  man. 

Morphology. — Bacilli  with  round  ends,  1.25  to  1.5  ju.  long  and  0.75  to  1  ju. 
thick ;  often  united  in  pairs  or  in  chains  of  three  elements. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Spore  forma- 
tion not  observed.  Upon  gelatin  plates  the  superficial  colonies  are  elevated 
and  sometimes  conical,  and  of  a  milk-white  color.  The  deep  colonies  are 
round  or  oval ;  the  centre  is  dark  green  and  is  surrounded  by  a  brownish- 
green  peripheral  zone.  Upon  the  surface  of  agar  a  yellowish-white  layer 
is  developed  very  slowly.  The  growth  upon  gelatin  is  rapid. 

Pathogenesis. — When  injected  subcutaneously  into  cats,  guinea-pigs,  or 
mice  it  produces  an  extensive  inflammatory  osdenia,  resulting  in  the  death 
of  the  animals. 

140.   BACILLUS  ALVEI. 

Synonym. — Bacillus  of  foul  brood  (of  bees). 

Obtained  by  Cheshire  and  Cheyne  (1885)  from  the  larvae  in  hives  infected 
with  "  foul  brood."  The  larvae  in  the  interior  of  cells  in  the  comb  die  and 
become  almost  fluid  as  a  result  of  parasitic  invasion  by  this  bacillus. 

Morphology. — Bacilli  with  rounded  ends,  from  2.5  to  5  //  in  length  (aver- 
age about  3.6  fi)  and  0.8  u  in  diameter.  Grow  out  into  filaments  and  form 
large  oval  spores  which  have  a  greater  diameter  than  the  rods  in  which  they 
are  developed — 1.07  n. 

Stains  readily  with  the  aniline  colors  usually  employed,  also  by  Gram's 
method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 


478  PATHOGENIC   AEROBIC   BACILLI 

ing,  motile  bacillus.  Forms  endogenous  spores.  Grows  readily  in  the  usual 
culture  media  at  the  room  temperature. 

In  gelatin  plates  small,  round  or  oval  colonies  are  formed,  which  later 
become  pear-shaped ;  a  branching  outgrowth  occurs  about  the  margins  of  the 
colonies,  and  especially  from  the  small  end  of  the  pear-shaped  mass.  In 
streak  cultures  upon  the  surface  of  gelatin  growth  occurs  first  along  the  impf- 
strich,  and  from  this  an  outgrowth  occurs  consisting  of  bacilli  in  a  single 
row  or  in  several  parallel  rows,  and  forming  irregular  or  circular  figures, 
from  which  other  similar  outgrowths  occur;  the  branching  outgrowths  may 
anastomose.  The  gelatin  is  liquefied  in  the  vicinity  of  these  lines  of  growth, 
forming  a  network  of  channels.  A  similar  growth  is  seen  upon  the  surface 
of  gelatin  stick  cultures,  and  along  the  line  of  puncture  white,  irregular 
masses  are  formed,  from  which  rather  coarse  branches  are  given  off  which 
often  have  a  club-shaped  extremity.  In  older  cultures  the  finer  branches 
disappear,  so  that  the  secondary  centres  of  growth  are  disconnected  from  the 
original  colonies ;  complete  liquefaction  of  the  gelatin  occurs  in  about  two 
weeks ;  the  liquefied  gelatin  has  a  yellowish  color  and  peculiar  odor.  Upon 
the  surface  of  nutrient  agar,  at  37°  C.,  a  white  layer  is  formed.  Upon  potato 
the  development  is  slow  and  results  in  the  formation  of  a  dry,  yellowish 
layer.  In  milk  coagulation  first  occurs,  and  the  coagulum  is  subsequently 
dissolved;  a  slightly  acid  reaction  is  produced.  This  bacillus  grows  best  in 
the  incubating  oven  at  37°,  and  does  not  develop  at  temperatures  below  16 3 
C.  The  spores  require  for  their  destruction  a  temperature  of  100°  C.  main- 
tained for  four  minutes  (determined  by  the  writer,  1887). 

Pathogenesis. — The  introduction  of  pure  cultures  of  this  bacillus  into 
hives  occupied  by  healthy  swarms  causes  them  to  become  infected  with  foul 
brood ;  grown  bees  also  become  infected  when  given  food  containing  the  ba- 
cillus (Cheshire).  Mice  injected  subcutaneously  with  a  considerable  quan- 
tity die  within  twenty-four  hours,  guinea-pigs  in  six  days  (Eisenberg). 
Small  amounts  injectea  beneath  the  skin  of  mice  or  rabbits  produce  no  appa- 
rent result. 

141.  BACILLUS  OF  ACNE  CONTAGIOSA  OF  HORSES. 

Obtained  by  Dieckerhoff  and  Grawitz  (1885)  from  pus  and  dried  scales 
from  the  pustules  of  ' '  acne  contagiosa  "  of  horses. 

Morphology. — Short  rods,  straight  or  slightly  bent,  0.2  jj.  in  diameter. 

Stains  best  with  an  aqueous  solution  of  fuchsin,  and  also  by  Gram's 
method ;  does  not  stain  well  with  Loffler's  alkaline  solution  of  methylene 
blue. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  In  gelatin 
stick  cultures  a  very  scantv  growth  occurs  along  the  line  of  puncture ;  upon 
the  surface  a  white  mass  forms  about  the  point  of  puncture.  Upon  blbod 
serum  and  nutrient  agar  an  abundant  growth  at  the  end  of  twenty-four 
hours  at  37°  C.,  consisting  of  white  colonies  along  the  impfstrich,  which 
later  have  a  yellowish-gray  color.  The  growth  is  more  abundant  and  rapid 
upon  blood  serum  than  upon  other  media. 

Pathogenesis. — Pure  cultures  of  the  bacillus  described  are  said  by  Diecker- 
hoff and  Grawitz  to  produce  typical  acne  pustules  when  rubbed  into  the  skin 
of  horses,  calves,  sheep,  and  dogs.  When  rubbed  into  the  intact  skin  of 
guinea-pigs  a  phlegmonous  erysipelatous  inflammation  was  produced,  and 
the  animal  died  at  the  end  of  forty -eight  hours  with  symptoms  of  toxaemia. 
Subcutaneous  injections  in  guinea-pigs  caused  toxaemia  and  death  at  theend 
of  twenty-four  hours.  At  the  autopsy  a  haemorrhagic  infiltration  of  the  in- 
testinal mucous  membrane  was  observed ;  the  bacilli  were  not  found  in  the 
internal  organs.  In  rabbits  pure  cultures  rubbed  into  the  intact  skin  caused 
a  development  of  pustules  and  a  severe  inflammation  of  the  subcutaneous 
connective  tissue,  from  which  the  animal  usually  recovered.  Subcutaneous 
injections  in  rabbits  sometimes  caused  a  fatal  toxtemia.  House  mice,  field 
mice,  and  white  mice  were  not  affected  by  the  application  of  cultures,  by 


NOT   DESCRIBED   IN   PREVIOUS   SECTIONS.  479 

rubbing,  to  the  uninjured  skin,  but  succumbed  to  subcutaneous  injections  in 
twenty-four  hours  or  between  the  flfth  and  tenth  days.  Those  which  died 
at  a  late  date  presented  the  pathological  appearances  which  characterize 
pyaemia. 

142.   BACILLUS  NO.    I  OF  ROTH. 

Obtained  by  Roth  (1890)  from  old  rags.  Resembles  Bacillus  coli  com- 
munis  and  Brieger's  bacillus  in  its  morphology  and  growth  in  various  culture 
media,  but,  according  to  Roth,  is  distinguished  from  these  bacilli  by  the  fact 
that  colonies  upon  gelatin  plates  are  thicker  and  more  opaque. 

Pathogenesis. — Pathogenic  for  rabbits  and  for  guinea-pigs  when  injected 
into  the  cavity  of  the  abdomen;  death  usually  occurs  within  twenty-four 
hours.  The  spleen  is  greatly  enlarged,  and  the  bacilli  are  found  in  cultures 
from  the  blood  and  various  organs. 

143.    BACILLUS   NO.    II   OF   ROTH. 

Obtained  by  Roth  (1890)  from  old  rags. 

Morphology. — Bacilli  with  round  ends,  0.6  to  1  fj,  broad  and  two  to  four 
times  as  long. 

Stains  with  the  usual  aniline  colors.  When  stained  by  Gram's  method 
it  is  decolorized  by  alcohol. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Grows  in  the  usual  culture  media  at  the 
room  temperature.  Upon  gelatin  plates  colonies  resembling  those  of  the 
colon  bacillus  are  developed  at  the  end  of  twenty-four  hours ;  on  the  third 
day  small,  drop-like,  shining,  bluish-white  colonies,  around  the  periphery  of 
which  a  commencing  extension  upon  the  surface  of  the  gelatin  is  seen.  Older 
colonies  are  seldom  more  than  one-half  centimetre  in  diameter,  and  are  some- 
what thicker  than  this ;  thev  are  nearly  transparent.  Upon  the  surface  of 
gelatin  stick  cultures  a  rather  moist,  yellowish-white  layer  with  dentate 
margins  is  developed.  Upon  potato  a  colorless  layer  is  developed,  which 
later  has  a  grayish  color. 

Pathogenic  for  rabbits  and  guinea-pigs  when  injected  into  the  abdominal 
cavity. 

144.   BACILLUS  OF  OKADA. 

Obtained  by  Okada  (1891)  from  dust  between  the  boards  of  a  floor. 

Morphology. — Short  rods  with  round  ends,  about  as  long  as  Bacillus 
murisepticus,  but  somewhat  thicker — about  twice  as  long  as  thick ;  solitary 
or  in  pairs;  in  old  cultures  may  grow  out  into  filaments. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Does  not  form  spores.  Grows  in  the  xisual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates,  at  the  end  of 
two  to  three  days,  small,  white,  spherical  colonies  are  developed.  Under 
the  microscope  these  are  seen  to  be  granular,  pale-brown  in  color,  and  with 
slightly  jagged  margins ;  the  superficial  colonies  after  several  days  are  con- 
siderably elevated  above  the  level  of  the  gelatin.  In  gelatin  stick  cultures 
development  occurs  as  a  white  thread  along  the  line  of  puncture,  and  upon 
the  surface  as  a  flat,  milk-white  layer  which  does  not  extend  to  the  walls  of 
the  test  tube.  Upon  agar,  at  37°  C.,  the  growth  is  rapid  and  the  surface  is 
nearly  covered  at  the  end  of  eighteen  hours  with  a  milk-white  layer ;  the  con- 
densation water  is  filled  with  a  viscid  mass  of  bacilli.  Upon  blood  serum 
the  growth  is  shining  and  almost  transparent.  In  bouillon  development  is 
rapid,  clouding  the  fluid  throughout,  and  a  cream-like  layer  forms  upon  the 
surface. 

Pathogenesis. — Rabbits  and  guinea-pigs  die  in  about  twenty  hours  after 
receiving  a  subcutaneous  injection  of  a  half-syringeful  of  a  bouillon  cul- 
ture, or  from  a  small  quantity  (two  ose)  from  a  gelatin  or  agar  culture.  In 


480  PATHOGENIC   AEROBIC   BACILLI 

mice  a  minute  quantity  of  a  pure  culture  invariably  proved  fatal  in  about 
twenty  hours.  Four  hours  after  the  inoculation  an  abundant  secretion  from 
the  lachrymal  glands  occurs,  and  soon  after  the  eyes  become  completely  closed. 
According  to  Okada,  this  bacillus  is  differentiated  from  the  bacillus  of 
Brieger,  and  from  Emmerich's  bacillus  which  it  greatly  resembles,  by  the 
fact  that  it  does  not  grow  upon  potato. 

145.    BACILLUS   OP  PURPURA   H^MORRHAGICA   OF   TIZZONI   AND 

GIOVANNINI. 

Obtained  by  Tizzoni  and  Giovannini  (1889)  from  the  blood  of  two  children 
who  died  of  purpura  haemorrhagica  following  impetigo. 

Morphology. — Bacilli  with  round  ends,  from  0.75  to  1.3  )J-  long  and  0.2 
to  0.4  ju  broad;  often  seen  in  pairs  or  in  groups  like  streptococci. 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Biological  Characters.—  An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Spore  formation  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  TJpon.  gelatin  plates  the 
colonies  at  first  resemble  those  of  Streptococcus  pyogenes.  Upon  the  surface 
small,  opaque  points  are  seen  at  the  end  of  forty-eight  hours,  which  at  the 
end  of  four  to  five  days  develop  into  spherical,  yellowish-gray  colonies  with 
irregular  margins,  surrounded  by  a  growth  resembling  tufts  of  curly  hair. 
Upon  agar  the  growth  is  similar,  but  more  rapid  and  of  a  pale  color,  often 
with  a  central  nucleus  surrounded  by  a  net-like  marginal  zone.  Upon 
blood  serum  the  growth  is  similar  to  that  upon  agar.  Upon  potato,  at  37° 
C.,  a  limited  development  occurs  about  the  point  of  inoculation,  which  has 
a  dark-yellow  color.  The  cultures  give  off  a  very  penetrating  odor. 

Pathogenesis. — Pathogenic  for  dogs,  rabbits,  and  guinea-pigs  when  in- 
jected subcutaneously.  Not  pathogenic  for  white  mice  or  pigeons.  The 
symptoms  resulting  from  a  subcutaneous  injection  are  said  to  be  fever,  al- 
buminuria  and,  in  some  cases,  anuria,  haemorrhagic  spots  upon,  the  skin, 
convulsions;  death  occurs  in  from  one  to  three  days.  At  the  autopsy  there 
are  found  oedema  about  the  point  of  inoculation,  haemorrhages  in  the  skin  and 
muscles,  and  sometimes  in  the  internal  organs  and  in  serous  cavities;  the 
blood  does  not  coagulate.  The  bacilli  are  found  in  the  subcutaneous  con- 
nective tissue,  but  not  in  the  blood  or  in  the  various  organs.  Sections  show 
coagulation  necrosis  of  the  liver  cells  and  of  the  renal  epithelium. 

146.    BACILLUS  OF  PURPURA  HSEMORRHAGICA  OF  BABES. 

Obtained  by  Babes  (1890)  from  the  spleen  and  lungs  of  an  individual  who 
died  from  purpura  haemorrhagica  with  symptoms  of  septicaemia.  Resembles 
the  bacillus  previously  described  by  Tizzoni  and  Giovannini,  and  still  more 
that  of  Kolb ;  but,  according  to  Babes,  differs  in  some  respects  from  both  of 
these,  although  they  all  belong  evidently  to  the  same  group. 

Morphology. — Bacilli  with  rounded  ends,  oval  or  pear-shaped,  about  0.3  M 
thick,  surrounded  by  a  narrow  capsule. 

Stains  with  the  aniline  colors,  but  not  deeply,  and  still  less  intensely  by 
Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Does  not  form  spores.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  In  gelatin  stick  cultures,  at  the 
end  of  three  days,  a  thin,  transparent,  irregular  layer  has  developed  upon 
the  surface,  and  a  whitish,  punctate  stripe  along  the  line  of  inoculation.  In 
agar  stick  cultures  an  abundant  development  occurs  along  the  line  of  punc- 
ture, and  at  the  end  of  three  days  the  growth  upon  the  surface  consists  of 
small,  moist,  transparent  drops;  later  of  larger,  flat,  shining,  yellowish- 
white  plaques  which  have  ill-defined  margins.  Upon  blood  serum  the  de- 
velopment is  somewhat  more  abundant  in  the  form  of  small,  white,  moist 
colonies  one  to  two  millimetres  broad.  Upon  potato,  at  the  end  of  three 
days,  moist,  whitish  drops  with  ill-defined  margins. 


NOT   DESCRIBED   IN  PREVIOUS   SECTIONS.  481 

Pathogenesis. — Inoculations  in  the  conjunctivas  of  rabbits  produce  ecchy- 
moses  of  the  conjunctiva.  At  the  autopsy  numerous  haemorrhagic  extrava- 
sations are  found  in  all  the  organs,  especially  in  the  lungs  and  liver ;  the 
spleen  is  enlarged ;  the  bacilli  can  be  recovered  in  pure  cultures  from  the 
various  organs.  Old  cultures  proved  to  have  lost  their  virulence.  Patho- 
genic for  mice,  which  die  from  general  infection  in  the  course  of  a  few  days ; 
the  spleen  is  enlarged,  and  haemorrhages  in  the  serous  membranes  are  usually 
seen. 

147.    BACILLUS  OF  PURPURA  H.EMORRHAGICA   OF  KOLB. 

Obtained  by  Kolb  (1891)  from  the  various  organs  of  three  individuals 
who  died  in  from  two  to  four  days  from  attacks  characterized  by  suddenly 
developed  fever,  purpura,  and  albuminous  urine. 

Morphology. — Oval  bacilli,  usually  in  pairs,  08  to  1.5/f  long  and  O.S/* 
broad,  surrounded  by  a  narrow  capsule,  which  is  only  seen  distinctly  in 
preparations  from  the  organs. 

Stains  with  the  aniline  colors,  but  not  deeply,  and  still  more  feebly  by 
Gram's  method. 

Biological  Characters.  — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  non-motile  bacillus.  Does  not  form  spores.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  In  gelatin  stick  cultures,  at  the  end 
of  four  days,  a  very  small,  thin,  hyaline  growth  is  seen  about  the  point  of 
inoculation.  The  development  is  more  abundant  along  the  line  of  puncture. 
Upon  the  surface  of  agar  a  thin  layer  is  formed  with  smooth  margins. 
Upon  potato,  at  the  end  of  three  to  four  days,  a  whitish,  moist,  shining  stripe 
is  seen  along  the  impfstrich  which  is  about  three  millimetres  broad. 

Pathogenesis. — Injections  of  0.5  to  1  cubic  centimetre  of  a  bouillon 
culture  into  the  abdominal  cavity  of  rabbits  cause  symptoms  of  general  in- 
fection in  the  course  of  a  few  days,  and  not  infrequently  haemorrhagic  ex- 
travasations are  seen  in  the  ear  muscles.  More  than  one  cubic  centimetre 
may  cause  death  in  from  one  to  three  days.  At  the  autopsy  haemorrhagic 
extravasations  are  found  in  the  subcutaneous  tissues  and  in  the  serous  and 
mucous  membranes.  The  blood  has  little  disposition  to  coagulate;  the 
bacillus  may  be  recovered  in  pure  cultures  from  the  various  organs.  In 
guinea-pigs  local  ecchymoses  are  sometimes  produced,  otherwise  not  patho- 
genic for  this  animal.  Pathogenic  for  mice,  which  die  from  general  infec- 
tion, after  being  inoculated  with  a  small  quantity  of  a  pure  culture,  in  from 
two  to  three  days;  spleen  enlarged;  lymphatic  glands  often  haemorrhagic. 
Not  fatal  to  dogs,  but  animals  which  were  inoculated  with  one  cubic  centi- 
metre of  a  bouillon  culture  and  subsequently  killed  proved  to  have  haemor- 
rhagic extravasations  in  the  various  organs. 

148.    BACILLUS   HEMINECROBIOPHILUS. 

Obtained  by  Arloing  (1889)  from  a  caseous  lymphatic  gland  in  a  guinea-pig. 

Morphology. — Bacilli  which  vary  greatly  in  length  and  are  sometimes  so 
short  as  to  resemble  micrococci  ("polymorphous");  usually  from  one  to 
four  u  long;  in  anaerobic  cultures  from  eight  to  twenty  u. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  slightly  motile  bacillus.  Spore  formation  n.ot  observed.  Grows 
rapidly  in  the  usual  culture  media — best  in  the  incubating  oven  at  35°  C. 
The  growth  upon  the  surface  of  gelatin  has  a  yellowish  color.  Upon  potato 
a  yellowish- white  layer  is  developed. 

Pathogenesis. — According  to  Arloing,  this  bacillus  is  not  pathogenic  when 
injected  into  healthy  tissues  in  dogs,  sheep,  guinea-pigs,  and  rabbits,  but 
when  the  tissues  have  previously  been  injured  it  produces  a  local  oedema  and 
necrotic  changes,  accompanied  by  gas  formation.  This  is  not  peculiar  to  the 
microorganism  described  by  Arloing,  which  appears  to  be  one  of  the  Proteus 
group. 


XIV. 
PATHOGENIC  ANAEROBIC  BACILLI. 

STRICTLY  anaerobic  bacilli  are  not  able  to  multiply  in  the  blood 
of  living  animals  ;  but  some  of  them  may  multiply  in  the  subcuta- 
neous connective  tissue  or  in  the  muscles,  when  introduced  by  in- 
oculation, and  are  pathogenic  because  of  the  local  inflammatory  or 
necrotic  processes  to  which  they  give  rise,  or  because  they  produce 
soluble  toxic  substances  which  are  absorbed  and  cause  death  by 
their  special  action  upon  the  nervous  system  or  by  general  toxaemia. 

149.    BACILLUS   TETANI. 

Synonyms. — The  bacillus  of  tetanus  ;  Tetanusbacillus,  Ger. 

Nicolaier  (1884)  produced  tetanus  in  mice  and  rabbits  by  intro- 
ducing garden  earth  beneath  their  skin,  and  showed  that  the  disease 
might  be  transmitted  to  other  animals  by  inoculations  with  pus  or 
cultures  in  blood  serum  containing  the  tetanus  bacillus,  which,  how- 
ever, he  did  not  succeed  in  obtaining  in  pure  cultures.  Carle  and 
Rattone  (1884)  showed  that  tetanus  is  an  infectious  disease,  which 
may  be  transmitted  by  inoculation  from  man  to  lower  animals — a 
fact  which  has  since  been  verified  by  the  experiments  of  Rosenbach 
and  others.  Obtained  in  pure  cultures  by  Kitasato  (1889). 

The  writer  produced  tetanus  in  a  rabbit  in  1880  by  injecting  be- 
neath its  skin  a  little  mud  from  the  street  gutters  in  New  Orleans. 
The  tetanus  bacillus  appears  to  be  a  widely  distributed  microorgan- 
ism in  the  superficial  layers  of  the  soil  in  temperate  and  especially  in 
tropical  regions.  In  Nicolaier 's  experiments  it  was  not  found  in  soil 
from  forests  or  in  the  deeper  layers  of  garden  earth. 

'Morphology. — Slender,  straight  bacilli,  with  rounded  ends, 
which  may  grow  out  into  long  filaments.  Spores  are  developed  at 
one  extremity  of  the  bacilli,  which  are  spherical  in  form  and  consid- 
erably greater  in  diameter  than  the  rods  themselves,  giving  the 
spore-bearing  bacilli  the  shape  of  a  pin. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 
The  method  of  Ziehl  may  be  employed  for  double-staining  bacilli  and 
spores. 


PATHOGENIC   ANAEROBIC   BACILLI. 


483 


Biological  Characters. — An  anaerobic,  liquefying,  motile 
bacillus.  Forms  spores.  Grows  at  the  room  temperature,  in  the 
absence  of  oxygen,  in  the  usual  culture  media.  Grows  best  at  a 
temperature  of  36°  to  38°  C.;  in  nutrient  gelatin,  at  20°  to  25°  C., 
development  is  first  seen  at  the  end  of  three  or  four  days  ;  does  not 
grow  at  a  temperature  below  14°  C.  Spores  are  formed  in  cultures 
kept  in  the  incubating  oven  at  36°  C. ,  at  the  end  of  thirty  hours  ; 
in  gelatin  cultures  at  20°  to  25°  C.,  at  the  end  of  a  week  (Kitasato). 
The  bacilli  exhibit  voluntary  movements  which  are  not  very  active  ; 
those  containing  spores  are  not  motile.  It  may  be  cultivated  in  an 
atmosphere  of  hydrogen,  but  does  not  grow  in  the  presence  of  oxy- 
gen— strictly  anaerobic — or  in  an  atmosphere  of  carbon  dioxide. 
The  addition  of  one  and  one-half  to  two  per  cent  of  grape  sugar  to 
nutrient  agar  or  gelatin  causes  the  development  to  be  more  rapid 


FIG.  159. 


FIG.  160. 


FIG.  159.— Tetanus  bacillus,  from  a  gelatin  culture,  x  1,000.  From  a  photomicrograph  by 
Pfeiffer. 

FIG.  160. — Tetanusbacillus,  from  an  agar  culture  ;  spore-bearing  rods,  x  1,000.  From  a  photo- 
micrograph by  Pfeiffer. 

and  abundant.     The  culture  medium  should  have  a  feebly  alkaline 
reaction. 

Colonies  in  gelatin  plates,  in  an  atmosphere  of  hydrogen,  re- 
semble somewhat  colonies  of  Bacillus  subtilis,  the  opaque  central 
portion  being  surrounded  by  a  circle  of  diverging  rays  ;  liquefaction 
is,  however,  much  slower,  and  the  resemblance  is  lost  after  a  short 
time.  Older  colonies  resemble  the  colonies  of  certain  microscopic 
fungi,  being  made  up  of  diverging  rays.  In  long  gelatin  stick  cul- 
tures development  occurs  along  the  line  of  puncture,  at  a  consid- 
erable distance  below  the  surface,  in  the  form  of  a  radiate  out- 
growth ;  the  gelatin  is  slowly  liquefied,  and  a  small  amount  of  gas  is 
at  the  same  time  formed.  In  peptonized  bouillon  having  a  slightly 
alkaline  reaction,  under  hydrogen  gas,  the  development  is  abundant 


484 


PATHOGENIC   ANAEROBIC   BACILLI. 


and  the  cultures  give  off  a  characteristic  odor — "  brenzlichen  Ge- 
ruch  "  (Kitasato). 

According  to  Kitasato,  blood  serum  is  not  a  very  favorable  me- 
dium for  the  growth  of  the  tetanus  bacillus,  and — contrary  to  the 

statement  of  Kitt,  Tizzoni,  and  others — 
it  does  not  cause  liquefaction  of  this 
medium. 

The  spores  of  the  tetanus  bacillus  re- 
tain their  vitality  for  months  in  a  desic- 
cated condition,  and  are  not  destroyed  in 
two  and  one-half  months  when  present 
in  putrefying  material  (Turco).  They 
withstand  a  temperature  of  80°  C.  main- 
tained for  an  hour,  but  are  killed  by 
five  minutes'  exposure  to  steam  at  100°  C. 
They  are  not  destroyed  in  ten  hours  by 
a  five-per-cent  solution  of  carbolic  acid, 
but  did  not  grow  after  fifteen  hours'  ex- 
posure in  the  same  solution.  A  five- 
per-cent  solution  of  carbolic  acid,  to 
which  0. 5  per  cent  of  hydrochloric  acid 
has  been  added,  destroys  them  in  two 
hours  ;  in  sublimate  solution  containing 
1  : 1,000  of  mercuric  chloride  they  are 
destroyed  at  the  end  of  three  hours,  or 
in  thirty  minutes  when  0.5  per  cent  of 
hydrochloric  acid  is  added  to  the  solu- 
tion. Kitasato  succeeded  in  obtaining 
pure  cultures  from  the  pus  formed  in 
the  vicinity  of  inoculation  wounds,  by 
destroying  the  associated  bacilli  after 
the  tetanus  bacilli  had  formed  spores. 

This  was  effected  by  heating  cultures  from  this  source  for  about  an 
hour  at  a  temperature  of  80°  C.  The  spores  of  the  tetanus  bacillus 
survived  this  exposure,  and  colonies  were  obtained  from  them  in  flat 
flasks  especially  devised  for  anaerobic  cultures  ;  from  these  colonies 
pure  cultures  in  nutrient  agar  or  gelatin — long  stick  cultures — or  in 
peptonized  bouillpn  were  easily  obtained. 

Brieger  (188G)  first  succeeded  in  obtaining  from  impure  cultures 
of  the  tetanus  bacillus  a  crystallizable  toxic  substance,  called  by  him 
tetanin,  which  was  found  to  kill  small  animals  in  very  minute  doses 
and  with  the  characteristic  symptoms  of  tetanus.  More  recently 
Kitasato  and  Weyl  have  obtained  the  same  substance,  by  following 
Briegers  method,  from  a  pure  culture  of  this  bacillus.  From  a 


FIG.  161.— Culture  of  Bacillus  tetanl 
in  nutrient  gelatin.    (Kitasato.) 


PATHOGENIC   ANAEROBIC   BACILLI.  485 

bouillon  made  from  one  and  one-fourth  kilogrammes  of  lean  beef,  with 
the  addition  of  twenty-five  grammes  of  peptone,  they  obtained  1.7118 
grammes  of  hydrochlorate  of  tetanin.  This  proved  fatal  to  white 
mice  in  six  hours  in  the  dose  of  0.05  gramme,  and  a  dose  of  0.105 
gramme  caused  characteristic  tetanic  convulsions  and  death  within 
an  hour.  The  bacteriologists  last  named  also  obtained  from  their 
cultures  the  tetanotoxin  of  Brieger.  Two  mice  were  inoculated  sub- 
cutaneously  with  0.003  gramme  of  this  substance ;  one  died  at  the 
end  of  five  hours  without  the  development  of  tetanic  symptoms  ; 
the  other  survived.  In  addition  to  these  substances,  indol,  phenol, 
and  butyric  acid  were  demonstrated  to  be  present  in  cultures  of  the 
tetanus  bacillus. 

According  to  Kitasato,  the  tetanus  bacillus  does  not  become  at- 
tenuated in  its  pathogenic  potency  by  cultivation  in  artificial  media, 
as  is  the  case  with  many  other  pathogenic  bacteria.  The  more 
recent  researches  of  Brieger  and  Frankel,  and  of  Kitasato,  show  that 
the  toxic  ptomaine  discovered  by  Brieger  in  1886  is  not  the  substance 
to  which  cultures  of  the  tetanus  bacillus  owe  their  great  and  pecu- 
liar pathogenic  power.  The  distinguished  German  chemist  and  his 
associate  have  succeeded  in  isolating  from  tetanus  cultures  a  toxal- 
bumin  which  is  far  more  deadly  than  tetanin. 

Pathogenesis. — The  experiments  of  Kitasato  (1889)  show  that 
pure  cultures  of  the  tetanus  bacillus  injected  into  mice,  rabbits,  or 
guinea-pigs  produce  typical  tetanic  symptoms  and  death.  As  the 
presence  of  this  bacillus  at  the  seat  of  injury,  in  cases  of  tetanus  in 
man,  has  now  been  demonstrated  by  numerous  observers,  there  is 
no  longer  any  question  that  tetanus  must  be  included  among  the 
traumatic  infectious  diseases,  and  that  the  bacillus  of  Mcolaier  and 
of  Kitasato  is  the  specific  infectious  agent.  Kitasato's  recently  pub- 
lished experiments  (1890)  show  that  cultures  of  the  tetanus  bacillus 
which  have  been  sterilized  by  filtration  through  porcelain  produce 
the  same  symptoms,  and  death,  in  the  animals  mentioned,  as  result 
from  inoculation  with  cultures  containing  the  bacillus.  It  is  evi- 
dent, therefore,  that  death  results  from  the  action  of  a  toxic  sub- 
stance produced  by  the  bacillus.  This  is  further  shown  by  the  fact 
that  the  bacillus  itself  cannot  be  obtained  in  cultures  from  the  blood 
or  organs  of  an  animal  which  has  succumbed  to  an  experimental  in- 
oculation with  an  unfiltered  culture ;  but  the  blood  of  an  animal 
killed  by  such  an  inoculation  contains  the  tetanus  poison,  and  when 
injected  into  a  mouse  causes  its  death  with  tetanic  symptoms. 

When  a  platinum  needle  is  dipped  into  a  pure  culture  of  the 

tetanus  bacillus  and  a  mouse  is  inoculated  with  it  subcutaneously, 

the  animal  invariably  falls  sick  within  twenty-four  hours  and  dies  of 

typical  tetanus  in  two  or  three  days.     Rats,  guinea-pigs,  and  rabbits 

41 


486  PATHOGENIC   ANAEROBIC   BACILLI. 

are  killed  in  the  same  way  by  somewhat  larger  quantities — 0.3  to  0.5 
cubic  centimetre  (Kitasato).  Pigeons  are  very  slightly  susceptible. 
The  tetanic  symptoms  are  first  developed  in  the  vicinity  of  the  point 
of  inoculation  ;  if  the  animal  is  inoculated  in  the  posterior  portion  of 
the  body  the  hind  legs  first  show  tetanic  contraction,  if  in  the  fore 
part  of  the  body  the  muscles  of  the  neck  are  first  affected.  At  the 
autopsy  there  is  a  certain  amount  of  hyperaemia  at  the  point  of  in- 
oculation, but  no  pus  is  formed  ;  in  inoculations  with  garden  earth, 
or  accidental  inoculations  in  man,  pus  is  commonly  found  in  the 
vicinity  of  the  inoculation  wound.  The  various  organs  are  normal 
in  appearance.  Kitasato  says  that  he  has  not  been  able  to  demon- 
strate the  presence  of  the  bacillus  or  of  spores  in  the  spinal  marrow, 
the  nerves,  muscles,  spleen,  liver,  lungs,  kidneys,  or  blood  from  the 
heart ;  nor  has  he  been  able  to  obtain  cultures  from  the  various 
organs.  In  mice  which  were  inoculated  at  the  root  of  the  tail 
Kitasato  was  able  to  demonstrate  the  presence  of  the  bacilli  at 
the  point  of  inoculation  by  the  microscopical  examination  of  an 
excised  piece  of  the  tissues  for  eight  to  ten  hours  after  the  inocula- 
tion ;  later  than  this  they  were  not  found.  In  pus  from  the  inocu- 
lation wounds  of  men  and  animals  accidentally  infected  the  bacilli 
are  present,  but  the  formation  of  spores  does  not  always  oc- 
cur. According  to  Kitasato,  the  sooner  death  has  occurred  after 
accidental  inoculation  the  less  likely  are  spores  to  be  found  in  the 
rods,  but  from  pus  in  which  no  spores  are  seen  cultures  of  the 
bacillus  may  be  obtained  in  which  spores  will  develop  in  the  usual 
manner. 

Guinea-pigs  are  even  more  susceptible  to  the  tetanus  poison  than 
mice,  and  rabbits  less  so.  The  amount  of  filtrate  from  a  slightly 
alkaline  bouillon  culture  required  to  kill  a  mouse  is  extremely  minute 
— 0.00001  cubic  centimetre  (Kitasato).  The  tetanic  symptoms  are  de- 
veloped within  three  days  ;  if  the  animal  is  not  affected  within  four 
days  it  escapes  entirely.  The  tetanus  poison  is  destroyed  by  a  tem- 
perature of  65°  C.  maintained  for  five  minutes,  or  60°  for  twenty 
minutes,  or  55°  for  an  hour  and  a  half  ;  in  the  incubating  oven  at 
37°  C.  it  gradually  loses  its  toxic  potency ;  in  diffuse  daylight,  also, 
its  toxic  power  is  gradually  lost ;  in  a  cool,  dark  place  it  retains  its 
original  potency  indefinitely  ;  in  direct  sunlight  it  is  completely  de- 
stroyed in  from  fifteen  to  eighteen  hours  ;  it  is  not  injured  by  being 
largely  diluted  with  distilled  water ;  it  is  destroyed  in  an  hour  by 
hydrochloric  acid  in  the  proportion  of  0. 55  per  cent ;  terchloride  of 
iodine  destroys  it  in  the  proportion  of  0.5  per  cent,  cresol  in  1  per 
cent — one  hour's  exposure.  In  general  it  is  destroyed  by  acids  and 
by  alkalies.  Blood  serum  from  cattle,  horses,  sheep,  rabbits,  rats,  or 
guinea-pigs  does  not  modify  its  toxic  properties. 


PATHOGENIC   ANAEROBIC   BACILLI.  487 

Recent  researches  by  Tizzoni  and  Cattani  show  that  tetanus 
spores  preserved  upon  silk  threads  become  attenuated  after  a  time 
when  preserved  in  a  dark  place  in  free  contact  with  the  air.  "Very 
virulent  cultures  liquefy  gelatin,  give  off  a  very  disagreeable  odor, 
and  have  a  decidedly  alkaline  reaction.  Less  virulent  cultures 
quickly  acquire  an  acid  reaction.  Cultures  of  which  the  virulence 
is  very  much  attenuated  grow  more  rapidly  and  abundantly  than 
virulent  cultures  and  produce  more  gas — in  hydrogen  at  37°  C. ;  they 
do  not  liquefy  gelatin  and  have  no  odor.  In  attenuated  cultures  de- 
generation forms  are  often  seen,  and  the  spores  are  frequently  elon- 
gated or  almost  rod-shaped.  Cultures  preserved  in  various  gases 
for  thirteen  to  fourteen  months  invariably  become  attenuated. 

Immunity. — Kitasato  was  not  able  to  produce  immunity  in  mice 
by  inoculations  with  minute  doses  of  the  poison,  or  with  a  filtrate 
which  had  been  exposed  to  various  degrees  of  temperature  by  which 
its  activity  was  diminished  or  destroyed.  But  immunity  lasting  for 
about  two  months  was  produced  in  rabbits  by  inoculating  them 
"with  the  filtrate  from  a  culture  of  the  tetanus  bacillus  and  subse- 
quently, in  the  same  locality,  with  three  cubic  centimetres  of  a  one- 
per-cent  solution  of  terchloride  of  iodine  ;  this  last  solution  was  in- 
jected subcutaneously  in  the  same  dose  at  intervals  of  twenty-four 
hours  for  five  days.  Of  fifteen  rabbits  treated  in  this  way  six  proved 
to  be  immune  against  large  doses  of  a  virulent  culture  of  the  tetanus 
bacillus.  The  same  treatment  was  not  successful  in  producing  im- 
munity in  mice  or  guinea-pigs,  but  the  important  discovery  was 
made  that  a  small  quantity  of  blood  (0.2  cubic  centimetre)  from  an 
immune  rabbit,  when  injected  into  the  abdominal  cavity  of  a  mouse, 
gave  it  immunity  from  the  effects  of  inoculations  with  the  tetanus 
bacillus.  Moreover,  mice  which  were  first  inoculated  with  a  virulent 
culture  of  the  bacillus,  and,  after  tetanic  symptoms  had  appeared,  re- 
ceived in  the  cavity  of  the  abdomen  an  injection  of  blood  serum  from 
an  immune  mouse,  were  preserved  from  death.  The  power  of  the 
blood  of  an  immune  animal  to  neutralize  the  tetanus  poison  was  fur~ 
ther  shown  by  mixing  the  filtrate  from  a  virulent  culture  with  blood 
serum  from  an  immune  animal  and  allowing  it  to  stand  for  twenty- 
four  hours ;  a  dose  three  hundred  times  greater  than  would  have 
sufficed  to  kill  a  mouse  proved  to  be  without  effect  after  such  admix- 
ture with  blood  serum — as  before  stated,  the  blood  serum  of  animals 
which  are  not  immune  has  no  effect  upon  the  poison.  The  duration 
of  immunity  induced  in  this  way  was  from  forty  to  fifty  days. 
Blood  serum  from  an  immune  rabbit,  preserved  in  a  cool,  dark  room, 
retains  its  power  of  neutralizing  the  tetanus  poison  for  about  a  week, 
after  which  time  it  gradually  loses  it.  Having  found  that  chickens 
have  a  natural  immunity  against  tetanus,  Kitasato  made  experiments 


488  PATHOGENIC   ANAEROBIC  BACILLI. 

to  ascertain  whether  their  blood  serum  would  also  neutralize  the 
tetanus  poison;  the  result  was  negative. 

That  the  tetanus  poison  is  present  in  the  blood  of  individuals  who 
die  from  tetanus  has  been  proved  by  Kitasato  by  injecting  a  small 
quantity  (0.2  to  0.3  cubic  centimetre)  of  blood  from  the  heart  of  a 
fresh  cadaver  into  mice;  the  animals  develop  typical  tetanic  symp- 
toms and  die  in  from  twenty  hours  to  three  days. 

Tizzoni  and  Cattani  have  recently  (1891)  reported  results  similar 
to  those  obtained  by  Kitasato.  By  repeated  inoculations  with  grad- 
ually increasing  doses  of  the  tetanus  poison  they  succeeded  in  mak- 
ing a  dog  and  two  pigeons  immune,  and  found  that  blood  serum 
from  this  immune  dog,  in  very  small  amount,  completely  destroyed 
the  toxic  power  of  a  filtrate  from  cultures  of  the  tetanus  bacillus — 
one  to  two  drops  of  serum  neutralized  0. 5  cubic  centimetre  of  filtrate 
after  fifteen  to  twenty  minutes'  contact.  They  also  ascertained  that 
small  amounts  of  blood  serum  from  this  immune  dog  injected  into 
other  dogs  or  white  mice  produced  immunity  in  these  animals  ;  but 
they  were  not  able  to  produce  immunity  in  guinea-pigs  or  rabbits  by 
the  same  method. 

In  a  later  communication  (May,  1891)  Tizzoni  and  Cattani  give 
an  account  of  their  experiments  made  with  a  view  to  determining 
the  nature  of  the  substance  in  the  blood  serum  of  an  immune  animal 
which  has  the  power  of  destroying  the  toxalbumin  of  tetanus — "  tet- 
anus antitoxin/*  They  found,  in  the  first  place,  that  this  antitoxin 
in  blood  serum  is  destroyed  in  half  an  hour  by  a  temperature  of  68° 
C. ;  further,  that  it  does  not  pass  through  a  dialyzing  membrane ; 
that  it  is  destroyed  by  acids  and  alkalies.  As  a  result  of  their  re- 
searches they  conclude  that  it  is  an  albuminous  substance  having  the 
nature  of  an  enzyme. 

Vaillard  has  succeeded  in  producing  immunity  in  rabbits  by  re- 
peated injections  into  the  circulation  of  filtered  cultures — in  all 
twenty  cubic  centimetres — which  had  been  exposed  for  one  hour  to 
a  temperature  of  60°  C.  At  a  temperature  of  65°  C.  both  the  toxic 
and  the  immunizing  action  is  destroyed. 

150.    BACILLUS   CEDEMATIS   MALIGNI. 

Synonyms. — Bacillus  of  malignant  oedema;  Vibrion  septique 
(Pasteur). 

Discovered  by  Pasteur  (1877);  carefully  studied  by  Koch  (1881). 
This  bacillus  is  widely  distributed,  being  found  in  the  superficial 
layers  of  the  soil,  in  dust,  in  putrefying  substances,  in  the  blood  of 
animals  which  have  been  suffocated  (by  invasion  from  the  intestine), 
in  foul  water,  etc. 

It  may  usually  be  obtained  by  introducing  beneath  the  skin  of  a 


PATHOGENIC   ANAEROBIC   BACILLI. 


489 


rabbit  or  a  guinea-pig  a  small  quantity  of  garden  earth.  The  animal 
dies  within  a  day  or  two,  and  this  bacillus  is  found  in  the  bloody 
serum  effused  in  the  subcutaneous  connective  tissue  for  a  consider- 
able distance  about  the  point  of  inoculation. 

Morphology. — Bacilli  from  3  to  3.5  jn  long  and  1  to  1.1  j*  broad; 


—  y  \ 


FIG.  162.— Bacillus  oedsmatis  maligni,  from  subcutaneous  connective  tissue  of  inoculated 
guinea-pig.    X  950.-   (Baumgarten.) 


<"• 

oo 


frequently  united  in  pairs,  or  chains  of  three  elements ;  may  grow 
out  into  long  filaments  15  to  40  /*  long — these  are  straight,  or  bent 
at  an  angle,  or  more  or  less  curved.     They  resemble  the  bacillus  of 
anthrax,  but  are  not  quite  as  broad,  have 
rounded  ends,  and  in  stained  preparations 
the  long  filaments  are  not  segmented  as  is 
the  case   with    the   anthrax    bacillus.     By 
Loffler's  method  of  staining  they  are  seen  to 
have  flagella  arranged  around  the  periphery 
of  the  cells.     Large,  oval  spores  may  be  de- 
veloped in  the  bacilli  (not  in  the  long  fila- 
ments), which  are  of  greater  diameter  than 
the  rods,  and  produce  a  terminal  or  central 
swelling  of  the  same,  according  to  the  loca- 
tion of  the  spore. 

Stains  readily  by  the  aniline  colors  usu- 
ally employed,  but  is  decolorized  when  treated  by  Gram's  method. 
In  stained  preparations  the  long  filaments  may  present  a  somewhat 
granular  appearance  from  unequal  action  of  the  staining  agent. 

Biological  Characters. — A  strictly  anaerobic,  liquefying,  mo- 
tile bacillus.     Forms  spores.      Grows  in  the  usual  culture  media 


FIG.  163.— Bacillus  cedema- 
tis  maligni,  from  an  agar  cul- 
ture, showing  spores.  X  1,000 
From  a  photomicrograph. 
(Frankel  and  Pfeiffer.) 


490 


PATHOGENIC   ANAEROBIC   BACILLI. 


when  oxygen  is  excluded — in  an  atmosphere  of  hydrogen.  Grows 
at  the  room  temperature — better  in  the  incubating  oven  at  37°  C. 
The  spores  are  formed  most  abundantly  in  cultures  kept  in  the  in- 
cubating oven,  but  may  also  be  formed  at  a  temperature  of  20°  C. 
In  the  bodies  of  animals  which  succumb  to  an  experimental  inocula- 
tion no  spores  are  found  immediately 
after  death,  but  the  bacilli  multiply  rap- 
idly in  the  cadaver,  and  form  spores 
when  the  temperature  is  favorable. 

The  malignant- oedema  bacillus  may 
be  cultivated  in  ordinary  nutrient  gela- 
tin, but  its  development  is  more  abun- 
dant when  one  to  two  per  cent  of  grape 
sugar  has  been  added  to  the  culture 
medium.  In  deep  stick  cultures  in  this 
medium  development  occurs  at  first  only 
near  the  bottom  of  the  line  of  puncture  ; 
the  gelatin  is  liquefied  and  has  a  grayish- 
white,  clouded  appearance  ;  an  abundant 
development  of  gas  occurs,  and  as  this 
accumulates  the  growth  and  liquefaction 
of  the  gelatin  extend  upward.  A  very 
characteristic  appearance  is  obtained 
when  the  bacilli  are  mixed  in  a  test 
tube  with  gelatin  which  has  been  liquefied  by  heat,  and  which  is  then 
allowed  to  solidify.  Spherical  colonies  are  developed,  in  the  course 
of  two  or  three  days,  in  the  lower  portion  of  the  gelatin  ;  these  are 
filled  with  liquefied  gelatin  of  a  grayish- white  color,  and  when  ex- 
amined with  a  low  power  are  seen  to  be  permeated  with  a  network 
of  filaments,  while  the  periphery  presents  a  radiate  appearance.  In. 
nutrient  agar  growth  also  occurs  at  the  bottom  of  a  deep  punc- 
ture ;  it  has  an  irregular,  jagged  outline  and  a  granular  appearance; 
the  considerable  development  at  the  deepest  portion  and  gradual 
thinning  out  above  give  the  growth  a  club  shape  ;  in  the  incubating 
oven  there  is  an  abundant  development  of  gas,  which  often  splits  up 
the  agar  medium  and  forces  the  upper  portion  against  the  cotton 
stopper.  An  abundant  development  of  gas  also  occurs  in  cultures 
in  blood  serum,  and  the  medium  is  rapidly  liquefied  ;  at  a  tempera- 
ture of  37°  it  is  changed  in  a  few  days  to  a  yellowish  fluid,  at  the 
bottom  of  which  some  irregular,  corroded  fragments  of  the  solidified 
serum  may  be  seen.  In  agar  plates,  placed  in  a  close  receptacle 
from  which  oxygen  is  excluded,  cloudy,  dull-white  colonies  are 
formed  which  have  irregular  outlines  and  under  the  microscope 
are  seen  to  be  made  up  of  branching  and  interlaced  filaments  radi- 


Fio.  164.— Bacillus  oedematis  ma- 
ligni,  cultures  in  nutrient  gelatin;  a, 
long  stick  culture;  b,  colonies  at  bot- 
tom of  gelatin  tube.  (Flugge.) 


PATHOGENIC   ANAEROBIC   BACILLI.  491 

ating  from  the  centre.  Cultures  of  the  malignant-oedema  bacillus 
give  off  a  peculiar,  disagreeable  odor,  which  cannot,  however,  be 
designated  as  "  putrefactive." 

Pathogenesis. — Pathogenic  for  mice,  guinea-pigs,  rabbits,  and, 
according  to  Kitt,  for  horses,  dogs,  goats,  sheep,  calves,  pigs,  chick- 
ens, and  pigeons.  According  to  Arloing  and  to  Chauveau,  cattle  are 
immune.  The  disease  is  rarely  developed  except  as  a  result  of  ex- 
perimental inoculations,  but  horses  occasionally  have  malignant 
oedema  from  accidental  inoculation,  and  cases  have  been  reported 
in  man — "gangrene  gazeuse."  A  small  quantity  of  a  pure  cul- 
ture injected  beneath  the  skin  of  a  susceptible  animal  gives  rise  to 
an  extensive  inflammatory  oedema  of  the  subcutaneous  connective 
tissue  and  of  the  superficial  muscles,  which  extends  from  the  point 
of  inoculation,  especially  towards  the  more  dependent  portions  of 
the  body.  The  bloody  serum  effused  is  without  odor  and  contains 
little  if  any  gas.  But  when  malignant  oedema  results  from  the  in- 
troduction of  a  little  garden  earth  beneath  the  skin  of  p,  guinea-pig  or 
other  susceptible  animal,  the  effused  serum  is  frothy  and  has  a  pu- 
trefactive odor,  no  doubt  from  the  presence  of  associated  bacteria. 
Injections  into  the  circulation  do  not  give  rise  to  malignant  oedema, 
unless  at  the  same  time  some  bacilli  are  thrown  into  the  connective 
tissue.  While  small  animals  usually  die  from  an  experimental  in- 
oculation with  a  moderately  small  quantity  of  a  pure  culture,  larger 
ones  (dogs,  sheep)  frequently  recover.  At  the  autopsy,  if  made  at 
once,  the  bacilli  are  found  in  great  numbers  in  the  effused  serum, 
but  not  in  blood  from  the  heart  or  in  preparations  made  from  the 
parenchyma  of  the  various  organs  ;  later  they  may  be  found  in  all 
parts  of  the  body  as  a  result  of  post-mortem  multiplication.  This 
applies  to  rabbits  and  to  guinea-pigs,  but  not  to  mice  ;  in  these  little 
animals  the  bacilli  may  find  their  way  into  the  blood  during  the  last 
hours  of  life,  and  their  presence  may  be  demonstrated  in  smear  prepa- 
rations of  blood  from  the  heart  or  from  the  parenchyma  of  the  spleen 
or  liver.  In  mice  the  spleen  is  considerably  enlarged,  dark  in  color, 
and  softened ;  in  rabbits  and  guinea-pigs  less  so.  With  this  excep- 
tion the  internal  organs  present  no  very  notable  pathological  changes. 

Animals  which  recover  from  malignant  oedema  are  said  to  be 
subsequently  immune  (Arloing  and  Chauveau).  Roux  and  Cham- 
berlain have  shown  that  immunity  may  be  induced  in  guinea-pigs  by 
injecting  filtered  cultures  of  the  malignant-oedema  bacillus  (about 
one  hundred  cubic  centimetres  of  a  bouillon  culture  in  three  doses) 
into  the  abdominal  cavity  ;  or,  better  still,  by  the  injection  of  fil- 
tered serum  from  animals  which  have  recently  succumbed  to  an  ex- 
perimental inoculation  (one  cubic  centimetre  repeated  daily  for 
even  or  eight  days). 


493 


PATHOGENIC   ANAEROBIC   BACILLI. 
151.   BACILLUS  CADAVERIS. 


Obtained  by  the  writer  (1839)  from  pieces  of  liver  and  kidney,  from  yel- 
low-fever cadavers,  which  had  been  preserved  for  forty-eight  hours  in  an 
antiseptic  wrapping,  at  the  summer  temperature  of  Havana;  also  in  two 


<.  V 

t 


P"»  ^^. 

^  %' 


Fio.  165. — Bacillus  cadaveris;  smear  preparation  from  liver  of  yellow-fever  cadaver,  kept 
twenty-four  hours  in  an  antiseptic  wrapping,    x  1,000.    From  a  photomicrograph.    (Sternberg.) 

cases  from  pieces  of  yellow-fever  liver  immediately  after  the  autopsy ;  also 
from  liver  preserved  in  an  antiseptic  wrapping  from  comparative  autopsies 
made  in  Baltimore. 

Morphology. — Large  bacilli  with  square  or  slightly  rounded  corners, 
from  1.5  to  4  #  in  length  and  about  1.2  u  broad;  frequently  associated  in 

pairs ;  may  grow  out  into  straight  or 
slightly  curved  filaments  of  from  5 
to  15  /*  in  length. 

Biological  Characters. — An  an- 
aerobic, non-motile  bacillus;  not 
cultivated  in  nutrient  gelatin;  not 
observed  to  form  spores. 

Bacillus  cadaveris  is  a  strict  anae- 
robic and  is  difficult  to  cultivate.  I 
have  succeeded  best  with  nutrient 
agar  containing  five  per  cent  of 
glycerin,  removing  the  oxygen 
thoroughly  by  passing  a  stream  of 
hydrogen  through  the  liquefied  me- 
dium. The  colonies  in  a  glycerin- 
agar  roll  tube  (containing  hydrogen 
and  hermetically  sealed)  are  opaque, 
irregular  in  outline,  granular,  and  of 
a  white  color  by  reflected  light. 
The  culture  medium  acquires  an 
acid  reaction  as  a  result  of  the  de- 
velopment of  the  bacillus. 
Liver  tissue  containing  this  bacillus,  after  having  been  kept  in  an  anti- 
septic wrapping  for  forty-eight  hours,  has  a  fresh  appearance,  a  very  acid  re- 
action, and  is  without  any  putrefactive  odor. 


Fia.  166.— Bacillus  cadaveris,  from  an  anae- 
robic culture  in  glycerin-agar.  X  1,000.  From 
a  photomicrograph.  (Sternberg.) 


PATHOGENIC  ANAEROBIC  BACILLI. 


493 


Pathogenesis. — Liver  tissue  containing  this  bacillus  is  very  pathogenic 
for  guinea-pigs  when  injected  subcutaneously,  and  causes  an  extensive  in- 
flammatory oedema  extending  from  the  point  of  inoculation.  Pure  cul- 
tures of  the  bacillus  are  less  pathogenic,  and  the  few  experiments  which  I 
made  in  Havana  gave  a  somewhat  contradictory  result,  recovery  having 
occurred  in  one  guinea-pig  which  received  a  subcutaneous  injection  of  ten 
minims  of  liquid  from  an  anaerobic  culture  in  glycerin-agar,  while  another 
died  at  the  end  of  twenty  hours  from  a  subcutaneous  injection  of  three 
minims,  with  extensive  inflammatory  oedema  in  the  vicinity  of  the  point  of 
inoculation. 


152.    BACILLUS   OF   SYMPTOMATIC   ANTHRAX. 

Synonyms. — Rauschbrandbacillus,  Ger. ;  Bacille  du  charbon 
symptomatique,  Fr. 

First  described  by  Bellinger  and  Feser  (1878);  carefully  studied 
and  its  principal  characters  determined  by  Arloing,  Cornevin,  and 
Thomas  (1880-83). 


FlQ.  167. 


FIG.  168. 


FIG.  167.— Bacillus  of  symptomatic  anthrax,  from  an  agar  culture.  X  1,000.  From  a  photomi- 
crograph. (Frfinkel  and  Pfeifler.) 

FIG.  168.— Bacillus  of  symptomatic  anthrax,  from  muscles  of  inoculated  guinea-pig.  From  a 
photomicrograph.  (Roux.) 

Found  in  the  affected  tissues  of  animals — principally  cattle — suf- 
fering from  "  black  leg,"  "  quarter  evil,"  or  symptomatic  anthrax  (Fr.  f 
"charbon  symptomatique";  Ger.,  "  Rauschbrand  ").  The  disease 
prevails  during  the  summer  months  in  various  parts  of  Europe,  and 
is  characterized  by  the  appearance  of  irregular,  emphysematous 
swellings  of  the  subcutaneous  tissue  and  muscles,  especially  over  the 

quarters,   hence  the  name   "quarter    evil."    The  muscles  in    the 
42 


494 


PATHOGENIC   ANAEROBIC   BACILLI. 


affected  areas  have  a  dark  color  and  contain  a  bloody  serum  in 
which  the  bacillus  is  found. 

Morphology. — Bacilli  with  rounded  ends,  from  three  to  five  /* 
long  and  0.5  to  0.6  /<  broad  ;  sometimes  united  in  pairs,  but  do  not 
grow  out  into  filaments.  The  spores  are  oval,  somewhat  flattened  on 
one  side,  thicker  than  the  bacilli,  and  lie  near  the  middle  of  the  rods, 
but  a  little  nearer  to  one  extremity.  The  bacilli  containing  spores 
are  somewhat  spindle-formed  (Kitasato).  "Involution  forms "  are 
quite  common  in  old  cultures  or  in  unfavorable 
media  ;  in  such  cultures  variously  distorted  and 
often  greatly  enlarged  bacilli  may  be  seen,  some 
being  greatly  swollen  in  the  middle  —  spindle- 
shaped.  When  properly  stained,  by  Loffler's 
method,  a  number  of  flagella  are  seen  around  the 
periphery  of  the  cells. 

Stains  with  the  aniline  colors  usually  em- 
ployed, but  not  by  Gram's  method.  Spore-bear- 
ing bacilli  may  be  double-stained  by  first  stain- 
ing the  spores  by  Ziehl's  method,  and  then  the 
bacilli  with  a  solution  of  methylene  blue. 

Biological  Characters. — An  anaerobic,  liq^- 
uefying^motilebacillus.  Forms  spores.  Grows 
at  the  room  temperature  in  the  usual  culture  media, 
in  the  absence  of  oxygen,  in  an  atmosphere  of  hy- 
drogen, but  not  in  carbon  dioxide.  This  bacillus 
grows  more  rapidly  and  abundantly  in  nutrient 
agar  or  gelatin  to  which  1.5  to  2  per  cent  of 
grape  sugar  or  five  per  cent  of  glycerin  has  been 
added.  Colonies  in  gelatin,  in  an  atmosphere  of 
hydrogen,  are  at  first  spherical,  with  irregular  out- 
lines and  a  wart-like  surface  ;  later  the  gelatin  is 
liquefied  around  them,  and  radiating  filaments 
grow  out  into  the  gelatin,  so  that  by  transmitted 
light  they  present  the  appearance  of  an  opaque 
central  mass  with  an  irregular  surface  surrounded 
by  rays.  In  stick  cultures  in  nutrient  gelatin,  at 
20°  to  25°  C.,  at  the  end  of  two  or  three  days 
development  occurs  at  the  bottom  of  the  line  of  puncture  to  within 
about  two  fingers'  breadth  of  the  surface  ;  the  gelatin  is  slowly 
liquefied  and  considerable  gas  is  formed.  In  old  cultures  the 
growth  and  liquefaction  of  the  gelatin  extend  nearly  to  the  sur- 
face. In  agar  stick  cultures,  in  the  incubating  oven,  develop- 
ment begins  within  a  day  or  two  and  extends  to  within  one 
finger's  breadth  of  the  surface ;  considerable  gas  is  evolved,  and 


FIG.  169.  —  Bacillus 
of  symptomatic  an- 
thrax; long  stick  cul- 
ture in  nutrient  gela- 
tin, ten  days  at  18°- 
80°  0.  (Kitasato.) 


PATHOGENIC  ANAEROBIC   BACILLI.  495 

the  cultures  have  a  peculiar,  acid,  penetrating  odor.  Development 
is  most  rapid  at  36°  to  38°  C.,  but  may  occur  at  a  temperature  of  16° 
to  18°  C. — not  lower  than  14°.  Spores  are  quickly  formed  in  cul- 
tures kept  in  the  incubating  oven — not  so  quickly  at  the  room  tem- 
perature. These  withstand  a  temperature  of  80°  C.  maintained  for 
an  hour,  but  are  killed  in  five  minutes  by  a  temperature  of  100°  C. 
(in  steam).  In  the  bodies  of  infected  animals  spores  are  not  formed 
until  after  the  death  of  the  animal,  at  the  end  of  twenty-four  to  forty- 
eight  hours  (Kitasato). 

The  spores  are  destroyed  by  a  five-per-cent  solution  of  carbolic 
acid  in  ten  hours,  and  the  bacilli,  in  the  absence  of  spores,  in  five 
minutes  ;  a  1  : 1,000  solution  of  mercuric  chloride  destroys  the  spores 
in  two  hours  (Kitasato).  According  to  Kitasato,  certain  shining 
bodies  of  irregular  form,  which  stain  readily  with  the  aniline  colors, 
are  to  be  seen  in  the  rods  as  they  are  found  in  the  bloody  serum  from 
an  animal  recently  dead  ;  but  these  are  not  spores,  as  some  bacterio- 
logists have  supposed. 

Pathogenesis. — Cattle,  which  are  immune  against  malignant 
oedema,  are  most  subject  to  infection  by  the  bacillus  of  symptomatic 
anthrax,  and  the  disease  produced  by  this  anaerobic  bacillus  prevails 
almost  entirely  among  them  ;  horses  are  not  attacked  spontaneously 
— i.  e. ,  by  accidental  infection — and  when  inoculated  with  a  culture  of 
this  bacillus  present  only  a  limited  local  reaction.  Swine,  dogs,  rab- 
bits, fowls,  and  pigeons  have  but  slight  susceptibility,  but  the  re- 
searches of  Arloing,  Cornevin,  and  Thomas,  and  of  Roger  show  that 
by  the  addition  of  a  twenty -per-cent  solution  of  lactic  acid  to  a  cul- 
ture its  virulence  is  greatly  increased,  and  animals  which  have  but 
little  susceptibility,  like  the  rabbit  or  the  mouse,  succumb  to  such  in- 
jections ;  similar  results  were  obtained  by  Roger  by  the  simultaneous 
injection  of  sterilized  or  non-sterilized  cultures  of  Bacillus  prodigiosus 
or  of  Proteus  vulgaris.  The  guinea-pig  is  the  most  susceptible  ani- 
mal. When  inoculated  subcutaneously  with  a  small  quantity  of  a 
pure  culture,  or  with  spores  attached  to  a  silk  thread,  it  dies  in  from 
twenty-four  to  thirty-six  hours.  At  the  autopsy  a  bloody  serum  is 
found  in  the  subcutaneous  tissues  in  the  vicinity  of  the  point  of  in- 
oculation, and  the  muscles  present  a  dark-red  or  black  appearance 
similar  to  that  in  cattle  affected  with  "  black  leg."  The  internal  or- 
gans present  no  notable  pathological  changes.  Immediately  after 
death  the  bacilli  are  found  only  in  the  effused  serum  and  the  affected 
tissues  near  the  point  of  inoculation,  but  later  they  multiply  in  the 
cadaver  and  are  found  throughout  the  body.  According  to  Kitasato, 
the  cultures  in  solid  media  preserve  their  virulence  for  an  indefinite 
period,  but  cultures  in  a  bouillon  made  from  the  flesh  of  guinea-pigs 
soon  lose  their  virulence.  Cultures  are  readily  attenuated  by  heat 


496  PATHOGENIC   ANAEROBIC   BACILLI. 

according  to  the  method  of  Toussaint  and  Chauveau  ;  a  temperature 
of  4:2°  to  43°  C.  is  suitable.  The  pathogenic  virulence  of  spores  may 
also  be  attenuated  by  subjecting  them  to  dry  heat — a  temperature  of 
80°  to  100°  C.  maintained  for  several  hours.  For  the  production  of 
immunity  in  cattle  Arloing,  Cornevin,  and  Thomas  recommend  the 
use  of  a  dried  powder  of  the  muscles  of  animals  which  have  suc- 
cumbed to  the  disease,  and  which  has  been  subjected  to  a  suitable 
temperature  to  insure  attenuation  of  the  pathogenic  virulence  of  the 
spores  contained  in  it.  Kitt,  who  has  made  extended  experiments 
with  this  bacillus,  recommends  that  the  muscles  be  first  dried  at  32° 
to  35°  C.  and  then  powdered.  Two  vaccines  are  then  prepared — a 
stronger  vaccine  by  exposure  of  a  portion  of  the  powder  to  a  tem- 
perature of  85°  to  90°  C.  for  six  hours,  and  a  weaker  vaccine  by  ex- 
posure for  six  hours  to  a  temperature  of  100°  to  104°  C.  (dry  heat). 
Inoculations  made  with  this  attenuated  virus — the  weakest  first  and 
subsequently  the  least  attenuated — give  rise  to  a  local  reaction  of 
moderate  intensity,  and  the  animal  is  subsequently  immune  from  the 
effects  of  the  most  virulent  material.  Immunity  may  also  be  secured 
by  intravenous  inoculations  ;  or,  in  guinea-pigs,  by  inoculations  with 
bouillon  cultures  which  have  been  kept  for  a  few  days  and  as  a  re- 
sult have  lost  their  original  virulence,  or  with  cultures  kept  in  an  in- 
cubating oven  at  a  temperature  of  42°  to  43°  C. ;  or  by  inoculation 
with  a  very  minute  quantity  of  a  pure  culture  ;  or  by  an  inoculation 
made  into  the  extremity  of  the  tail ;  or  by  inoculations  with  filtered 
cultures  (Roux  and  Chamberlain),  or  with  cultures  sterilized  by  heat 
(Kitasato).  It  has  been  claimed  (Roux)  that  animals  which  have 
been  made  immune  against  symptomatic  anthrax  are  also  immune 
against  malignant  oedema.  But  in  a  carefully  conducted  series  of 
experiments  Kitasato  was  unable  to  confirm  this  ;  he  found  that 
guinea-pigs  which  had  an  immunity  against  the  most  virulent  cul- 
tures of  the  Rauschbrand  bacillus  succumbed  invariably  to  malig- 
nant oedema  when  inoculated  subcutaneously  with  the  bacillus  of 
malignant  oedema. 


STERNBERG'S  BACTERIOLOGY. 

\  Vv^i5^\  u 


\J 


Spirillum  Obermeieri  in  blood  of  two  monkeys, 
inoculated  after  removal  of  spleen.. 
(  S  oudakewi  \rch). 


XV. 
PATHOGENIC  SPIRILLA. 

153.    SPIRILLUM   OBERMEIERI. 

Synonyms. — Spirochsete  Obermeieri ;  Spirillum  of  relapsing  fe- 
ver ;  Die  Recur rensspirochate. 

Discovered  by  Obermeier  (1873)  in  the  blood  of  persons  suffering 
from  relapsing  fever. 

This  spirillum  is  present,  in  very  great  numbers,  in  the  blood  of 
relapsing-fever  patients  during  the  febrile  paroxysms.  It  has  not 
been  found  under  any  other  circumstances,  and  its  etiological  rela- 
tion to  the  disease  with  which  it  is  associated  is  generally  admitted. 

Morphology. — Very  slender,  flexible,  spiral  or  wavy  filaments, 
with  pointed  ends  ;  from  sixteen  to  forty  /*  in  length  and  consider- 
ably thinner  than  the  cholera  spirillum — about  0.1  /*.  Koch  has 
demonstrated  the  presence  of  flagella  (Eisenberg). 

Stains  readily  with  the  aniline  colors,  especially  with  fuchsin, 
Bismarck  brown,  and  in  Loffler's  solution  of  methylene  blue. 

Biological  Characters. — An  aerobic,  motile  spirillum  which 
has  not  been  cultivated  in  artificial  media.  This  spirillum  appears  to 
be  a  strict  parasite,  whose  habitat  is  the  blood  of  man.  The  disap- 
pearance of  the  parasite  from  the  blood  soon  after  the  termination 
of  a  febrile  paroxysm,  and  its  reappearance  during  subsequent  par- 
oxysms, have  led  to  the  inference  that  it  must  form  spores,  but  this 
has  not  been  demonstrated.  In  fresh  preparations  from  the  blood 
the  spirillum  exhibits  active  progressive  movements,  accompanied 
by  very  rapid  rotation  in  the  long  axis  of  the  spiral  filaments,  or  by 
undulatory  movements.  The  movements  are  so  vigorous  that  the 
comparatively  large  red  blood  corpuscles  are  seen,  under  the  micro- 
scope, to  be  thrown  about  by  the  slender  spiral  filaments,  which  it  is 
difficult  to  see  in  unstained  preparations.  When  preserved  in  a  one- 
half -per-cent  salt  solution  they  continue  to  exhibit  active  movements 
for  a  considerable  time.  Efforts  to  cultivate  this  spirillum  in  artificial 
media  have  thus  far  been  unsuccessful,  although  Koch  has  observed 
an  increase  in  the  length  of  the  spirilla  and  the  formation  of  a 
tangled  mass  of  filaments. 


498 


PATHOGENIC    SPIRILLA. 


In  experiments  made  by  Heydenreich  the  spirillum  was  found  to 
preserve  its  vitality  (motility)  for  fourteen  days  at  a  temperature  of 


FIG.    170.— Spirillum    Obermeieri   in   blood   of   man.     x   1,000.     From   a   photomicrograph. 
(Frankel  and  Pfeiffer. ) 

1G°  to  22°  C.,  for  twenty  hours  at  37°,  and  at  43.5°  for  two  or  three 
hours  only. 

Pathogenesis. — Causes  in  man  the  disease  known  as  relapsing 
fever.     Munch  and  Moczutkowsky  have  produced  typical  relapsing 


FIG.  171.— Spirillum  Obermeieri  in  blood  of  an  inoculated  ape.    x  700.    (Koch. 

fever  in  healthy  persons  by  inoculating  them  with  blood  containing 
the  spirillum  of  Obermeier.  The  spirilla  are  found  in  the  blood  dur- 
ing the  febrile  paroxysm,  and  for  a  day  or  two,  at  the  outside,  after 


PATHOGE^TIC   SPIRILLA.  499 

its  termination  ;  sometimes  they  are  present  in  great  numbers,  and 
at  others  can  only  be  found  by  searching  several  microscopic  fields; 
they  are  not  present  in  the  various  secretions — urine,  sweat,  saliva, 
etc.  In  fatal  cases  the  principal  pathological  changes  are  found  in 
the  spleen,  which  is  greatly  enlarged,  and  in  the  liver  and  marrow 
of  the  bones,  which  contain  inflammatory  and  necrotic  foci.  Koch 
and  Carter  have  succeeded  in  transmitting  the  disease  to  monkeys 
by  subcutaneous  inoculations  with  small  amounts  of  defibrinated 
blood  containing  the  spirillum.  After  an  incubation  period  of  seve- 
ral days  typical  febrile  paroxysms  were  developed,  during  which 
the  actively  motile  spirilla  were  found  in  the  blood  in  large  numbers. 
Blood  from  one  animal,  taken  during  the  attack,  induced  a  similar 
febrile  paroxysm  when  inoculated  into  another  of  the  same  species — 
relapses,  such  as  characterize  the  disease  in  man,  were  not  observed. 
Onl  attack  did  not  preserve  the  animals  experimented  upon  from  a 
similar  attack  when  they  were  again  inoculated  after  an  interval  of 
a  few  days.  Recently  Soudakewitch  (1891)  has  made  successful  in- 
oculation experiments  in  monkeys,  and  has  shown  that  in  monkeys 
from  which  the  spleen  has  previously  been  removed  the  spirilla  con- 
tinue to  multiply  very  abundantly  in  the  blood  and  the  disease  has  a 
fatal  termination,  whereas  in  monkeys  from  which  the  spleen  has 
not  been  removed  the  spirilla  disappear  from  the  blood  within  a  few 
days  after  tlie  access  of  the  febrile  paroxysm  and  the  animal  recovers. 

154.    SPIRILLUM  ANSERUM. 

Synonym. — Spirochaeta  anserina  (Sakharoff). 

Obtained  by  Sakharoff  (1890)  from  the  blood  of  geese  affected  by  a  fatal 
form  of  septicaemia  due  to  this  spirillum.  This  disease  prevails  among  geese 
in  Caucasia,  especially  in  swampy  regions,  appearing  annually  and  destroy- 
ing a  large  number  of  the  domestic  geese. 

Morphology. — Resembles  the  spirillum  of  relapsing  fever.  The  long  and 
flexible  spiral  filaments,  when,  the  disease  is  at  its  height,  are  often  seen  in 
interlaced  masses,  around  the  margins  of  which  radiate  single  filaments 
w.hich  by  their  movements  cause  the  whole  mass  to  change  its  place,  as  if  it 
were  a  single  organism.  These  masses  are  sometimes  so  large  that  a  single 
one  occupies  the  entire  field  of  the  microscope. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  motile  spirillum.  Not  cultivated 
in  artificial  media.  The  movements  are  very  active,  resembling  those  of 
Spirillum  Obermeieri,  but  cease  in  an  hour  or  two  in  preparations  made  from 
the  blood  of  geese  containing  it. 

Pathogenesis. — A  small  quantity  of  blood  from  an  infected  goose  inocu- 
lated into  a  healthy  animal  of  the  same  species  induces  the  disease  after  a 
period  of  incubation  of  four  to  five  days.  The  infected  goose  ceases  to  eat, 
becomes  apathetic,  remaining1  in  one  place,  and  usually  dies  at  the  end  of  a 
week  ;  the  temperature  is  increased,  and  in  some  cases  there  is  diarrhoea. 
The  spirilla  are  found  in  the  blood  at  the  outset  of  the  malady,  but  after 
death  they  are  not  seen  either  in  the  blood  or  in  the  various  organs.  The 
heart  and  the  liver  are  found  to  have  undergone  a  fatty  degeneration,  and 
yellowish,  cheesy  granules  the  size  of  a  millet  seed  are  seen  upon  the  surface 
of  these  organs.  The  spleen  is  soft  and  easily  broken  up  by  the  fingers. 


500 


PATHOGENIC   SPIRILLA. 


Inoculations  into  chickens  and  pigeons  were  without  result  ;  in  one 
chicken  the  spirilla  were  found  in  the  blood  on  the  fourth  day  after  inocula- 
tion, but  the  fowl  recovered. 

155.    SPIRILLUM   CHOLERA   ASIATICS. 

Synonyms. — Spirillum  ("  bacillus  ")  of  cholera;  Comma  bacillus 
of  Koch ;  Kommabacillus  der  Cholera  Asiaticse ;  Bacille-virgule 
cholerigene. 

Discovered  by  Koch  (1884)  in  the  excreta  of  cholera  patients  and 
in  the  contents  of  the  intestine  of  recent  cadavers. 

The  researches  of  Koch,  made  in  Egypt  and  in  India  (1884),  and 
subsequent  researches  by  bacteriologists  in  various  parts  of  the 
world,  show  that  this  spirillum — so-called  "  comma  bacillus" — is  con- 
stantly present  in  the  contents  of  the  intestine  of  cholera  patients 
during  the  height  of  the  disease,  and  that  it  is  not  found  in  the  con- 
tents of  the  intestine  of  healthy  persons  or  of  those  suffering  from 


FIG.  172.  FIG.  173. 

FIG.  172.— Spirillum  choleras  Asiaticae.    X  1,000.    From  a  photomicrograph.    (Koch.) 
FIG.  178.— Spirillum  cholera?  Asiaticse,  involutic-i  forms.    X  700.    (Van  Ermengem.) 

other  diseases  than  cholera.  The  etiological  relation  of  this  spiril- 
lum to  Asiatic  cholera  is  now  generally  admitted  by  bacteriologists. 
Morphology. — Slightly  curved  rods  with  rounded  ends,  from  0.8 
to  2  /*  in  length  and  about  0.3  to  0.4 /^  in  breadth.  The  rods  are 
usually  but  slightly  curved,  like  a  comma,  but  are  occasionally  in 
the  form  of  a  half-circle,  or  two  united  rods  curved  in  opposite 
directions  may  form  an  S-shaped  figure.  Under  certain  circum- 
stances the  curved  rods  grow  out  into  long,  spiral  filaments,  which 
may  consist  of  numerous  spiral  turns,  and  in  hanging-drop  cultures 
the  S-shaped  figures  may  also  be  seen  to  form  the  commencement 
of  a  spiral ;  in  stained  preparations  the  spiral  character  of  the  long 
filaments  is  often  obliterated,  or  nearly  so.  When  development  is 
very  rapid  the  short,  curved  rods  or  S-shaped  spirals  only  are  seen  ; 
but  in  hanging-drop  cultures,  or  in  media  in  which  the  develop. 


PATHOGENIC   SPIRILLA. 


501 


ment  is  retarded  by  an  unfavorable  temperature,  the  presence  of  a 
little  alcohol,  etc.,  the  long,  spiral  filaments  are  quite  numerous,  and 
bacteriologists  generally  agree  that  the  so-called  "  comma  bacillus  " 
is  really  only  a  fragment  of  a  true  spirillum.  By  Loffler's  method 
of  staining  the  rods  may  be  seen  to  have  a  single  terminal  flagel- 
lum.  In  old  cultures  the  bacilli  frequently  lose  their  characteristic 
form  and  become  variously  swollen  and  distorted — involution  forms. 
Hueppe  has  described  the  appearance  of  spherical  bodies  in  the 
course  of  the  spiral  filaments,  which  he  believes  to  be  reproductive 
elements — so-called  arthrospores. 

Stains  with  the  aniline  colors  usually  employed,  but  not  as  quick- 
ly as  many  other  bacteria ;   an  aqueous  solution  of  fuchsin  is  the 


FIG.  174.  FIG.  175. 

FIG.  174.— Spirillum  cholerae  Asiatic®;  colonies  upon  gelatin  plate,  end  of  thirty  hours,  x  ICO. 
Photograph  by  Frankel  and  Pfeiffer. 

FIG.  175.— Spirillum  cholerse  Asiaticae,  from  a  gelatin  culture,  x  1,000.  From  a  photomicro- 
graph. (Frankel  and  Pfeiffer.) 

most  reliable  staining  agent;  is  decolorized  by  iodine  solution — 
Gram's  method.  Sections  may  be  stained  with  Loffler's  solution. 

Biological  Characters. — An  aerobic  (facultative  anaerobic), 
liquefying,  motile  spirillum.  Grows  in  the  usual  culture  media  at 
the  room  temperature — more  rapidly  in  the  incubating  oven.  Does 
not  grow  at  a  temperature  above  42°  or  below  14°  C.  Does  not  form 
endogenous  spores  (forms  arthrospores,  according  to  Hueppe  ?). 

In  gelatin  plate  cultures,  at  22°  C. ,  at  the  end  of  twenty-four 

hours  small,  white  colonies  may  be  perceived  in  the  depths  of  the 

gelatin ;  these  grow  towards  the  surface  and  cause  liquefaction  of 

the  gelatin  in  the  form  of  a  funnel  which  gradually  increases  in 

43 


502 


PATHOGENIC   SPIRILLA. 


depth,  and  at  the  bottom  of  which  is  seen  the  colony  in  the  form  of 
a  small,  white  mass  ;  as  a  result  of  this  the  plates  on  the  second  or 
third  day  appear  to  be  perforated  with  numerous  small  holes  ;  later 

the  gelatin  is  entirely  liquefied.  Under 
a  low  power  the  young  colonies,  before 
liquefaction  has  commenced,  present  a 
rather  characteristic  appearance ;  they 
are  of  a  white  or  pale-yellow  color,  and 
have  a  more  or  less  irregular  outline, 
the  margins  being  rough  and  uneven; 
the  texture  is  coarsely  granular,  and  the 
surface  looks  as  if  it  were  covered  with 
little  fragments  of  broken  glass,  while 

the  colony  has  a  shining  appearance  ;  when  liquefaction  commences  an 
ill-defined  halo  is  first  seen  to  surround  the  granular  colony,  which 
by  transmitted  light  has  a  peculiar  roseate  hue.  In  stick  cultures  in 
nutrient  gelatin  development  occurs  all  along  the  line  of  inoculation, 


FIG.  176.— Colonies  of  the  cholera 
spirillum;  o,  end  of  twenty  hours;  6, 
end  of  thirty  hours;  c,  end  of  forty- 
eight  hours;  d,  after  liquefaction  of 
the  gelatin.  (Flugge.) 


FIG.  177.— Spirillum  cholerse  Asiaticee;  a,  one  day  old;  6,  three  days  old;  c,  fourdays  old;  d,  five 
days  old;  e,  seven  days  old;  /,  10  days  old.    From  photographs  by  Koch. 

but  liquefaction  of  the  gelatin  first  occurs  only  near  the  surface  ;  on 
the  second  day,  at  22°  C.,  a  short  funnel  is  formed  which  has  a 
comparatively  narrow  mouth,  and  the  upper  portion  of  which  con- 
tains air,  while  just  below  this  is  a  whitish,  viscid  mass  ;  later  the 
funnel  increases  in  depth  and  diameter,  and  at  the  end  of  from  four 
to  six  days  may  reach  the  edge  of  the  test  tube ;  in  from  eight  to 
fourteen  days  the  upper  two-thirds  of  the  gelatin  is  completely  lique- 
fied. Owing  to  the  slight  liquefaction  which  occurs  along  the  line  of 
growth  during  the  first  three  or  four  days,  the  central  mass  which 


PATHOGENIC   SPIRILLA. 


503 


had  formed  along  the  line  of  inoculation  settles  down  as  a  curled 
or  irregularly  bent,  yellowish-white  thread  in  the  lower  part  of  a 
slender  tube  filled  with  liquefied  gelatin,  the  upper  part  of  which 
widens  out  and  is  continuous  with  the  funnel  above.  Upon  the  sur- 
face of  nutrient  agar  a  moist,  shining,  white  layer  is  formed  along 
the  line  of  inoculation — impfstrich.  Blood  serum  is  slowly  liquefied 
by  this  spirillum.  Upon  the  surface  of  cooked  potato,  in  the  incu- 
bating oven,  a  rather  thin  and  semi-transparent  brown  or  grayish- 
brown  layer  is  developed.  In  bouillon  the  development  is  rapid  and 
abundant,  especially  in  the  incubating  oven  ;  the  fluid  is  only  slightly 


W 


FIG.  178.— Cultures  in  nutrient  gelatin,  at  the  room  temperature  (16°  to  18°  C.),  at  the  com- 
mencement of  thefourth  day;  a.  Spirillum  choleras  Asiatic®;  6,  Spirillum tyrogenum;  c,  Spirillum 
of  Finkler  and  Prior.  (Baumgarten.) 

clouded,  but  the  spirilla  accumulate  at  the  surface,  forming  a  wrin- 
kled membranous  layer.  Sterilized  milk  is  also  a  favorable  culture 
medium.  In  general  this  spirillum  grows  in  any  liquid  containing  a 
small  quantity  of  organic  pabulum  and  having  a  slightly  alkaline 
reaction.  An  acid  reaction  of  the  culture  medium  prevents  its  de- 
velopment, as  a  rule,  but  it  has  the  power  of  gradually  accommo- 
dating itself  to  the  presence  of  vegetable  acids,  and  grows  upon 
potatoes— in  the  incubator  only — which  have  a  slightly  acid  reaction. 
Abundant  development  occurs  in  bouillon  which  has  been  diluted 
with  eight  or  ten  parts  of  water,  and  the  experiments  of  Wolffhugel 


504  PATHOGENIC   SPIRILLA. 

and  Riedel  show  that  it  also  multiplies  to  some  extent  in  sterilized 
river  or  well  water,  and  that  it  preserves  its  vitality  in  such  water 
for  several  months.  But  in  milk  or  water  which  contains  other  bac- 
teria it  dies  out  in  a  few  days.  Gruber  and  Schottelius  have  shown, 
however,  that  in  bouillon  which  is  greatly  diluted  the  cholera  spiril- 
lum may  take  the  precedence  of  the  common  saprophytic  bacteria, 
and  that  they  form  upon  the  surface  of  such  a  medium  the  charac- 
teristic wrinkled  film.  Koch  found  in  his  early  investigations  that 
rapid  multiplication  may  occur  upon  the  surface  of  moist  linen,  and 
also  demonstrated  the  presence  of  this  spirillum  in  the  foul  water  of 
a  "  tank "  in  India  which  was  used  by  the  natives  for  drinking 
purposes.  In  the  experiments  of  Bolton  (1886)  the  cholera  spirillum 
was  found  to  multiply  abundantly  in  distilled  water  to  which 
bouillon  was  added  in  the  proportion  of  fifteen  to  twenty-five  parts 
in  one  thousand. 

The  thermal  death-point  of  the  cholera  spirillum  in  recent  cul- 
tures in  flesh-peptone-gelatin,  as  determined  by  the  writer  (1887),  is 
52°  C. ,  the  time  of  exposure  being  four  minutes  ;  a  few  colonies  only 
developed  after  exposure  to  a  temperature  of  50°  for  ten  minutes. 
In  Kitasato's  experiments  (1889)  ten  or  even  fifteen  minutes'  expo- 
sure to  a  temperature  of  55°  C.  was  not  always  successful  in  destroy- 
ing the  vitality  of  the  spirillum,  although  in  certain  cultures  exposure 
to  50°  for  fifteen  minutes  was  successful.  He  was  not,  however, 
able  to  find  any  difference  between  old  and  recent  cultures  as  regards 
resistance  to  heat  or  to  desiccation.  In  a  moist  condition  this  spiril- 
lum retains  its  vitality  for  months — as  much  as  nine  months  in  agar 
and  about  two  months  in  liquefied  gelatin.  It  is  quickly  destroyed 
by  desiccation,  as  first  determined  by  Koch,  who  found  that  it  did 
not  grow  after  two  or  three  hours  when  dried  in  a  thin  film  on  a 
glass  cover.  In  Kitasato's  experiments  (1889)  the  duration  of  vital- 
ity was  found  to  vary  from  a  few  hours  to  thirteen  days,  the  differ- 
ence depending  largely  upon  the  thickness  of  the  film.  When  dried 
upon  silk  threads  they  may  retain  their  vitality  for  a  considerably 
longer  time  (Kitasato).  Very  numerous  experiments  have  been 
made  to  determine  the  amount  of  various  disinfecting  agents  re- 
quired to  destroy  the  vitality  of  this  microorganism.  We  give  be- 
low the  results  recently  reported  by  Boer  (1890),  whose  experiments 
were  made  in  Koch's  laboratory.  -  Experiments  upon  a  culture  in 
bouillon  kept  for  twenty-four  hours  in  the  incubating  oven,  time  of 
exposure  two  hours  :  hydrochloric  acid,  1  : 1,350 ;  sulphuric  acid, 
1  : 1,300  ;  caustic  soda,  1  : 150  ;  ammonia,  1  :  350  ;  mercuric  cyanide, 
1  : 60,000  ;  gold  and  sodium  chloride,  1  : 1,000  ;  silver  nitrate,  1: 4,000; 
arsenite  of  soda,  1  : 400  ;  malachite  green,  1  :  5,000  ;  methyl  violet, 
1  : 1,000  ;  carbolic  acid,  1  :400  ;  creolin,  1  : 3,000  ;  lysol,  1  :500.  In 


PATHOGENIC    SPIRILLA.  505 

Bolton's  experiments  (1887)  mercuric  chloride  was  effective  in  two 
hours  in  the  proportion  of  1  : 10,000  ;  sulphate  of  copper,  1  : 500. 

The  low  thermal  death-point  and  comparatively  slight  resisting 
power  for  desiccation  and  chemical  agents  indicate  that  this  spiril- 
lum does  not  form  spores,  and  most  bacteriologists  agree  that  this 
is  the  case.  Hueppe,  however,  has  described  a  mode  of  spore  for- 
mation which  is  different  from  that  which  occurs  among  the  bacilli, 
viz. ,  the  formation  of  so-called  arthrospores  ;  these  are  said  to  be 
developed  in  the  course  of  the  spiral  threads,  not  as  endogenous  re- 
fractive spores,  but  as  spherical  bodies  which  have  a  somewhat 
greater  diameter  than  the  filament  and  are  somewhat  more  refrac- 
tive. This  mode  of  spore  formation  has  not  been  observed  by  Kita- 
sato  and  other  bacteriologists  who  have  given  attention  to  the  ques- 
tion, and  cannot  be  considered  as  established.  In  competition  with 
the  ordinary  putrefactive  bacteria  the  cholera  spirillum  soon  disap- 
pears, and,  as  determined  by  Neffelman  and  by  Kitasato,  they  only 
survive  for  a  few  days  when  mixed  with  normal  fseces. 

A  test  for  the  presence  of  the  cholera  spirillum  has  been  found 
by  Bujwid  and  by  Dunham  in  the  reddish-violet  color  produced  in 
bouillon  cultures  containing  peptone,  or  in  cultures  in  nutrient  gela- 
tin, when  a  small  quantity  of  sulphuric  acid  is  added  to  the  culture. 
According  to  Frankel,  this  test  serves  to  distinguish  it  from  the  ordi- 
nary bacteria  of  the  intestine  and  from  the  Finkler-Prior  spirillum, 
but  not  from  Metschnikoff's  spirillum  ("  vibrio  ").  The  reaction  is 
shown  by  bouillon  cultures  which  have  been  in  the  incubating  oven 
for  ten  or  twelve  hours,  and  by  gelatin  cultures  in  which  liquefac- 
tion has  occurred.  The  sulphuric  acid  used  should  be  quite  pure  ; 
the  color  quickly  appears  and  is  reddish- violet  or  purplish-red.  Ac- 
cording to  Salkowski,  the  red  color  is  due  to  the  well-known  indol 
reaction,  which  in  cultures  of  the  cholera  spirillum  is  exceptionally 
intense  and  rapid  in  its  development.  A  test  which  is  said  to  dis- 
tinguish cultures  of  the  cholera  spirillum  from  the  spirillum  of  De- 
neke  and  that  of  Finkler-Prior,  has  been  proposed  by  Cahen.  This 
consists  in  adding  a  solution  of  litmus  to  the  bouillon  and  in  making 
the  culture  at  37°  C.  The  cholera  cultures  show  on  the  following 
day  a  decoloration  which  does  not  occur  at  this  temperature  with  the 
other  spirilla  named. 

For  determining  as  promptly  as  possible  whether  certain  suspected 
excreta  contain  cholera  spirilla,  a  little  of  the  material  may  be  used 
to  inoculate  greatly  diluted  bouillon,  gelatin  plates  being  made  at 
the  same  time.  At  the  end  of  ten  or  twelve  hours  the  cholera  spiril- 
lum, if  present,  will  already  have  formed  a  characteristic  wrinkled 
film  upon  the  surface  ;  a  little  of  this  should  be  used  to  start  a  new 
culture  in  diluted  bouillon,  and  a  series  of  gelatin  plates  made  from 


506  PATHOGENIC   SPIRILLA. 

it,  after  which  the  color  test  may  be  applied.  The  result  of  this,  in 
connection  with  the  morphology  of  the  microorganisms  forming  the 
film  and  the  character  of  growth  in  the  gelatin  plates,  will  estab- 
lish the  diagnosis  if  the  cholera  spirillum  is  present  in  considerable 
numbers.  If  but  few  are  present  in  the  original  material  it  may  be 
necessary  to  make  two  or  more  series  of  plates  and  bouillon  cultures 
before  a  pure  culture  can  be  obtained  and  a  positive  diagnosis  made. 

Brieger  has  succeeded  in  isolating  several  toxic  ptomaines  from 
cultures  of  the  cholera  bacillus,  some  of  which  had  previously  been 
obtained  from  other  sources — cadaverin,  putrescin,  creatinin,  me- 
thyl-guanidin.  In  addition  to  these  he  obtained  two  toxic  sub- 
stances not  previously  known.  One  of  these  is  a  diamin,  resembling 
trimethylenediamin  ;  it  gave  rise  to  cramps  and  muscular  tremor  in 
inoculated  animals.  The  other  poison  reduced  the  frequency  of  the 
heart's  action  and  the  temperature  of  the  body  in  the  animals  sub- 
jected to  experiment.  In  more  recent  researches  made  by  Brieger 
and  Frankel  (1890)  a  toxalbumin  was  obtained  from  cholera  cultures 
which,  when  injected  subcutaneously  into  guinea-pigs,  caused  their 
death  in  two  or  three  days,  but  had  no  effect  upon  rabbits. 

Pfeiffer  has  recently  (1892)  published  his  extended  researches  re- 
lating to  the  cholera  poison.  He  finds  that  recent  aerobic  cultures  of 
the  cholera  spirillum  contain  a  specific  toxic  substance  which  is  fatal 
to  guinea-pigs  in  extremely  small  doses.  This  substance  stands 
inclose  relation  with  the  bacterial  cells  and  is  perhaps  an  integral 
part  of  the  same.  The  spirilla  may  be  killed  by  chloroform,  thymol, 
or  by  desiccation  without  apparent  injury  to  the  toxic  potency  of 
this  substance.  It  is  destroyed,  however,  by  absolute  alcohol,  by 
concentrated  solutions  of  neutral  salts,  and  by  the  boiling  tempera- 
ture, and  secondary  toxic  products  are  formed  which  have  a  similar 
physiological  action  but  are  from  ten  to  twenty  times  less  potent. 

Similar  toxic  substances  were  obtained  by  Pfeiffer  from  cultures  of 
Finkler-Prior's  spirillum  and  from  Spirillum  Metschnikovi.  The  spi- 
rillum is  not  found  in  the  blood  or  in  the  various  organs  of  individu- 
als who  have  succumbed  to  an  attack  of  cholera,  but  it  is  constantly 
found  in  the  alvine  discharges  during  life  and  in  the  contents  of  the 
intestine  examined  immediately  after  death ;  frequently  in  almost  a 
pure  culture  in  the  colorless  "  rice-water  "  discharges.  It  is  evident, 
therefore,  that  if  we  accept  it  as  the  etiological  agent  in  this  disease, 
the  morbid  phenomena  must  be  ascribed  to  the  absorption  of  toxic 
substances  formed  during  its  multiplication  in  the  intestine.  In  cases 
which  terminated  fatally  after  a  very  brief  sickness  Koch  found  but 
slight  changes  in  the  mucous  membrane  of  the  intestine,  which  was 
slightly  swollen  and  reddened  ;  but  in  more  protracted  cases  the  fol- 
licles and  Peyer's  patches  were  reddened  around  their  margins,  and 


PATHOGENIC   SPIRILLA. 


507 


an  invasion  of  the  mucous  membrane  by  the  "  comma  bacilli "  was 
observed  in  properly  stained  sections ;  they  penetrated  especially 
the  follicles  of  Lieberkiihn,  and  in  some  cases  were  seen  between  the 
epithelium  and  basement  membrane.  As  a  rule,  the  spirillum  is  not 
present  in  vomited  matters,  but  Koch  found  it  in  small  numbers  in 
two  cases  and  Nicati  and  Rietsch  in  three.  In  about  one  hundred 
cases  in  which  Koch  examined  the  excreta,  or  the  contents  of  the  in- 
testine of  recent  cadavers,  during  his  stay  in  Egypt,  in  India,  and  in 
Toulon,  his  "  comma  bacillus"  was  constantly  found,  and  other  ob- 
servers have  fully  confirmed  him  in  this  particular — Mcati  and 
Rietsch  in  thirty-one  cases  examined  at  Marseilles  ;  Pf eiffer,  twelve 
cases  in  Paris ;  Schottelius  in  cases  examined  in  Turin ;  Ceci  in 


^dCi     k*»WW(<$0 

%tft 


"a 


FIG.  179.— Section  through  mucous  membrane  of  intestine  from  cholera  cadaver;  a  tubular 
gland  (a)  is  cut  obliquely;  in  the  interior  of  this  (6),  and  between  the  epithelial  and  basement 
membrane,  are  numerous  spirilla.  X  600.  (Flugge.) 

Genoa,  etc.  On  the  other  hand,  very  numerous  control  experiments 
made  by  Koch  and  others  show  that  it  is  not  present  in  the  alvine 
discharges  of  healthy  persons  or  in  the  contents  of  the  intestine  of 
those  who  die  from  other  diseases.  In  the  writer's  extended  bacte- 
riological studies  of  the  excreta,  and  contents  of  the  intestine  of  ca- 
davers, in  yellow  fever,  he  has  not  once  encountered  any  microor- 
ganism resembling  the  cholera  spirillum. 

As  none  of  the  lower  animals  are  liable  to  contract  cholera  during 
the  prevalence  of  an  epidemic,  or  as  a  result  of  the  ingestion  of  food 
contaminated  with  choleraic  excreta,  we  have  no  reason  to  expect 
that  pure  cultures  of  the  spirillum  introduced  by  subcutaneous  inocu- 
lation or  by  the  mouth  will  give  rise  in  them  to  a  typical  attack  of 


508  PATHOGENIC   SPIRILLA. 

cholera.  Moreover,  it  has  been  shown  by  experiment  that  this  spi- 
rillum is  very  sensitive  to  the  action  of  acids,  and  is  quickly  de- 
stroyed by  the  acid  secretions  of  the  stomach,  of  man  or  the  lower 
animals,  when  the  functions  of  this  organ  are  normally  performed. 
By  a  special  method  of  procedure,  however,  Nicati  and  Rietsch,  and 
Koch,  have  succeeded  in  producing  in  guinea-pigs  choleraic  symp- 
toms and  death.  The  first-named  investigators  injected  cultures  of 
the  spirillum  into  the  duodenum,  after  first  ligating  the  biliary  duct; 
the  animals  experimented  upon  died,  and  the  intestinal  contents  con- 
tained the  spirillum  in  large  numbers.  The  fact  that  this  procedure 
involves  a  serious  operation  which  alone  might  be  fatal,  detracts 
from  the  value  of  the  results  obtained.  Koch's  experiments  on 
guinea-pigs  are  more  satisfactory,  and,  having  been  fully  controlled 
by  comparative  experiments,  show  that  the  ' '  comma  bacillus "  is 
pathogenic  for  these  animals  when  introduced  in  a  living  condition 
into  the  intestine.  This  was  accomplished  by  first  neutralizing  the 
contents  of  the  stomach  with  a  solution  of  carbonate  of  soda — five 
cubic  centimetres  of  a  five-per-cent  solution,  injected  into  the  stomach 
through  a  pharyngeal  catheter.  For  the  purpose  of  restraining  in- 
testinal peristalsis  the  animal  also  receives,  in  the  cavity  of  the  abdo- 
men, a  tolerably  large  dose  of  laudanum — one  gramme  tincture  of 
opium  to  two  hundred  grammes  of  body  weight.  The  animals  are 
completely  narcotized  by  this  dose  for  about  half  an  hour,  but  re- 
cover from  it  without  showing  any  ill  effects.  Soon  after  the  ad- 
ministration of  the  opium  a  bouillon  culture  of  the  cholera  spirillum 
is  injected  into  the  stomach  through  a  pharyngeal  catheter.  As  a 
result  of  this  procedure  the  animal  shows  an  indisposition  to  eat  and 
other  signs  of  sickness,  its  posterior  extremities  become  weak  and 
apparently  paralyzed,  and,  as  a  rule,  death  occurs  within  forty-eight 
hours.  At  the  autopsy  the  small  intestine  is  found  to  be  congested 
and  is  filled  with  a  watery  fluid  containing  the  spirillum  in  great 
numbers.  Comparatively  large  quantities  of  a  pure  culture  injected 
into  the  abdominal  cavity  of  rabbits  or  of  mice  often  produce  a  fatal 
result  within  two  or  three  hours  ;  and  Nicati  and  Rietsch  have  ob- 
tained experimental  evidence  of  the  pathogenic  power  of  filtered  cul- 
tures not  less  than  eight  days  old.  The  most  satisfactory  evidence 
that  this  spirillum  is  able  to  produce  cholera  in  man  is  afforded  by  an 
accidental  infection  which  occurred  in  Berlin  (1884),  in  the  case  of  a 
young  man  who  was  one  of  the  attendants  at  the  Imperial  Board  of 
Health  when  cholera  cultures  were  being  made  for  the  instruction  of 
students.  Through  some  neglect  the  spirillum  appears  to  have  been 
introduced  into  his  intestine,  for  he  suffered  a  typical  attack  of 
cholera,  attended  by  thirst,  frequent  watery  discharges,  cramps  in 
the  extremities,  and  partial  suppression  of  urine.  Fortunately  he 


PATHOGENIC   SPIRILLA.  509 

recovered  ;  but  the  genuine  nature  of  the  attack  was  shown  by  the 
symptoms  and  by  the  abundant  presence  of  the  "  comma  bacillus" 
in  the  colorless,  watery  discharges  from  his  bowels.  Nicati  and 
Kietsch  observed  a  certain  degree  of  attenuation  in  the  pathogenic 
power  of  the  spirillum  after  it  had  been  cultivated  for  a  considerable 
time  at  20°  to  25°  C.  ;  and  the  observation  has  since  been  made  that 
cultures  which  have  been  kept  up  from  Koch's  original  stock  have 
no  longer  the  primitive  pathogenic  potency. 

Cunningham,  as  a  result  of  recent  researches  made  in  Calcutta 
(1891),  arrives  at  the  conclusion  that  Koch's  "  comma  bacillus"  can- 
not be  accepted  as  the  specific  etiological  agent  in  this  disease.  This 
conclusion  is  based  upon  the  results  of  his  own  bacteriological 
studies,  which  may  be  summed  up  as  follows  :  First,  in  many  un- 
doubted cases  of  cholera  he  has  failed  to  find  comma  bacilli.  Sec- 
ond, in  one  case  he  found  three  different  species.  Third,  in  one  case 
the  reaction  with  acids  could  not  be  obtained.  From  sixteen  cases 
in  which  Cunningham  made  cultures  he  obtained  ten  different  vari- 
eties of  comma  bacilli,  the  characters  of  which  he  gives  in  his  pub- 
lished report.  It  may  be  that  in  India,  which  appears  to  be  the 
permanent  habitat  of  the  cholera  spirillum,  many  varieties  of  this 
microorganism  exist ;  but  extended  researches  made  in  the  laborato- 
ries of  Europe  show  that  Cunningham  is  mistaken  in  supposing  that 
spirilla  resembling  Koch's  "  comma  bacillus  "  are  commonly  present 
in  the  intestine  of  healthy  persons.  The  view  advocated  is  that 
during  the  attack  these  spirilla  are  found  in  increased  numbers  be- 
cause conditions  are  more  favorable  for  their  development,  but  that 
they  have  no  etiological  import.  The  writer  would  remark  that,  in 
very  extended  researches  made  in  the  United  States  and  in  Cuba,  he 
has  never  found  any  microorganism  resembling  Koch's  cholera  spi- 
rillum in  the  faeces  of  patients  with  yellow  fever  or  of  healthy  indi- 
viduals, or  in  the  intestinal  contents  of  yellow-fever  cadavers. 

156.    SPIRILLUM  OF  FINKLER  AND   PRIOR. 

Synonym. — Vibrio  proteus. 

Obtained  by  Finkler  and  Prior  (1884)  from  the  faeces  of  patients  with 
cholera  nostras,  after  allowing  the  dejecta  to  stand  for  some  days.  Subse- 
quent researches  have  not  sustained  the  view  that  this  spirillum  is  the  speci- 
fic cause  of  cholera  morbus. 

Morphology. — Resembles  the  spirillum  of  Asiatic  cholera,  but  the  curved 
segments  ("  bacilli"  )  are  somewhat  longer  and  thicker  and  not  so  uniform 
in  diameter,  the  central  portion  being  usually  thicker  than  the  somewhat 
pointed  ends ;  forms  spiral  filaments,  which  are  not  as  numerous,  and  are 
usually  shorter  than  those  formed  by  the  cholera  spirillum.  In  unfavorable 
media  involution  forms  are  common — large  oval,  spherical,  or  spindle- 
shaped  cells,  etc.  Has  a  single  flagellum  at  one  end  of  the  curved  segments, 
which  is  from  one  to  one  and  one-half  times  as  long  as  these. 

Stains  with  the  usual  aniline  colors — best  with  an  aqueous  solution  of 
fuchsin. 

44 


510 


PATHOGENIC   SPIRILLA. 


Biological  Characters. — Anaerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  spirillum.  Spore  formation  not  demonstrated.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  small, 
white,  punctiform  colonies  are  developed  at  the  end  of  twenty  four  hours, 
which  under  the  microscope  are  seen  to  be  finely  granular  and  yellowish  or 
yellowish-brown  in  color ;  liquefaction  of  the  gelatin  around  these  colonies 
progresses  rapidly,  and  at  the  end  of  forty-eight  hours  is  usually  complete  in 
plates  where  they  are  numerous.  Isolated  colonies  on  the  second  day  form 
saucer-shaped  depressions  in  the  gelatin  the  size  of  lentils,  having  a  sharply 
defined  border.  In  gelatin  stick  cultures  liquefaction  progresses  much  more 
rapidly  than  in  similar  cultures  of  the  cholera  spirillum,  and  a  stocking- 
shaped  pouch  of  liquefied  gelatin  is  already  seen  on  the  second  day,  which 
rapidly  increases  in  dimensions,  so  that  by  the  end  of  a  week  the  gelatin  is 
usually  completely  liquefied ;  upon  the  surface  of  the  liquefied  medium  a 
whitish  film  is  seen.  Upon  agar  a  moist,  slimy  layer,  covering  the  entire 
surface,  is  quickly  developed.  The  growth  in  blood  serum  is  rapid  and 


FIG.  180. 


Fia.  181.  FIG.  182. 

Fio.  180.— Spirillum  of  Finkler  and  Prior,  from  a  gelatin  culture.  X  1,000.  From  a  photomicro- 
graph. (Frankel  and  Pfeiffer.) 

Fia.  181.— Spirillum  of  Finkler  and  Prior;  colonies  upon  gelatin  plate;  a,  end  of  sixteen  hours; 
b,  end  of  twenty-four  hours;  c;  end  of  thirty-six  hours.  X  80.  (Flugge  ) 

Fia.  182.— Spirillum  of  Finkler  and  Prior;  culture  in  nutrient  gelatin;  c,  two  days  old;  d,  four 
days  old.  (Flugge.) 

causes  liquefaction  of  the  medium.  Upon  potato  this  spirillum  ^rows  at  the 
room  temperature  and  produces  a  slimy,  grayish-yellow,  glistening  layer, 
which  soon  extends  over  the  entire  surface.  The  cholera  spirillum  does  not 
grow  upon  potato  at  the  room  temperature.  The  cultures  of  the  Finkler- 
Prior  spirillum  give  off  a  tolerably  strong  putrefactive  odor,  and,  according 
to  Buchner,  in  media  containing  sugar  an  acid  reaction  is  produced  as  a  re- 
sult of  their  development.  They  have  a  greater  resistance  to  desiccation  than 
the  cholera  spirillum. 

Pathogenesis. — Pathogenic  for  guinea-pigs  when  injected  into  the 
stomach  by  Koch's  method,  after  previous  injection  of  a  solution  of  car- 
bonate of  soda,  but  a  smaller  proportion  of  the  animals  die  from  such  injec- 
tions (Koch).  At  the  autopsy  the  intestine  is  pale,  and  its  watery  contents, 


PATHOGENIC   SPIRILLA.  511 

which  contain  the  spirilla  in  great  numbers,  have  a  penetrating,  putrefactive 
odor. 

157.    SPIRILLUM   TYROGENUM. 

Synonyms. — Spirillum  of  Deneke;  Kasespirillen. 
Obtained  by  Deneke  (1885)  from  old  cheese. 

Morphology. — Curved  rods  and  long,  spiral  filaments  resembling  the 
spirilla  of  Asiatic  cholera.  The  diameter  of  the  curved  segments  is  some- 
what less  than  that  of  the  cholera  spirillum,  and  the  turns  in  the  spiral  fila- 
ments are  lower  and  closer  together.  The  diame- 
ter of  the  "commas"  is  uniform  throughout,  so 
that  this  spirillum  more  closely  resembles  the 
cholera  spirillum  than  does  that  of  Finkler  and 
Prior. 

Stains  with  the  usual  aniline    colors — best 
with  an  aqueous  solution  of  fuchsin. 

Biological  Characters. — An  aerobic  and  fac- 

ultative  anaerobic,  liquefying,  motile  spirillum.  ^•=" 

Spore  formation  not   demonstrated.     Grows  in 

the  usual  culture  media  at  the  room  temperature        FIG.  183.  —  Spirillum  tyroge- 
— more  rapidly  than  the  cholera  spirillum  and     num.    x  ~oo.   (Flugge.) 
less  so  than  that  of  Finkler  and  Prior.      Upon 

gelatin  plates  small,  punctiform  colonies  are  developed,  which  on  the  second 
day  are  about  the  size  of  a  pin's  head  and  have  a  yellowish  color ;  under 
the  microscope  they  are  seen  to  be  coarsely  granular,  of  a  yellowish-green 
color  in  the  centre  and  paler  towards  the  margins.  The  outlines  of  the  colo- 
nies are  sharply  denned  at  first,  but  later,  when 
liquefaction  has  commenced,  the  sharp  contour 
is  no  longer  seen.  At  first  liquefaction  of  the 
gelatin  causes  funnel-shaped  cavities  resembling 
those  formed  by  the  cholera  spirillum,  but  lique- 
faction is  more  rapid.  In  gelatin  stick  cultures 
.  liquefaction  occurs  all  along  the  line  of  punc- 

ture, and  the  spirilla  sink  to  the  bottom  of  the 

FIG  i84.-Spiriiiumtyrogenum;  liquefied  gelatin  in  the  form  of  a  coiled  mass, 
colonies  in  gelatin  plate;  a,  end  while  a  thin,  yellowish  layer  forms  upon  the 
of  sixteen  hours;  b,  end  of  twen-  surface ;  complete  liquefaction  usually  occurs  in 
ty-four  hours;  c,  ead  of  thirty-  about  two  weeks.  Upon  the  surface  of  agar  a 
six  hours.  X80.  (Flugge.)  thin5  veliowish  iayer  forms  along  the  impf- 

strich.     Upon  potato,  at  a  temperature  of  37°  C., 

a  thin,  yellow  layer  is  usually  developed   (not    always  — Eisenberg) ;   this 
contains,  as  a  rule,  beautifully  formed,  long,  spiral  filaments. 

Pathogenesis. — Pathogenic  for  guinea-pigs  when  introduced  into  the 
stomach  by  Koch's  method ;  three  out  of  fifteen  animals  treated  in  this  way 
succumbed. 

158.    SPIRILLUM  METSCHNIKOVI. 

Synonym. — Vibrio  Metschnikovi  (Gameleia). 

Obtained  by  Gameleia  (1888)  from  the  intestinal  contents  of  chickens 
dying  of  an  infectious  disease  which  prevails  in  certain  parts  of  Russia  dur- 
ing the  summer  months,  and  which  in  some  respects  resembles  fowl  cholera. 
The  experiments  of  Gameleia  show  that  the  spirillum  under  consideration  is 
the  cause  of  the  disease  referred  to,  which  he  calls  gastro-enteritis  cholerica. 

Morphology. — Curved  rods  with  rounded  ends,  and  spiral  filaments;  the 
curved  segments  are  usually  somewhat  shorter,  thicker,  and  more  decidedly 
curved  than  the  "  comma  bacillus  "  of  Koch.  The  size  differs  very  consid- 
erably in  the  blood  of  inoculated  pigeons,  the  diameter  being  sometimes 
twice  as  great  as  that  of  the  cholera  spirillum,  and  at  others  about  the  same. 
A  single,  long,  undulating  flagellum  may  be  seen  at  one  extremity  of  the 
spiral  filaments  or  curved  rods  in  properly  stained  preparations. 


512 


PATHOGENIC   SPIRILLA. 


Stains  with  the  usual  aniline  colors,  but  not  hy  Gram's  method. 
Biological  Characters. — An  aerobic  (facultative  anaerobic  ?),  liquefy- 
ing, motile  spirillum.  According1  to  Gamaleia,  endogenous  spores  are  formed 
by  this  spirillum;  but  Pfeiffer  does  not  confirm  this  observation,  and  it  must 
be  considered  extremely  doubtful  in  view  of  the  slight 
resistance  to  heat— killed  in  five  minutes  by  a  temperature 
of  50°  O.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Upon  gelatin  plates  small,  white,  puncti- 
form  colonies  are  developed  at  the  end  of  twelve  to  six- 
teen hours  ;  these  rapidly  increase  in  size  and  cause  lique- 
faction of  the  gelatin,  which  is,  however,  much  more  rapid 
with  some  than  with  others.  At  the  end  of  three  days 
large,  saucer-like  areas  of  liquefaction  may  be  seen,  resem- 
bling- that  produced  by  the  Finkler-Prior  spirillum  and  the 
contents  of  which  are  turbid,  while  other  colonies  have 
produced  small,  funnel-shaped  cavities  filled  with  trans- 
parent, liquefied  gelatin  and  resembling1  colonies  of  the 
cholera  spirillum  of  the  same  age.  Under  the  microscope 
the  larger  liquefied  areas  are  seen,  to  contain  yellowish- 
brown  granular  masses  which  are  in  active  movement,  and 
the  margins  are  surrounded  by  a  border  of  radiating  fila- 
ments. In  gelatin  stick  cultures  the  growth  resembles  that 
of  the  cholera  spirillum,  but  the  development  is  more  rap- 
id. Upon  agar,  at  37°  C.,  a  yellowish  layer  resembling 
that  formed  by  the  cholera  spirillum  is  quickly  developed. 
Upon  potato  no  growth  occurs  at  the  room  temperature, 
but  at  37°  C.  a  yellowish-brown  or  chocolate-colored  layer 
is  formed,  which  closely  resembles  that  produced  by  the 
cholera  spirillum  under  the  same  circumstances.  In  bouil- 
lon, at  37°  C.,  development  is  extremely  rapid,  and  the 
liquid  becomes  clouded  and  opaque,  having  a  grayish-white 
color,  while  a  thin,  wrinkled  film  forms  upon  the  surface. 
When  muriatic  or  sulphuric  acid  is  added  to  a  culture  in 
peptonized  bouillon  a  red  color  is  produced  similar  to  that 
produced  in  cultures  of  the  cholera  spirillum,  and  even  more  pronounced. 
In  milk,  at  35°  C.,  rapid  development  occurs,  and  the  milk  is  coagulated  at 
the  end  of  a  week ;  the  precipitated  casein  accumulates  at  the  bottom  of  the 
tube  in  irregular  masses  and  is  not  redissolved.  The  milk  acquires  a  strongly 
acid  reaction  and  the  spirilla  quickly  perish. 

Pathogenesis. — Pathogenic  for  chickens,  pigeons,  and  guinea-pigs;  rab- 
bits and  mice  are  refractory  except  for  very  large  doses.  Chickens  suffering 
from  the  infectious  disease  caused  by  this  spirillum  remain  quiet  and  somno- 
lent, with  ruffled  feathers ;  they  have  diarrhoea ;  the  temperature  is  not  ele- 
vated above  the  normal,  as  is  the  case  in  chicken  cholera.  At  the  autopsy 
the  most  constant  appearance  is  hyperaemia  of  the  entire  alimentary  canal. 
A  grayish-yellow  liquid,  more  or  less  mixed  with  blood,  is  found  in  con- 
siderable quantity  in  the  small  intestine ;  the  spleen  is  not  enlarged  and  the 
organs  generally  are  normal  in  appearance.  In  adult  chickens  the  spirillum 
is  not  found  in  the  blood,  but  in  young  ones  its  presence  may  be  verified  by 
the  culture  method  and  by  inoculation  into  pigeons,  which  die  in  from 
twelve  to  twenty  hours  after  being  inoculated  with  two  to  four  cubic  cen- 
timetres. The  pathological  appearances  in  pigeons  correspond  with  those 
found  in  chickens,  but  usually  the  spirillum  is  found  in  great  numbers  in 
blood  taken  from  the  heart.  A  few  drops  of  a  pure  culture  inoculated  sub- 
cutaneously  in  pigeons  or  injected  into  the  muscles  cause  their  death  in 
eight  to  twelve  hours.  Gameleia  claims  that  the  virulence  of  cultures  is 
greatly  increased  by  successive  inoculations  in  pigeons,  but  Pfeiffer  has 
shown  that  very  minute  doses  are  fatal  to  pigeons  and  that  no  decided  in- 
crease of  virulence  occurs  as  a  result  of  successive  inoculations.  According 
to  Gameloa,  chickens  may  be  infected  by  giving  them  food  contaminated 


FIG  185.—  Spiril- 
lum Metschnikovi ; 
culture  in  nutrient 
gelatin, end  of  forty- 
eight  hours  Froma 
photograph.  (Fran- 
kel  and  Pfeiffer.) 


PATHOGENIC   SPIRILLA.  513 

with  the  cultures  of  the  spirillum,  but  pigeons  resist  infection  in  this  way. 
Guinea-pigs  usually  die  in  from  twenty  to  twenty-four  hours  after  receiving 
a  subcutaneous  inoculation  ;  at  the  autopsy  an  extensive  subcutaneous 
oedema  is  found  in  the  vicinity  of  the  point  of  inoculation,  and  a  superficial 
necrosis  may  be  observed  ;  the  blood  and  the  organs  generally  contain  the 
4 '  vibrio  "  in  great  numbers,  showing  that  the  animals  die  from  general  in- 
fection— acute  septicaemia.  When  infection  occurs  in  these  animals  by  way 
of  the  stomach  the  intestine  will  be  found  highly  inflamed  and  its  liquid  con- 
tents will  contain  numerous  spirilla. 

Gameleia  has  shown  that  pigeons  and  guinea-pigs  may  be  made  immune 
by  inoculating  Lthem  with  sterilized  cultures  of  the  spirillum — sterilized  by 
heat  at  100°  C.  ^Old  cultures  contain  more  of  the  toxic  substance  than  those 
of  recent  date.  Thus  two  to  three  cubic  centimetres  of  a  culture  twenty  days 
old  will  kill  a  guinea-pig  when  injected  subcutaneously,  while  five  cubic 
centimetres  of  a  culture  five  days  old  usually  fail  to  do  so.  According  to 
Pfeiffer,  old  cultures  have  a  decidedly  alkaline  reaction,  and  their  toxic  power 
is  neutralized  by  the  addition  of  sulphuric  acid. 

Gameleia  has  claimed  that  by  passing  the  cholera  spirillum  of  Koch 
through  a  series  of  pigeons,  by  successive  inoculation,  its  pathogenic  power 
is  greatly  increased,  and  that  when  sterilized  cultures  of  this  virulent  vari- 
ety of  the  ' '  comma  bacillus  "  are  injected  into  pigeons  they  become  immune 
against  the  pathogenic  action  of  the  "  vibrio  Metschnikoff,  and  the  reverse. 
Pfeiffer  (1889),  in  an  extended  and  carefully  conducted  research,  was  not 
able  to  obtain  any  evidence  in  support  of  this  claim. 


XVI. 

BACTERIA    IN    INFECTIOUS    DISEASES    NOT    PROVED 
TO  BE  DUE  TO  SPECIFIC  MICROORGANISMS. 

IN  the  present  chapter  we  shall  give  a  brief  account  of  the  re- 
searches which  have  been  made  relating  to  the  presence  of  bacteria, 
in  a  number  of  diseases,  in  which  these  researches  have  thus  far 
failed  to  settle  in  a  definite  manner  the  etiology  of  the  diseases 
named.  For  convenience  of  reference  we  shall  arrange  these  diseases 
in  alphabetical  order. 

ALOPECIA. 

Robinson  (1888)  claims  to  have  found,  in  sections  from  the  diseased  skin 
in  a  case  of  alopecia  areata,  micrococci  having  a  diameter  of  about  0.8  ju,  usu- 
ally united  in  pairs  and  associated  in  zoogloea  masses.  They  were  located 
for  the  most  part  in  the  lymph  spaces  of  the  central  portion  of  the  chorium. 
They  stained  with  the  usual  aniline  colors  and  also  by  G-ram's  method.  No 
culture  or  inoculation  experiments  were  made. 

Kasauli  (1889)  obtained  from  the  margins  of  the  affected  patches  in  alope- 
cia areata  a  bacillus  about  two  to  three  times  as  long  as  broad,  and  which 
formed  spores.  It  was  attached  to  hairs  withdrawn  from  the  diseased 
patches,  and  was  easily  cultivated  in  various  media. 

Vaillard  and  Vincent  (1890),  in  a  form  of  alopecia  resembling  favus,  ob- 
tained by  cultivation,  from  hairs  pulled  out  from  the  diseased  patches,  a  mi- 
crococcus;  this  was  also  found  in  the  hair  follicles  in  stained  sections.  The 
diameter  of  this  micrococcus  was  about  one  ju  ;  it  was  easily  stained  with  the 
aniline  colors  and  by  Gram's  method  ;  grew  in  nutrient  gelatin,  causing 
liquefaction  ;  did  not  grow  well  upon  potato  ;  was  pathogenic  for  mice. 
When  applied  to  the  surface  of  the  body  of  guinea-pigs  or  rabbits,  by  rub- 
bing, alopecia  resulted  similar  to  that  in  the  cases  from  which  the  micrococ- 
cus was  first  obtained. 

BERI-BERI. 

Lacerda  (1887)  claims  to  have  demonstrated  the  presence  of  cocci,  some- 
times united  in  chains,  in  the  blood  and  tissues  of  persons  affected  with  beri- 
beri, and  also  to  have  produced  in  rabbits,  by  inoculation  with  his  cultures, 
certain  symptoms  resembling  those  which  characterize  this  disease. 

Pekefharing  and  Winkler  (1887)  have  also  obtained  by  cultivation,  from 
the  blood  of  patients  with  beri-beri,  various  forms  of  bacteria,  but  princi- 
pally cocci ;  these  are  described  as  being  usually  associated  in  pairs  or  in  ir- 
regular groups,  as  forming  a  milk-white  mass  upon  agar,  and  as  liquefying 
gelatin.  According  to  the  authors  named,  injection  into  rabbits  of  cultures 
of  this  coccus  gave  rise  to  multiple  nerve  degeneration,  such  as  is  seen  in 
cases  of  beri-bei'i  in  man. 

Eykmann  (1888)  failed  to  obtain  cultures  from  the  blood  of  patients  with 
beri-beri,  but  demonstrated  the  presence  of  slender  bacilli  similar  to  those 


BACTERIA  IN  CERTAIN  INFECTIOUS   DISEASES.  515 

which  Pekelharing  and  Winkler  encountered  in  some  of  their  cases.  These 
failed  to  grow  in  the  usual  culture  media. 

In  his  latest  communication  upon  the  subject  Pekelharing  says  that  in 
twelve  cases  out  of  fifteen  he  obtained  cultures  of  micrococci,  and  bacilli  in 
three  out  of  fifteen.  From  his  inoculation  experiments  he  concludes  that 
the  micrococci  found  are  the  cause  of  the  morbid  phenomena  which  charac- 
terize the  disease. 

When  in  Rio  de  Janeiro  (1887)  the  writer  collected  blood  from  the  finger 
from  four  typical  cases  of  beri-beri,  selected  by  Dr.  Lacerda,  and  introduced 
it  into  the  usual  culture  media.  The  result  of  this  experiment  was  negative, 
agreeing  in  this  regard  with  the  results  obtained  by  Eykmann. 

BRONCHITIS. 

Lumnitzer  (1888)  obtained  from  the  sputum  of  a  patient  with  putrid 
oronchitis  a  bacillus  which  proved  to  be  pathogenic  for  mice  and  for  rabbits, 
and  the  cultures  of  which  gave  off  a  characteristic  odor,  similar  to  that  of 
the  putrid  bronchial  secretion  in  his  patient. 

Picchini  (1889),  in  three  cases  of  "  croupous  bronchitis,"  made  culture  ex- 
periments and  isolated  three  different  micrococci ;  one  developed  upon  nutri- 
ent gelatin  as  a  grayish- white  mass  and  did  not  liquefy;  one  as  a  reddish- 
gray  mass,  also  non-liquef ying ;  the  third  form  was  always  associated  with 
these  two. 

CARCINOMA. 

Various  microorganisms  have  occasionally  been  found  in  carcinomatous 
growths,  and  especially  in  those  which  have  undergone  ulceration ;  but  that 
any  one  of  these  bears  an  etiological  relation  to  such  malignant  tumors  has 
not  been  demonstrated. 

CEREBRO-SPINAL  MENINGITIS. 

Various  microorganisms  have  been  found  by  bacteriologists  in 
the  exudate  of  cerebro-spinal  meningitis,  and  there  seems  to  be  but 
little  doubt  that  the  meningeal  inflammation  is  due  to  their  presence, 
as  the  bacteria  usually  found  are  pathogenic  for  certain  of  the  lower 
animals,  and  when  introduced  into  a  serous  cavity  they  give  rise  to 
a  fibrinous  or  purulent  inflammatory  process.  The  researches  of 
Weichselbaum,  Netter,  and  others  show  that  Micrococcus  pneumo- 
nia croupossB  (" diplococcus  pneumonia")  is  the  microorganism 
most  frequently  found,  and  next  to  this  the  Diplococcus  intercellula- 
ris  meningitidis  of  Weichselbaum.  Streptococcus  pyogenes  has  also 
been  found  in  a  certain  proportion  of  the  cases — four  out  of  twenty- 
five  cases  of  purulent  meningitis  studied  by  Netter. 

Bonome,  in  a  series  of  cases  studied  by  him,  obtained  a  micrococ- 
cus  closely  resembling  Micrococcus  pneumonise  crouposse,  but  which 
he  believes  not  to  be  identical  with  it  (see  Micrococcus  of  Bonome, 
No.  40). 

For  further  details  see  the  descriptive  accounts  of  the  micro- 
organisms above  referred  to. 

CHANCROID. 

Ducrey,  in  an  extended  research  (1890),  was  not  able  to  cultivate  any 
specific  microorganism  from  the  pus  of  soft  chancres,  or  of  buboes  resulting 


516  BACTERIA   IN   INFECTIOUS   DISEASES   NOT   PROVED 

from  these  ulcers.  Various  common  microorganisms  were  obtained  in  cul- 
tures from  the  chancroidal  ulcers,  but  a  negative  result  was  obtained  in  his 
cultures  from  the  pus  of  buboes.  In  pustules  developed  upon  the  arm  from 
the  inoculation  of  chancroidal  virus  he  found  constantly  a  bacillus  which 
did  not  grow  in  artificial  cultures.  This  was  about  1.48  fi  longandO.5/* 
thick,  with  round  ends.  It  was  readily  stained  with  a  solution  of  f  uchsin, 
but  not  by  Gram's  method. 

CHOLERA  INFANTUM. 

The  researches  of  Booker  and  of  Jeffries  do  not  support  the  idea 
that  cholera  infantum  is  due  to  the  presence  of  a  specific  microor- 
ganism in  the  intestine,  but  rather  that  the  symptoms  are  due  to  the 
absorption  of  toxic  products  formed  in  the  alimentary  canal,  or  in 
the  child's  food  before  it  is  ingested,  as  a  result  of  the  multiplication 
and  ferment  action  of  various  microorganisms,  and  especially  of 
certain  putrefactive  bacteria.  The  common  putrefactive  bacillus, 
Proteus  vulgaris,  and  other  species  nearly  related  to  this,  were  found 
by  Booker  in  a  considerable  proportion  of  his  cases,  and  he  is  dis- 
posed to  believe  that  these  putrefactive  bacteria  play  an  important 
part  in  the  development  of  the  morbid  phenomena  which  character- 
ize the  disease.  Jeffries,  after  reviewing  the  various  theories  which 
have  been  advanced  in  explanation  of  the  etiology  of  cholera  infan- 
tum, says  :  "  Bacteria  I  believe  to  be  at  the  bottom  of  the  disease — 
that  is,  rule  bacteria  out  of  all  foods  and  the  alimentary  canal,  and 
summer  diarrhoea  would  cease  to  be."  Upon  another  page  of  his 
memoir  he  says  :  "  Passing  a  step  further,  the  symptoms,  patho- 
logy, and  etiology  of  summer  diarrhoea  stand  in  close  relationship 
with  the  group  of  symptoms  first  clearly  brought  to  light  by  Panum 
as  putrid  infection.  The  animals  poisoned  by  the  injection  of  pu- 
trid fluids,  sterile  or  not,  sicken  and  die  with  two  variable  groups  of 
symptoms  :  one  referable  to  the  nervous  system,  the  other  to  the  in- 
testines, diarrhoea  being  a  prominent  symptom,  and  the  autopsy  re- 
vealing inflammatory  changes  in  the  intestine/' 

CHOLERA   NOSTRAS. 

What  has  been  said  above  with  reference  to  cholera  infantum 
applies  as  well  to  cholera  nostras.  This  has  not  been  shown  to  be 
due  to  the  presence  in  the  alimentary  canal  of  a  particular  micro- 
organism ;  but  it  can  scarcely  be  doubted  that  the  morbid  pheno- 
mena are  induced  by  the  development  of  toxic  substances  as  a  result 
of  the  ferment  action  of  various  species  of  bacteria. 

Finkler  and  Prior  (1884)  obtained  from  the  faeces  of  patients 
with  cholera  nostras  a  spirillum  which  they  supposed  to  be  the  spe- 
cific cause  of  this  disease,  but  subsequent  researches  have  not  con- 
firmed their  conclusion.  Thus,  in  seven  cases  studied  by  bacterio- 


TO   BE   DUE   TO    SPECIFIC    MICROORGANISMS.  517 

logical  methods  in  Koch's  laboratory  during  the  years  1885,  1886y 
and  1887,  the  spirillum  of  Finkler  and  Prior  was  not  found  in  a 
single  instance  (Frank). 

CONJUNCTIVITIS. 

The  various  forms  of  conjunctivitis  have  been  ascribed  to  the 
specific  action  of  bacteria.  That  this  is  true  as  regards  gonorrhoeal 
ophthalmia  is  now  generally  admitted,  and  there  is  some  reason  to 
believe  that  the  bacillus  discovered  by  Koch  and  studied  by  Kartulis 
(see  Bacillus  of  Kartulis)  is  the  cause  of  one  form  of  "  Egyptian 
catarrhal  conjunctivitis."  The  non-infectious  forms  of  conjunctivitis 
can  scarcely  be  supposed  to  be  due  to  the  action  of  specific  micro- 
organisms ;  but  it  is  probable  that  an  inflammation  resulting  from 
any  cause,  such  as  a  chemical  or  mechanical  irritant,  may  be  aggra- 
vated and  become  chronic  as  a  result  of  the  presence  of  various 
microorganisms,  and  especially  of  the  pyogenic  micrococci. 

With  reference  to  the  so-called  bacillus  of  xerosis,  the  researches 
of  Schreiber,  made  in  Neisser's  laboratory,  show  that  it  is  not  pecu- 
liar to  xerosis,  but  that  it  is  often  found  quite  as  abundantly  in 
other  eye  affections  and  also  in  the  healthy  con-'unctival  sac. 

CORYZA. 

Hajek  found  in  the  secretions  of  acute  nasal  catarrh  a  large  diplococcus, 
called  by  him  "  Diplococcus  coryzae,"  and  probably  identical  with  the  diplo- 
coccus  previously  obtained  by  Klebs  from  the  same  source.  This  was  most 
abundant  during  the  early  stage  of  the  disease,  when  the  secretion  from  the 
nasal  mucous  membrane  was  thin  and  abundant  ;  later  various  other  micro- 
organisms were  encountered  in  greater  numbers,  and  among  them  Fried- 
lander's  bacillus.  There  is  no  satisfactory  evidence  that  the  diplococcus  of 
Hajek  or  any  other  known  bacteria  are  directly  concerned  in  the  etiology  of 
this  affection.  To  what  extent  chronic  nasal  catarrh  is  due  to  the  action  of 
microorganisms  is  also  uncertain,  but  it  appears  probable  that  tbey  play  an 
important  part  in  maintaining  such  inflammations ;  and  in  ozsena  the  offen- 
sive odor  of  the  nasal  secretions  is  no  doubt  due  to  the  presence  of  certain 
bacteria,  whatever  may  be  the  relation  of  these  to  tbe  morbid  process  which 
gives  rise  to  the  chronic  discharge.  (See  Bacillus  fcetidus  ozaenas  of  Hajek.) 

CYSTITIS. 

Various  species  of  bacteria  have  been  found  in  the  urine  in  cases 
of  cystitis,  and  it  appears  probable  that  some  of  these  are  directly  or 
indirectly  concerned  in  keeping  up  the  vesical  inflammation  in 
chronic  cases  of  this  disease.  Whether  any  one  of  the  species  found 
is  capable  of  producing  cystitis  when  introduced  into  the  healthy 
bladder  is  uncertain.  On  the  other  hand,  we  have  rather  numerous 
observations  which  show  that  there  may  be  bacteriuria  without  cys- 
titis. Thus  Schottelius  and  Reinhold  report  a  case  of  heart  disease 
in  which  certain  bacilli  were  found  in  the  urine  in  considerable 
numbers,  and  in  a  pure  culture,  during  the  entire  time  that  the 
45 


518  BACTERIA  IN  INFECTIOUS   DISEASES  NOT   PROVED 

patient  was  under  observation,  and  in  which  there  was  no  cystitis  or 
other  symptoms  that  could  be  ascribed  to  the  presence  of  this  bacillus. 

In  the  extended  researches  of  Rovsing — thirty  cases  of  cystitis — 
the  following  results  were  obtained  :  In  one  case  diagnosed  as  cys- 
titis no  bacteria  were  found  ;  in  three  cases  culture  experiments  gave 
a  negative  result,  but  the  tubercle  bacillus  was  found  in  the  urine  by 
microscopical  examination — in  these  cases  the  urine  was  strongly 
acid ;  in  twenty-six  cases  the  urine  was  ammoniacal,  and  in  all  of 
these  bacteria  were  found — usually  but  a  single  species.  All  of  these 
grew  in  the  usual  culture  media  except  the  tubercle  bacillus,  which 
in  two  cases  was  associated  with  some  other  species,  and  all  pro- 
duced alkaline  fermentation  in  sterile  urine  when  added  to  it  in  pure 
cultures.  The  following  species  were  found :  Tubercle  bacillus, 
Staphylococcus  pyogenes  aureus,  Staphylococcus  pyogenes  albus, 
Staphylococcus  pyogenes  citreus,  Streptococcus  pyogenes  urese 
(n.  sp.),  Diplococcus  pyogenes  urese  (n.  sp.),  Coccobacillus  pyogenes 
ureas  (n.  sp.),  Micrococcus  pyogenes  urese  flavus  (n.  sp.),  Diplococcus 
urese  trifoliatus  (n.  sp.),  Streptococcus  urese  rugosus  (n.  sp.),  Diplo- 
coccus urese  (n.  sp.),  Coccobacteria  urese  (n.  sp.). 

Pure  cultures  of  all  of  these  species  introduced  into  the  bladder  of 
rabbits  failed  to  induce  cystitis,  even  when  injected  in  considerable 
quantities.  But  when  retention  of  urine  was  effected  artificially  for 
six  to  twelve  hours,  allowing  time  for  ammoniacal  fermentation  to 
occur,  cystitis  was  developed.  When  the  pyogenic  species  were  in- 
troduced under  these  circumstances  a  suppurative  inflammation  of 
the  mucous  membrane  occurred  ;  the  non-pyogenic  species  caused  a 
catarrhal  cystitis.  Rovsing  records  the  important  fact,  as  bearing 
upon  the  etiology  of  cystitis,  that  in  twenty  of  the  cases  examined 
the  bladder  had  been  invaded  by  the  finger  or  by  instruments  prior 
to  the  development  of  cystitis. 

Lundstrom  (1890)  isolated  from  alkaline  urine  obtained  from 
patients  with  cystitis  two  species  of  staphylococci — Staphylococcus 
urese  candidus  and  Staphylococcus  urese  liquefaciens ;  from  albu- 
minous, acid  urine  he  obtained  Streptococcus  pyogenes.  Krogius 
obtained  from  the  urine  of  individuals  suffering  from  cystitis  a 
bacillus  which  he  calls  Urobacillus  liquefaciens  septicus.  Schnitzler 
(1890)  found  the  same  bacillus,  or  one  very  similar  to  it,  in  thirteen 
out  of  twenty  cases  of  purulent  cystitis  examined  by  him.  In  eight 
of  these  cases  it  was  obtained  from  the  urine  in  pure  cultures,  and  in 
five  it  was  associated  with  other  bacteria.  In  twelve  of  these  twenty 
cases  the  cystitis  resulted  directly  from  catheterization  ;  in  the  others 
it  occurred  in  individuals  suffering  from  stricture  or  from  calculus. 

When  cultures  of  this  bacillus  were  injected  into  a  vein  in  rab- 
bits, the  animals  died  in  from  three  to  eight  days,  and  in  every 


TO   BE   DUE   TO   SPECIFIC   MICROORGANISMS.  519 

instance  an  intense  nephritis  was  observed  at  the  autopsy — twice 
with  the  formation  of  small  abscesses.  The  bacillus  was  found  in 
the  blood  and  the  organs  generally.  Injections  into  the  bladder  of 
rabbits  almost  always  gave  rise  to  a  severe  purulent  cystitis — large 
rabbits  were  selected  and  great  care  taken  not  to  injure  the  mucous 
membrane  of  the  bladder.  Schnitzler  was  not  able  to  induce  cystitis 
in  rabbits  by  injecting  in  the  same  way  considerable  quantities  of  a 
culture  of  Staphylococcus  pyogenes  aureus. 

Guyon  (1888)  did  not  succeed  in  inducing  cystitis  by  the  injection 
of  pure  cultures  of  various  microorganisms  into  the  bladder,  unless 
he  at  the  same  time  produced  an  artificial  retention  of  urine.  His 
experimental  results  are  therefore  in  accord  with  those  of  Rovsing, 
who  found  that  without  mechanical  injury,  or  artificial  retention 
until  ammomacal  fermentation  had  occurred,  no  results  followed  his 
injections  into  the  bladder. 

DEXGUE. 

McLaughlin  (1886)  has  claimed  to  find  micrococci  in  the  blood  of  pa- 
tients suffering  from  dengue.  No  satisfactory  evidence  of  their  etiological 
relation  has  been  presented,  and  his  observations  have  not  yet  been  con- 
firmed by  other  investigators. 

ECZEMA  EPIZOOTICA. 

Synonym. — Foot  and  mouth  disease. 

This  is  an  infectious  disease  of  horned  cattle,  characterized  by  a  vesicular 
eruption  in  the  mouth  and  about  the  feet.  It  affects  also  sheep  and  pigs 
and  may  be  communicated  to  man. 

Up  to  the  present  time  no  satisfactory  demonstration  has  been  made  of 
the  specific  infectious  agent ;  but  Schottelius  has  recently  (1892)  described  a 
microorganism  which  he  thinks  may  bear  an  etiological  relation  to  the  dis- 
ease. His  inoculation  experiments  do  not,  however,  sustain  this  view,  inas- 
much as  the  characteristic  vesicles  were  never  developed  in  inoculated 
calves,  and  experiments  upon  other  animals  gave  a  negative  result.  In 
young  cattle  small  doses  (one  cubic  centimetre)  of  a  bouillon  culture  gave 
rise  to  a  slight  fever  and  loss  of  appetite,  while  larger  doses  produced  an  in- 
tense fever,  salivation,  and  great  debility.  But  recovery  occurred  at  the 
end  of  five  or  six  days  without  any  aphthous  eruption.  Schottelius  obtained 
from  the  clear  contents  of  the  vesicles  in  the  mouth  various  bacteria 
which  he  believes  to  have  been  accidentally  present.  After  making  a  con- 
siderable number  of  culture  experiments  his  attention  was  attracted  by  a 
spherical  microorganism,  united  in  chains,  which  grew  very  slowly  in  the 
ordinary  culture  media.  This  he  describes  as  follows  : 

The  individual  cells  vary  greatly  in  diameter,  and  are  considerably  larger 
than  known  micrococci ;  they  are  associated  in  longer  or  shorter  chains,  and 
are  endowed  with  active  movements.  According  to  Schottelius,  they  be- 
long to  the  "gfrepfocflfat"  rather  than  to  the  streptococci.  They  do  not 
stain  readily  with  methylene  blue,  but  may  be  stained  with  gentian  violet 
and  by  Gram's  method.  Development  does  not  occur  at  temperatures  below 
37°  to  39°  C.  The  most  suitable  culture  medium  was  found  to  be  bouillon  or 
glycerin  agar  to  which  formate  of  soda  had  been  added  (amount  ?).  Growth 
occurred  in  an  atmosphere  of  COa  as  well  as  in  atmospheric  air.  Upon 
plates  of  nutrient  agar — containing  glycerin  and  formate  of  soda— at  37°  C., 


520  BACTERIA   IN   INFECTIOUS   DISEASES   NOT   PROVED 

very  delicate,  almost  transparent  colonies  developed ;  they  were  of  a  pearl- 
gray  color;  with  an  irregular,  rosette-like  margin ;  in  the  course  of  several 
weeks  they  attained  a  diameter  of  one  to  one  and  one-half  millimetres. 
Upon  potato  a  scanty,  grayish- white,  dry  layer  is  developed.  Under  the 
most  favorable  conditions  the  development  was  very  slow — not  more  rapid 
than  that  of  the  tubercle  bacillus. 

EMPYEMA. 

A.  Frankel  (1888),  as  a  result  of  his  bacteriological  studies  in 
twelve  cases  of  empyema,  divides  the  cases  into  four  groups.  In 
one  group  of  three  cases  Streptococcus  pyogenes  was  the  only  micro- 
organism obtained  in  his  cultures  or  seen  in  stained  preparations  of 
pus  from  the  pleural  cavity.  In  a  second  group  of  three  cases,  oc- 
curring in  the  course  of  a  pneumonia,  the  only  microorganism  pre- 
sent was  "  diplococcus  pneumonias  "  (Micrococcus  pneumonias  crou- 
posae).  The  third  group  included  four  cases  of  tubercular  empyema  ; 
in  one  of  these  tubercle  bacilli  only  were  found  in  pus  from  the 
pleural  cavity,  in  one  case  streptococci  were  found,  and  in  two  no 
microorganisms  were  found.  In  the  fourth  group  of  two  cases  the 
empyema  resulted  from  the  opening  of  an  abscess  into  the  pleural 
cavity,  and  streptococci  were  found  in  the  pus. 

Xetter,  in  a  series  of  forty-six  cases  examined  by  him,  found 
Micrococcus  pneumonias  crouposas  in  fourteen.  Koplik  (1890)  found 
the  same  microorganism  in  seven  cases  examined  by  him,  and  Strep- 
tococcus pyogenes  in  two  cases. 

ENDOCARDITIS. 

The  experimental  evidence  relating  to  endocarditis  is  similar  to 
that  in  cystitis.  The  injection  of  the  microorganisms  found  attached 
to  the  diseased  structures  into  the  circulation  of  lower  animals  does 
not  produce  endocarditis  unless  the  valves  have  been  previously  in- 
jured by  mechanical  violence  or  by  chemical  irritants.  If  some 
doubt  remains  among  pathologists  as  to  the  etiological  relation  of  the 
microorganisms  found,  the  serious  secondary  results  of  the  mycotic 
invasion  are  well  established.  In  a  series  of  twenty-nine  cases 
studied  by  Weichselbaum  (1885-1888)  the  following  results  were  ob- 
tained :  In  eight  the  result  of  culture  experiments  and  microscopical 
examination  was  negative;  in  seven  "diplococcus  pneumonias"' 
(Micrococcus  pneumonias  crouposas)  was  found  ;  in  six  Streptococcus 
pyogenes ;  in  two  Staphylococcus  pyogenes  aureus ;  in  two  Bacillus 
endocarditidis  griseus  (Weichselbaum) ;  in  one  Micrococcus  endocar- 
ditidis  rugatus  (Weichselbaum)  ;  in  one  Bacillus  endocarditidis  cap- 
sulatus  (Weichselbaum) ;  in  two  cases  a  bacillus  which  he  did  not 
succeed  in  cultivating.  For  further  details  see  the  descriptions  of 
microorganisms  referred  to. 


TO  BE   DUE   TO   SPECIFIC   MICROORGANISMS.  521 

ERYTHEMA. 

Cordua  (1885)  obtained  from  a  series  of  cases  of  an  erysipelatpid  skin 
affection  of  the  fingers  and  hands,  which  he  identified  as  corresponding  with 
eiythema  exudativum  multiforme  of  Hebra,  a  micrococcus  resembling 
Staphylococcus  pyogenes  albus  in  its  biological  characters,  but  which  he  de- 
scribes as  being  three  to  four  times  as  large.  Inoculations  in  animals  were 
without  result,  but  two  inoculations  upon  his  own  hand  produced  a  dark-red 
tumefaction  in  the  vicinity  of  the  point  of  inoculation  resembling  that  in  the 
individuals  from  whom  he  obtained  his  cultures. 

In  two  cases  of  "  polymorphous  erythema  "  Haushalter  (1887)  isolated  a 
streptococcus  which  did  not  produce  an  erysipelatous  inflammation  when  in- 
oculated into  the  ear  of  rabbits,  and  which  he  supposed  to  be  a  different  species 
from  the  now  better  known  Streptococcus  pyogenes  (?).  In  five  cases  of 
erythema  nodosum  in  children  Demme  obtained  a  bacillus  which  his  in- 
oculation experiments  proved  to  be  pathogenic,  and  which  was  perhaps  con- 
cerned in  the  etiology  of  the  skin  affection  from  which  his  cultures  were  ob- 
tained (see  Bacillus  of  Demme,  No.  107). 

GRANULOMA  FUNGOIDES   (MYCOSIS  FUNGOIDES). 

Rindfleisch  (1885)  and  Auspitz  (1885)  report  the  presence  of  streptococci 
in  the  capillary  vessels  of  the  papillary  body  and  of  the  subcutaneous  tissue 
in  the  affected  localities  in  cases  of  this  disease.  That  the  streptococcus 
differs  from  Streptococcus  pyogenes,  as  Auspitz  supposes,  has  not  been  defi- 
nitely established. 

HYDROPHOBIA. 

Notwithstanding  the  extended  researches  made,  especially  in  Pasteur's 
laboratory,  the  etiology  of  hydrophobia  still  remains  unsettled.  It  has  been 
demonstrated  by  experiment  that  the  virus  of  the  disease  is  located  in  the 
brain,  spinal  marrow,  and  nerves  of  animals  which  have  succumbed  to  the 
disease,  as  well  as  in  the  salivary  secretions  of  rabid  animals,  and  that  the 
disease  may  be  transmitted  by  intravenous  inoculation,  or  by  introducing  a 
small  quantity  of  virus  beneath  the  dura  mater,  with  greater  certainty  than 
by  subcutaneous  inoculations.  But  the  exact  nature  of  this  virus  has  not  been 
determined.  The  fact  that  a  considerable  interval  elapses  after  inoculation 
before  the  first  symptoms  are  developed  indicates  that  there  is  a  multiplica- 
tion of  the  virus  in  the  body  of  the  infected  animal;  and  this  is  further 
shown  by  the  fact  that  after  death  the  entire  brain  and  spinal  marrow  of  the 
animal  have  a  virulence  equal  to  that  of  the  material  with  which  it  was  in- 
oculated in  the  first  instance.  The  writer's  experiments  (1887)  show  that  this 
virulence  is  neutralized  by  a  temperature  of  60°  C.  maintained  for  ten  min- 
utes—a temperature  which  is  fatal  to  all  known  pathogenic  bacteria  in  the 
absence  of  spores.  But  recent  experiments  show  that  certain  toxic  products 
of  bacterial  growth  are  destroyed  by  the  same  temperature.  We  are,  there- 
fore, not  justified  in  assuming  that  the  morbid  phenomena  are  directly  due 
to  the  presence  of  a  living  mici'oorganism ;  and,  indeed,  it  seems  probable, 
from  what  we  already  know,  that  the  symptoms  developed  and  the  death  of 
the  animal  are  due  to  the  action  of  a  potent  chemical  poison  of  the  class 
known  as  toxalbumins.  But,  if  this  is  true,  we  have  still  to  account  for  the 
production  of  the  toxic  albuminoid  substance,  and,  in  the  present  state  of 
knowledge,  have  no  other  way  to  explain  its  increase  in  the  body  of  the  in- 
fected animal  than  the  supposition  that  a  specific,  living  germ  is  present  in 
the  virulent  material,  the  introduction  of  which  into  the  body  of  a  suscep- 
tible animal  gives  rise  to  morbid  phenomena  characterizing  an  attack  of 
rabies. 

Pasteur  and  his  associates  have  thus  far  failed  to  demonstrate  the  pre- 
sence of  microorganisms  in  the  virulent  tissues  of  animals  which  have  suc- 
cumbed to  an  attack  of  rabies.  Babes  has  obtained  micrococci  in  cultures 


522 


BACTERIA  IN   INFECTIOUS   DISEASES   NOT   PROVED 


from  the  brain  and  spinal  cord  of  rabid  animals,  and  states  in  his  article  on 
hydrophobia  in  "  Les  Bacteries"  (second  edition,  page  791)  that  pure  cultures 
of  the  second  and  third  generations  induced  rabies  in  susceptible  animals ;  but 
his  own  later  researches  do  not  appear  to  have  established  the  etiological  re- 
lation of  this  micrococcus. 

Gibier  (1884)  has  reported  the  presence  of  spherical  refractive  granules, 
resembling  micrococci,  in  the  brain  of  rabid  animals,  which  he  demonstrated 
by  rubbing  up  a  little  of  the  cerebral  substance  with  distilled  water.  As 
these  supposed  micrococci  did  not  stain  with  the  usual  aniline  colors  and 
were  not  cultivated,  it  appears  very  doubtful  whether  the  refractive  granules 
seen  were  really  microorganisms. 

Fol  (1885)  claims  to  have  demonstrated  the  presence  of  minute  cocci,  0.2  u 
in  diameter,  in  sections  of  spinal  cord  from  rabid  animals,  by  Weigert's 
method  of  staining.  The  cords  were  hardened  in  a  solution  of  bichromate 
of  potash  and  sulphate  of  copper,  colored  with  a  solution  of  hsematoxylon, 
and  decolorized  in  a  solution  of  ferrocyanide  of  potash  and  borax. 

The  writer  (1887)  has  made  similar  preparations,  carefully  following  the 
method  as  described  by  Fol,  but  was  not  able  to  demonstrate  the  presence  of 
microorganisms  in  the  numerous  sections  made.  Nor  have  the  observations 
of  Fol  been  confirmed  by  the  researches  of  other  bacteriologists  who  have 
given  their  attention  to  the  subject  since  the  publication  of  his  paper. 

With  reference  to  the  results  of  Pasteur's  protective  inoculations,  we 
may  say  that  it  is  now  pretty  generally  admitted  that  the  published  statistics 
demonstrate  the  prophylactic  value  of  the  method  as  practised  at  the  Pasteur 
Institute  in  Paris. 

In  a  paper  by  Perdrix  published  in  the  Annales  de  Tlnstitut  Pasteur, 
vol.  iv.,  1890,  the  following  statistics  are  given  for  the  years  1886-89: 


Year. 

Number  treated. 

Teaths. 

Mortality. 

1886       

2,671 

25 

0  94# 

1837  

1,770 

13 

0  73 

1888  

1,622 

9 

0  55 

1889...  

1,830 

6 

0  33 

Total     - 

7,893 

53 

0.67£ 

This  table  includes  only  those  deaths  which  occurred  at  least  fifteen  days 
after  the  treatment  was  terminated.  When  all  deaths  are  included  the  fig- 
ures are  as  follows : 


Year. 

Number  treated. 

Deaths. 

Mortality. 

1886  

2  682 

36 

1  34£ 

1887  

1  778 

21 

1  18 

1888  

1  625 

13 

0  74 

1889            

1  834 

10 

0  54 

Total  

7,919 

79 

0.92# 

In  the  statistics  of  the  Pasteur  Institute  the  cases  have  from  the  com- 
mencement been  classified  as  follows  : 

A.  Persons  bitten  by  animals  proved  to  be  rabid  by  experimental  inocu- 
lations in  other  animals. 

B.  Persons  bitten  by  animals  examined  by  veterinary  surgeons  and  pro- 
nounced by  them  to  be  rabid. 

C.  Persons  bitten  by  animals  suspected  of  being  rabid. 

The  following  table  gives  the  results  in  accordance  with  this  classification : 


TO   BE   DUE   TO    SPECIFIC   MICROORGANISMS. 


523 


A. 

B. 

c. 

Number 
treated. 

Died. 

Mortality. 

Number 
treated. 

Died. 

Mortality. 

Number 
treated. 

Died. 

Mortality. 

1886... 

223 

5 

2.15* 

1,931 

24 

1.24* 

518 

7 

1.35# 

1887.... 

357 

2 

0.56 

1,161 

15 

1.29 

260 

4 

1.54 

1888.  .  .  . 

403 

7 

1.74 

974 

4 

0.41 

248 

1 

0.40 

1889... 

348 

4 

1.15 

1,188 

3 

0.25 

298 

3 

1.00 

Total. 

1,341 

18 

1.84* 

5,254 

46 

0.88* 

1,324 

15 

1.18* 

At  the  meeting  of  the  Tenth  International  Medical  Congress  in  Berlin 
(1890),  Babes  reported  that  in  the  Pasteur  Institute  at  Bucharest  about  three 
hundred  persons  are  inoculated  yearly,  with  a  mortality  of  0.4  per  cent,  in 
cases  bitten  by  dogs,  most  of  which  were  demonstrated  to  have  been  rabid 
by  inoculation  experiments  made  at  the  Institute. 

The  recent  researches  of  Tizzoni  and  Schwartz  (1892)  show  that 
the  blood  of  rabbits  which  have  an  artificial  immunity  against  ra- 
bies contains  an  antitoxine  which  has  the  power  of  neutralizing  the 
virus  of  rabies,  either  in  a  test  tube  or  in  the  body  of  an  inoculated 
animal.  Their  experiments  indicate  the  possibility  of  curing  rabies 
in  man  by  subcutaneous  inoculations  of  this  antitoxine  extracted 
from  the  blood  serum  of  immune  rabbits. 

ICTERUS. 

Karlinsky  (1890),  in  a  series  of.  five  cases  of  "  infectious  icterus  "  attended 
with  fever,  found  in  the  blood,  during  the  height  of  the  attack,  curved 
bacilli  from  two  to  six  «  long  and  one-third  to  one  /<  broad,  which  were  readily 
stained  by  the  usual  aniline  colors,  but  not  by  Gram's  method.  These  he 
did  not  succeed  in  cultivating  in  any  of  the  culture  media  usually  employed. 

Ducamp  (1890)  has  also  given  an  account  of  a  "  slight  epidemic  of  infec- 
tious icterus,"  which  he  supposes  to  have  been  due  to  microorganisms. 

LEPROSY. 

No  satisfactory  experimental  demonstration  that  the  Bacillus 
leprse  is  the  cause  of  the  disease  with  which  it  is  associated  has  yet 
been  made ;  but  there  is  very  little  doubt  among  bacteriologists  and 
pathologists  that  such  is  the  case.  For  the  facts  relating  to  its  pre- 
sence in  leprous  tissues,  its  morphology,  etc. ,  the  reader  is  referred 
to  the  descriptive  account  of  Bacillus  leprae  (No.  53,  page  394). 


MALARIA. 

Klebs  and  Tommasi-Crudeli,  as  a  result  of  researches  made  by  them  in 
the  vicinity  of  Rome  (1879),  announced  the  discovery  of  a  bacillus  which 
they  supposed  to  be  the  cause  of  malarial  fevers — their  Bacillus  mala- 
ria?. The  writer  repeated  their  experiments  the  following  year  (1880)  in  the 
vicinity  of  New  Orleans,  and  reported  as  follows : 

' '  Among  the  organisms  found  upon  the  surface  of  swamp  mud  near 
New  Orleans,  and  in  the  gutters  within  the  city  limits,  are  some  which 
closely  resemble,  and  perhaps  are  identical  with,  the  Bacillus  malariae  of 


524:  BACTERIA   IN  INFECTIOUS  DISEASES   NOT   PROVED 

Klebs  and  Tommasi-Crudeli;  but  thei-e  is  no  satisfactory  evidence  that  these 
or  any  of  the  other  bacterial  organisms  found  in  such  situations,  when  in- 
jected beneath  the  skin  of  a  rabbit,  give  rise  to  a  malarial  fever  corre- 
sponding' with  the  ordinary  paludal  fevers  to  which  man  is  subject. 

' '  The  evidence  upon  which  Klebs  and  Tommasi-Crudeli  have  based  their 
claim  of  the  discovery  of  a  Bacillus  malariae  cannot  be  accepted  as  sufficient ; 
(a)  because  in  their  experiments  and  in  my  own  the  temperature  curve  in 
the  rabbits  experimented  upon  has  in  no  case  exhibited  a  marked  and  dis- 
tinctive paroxysmal  character;  (6)  because  healthy  rabbits  sometimes  exhi- 
bit diurnal  variations  of  temperature  (resulting  apparently  from  changes  in 
the  external  temperature)  as  marked  as  those  shown  in  their  charts ;  (c)  be- 
cause changes  in  the  spleen  such  as  they  describe  are  not  evidence  of  death 
from  malarial  fever,  inasmuch  as  similar  changes  occur  in  the  spleens  of 
rabbits  dead  from  septicaemia  produced  by  the  subcutaneous  injection  of 
human  saliva;  (d)  because  the  presence  of  dark-colored  pigment  in  the 
spleen  of  a  rabbit  cannot  be  taken  as  evidence  of  death  from  malarial  fever, 
inasmuch  as  this  is  frequently  found  in  the  spleens  of  septicaemic  rabbits." 

Later  researches  have  also  failed  to  confirm  the  supposed  discovery  of 
Klebs  and  Tommasi-Crudeli,  and  it  is  now  generally  admitted  that  there  is 
no  satisfactory  evidence  in  favor  of  the  view  that  microorganisms  of  this 
class  are  concerned  in  the  etiology  of  the  malarial  fevers.  On  the  other 
hand,  we  have  now  very  extended  observations  which  indicate  that  the  blood 
parasite  discovered  by  Laveran  (1881)  in  the  blood  of  patients  suffering  from 
various  forms  of  malarial  fever  bears  an  etiological  relation  to  fevers  of  this 
class.  This  haematozoon  belongs  to  quite  a  different  class  of  microorgan- 
isms. It  was  first  described  by  Laveran  as  the  Oscillaria  malarias,  but  is 
more  frequently  spoken  of  at  present  as  the  Plasmodium  malariae. 

MEASLES. 

The  etiology  of  measles  and  of  the  specific  eruptive  febrile  diseases  gene- 
rally still  remains  unsettled.  The  occasional  presence  of  micrococci  in  the 
blood  of  patients  with  measles,  which  has  been  noted,  is  without  doubt  due  to 
a  secondary  or  mixed  infection  by  one  of  the  common  pyogenic  micrococci. 
In  pneumonia  occurring  during  the  course  of  an  attack  of  measles  the  Mi- 
crococcus  pneumonias  crouposae  is  usually  found  in  the  pulmonary  exudate. 

No  great  importance  can  be  attached  to  the  observations  made,  with  re- 
ference to  the  presence  of  microorganisms  in  this  disease,  prior  to  the  intro- 
duction of  Koch's  plate  method  and  the  use  of  solid  culture  media  for  the 
differentiation  of  bacteria  similar  in  their  morphology.  Recently  (1892) 
Canon  and  Pielicke,  of  Berlin,  have  announced  the  discovery  of  a  minute 
bacillus  in  the  blood  of  patients  (fourteen)  with  measles,  which  may  turn  out 
to  be  the  specific  infectious  agent  in  this  disease.  But  this  cannot  be  con- 
sidered demonstrated  by  the  researches  thus  far  made.  (See  Bacillus  of 
Canon  and  Pielicke,  No.  486.) 

MENINGITIS. 

See  Cerebro-spinal  meningitis,  page  515. 

NEPHRITIS. 

The  various  microorganisms  which  have  occasionally  been  found  in  the 
urine  of  cases  of  nephritis  are  probably  not  directly  related  to  the  renal  dis- 
ease. Numerous  observations  are  on  record  which  show  that  pathogenic 
microorganisms  present  in  the  blood  or  tissues  may  find  their  way  into  the 
urine  during  the  course  of  the  disease  due  to  their  presence.  In  these  cases 
it  is  probable  that  the  passage  of  bacteria  into  the  urine  depends  upon  struc- 
tural changes  in  the  kidneys ;  but  that  these  changes  are  directly  due  to  the 
bacteria  is  by  no  means  established.  As  an  example  we  may  mention  that 


TO  BE  DUE  TO   SPECIFIC  MICROORGANISMS.  525 

the  bacillus  of  typhoid  fever  is  occasionally  found  iu  the  urine  during  an 
attack  of  this  disease. 

Letzerich  (1887)  has  described  a  form  of  nephritis  which  he  ascribes  to  a 
bacillus  found  by  him  in  the  urine  and  in  sections  of  the  kidneys  of  rabbits 
inoculated  with  a  culture  of  this  bacillus. 

Lustgarten  and  Manneberg  (1887)  in  three  cases  of  acute  Bright's  disease 
found  streptococci  in  the  urine,  which  they  suppose  to  have  had  an  etiologi- 
cal  relation  to  the  renal  disease.  The  following  year  Manneberg  reported 
eleven  additional  cases,  in  eight  of  which  he  found  the  same  streptococcus, 
which  he  believes  to  be  different  from  Streptococcus  pyogenes,  but  this  can- 
not be  considered  as  established.  Nor  has  he  shown  that  the  streptococcus 
obtained  by  him  from  the  urine  was  present  in  the  kidneys  of  his  patients, 
or  that  pure  cultures  of  this  streptococcus  produce  acute  nephritis  when  in- 
oculated into  lower  animals. 


OSTEOMYELITIS. 

The  evidence  with  reference  to  the  presence  of  Staphylococcus 
pyogenes  aureus  in  acute  osteomyelitis  and  its  probable  etiological 
relation  to  the  cases  in  which  it  is  found,  is  given  in  the  article  de- 
scriptive of  this  microorganism  ;  but  the  researches  of  Kraske  (1886) 
and  of  Lamelongue  and  Achard  (1890)  show  that  the  "  golden  sta- 
phylococcus  "  is  not  always  found  in  osteomyelitis.  The  last-named 
investigators,  in  a  series  of  thirteen  cases,  found  Staphylococcus 
pyogenes  aureus  in  four  only,  and  in  one  of  these  Staphylococcus 
pyogenes  albus  was  also  present  ;  in  three  cases  Staphylococcus 
pyogenes  albus  was  obtained  in  pure  cultures  ;  in  two  cases  it  was 
associated  with  Streptococcus  pyogenes  ;  and  in  two  cases  a  strepto-. 
coccus  was  found  which  resembled  Streptococcus  pyogenes  and  yet 
differed  from  it  in  some  particulars. 

OTITIS  MEDIA. 

In  otitis  media  various  microorganisms  have  been  found  in  pus 
obtained  by  paracentesis  of  the  tympanum,  as  well  as  in  the  chronic 
discharge  after  perforation ;  and  there  can  be  but  little  doubt  that 
these  microorganisms  are  responsible,  directly  or  indirectly,  for  the 
inflammatory  process  and  pus  formation.  The  following  species  are 
most  frequently  found  in  the  purulent  discharge  in  recent  cases 
of  otitis  media :  Micrococcus  pneumoniae  crouposa3  ("  diplococcus 
pneumonise  "),  Streptococcus  pyogenes,  Staphylococcus  pyogenes  al- 
bus, Staphylococcus  pyogenes  aureus,  Friedlander's  bacillus.  The 
following  have  also  been  found  occasionally  :  Staphylococcus  tenuis, 
Bacillus  tenuis,  Micrococcus  tetragenus,  Bacillus  pyocyanus. 

According  to  Zaufal,  Micrococcus  pneumonice  crouposa3  is  most 
frequently  found  in  cases  which  result  from  exposure  to  cold,  while 
the  ordinary  pus  cocci  are  more  frequently  found  in  otitis  which  is 
secondary  to  specific  febrile  diseases. 


526  BACTERIA   IX   INFECTIOUS   DISEASES   NOT   PROVED 

OZJENA. 

The  researches  of  Thost,  Klamann,  Hajek,  and  others  show  that 
Friedlander's  bacillus  is  present  in  the  nasal  secretions  in  a  consider- 
able proportion  of  the  cases  of  ozsena,  but  its  etiological  relation  to 
the  morbid  condition  which  gives  rise  to  the  offensive  discharge  has 
not  been  established. 

Thost  found  this  bacillus  in  twelve  out  of  seventeen  cases  studied 
by  him,  and  frequently  almost  in  a  pure  culture  ;  but  he  also  found 
it  in  rhinitis  from  syphilitic  ulceration,  from  polypus,  and  in  simple 
coryza. 

Hajek  found  Friedlander's  bacillus  in  seven  out  of  ten  cases 
studied  by  him,  but  it  was  associated  with  various  other  species  of 
bacteria,  and  especially  with  the  pyogenic  micrococci  and  with  Ba- 
cillus fluorescens  liquefaciens.  He  also  obtained  almost  constantly 
his  Bacillus  fcetidus  ozyenoe  (No.  Ill),  which  appears  to  have  been 
the  cause  of  the  foetid  odor  of  the  nasal  discharge. 

Marano  (1890)  in  ten  cases  of  ozsena  found  a  capsule  bacillus  in 
the  nasal  secretions  which  closely  resembles  Friedlander's  bacillus, 
but  which  he  believes  not  to  be  identical  with  it. 

PAROTITIS. 

No  demonstration  of  a  specific  microorganism  in  mumps  has  been 
made,  but  in  non-specific,  suppurative  parotitis  one  or  other  of  the 
pyogenic  micrococci  appears  to  be  the  cause  of  the  inflammation  and 
pus  formation.  In  parotitis  occurring  as  a  complication  of  pneu- 
monia Micrococcus  pneumonise  crouposse  has  been  found  as  the  only 
microorganism  in  pus  from  the  inflamed  gland  (Testi,  Duplay). 

PEMPHIGUS. 

Demme  (1886)  has  cultivated  a  diplococcus  from  a  case  of  acute 
pemphigus  which  possibly  is  related  to  this  disease  (see  Micrococcus 
of  Demme,  No.  27,  page  319).  The  same  coccus  was  found  by  Dahn- 
hardt  in  a  similar  case. 

PERITONITIS. 

That  peritonitis  usually  results  from  the  presence  of  micro- 
organisms in  the  cavity  of  the  abdomen  seems  to  be  pretty  well 
established  by  experimental  evidence  and  by  bacteriological  re- 
searches in  cases  of  this  disease.  Mechanical  irritants,  like  finely 
powdered  glass  (writer's  experiments),  introduced  into  the  cavity  of 
the  abdomen  of  rabbits,  do  not  cause  peritonitis  unless  microorgan- 
isms are  introduced  at  the  same  time ;  the  minute  fragments  of 
glass  become  encysted  and  the  animal  remains  in  good  health.  But 
Pernice  has  shown  that  peritonitis  may  be  induced  in  rabbits  and  in 


TO   BE   DUE   TO   SPECIFIC   MICROORGANISMS.  527 

guinea-pigs  by  injecting  into  the  cavity  of  the  abdomen  various 
chemical  substances,  such  as  concentrated  mineral  acids,  acetic  acid, 
phenol,  nitrate  of  silver,  etc.  It  is  also  demonstrated  by  numerous 
experiments  that  pure  cultures  of  various  bacteria  injected  into  the 
cavity  of  the  abdomen  of  the  animals  mentioned  may  produce  a 
fibrinous  or  a  purulent  peritonitis.  Among  these  is  the  Bacillus  coli 
communis,  which  is  constantly  present  in  the  intestine  of  healthy 
persons ;  and  in  peritonitis  following  perforation  of  the  bowel  it  is 
probable  that  this  bacillus  is  responsible,  in  part  at  least,  for  the  in- 
tense peritoneal  inflammation  which  so  quickly  occurs.  In  puerperal 
peritonitis  the  pus  cocci,  and  especially  Streptococcus  pyogenes, 
appear  to  be  the  usual  cause  of  the  inflammatory  process. 

Weichselbaum  has  observed  two  cases  of  primary  peritonitis  and 
pleuritis  apparently  induced  by  Micrococcus  pneumonise  crouposse, 
as  this  microorganism  was  found  in  the  exudate  into  the  peritoneal 
cavity.  The  same  author,  in  a  case  of  peritonitis  resulting  from 
rupture  of  the  spleen  in  the  course  of  typhoid  fever,  obtained  a  pure 
culture  of  the  typhoid  bacillus  from  the  peritoneal  cavity. 

The  recently  published  (1891)  results  of  A.  Frankel's  researches 
are  as  follows  :  In  thirty-one  cases  examined  pure  cultures  were 
obtained  in  twenty,  viz. :  Bacillus  coli  communis,  nine  times  ;  strep- 
tococci, seven  times ;  Bacillus  lactis  aerogenes,  twice ;  Micrococcus 
pneumonise  crouposae,  once  ;  Staphylococcus  pyogenes  aureus,  once. 
In  three  cases  Bacillus  coli  communis  was  present  in  association  with 
other  bacilli,  and  in  four  cases  the  bacteriological  examination  gave 
a  negative  result. 

PLEURITIS. 

See  Empyema,  page  520. 

PLEURO-PNEUMONIA   OF   CATTLE. 

This  is  an  infectious  disease,  the  etiology  of  which  is  still  undetermined, 
notwithstanding  the  researches  of  numerous  bacteriologists.  Various  bac- 
teria have  been  isolated  from  the  exudate  into  the  pulmonary  alveoli,  but 
there  is  no  satisfactory  proof  that  any  one  of  these  is  the  specific  cause  of  the 
disease. 

PURPURA  H^EMORRHAGICA. 

See  account  of  bacilli  found  in  purpura  hsemorrhagica  by  Babes 
(No.  146),  Kolb  (No.  147),  and  Tizzoni  and  Giovannini  (No.  145). 

RHINOSCLEROMA. 

See  Bacillus  of  rhinoscleroma  (No.  58). 

SCARLET   FEVER. 

The  specific  infectious  agent  in  scarlet  fever  has  not  been  demonstrated. 
In  the  diphtheritic  exudate  frequently  seen  in  the  angina  of  scarlet  fever  a 


528  BACTERIA   IX   INFECTIOUS   DISEASES   NOT   PROVED 

streptococcus  is  commonly  found  which  appears  to  be  identical  with  Strep- 
tococcus pyogenes;  and  in  the  secondary  affections  which  occur  in  the 
course  of  this  disease  or  during1  convalescence,  when  suppuration  occurs,  one 
or  the  other  of  the  common  pyogenic  micrococci  is  usually  found  and  is 
doubtless  the  cause  of  the  local  inflammatory  process.  (See  Otitis  media, 
page  525.) 

SYPHILIS. 

The  etiology  of  syphilis  has  not  been  determined  by  the  researches  of 
bacteriologists.  For  an  account  of  the  microorganisms  which  have  been  en- 
countered in  syphilitic  lesions  the  reader  is  referred  to  the  article  on  the 
Bacillus  of  Lustgarten  (No.  55). 

"TEXAS  FEVER"  OF  CATTLE. 

Billings  (1888)  has  announced  the  discovery  of  a  bacillus  in  the  blood  of 
cattle  suffering  from  Texas  fever,  which  he  supposes  to  be  the  cause  of  this 
disease,  but  the  investigations  of  other  bacteriologists  have  failed  to  confirm 
the  alleged  discovery.  It  appears  probable  that  a  mistake  in  diagnosis  was 
made,  and  that  the  disease  studied  by  Billings  was  an  infectious  form  of 
septicaemia  in  cattle  similar  to  the  Rinderseuche  of  German  authors.  The 
microorganism  which  he  has  described  as  coming  from  the  blood  of  the  in- 
fected animals  resembles  in  its  morphology  Bacillus  septicaemias  hsemor- 
rhagicee  (No.  61),  and,  if  not  identical  with  this  widely  distributed  species, 
appears  to  be  very  nearly  related  to  it. 

TYPHUS   FEVER. 

The  etiology  of  typhus  fever  has  not  been  determined  in  a  definite  man- 
ner. Hlava  (1888)  has  described  a  "  strep tobacillus  "  which  he  supposes  to 
be  concerned  in  the  etiology  of  this  extremely  contagious  disease ;  but  it  has 
been  shown  by  other  investigators  that  this  bacillus  is  not  constantly  present, 
and  there  is  no  satisfactory  evidence  that  it  is  the  specific  infectious  agent. 
Thoinot  and  Calmette  encountered  the  streptobacillus  of  Hlava  and  various 
other  microorganisms  in  a  certain  proportion  of  the  cases  examined  by  them ; 
but  no  one  of  these  was  constantly  present.  "An  interesting  organism," 
which  they  did  not  succeed  in  cultivating,  was  found  in  the  blood  of  all 
cases  examined  by  the  investigators  last  mentioned. 

VARICELLA. 

Various  microorganisms  have  been  found  in  the  contents  of  the  vesicles 
and  pustules  of  varicella,  but  there  is  no  evidence  that  any  one  of  these 
bears  an  etiological  relation  to  this  specific  eruptive  fever. 

VARIOLA  AND  VACCINIA. 

The  etiology  of  small-pox  still  remains  undetermined.  The  common  pus 
cocci  and  various  other  microorganisms  are  found  in  the  characteristic  pus- 
tular eruption,  and  vai'ious  microorganisms  have  been  isolated  from  vac- 
cine vesicles ;  but  no  one  of  these  has  been  shown  to  possess  the  specific 
pathogenic  power  of  unfiltered  lymph  from  the  same  source.  The  experi- 
ments of  Carstens  and  Coert  show  that  the  specific  virulence  of  vaccine 
lymph  is  destroyed  by  ten  minutes'  exposure  to  a  temperature  of  54°  C.  And 
the  writer's  experiments  show  that  various  disinfecting  agents  tested — chlo- 
rine, sulphur  dioxide,  nitrous  acid — destroy  the  infective  virulence  of  lymph 
dried  upon  ivory  points  in  about  the  same  proportion  as  is  required  for  the 
destruction  of  some  of  the  best-known  pathogenic  bacteria.  But  this  does 
not  prove  that  virulence  depends  upon  the  presence  of  a  living  microorgan- 
ism, however  probable  this  appears,  for  certain  toxalbumins  are  likewise 


TO   BE   DUE   TO   SPECIFIC   MICROORGANISMS.  529 

destroyed  by  a  correspondingly  low  temperature  and  by  the  action  of  vari- 
ous chemical  disinfectants. 

YELLOW    FEVER. 

In  the  writer's  ' '  Report  upon  the  Prevention  of  Yellow  Fever  by  Inocu- 
lation," submitted  in  March,  1888,  the  following  conclusions  are  given  as 
the  result  of  his  investigations  at  the  date  of  this  report : 

Conclusions. 

Facts  relating  to  the  endemic  and  epidemic  prevalence  of  yellow  fever, 
considered  in  connection  with  the  present  state  of  knowledge  concerning  the 
etiology  of  other  infectious  diseases,  justify  the  belief  that  yellow  fever  is 
due  to  a  living  microorganism  capable  of  development  under  favorable  local 
and  meteorological  conditions  external  to  the  human  body,  and  of  establish- 
ing new  centres  of  infection  when  transported  to  distant  localities. 

Inasmuch  as  a  single  attack  of  yellow  fever,  however  mild,  protects,  as  a 
rule,  from  future  attacks,  there  is  reason  to  hope  that  similar  protection  would 
result  if  a  method  could  be  discovered  of  inducing  a  mild  attack  of  the  dis- 
ease by  inoculation  or  otherwise. 

The  hypothetical  yellow-fever  germ,  multiplying  external  to  the  human 
body  in  unsanitary  places  in  tropical  regions  where  the  disease  is  endemic, 
or  during  the  summer  months  in  the  area  of  ics  occasional  epidemic  preva- 
lence, establishes  infected  localities,  and  susceptible  persons  contract  yellow 
fever  by  exposure  in  these  infected  areas.  We  infer,  therefore,  a  priori, 
that  the  yellow-fever  germ  invades  the  system  by  the  respiratory  tract,  by 
the  alimentary  canal,  or  from  the  general  surface  of  the  body,  and  it  should 
be  found  in  the  blood  and  tissues,  or  in  the  alimentary  canal,  or  upon  the 
surface. 

Another  possibility  presents  itself,  viz. ,  that  the  germ  multiplying  in  un- 
sanitary localities  external  to  the  body  produces  a  volatile  poison  which 
contaminates  the  air,  and  that  an  attack  is  induced  by  the  toxic  effects  of 
this  potent  chemical  poison.  The  more  or  less  prolonged  period  of  incuba- 
tion— two  to  five  days — in  numerous  cases  in  which  the  attack  has  been  de- 
veloped after  removal  from  the  infected  locality,  is  opposed  to  this  latter 
hypothesis. 

In  the  light  of  what  is  known  of  the  etiology  of  other  infectious  dis- 
eases, the  hypothesis  that  the  germ  really  finds  entrance  to  the  body  of 
the  person  attacked  and  multiplies  within  it  is  that  which  presents  itself  as 
most  probable,  and  it  hardly  seems  worth  while  to  consider  any  other,  un- 
less this  is  proved  by  a  complete  investigation  not  to  be  true. 

Naturally  the  attention  of  investigators  has  first  been  given  to  a  search 
for  the  "  germ  "  in  the  blood  of  those  attacked  and  in  the  blood  and  tissues 
of  the  victims  of  the  malady. 

The  researches  made  up  to  the  present  time  have  failed  to  demonstrate 
the  constant  presence  of  any  microorganism  in  the  blood  and  tissues  of 
those  attacked. 

My  own  researches,  recorded  in  the  foregoing  report,  show  that  no  such 
microorganism  as  Dr.  Domingos  Freire,  of  Brazil,  has  described  in  his  pub- 
lished works,  or  as  he  presented  to  me  as  his  yellow-fever  germ  at  the  time 
of  my  visit  to  Brazil,  is  found,  as  he  asserts,  in  the  blood  and  tissues  of 
typical  cases  of  yellow  fever.  There  is  no  satisfactory  evidence  that  the 
method  of  inoculation  practised  by  Dr.  Domingos  Freire  has  any  prophy- 
lactic value. 

The  claims  of  Dr.  Carmona  y  Valle,  of  Mexico,  to  have  discovered  the 
specific  cause  of  yellow  fever  have  likewise  no  scientific  basis,  and  he  has 
failed  to  demonstrate  the  protective  value  of  his  proposed  method  of  pro- 
phylaxis. 

It  is  highly  important,  in  the  interest  of  science  and  of  the  public  health, 
that  further  investigations  be  made  by  more  exact  methods  which  have 


530  BACTERIA   IX   INFECTIOUS    DISEASES   NOT   PROVED 

been  perfected  since  Drs.  Freire  and  Carmona  made  their  researches,  and 
with  which  they  were  evidently  not  familiar. 

The  failure  thus  far  to  find  a  specific  microorganism  in  the  blood  or  tis- 
sues makes  it  desirable  that  a  thorough  research  should  be  made  with  refe-' 
rence  to  the  microorganisms  present  in  the  alimentary  canal,  for  it  is  possible 
that  in  yellow  fever,  as  in  cholera,  the  disease  is  induced  by  a  microorgan- 
ism which  multiplies  in  this  situation.  Additional  researches  are  also  re- 
quired before  we  can  say  definitely  that  there  is  no  germ  demonstrable  in 
the  blood  and  tissues.  Having  exhausted  our  resoui'ces  by  the  method  of 
direct  examination,  and  by  cultures  from  blood  drawn  during  life,  it  is 
highly  desirable  that  various  culture  media  should  be  inoculated  with  mate- 
rial taken,  with  proper  precautions,  from  the  various  organs  at  the  earliest 
possible  moment  after  death. 

The  results  of  subsequent  investigations  made  by  the  writer  in  Cuba 
during  the  summers  of  1888  and  1889  are  given  in  the  following  summary 
statement  from  the  Transactions  of  the  Tenth  International  Medical  Con- 
gress (Berlin,  1890) : 

Bacteriological  Researches  in  Yellow  Fever. 

The  report  relates  to  investigations  made  in  Havana,  Cuba,  during  the 
summers  of  1888  and  1889,  in  Decatur,  Alabama,  during  the  autumn  of  1888, 
and  in  the  pathological  and  biological  laboratories  of  the  Johns  Hopkins 
University  during  the  winters  of  1888  and  1889. 

Forty -two  autopsies  were  made  in  typical  cases  of  yellow  fever  and  seven- 
teen autopsies  in  other  diseases  for  comparative  researches. 

Aerobic  and  anaerobic  cultures  were  made  from  the  blood,  the  liver,  the 
kidney,  the  urine,  the  stomach,  and  the  intestine. 

The  experimental  data  recorded  in  this  report  show  that : 

The  specific  infectious  agent  in  yellow  fever  has  not  been  demonstrated. 

The  most  approved  bacteriological  methods  fail  to  demonstrate  the  con- 
stant presence  of  any  particular  microorganism  in  the  blood  and  tissues  of 
yellow-fever  cadavers. 

The  microorganisms  which  are  sometimes  obtained  in  cultures  from  the 
blood  and  tissues  are  present  in  comparatively  small  numbers ;  and  the  one 
most  frequently  found  (Bacterium  coli  commune)  is  present  in  the  intestine 
of  healthy  individuals,  and  consequently  its  occasional  presence  cannot  have 
any  etiological  import. 

A  few  scattered  bacilli  are  present  in  the  liver,  and  probably  in  other  or- 
gans, at  the  moment  of  death.  This  is  shown  by  preserving  portions  of 
liver,  obtained  at  a  recent  autopsy,  in  an  antiseptic  wrapping. 

At  the  end  of  twenty-four  to  forty-eight  hours  the  interior  of  a  piece  of 
liver  so  preserved  contains  a  large  number  of  bacilli  of  various  species,  the 
most  abundant  being  those  heretofore  mentioned  as  occasionally  found  in 
fresh  liver  tissue,  viz. ,  Bacterium  coli  commune  and  Bacillus  cadaveris. 

Blood,  urine,  and  crushed  liver  tissue  obtained  from  a  recent  autopsy  are 
not  pathogenic  in  moderate  amounts  for  rabbits  or  guinea-pigs. 

Liver  tissue  preserved  in  an  antiseptic  wrapping  at  a  temperature  of  28° 
to  30°  C.,  for  forty -eight  hours,  is  very  pathogenic  for  guinea-pigs  when  in- 
jected subcutaneously. 

This  pathogenic  power  appears  to  be  due  to  the  microorganisms  present 
and  to  the  toxic  products  developed  as  a  result  of  their  growth.  It  is  not 
peculiar  to  yellow  fever,  inasmuch  as  material  preserved  in  the  same  way 
at  comparative  autopsies,  in  which  death  resulted  from  accident  or  other 
diseases,  has  given  a  similar  result. 

Having  failed  to  demonstrate  the  presence  of  a  specific  ' '  germ  "  in  the 
blood  and  tissues,  it  seems  probable  that  it  is  to  be  found  in  the  alimentary 
canal,  as  is  the  case  in  cholera.  But  the  extended  researches  made,  and  re- 
corded in  the  present  report,  show  that  the  contents  of  the  intestines  of  yel- 


TO  BE   DUE   TO   SPECIFIC   MICROORGANISMS.  531 

low-fever  cases  contain  a  great  variety  of  bacilli,  and  not  a  nearly  pure  cul- 
ture of  a  single  species,  as  is  the  case  in  recent  and  typical  cases  of  cholera. 

Comparatively  few  liquefying  bacilli  are  found  in  the  faeces  discharged 
during  life,  or  in  the  intestinal  contents  collected  soon  after  death  from  yel- 
low-fever cadavers.  On  the  other  hand,  non-liquefying  bacilli  are  very 
abundant. 

The  one  most  constantly  and  abundantly  present  is  the  Bacterium  coli 
commune  of  Escherich. 

This  is  associated  with  various  other  bacilli,  some  of  which  are  strict 
anaerobics  and  some  facultative  anaerobics. 

Among  the  facultative  anaerobics  is  one — my  Bacillus  X — which  has  been 
isolated  by  the  culture  method  in  a  considerable  number  of  cases  and  may 
have  been  present  in  all.  This  bacillus  has  not  been  encountered  in  the 
comparative  experiments  made.  It  is  very  pathogenic  for  rabbits  when  in- 
jected into  the  cavity  of  the  abdomen. 

It  is  possible  that  this  bacillus  is  concerned  in  the  etiology  of  yellow  fever, 
but  no  satisfactory  evidence  that  this  is  the  case  has  been  obtained  by  experi- 
ments on  the  lower  animals,  and  it  has  not  been  found  in  such  numbers  as 
to  warrant  the  inference  that  it  is  the  veritable  infectious  agent. 

All  other  microorganisms  obtained  in  pure  cultures  from  yellow-fever 
cadavers  appear  to  be  excluded,  either  by  having  been  identified  with  known 
species,  or  by  having  been  found  in  comparative  researches  made  outside  of 
the  area  of  yellow-fever  prevalence,  or  by  the  fact  that  they  have  only  been 
found  in  small  numbers  and  in  a  limited  number  of  cases. ' 

Finally  we  remark  that  many  facts  relating  to  the  origin  and  extension 
of  yellow-fever  epidemics  give  support  to  the  inference  that  the  specific  in- 
fectious agent  is  present  in  the  dejecta  of  those  suffering  from  the  disease, 
and  that  accumulations  of  faecal  matter,  and  of  other  organic  material  of  ani- 
mal origin,  furnish  a  suitable  nidus  for  the  development  of  the  "germ" 
when  climatic  conditions  are  favorable  for  its  growth. 

It  may  be  that  such  a  nidus  is  essential,  and  that  the  culture  media 
usually  employed  by  bacteriologists  do  not  afford  a  suitable  soil  for  this  par- 
ticular microbe. 

It  is  also  possible  that  its  development  depends  upon  the  presence  of  other 
microorganisms  found  in  faecal  matter,  which  give  rise  to  chemical  products 
required  for  the  development  of  this  one. 

Some  of  the  microorganisms  present  in  the  dejecta  of  yellow-fever  pa- 
tients, as  shown  by  stained  smear  preparations,  have  not  developed  in  the 
cultures  made,  either  aerobic  or  anaerobic.  One  extremely  slender  filiform 
bacillus,  which  can  only  be  seen  with  high  powers  and  which  is  quite  abun- 
dant in  some  of  my  preparations,  has  never  been  obtained  in  the  cultures 
made,  and  no  doubt  there  are  others  in  the  same  category. 

That  the  yellow-fever  germ  is  a  strict  anaerobic,  or  that  it  will  only  grow 
in  a  special  nidus,  may  be  inferred  from  certain  facts  relating  to  the  exten- 
sion of  epidemics. 

There  is  no  evidence  that  yellow  fever  is  propagated  by  contamination  of 
the  supply  of  drinking  water,  as  frequently,  and  probably  usually,  occurs  in 
the  case  of  typhoid  fever  and  cholera.  Moreover,  epidemics  extend  in  a 
more  deliberate  manner  and  are  restricted  within  a  more  definite  area  than 
is  the  case  with  cholera  and  typhoid  fever.  It  is  usually  at  least  ten  days  or 
two  weeks  after  the  arrival  of  an  infected  vessel  or  of  a  person  sick  with  the 
disease  before  cases  of  local  origin  occur;  and  these  cases  occur  in  the  imme- 
diate vicinity  of  the  imported  case  or  infected  vessel.  When  the  disease  has 
effected  a  lodgment  the  area  of  infection  extends  slowly  and  usually  has 
well-defined  boundaries.  In  towns  and  cities  having  a  common  water  sup- 

1  The  possibility,  of  course,  remains  that  the  specific  infectious  agent  in  yellow 
fever  may  belong  to  an  entirely  different  class  of  microorganisms  from  the  bacteria, 
or  that  it  may  be  ultra-microscopic  or  not  capable  of  demonstration  in  the  tissues 
by  the  staining  methods  usually  employed  by  bacteriologists. 


532  BACTERIA  IN  CERTAIN   INFECTIOUS   DISEASES. 

ply  one  portion  remains  perfectly  healthy,  while  another,  and  usually  the 
most  filthy  portion,  may  be  decimated  by  the  scourge. 

The  experimental  evidence  recorded,  and  the  facts  just  stated,  seem  to 
justify  the  recommendation  that  the  dejecta  of  yellow-fever  patients  should 
be  regarded  as  infectious  material,  and  that  such  material  should  never  be 
thrown  into  privy  vaults  or  upon  the  soil  until  it  has  been  completely  disin- 
fected. 

This  rule  thoroughly  enforced,  together  with  an  efficient  quarantine  ser- 
vice and  proper  attention  to  the  sanitary  police  of  our  exposed  seaport  cities, 
would,  I  believe,  effectually  prevent  this  pestilential  disease  from  again  ob- 
taining a  foothold  within  the  limits  of  the  United  States. 


XVII. 
CLASSIFICATION  OF  PATHOGENIC  BACTERIA. 

A.    BACTERIA     BELIEVED     TO     BE    THE     CAUSE     OP    INFECTIOUS 
DISEASES  IN  MAN. 

Traumatic  infections:  Staphylococcus  pyogenes aureus  (No.  1); 
Staphylococcus  pyogenes  albus  (No.  2);  Streptococcus  pyogenes 
(No.  5). 

Gonorrhceal  infections  :  Micrococcus  gonorrhoeas  (No.  6). 

Croupous  pneumonia :  Micrococcus  pneumonias  crouposse 
(No.  8). 

Anthrax  ("-wool-sorters'  disease")  :    Bacillus  anthracis  (No.  45). 

Typhoid  fever :  Bacillus  typhi  abdominalis  (No.  46). 

Diphtheria :  Bacillus  diphtherias  (No.  47). 

Epidemic  influenza :  Bacillus  of  influenza  (No.  52). 

Tuberculosis :  Bacillus  tuberculosis  (No.  53). 

Leprosy :  Bacillus  lepras  (No.  54). 

Glanders :  Bacillus  mallei  (No.  55). 

Tetanus :  Bacillus  tetani  (No.  149). 

Relapsing  fever :  Spirillum  Obermeieri  (No.  153). 

Cholera  :  Spirillum  choleras  Asiaticas  (No.  155). 

B.    BACTERIA     ASSOCIATED    WITH    DISEASES    OF   MAN   WHICH   HAVB 

BEEN       SUPPOSED,      ON      MORE      OR       LESS       SATISFACTORY 

EVIDENCE,    TO   BE   THE   CAUSE   OF   THESE   DISEASES. 

Pneumonia  :  Bacillus  of  Friedlander  (No.  7). 

Meningitis :  Diplococcus  intercellularis  meningitidis  (No.  9) ; 
Micrococcus  pneumonias  crouposas  (No.  8);  Bacillus  meningitidis 
purulentas  (No.  131). 

Biskra  button — "Clou  de  Biskra'':  Micrococcus  of  Heyden- 
reich  (No.  26). 

Pemphigus  acutus :  Micrococcus  of  Demme  (No.  27). 

Bright' s  disease :  Streptococcus  of  Manneberg  (No.  28);  Bacillus 
of  Letzerich  (No.  109). 
46 


534  CLASSIFICATION   OF   PATHOGENIC   BACTERIA. 

Endocarditis:  Staphylococcus  pyogenes  aureus  (No.  1);  Micro- 
coccus  pneumonias  crouposoa  (No.  8);  Micrococcus  endocarditidis 
rugatus  (No.  29);  Bacillus  endocarditidis  griseus  (No.  104);  Bacillus 
endocarditidis  capsulatus  (No.  105). 

Syphilis:  Bacillus  of  Lustgarten  (No.  56);  Bacillus  of  Eve  and 
Lingard  ;  Micrococcus  of  Disse  and  Taguchi. 

Rhinoscleroma :  Bacillus  of  rhinoscleroma  (?)  (No.  58). 

Erythema  nodosum :  Bacillus  of  Demme  (No.  107). 

Green  diarrhoea  of  infants  :  Bacillus  of  Lesage  (No.  106). 

Noma  :  Bacillus  nomse  (?)  (No.  110). 

Ozcence :  Bacillus  foetidus  ozssn.se,  (No.  111). 

Bronchitis  :  Bacillus  of  Lumnitzer  (No.  112). 

Sycosis :  Bacillus  of  Tommasoli  (No.  113). 

Whooping  cough  :  Bacillus  of  Afanassiew  (No.  119). 

Influenza  :  Micrococcus  of  Kirchner  (No.  38) ;  Micrococcus  No. 
II.  of  Fischel  (No.  39). 

Measles :  Bacillus  of  Canon. 

Senile  gangrene :  Bacillus  of  Tricomi  (No.  128). 

Cystitis  :  Bacillus  septicus  vesicae  (No.  132). 

Egyptian  ophthalmia :  Bacillus  of  Kartulis  (No.  138). 

Trachoma  :  Micrococcus  of  trachoma  (?)  (No.  17). 

Purpura  hcemorrhagica :  Bacillus  of  Babes  (No.  146);  Bacillus 
of  Kolb  (No.  147);  Bacillus  of  Tizzoni  and  Giovannini  (No.  145). 

Cholera  infantum :  Proteus  vulgaris  (No.  97). 

Cholera  nostras  :  Spirillum  of  Finkler  and  Prior  (No.  156). 

Peritonitis :  Bacillus  coli  communis  (No.  89) ;  Staphylococcus 
pyogenes  aureus  (No.  1);  Streptococcus  pyogenes  (No.  5). 

Pleuritis  :  Micrococcus  pneumonias  crouposae  (No.  8). 

C.    BACTERIA   PROVED   TO   BE   THE   CAUSE   OF   INFECTIOUS   DISEASES 
IN   THE   LOWER   ANIMALS. 

Anthrax :  Bacillus  anthracis  (No.  45). 

Tuberculosis  :  Bacillus  tuberculosis  (No.  53). 

Glanders  :  Bacillus  mallei  (No.  55). 

Septiccemia  in  cattle — "  Rinderseuche  "  :  Bacillus  septicaemias 
haemorrhagicae  (No.  61). 

Swine  plague — "  Schweineseuche,"  Loffler  and  Schiitz  :  Bacil- 
lus septicaemias  haemorrhagicae  (No.  61). 

Symptomatic  anthrax — "black  leg''  in  cattle;  Bacillus  of 
symptomatic  anthrax  (No.  352). 

Farcy  in  cattle  :  Bacillus  of  Nocard  (No.  60). 

Septiccemia  in  deer — "Wildseuche"  :  Bacillus  septicaemias  haem- 
orrhagicse  (No.  61). 


CLASSIFICATION   OP   PATHOGENIC   BACTERIA.  535 

Hog  cholera  :  Bacillus  of  hog  cholera  (No.  63). 

Swine  plague,  Marseilles  :  Bacillus  of  swine  plague  (No.  65). 

Septicaemia  in  ferrets :  Bacillus  of  swine  plague,  Marseilles 
(No.  65). 

"  Myko-desmoids  "  of  the  horse  :  Micrococcus  botryogenus  (No. 
19). 

Septicaemia  in  geese  :  Spirillum  anserum  (No.  154). 

Bovine  mastitis :  Micrococcus  of  bovine  mastitis  (No.  21);  Strep- 
tococcus of  mastitis  in  cows  (No.  31). 

Mastitis  in  sheep  :  Micrococcus  of  gangrenous  mastitis  in  sheep 
(No.  30). 

Pneumonia  in  horses:  Diplococcus  of  pneumonia  in  horses 
(No.  32). 

Contagious  coryza  in  horses — "  Druse  der  Pferde  "  •.  Strepto- 
coccus coryzae  contagiossB  equorum  (No.  33). 

Hog  erysipelas — "^rouget,"  "rothlauf":  Bacillus  erysipelatos 
suis  (No.  67). 

Septicaemia  in  parrots — "gray  parrot  disease  "  :  Streptococcus 
perniciosus  psittacorum  (No.  43). 

Diphtheria  in  pigeons :  Bacillus  diphtherias  columbrarum 
(No.  49). 

Foivl  cholera :,  Bacillus  septicaemise  hsemorrhagicse  (No.  61);  Ba- 
cillus gallinarum  (No.  77). 

Cholera  in  ducks  :  Bacillus  of  Cornil  and  Toupet  (No.  62). 

Grouse  disease :  Bacillus  of  grouse  disease  (No.  76). 

Septiccemia  in  fowls:  Spirillum  Metschnikovi  (No.  158). 

Septiccemia  in  frogs,  etc.  :  Bacillus  hydrophilus  fuscus  (No. 
81). 

Infectious  diseases  of  bees  :  Bacillus  alvei  (No.  140) ;  Bacillus 
of  Canestrini  (No.  295). 

Infectious  diseases  of  silkworms:  Streptococeus  bombycis 
(No.  24)  ;  Nosema  bombycis  (No.  25). 

D.    BACTERIA  FROM  VARIOUS  SOURCES  FOUND   BY  EXPERIMENT   TO 
BE  MORE  OR  LESS  PATHOGENIC  FOR  LOWER  ANIMALS. 

From  the  pus  of  abscesses  and  open  wounds  :    ^ 
Staphylococcus  pyogenes  aureus  (No.  1). 
Staphylococcus  pyogenes  albus  (No.  2). 
Streptococcus  pyogenes  (No.  5). 
Staphylococcus  pyosepticus  (No.  42). 
Bacillus  of  Belfanti  and  Pascarola  (No.  64). 
Bacillus  pyogenes  fcetidus  (No.  72). 
Bacillus  pyocyanus  (No.  95). 


536  CLASSIFICATION   OP   PATHOGENIC   BACTERIA. 

Micrococcus  of  Heydenreich  (No.  26). 
Proteus  of  Karlinsky  (No.  98). 


From  infected  animals  : 

Micrococcus  of  bovine  pneumonia  (No.  22). 
Hsematococcus  bovis  (No.  34). 
Pseudo-diplococcus  pneumonias  (No.  36). 
Bacillus  of  Ribbert  (No.  51). 
Bacillus  enteritidis  (No.  75). 
Bacillus  capsulatus  (No.  80). 
Bacillus  of  Schou  (No.  114). 
Pneumobacillus  liquefaciens  bovis  (No.  120). 

From  the  buccal,  nasal,  or  bronchial  secretions  of  man 

Bacillus  of  Friedlander  (No.  7). 
Micrococcus  pneumonia  crouposse  (No.  8). 
Staphylococcus  salivarius  pyogenes  (No.  10). 
Micrococcus  salivarius  septicus  (No.  15). 
Micrococcus  tetragenus  (No.  18). 
Micrococcus  of  Manfredi  (No.  20). 
Micrococcus  gingivse  pyogenes  (No.  35). 
Micrococcus  No.  II.  of  Fischel  (No.  39). 
Bacillus  of  rhinoscleroma  (No.  58). 
Bacillus  crassus  sputigenus  (No.  71). 
Bacillus  smaragdinus  foetidus  (No.  78). 
Bacillus  tenuis  sputigenus  (No.  82). 
Bacillus  of  Lmnnitzer  (No.  112). 
Bacillus  of  Afanassiew  (No.  119). 
Bacillus  gingivse  pyogenes  (No.  122). 
Bacillus  dentalis  viridans  (No.  123). 
Bacillus  pulpse  pyogenes  (No.  124). 

From  fceces  : 

Bacillus  coprogenus  parvus  (No.  68). 
Bacillus  cavicida  (69). 
Bacillus  coli  communis  (No.  89). 
Bacillus  lactis  aerogenes  (No.  90). 
Bacillus  leporis  lethalis  (No.  94). 
Bacillus  of  Lesage  (No.  106). 
Bacillus  coprogenes  fcetidus  (No.  116). 
Bacillus  of  Gessner  (No.  133). 
Spirillum  of  Finkler  and  Prior  (No.  156). 


CLASSIFICATION  OF   PATHOGENIC   BACTERIA.  537 

From  urine : 

Streptococcus  of  Manneberg  (No.  28). 
Bacillus  of  Letzerich  (No.  109). 
Bacillus  septicus  vesicse  (No.  132). 

From  cadavers  and  from  putrefying  material : 

Diplococcus  intercellularis  meningitidis  (No.  9). 

Streptococcus  septicus  liquefaciens  (No.  37). 

Bacillus  of  Koubasoff  (No.  59). 

Bacillus  cavicida  Havaniensis  (No.  70). 

Proteus  hominis  capsulatus  (No.  73). 

Bacillus  erysipelatos  suis  (mouse  septicaemia)  (No.  67). 

Bacillus  septicaemias  ha3morrhagicse  (rabbit  septicaemia)  (No. 
61). 

Proteus  capsulatus  septicus  (No.  74). 

Bacillus  pneumosepticus  (No.  79). 

Bacillus  acidiformans  (No.  92). 
Bacillus  cuniculicida  Havaniensis  (93). 
Bacillus  pseudo-tuberculosis  (No.  121). 
Bacillus  septicus  keratomalacise  (No.  125). 
Bacillus  septicus  acuminatus  (No.  126). 
Bacillus  septicus  ulceris  gangrsenosi  (No.  127). 
Bacillus  albus  cadaveris  (No.  129). 
Bacillus  meningitidis  purulentae  (No.  131). 
Bacillus  chromo-aromaticus  (No.  134). 
Bacillus  cadaveris  (No.  151). 
Proteus  vulgaris  (No.  97). 
Proteus  mirabilis  (No.  99). 
Proteus  Zenkeri  (No.  100). 
Proteus  septicus  (No.  101). 
Proteus  lethalis  (No.  102). 

From  the  soil  : 

Streptococcus  septicus  (No.  23), 
Bacillus  septicus  agrigenus  (No.  66). 
Bacillus  cedematis  aerobicus  (No.  108). 
Bacillus  cedematis  maligni  (No.  150). 
Bacillus  tetani  (No.  149). 
Bacillus  muscoides  (No.  401). 

From  various  sources : 

Bacillus  oxytocus  perniciosus  (No.  117) — from  milk. 
Bacillus  saprogenes  II.  (No.  118) — from  sweating  feet. 
Bacillus  canalis  capsulatus  (No.  135) — from  sewers. 


538  CLASSIFICATION   OF   PATHOGENIC   BACTERIA. 

Bacillus  canalis  parvus  (No.  136) — from  sewers. 

Bacillus  indigogenus  (No.  137) — from  leaves  of  the  indigo 

plant. 

Bacillus  of  Utpadel  (No.  139)— from  dust. 
Bacillus  of  Okada  (No.  144)— from  dust. 
Spirillum  tyrogenum  (No.  157)— from  cheese. 
Micrococcus  endocarditidis  rugatus  (No.  29) — cardiac  valves. 
Bacillus  endocarditidis  griseus  (No.  104) — cardiac  valves. 
Bacillus  endocarditidis  capsulatus  (No.  105) — cardiac  valves. 


PART   FOURTH. 


SAPROPHYTES. 

I.  BACTERIA  IN  THE  AIR.    II.  BACTERIA  IN  WATER.    III.   BACTERIA  IN 
THE  SOIL.    IV.  BACTERIA  ON  THE  SURFACE  OF  THE  BODY  AND  OF  EX- 
POSED Mucous  MEMBRANES.    V.  BACTERIA  OF  THE  STOMACH  AND 
INTESTINE.    VI.  BACTERIA  OF  CADAVERS  AND  OF  PUTREFYING 
MATERIAL  FROM  VARIOUS  SOURCES.    VII.  BACTERIA  IN  AR- 
TICLES OF  FOOD.    VIII.  NON-PATHOGENIC  MICROCOCCI. 
IX.    NON-PATHOGENIC   BACILLI.    X.  NON-PATHO- 
GENIC SPIRILLA.      XI.    LEPTOTRICHE^E    AND 
CLADOTRICHE^E.    XII.    ADDITIONAL  SPE- 
CIES OF  BACTERIA    NOT    CLASSIFIED. 
XIII.  BACTERIOLOGICAL  DIAGNOSIS. 


I. 

BACTERIA  IN  THE   AIR. 

THE  saprophy tic  bacteria  are  found  wherever  the  organic  material 
which  serves  as  their  pabulum  is  exposed  to  the  air  under  conditions 
favorable  to  their  growth.  The  essential  conditions  are  presence  of 
moisture  and  a  suitable  temperature.  The  organic  material  may  be 
in  solution  in  water  or  in  the  form  of  moist  masses  of  animal  or 
vegetable  origin,  and  the  temperature  may  vary  within  considerable 
limits — 0°  to  70°  C.  But  the  species  which  takes  the  precedence  will 
depend  largely  upon  special  conditions.  Thus  certain  species  multi- 
ply abundantly  in  water  which  contains  comparatively  little  organic 
pabulum,  and  others  require  a  culture  medium  rich  in  albuminous 
material  or  in  carbohydrates  ;  some  grow  at  a  comparatively  low  or 
high  temperature,  while  others  thrive  only  at  a  temperature  of  20°  to 
40°  C.  or  have  a  still  more  limited  range ;  some  require  an  abun- 
dant supply  of  oxygen,  and  others  will  not  grow  in  the  presence  of 
this  gas.  Our  statement  that  saprophytic  bacteria  are  found  wherever 
the  organic  material  which  serves  as  their  pabulum  is  exposed  to  the 
air — under  suitable  conditions — relates  to  the  fact  that  it  is  through 
the  air  that  these  bacteria  are  distributed  and  brought  in  contact 
with  exposed  material.  It  is  a  matter  of  common  laboratory  experi- 
ence that  sterilized  organic  liquids  quickly  undergo  putrefactive  de- 
composition when  freely  exposed  to  the  air,  and  may  be  preserved  in- 
definitely when  protected  from  the  germs  suspended  in  the  air  by 
means  of  a  cotton  air  filter.  But  the  organic  pabulum  required  for 
the  nourishment  of  these  bacteria  is  not  found  in  the  air  in  any  con- 
siderable amount,  and  if  they  ever  multiply  in  the  atmosphere  it 
must  be  under  very  exceptional  conditions.  Their  presence  is  due  to 
the  fact  that  they  are  wafted  from  surfaces  where  they  exist  in  a 
desiccated  condition,  and,  owing  to  their  levity,  are  carried  by  the 
wind  to  distant  localities.  But,  under  the  law  of  gravitation,  when 
not  exposed  to  the  action  of  currents  of  air  they  constantly  fall 
again  upon  exposed  surfaces,  which,  if  moist,  retain  them,  or  from 
which,  if  dry,  they  are  again  wafted  by  the  next  current  of  air. 
Under  these  circumstances  it  is  easy  to  understand  why,  as  deter- 


542 


BACTERIA   IX   THE   AIR. 


mined  by  investigation,  more  bacteria  are  found  near  the  surface  of 
the  earth  than  at  some  distance  above  the  surface,  more  over  the 
land  than  over  the  ocean,  more  in  cities  with  their  dust-covered 
streets  than  in  the  country  with  its  grass-covered  fields. 

Careful  experiments  have  shown  that  bacteria  do  rot  find  their 
way  into  the  atmosphere  from  the  surface  of  liquids,  unless  portions 
of  the  liquid  containing  them  are  projected  into  the  air  by  some 
mechanical  means,  such  as  the  bursting  of  bubbles  of  gas.  Cultures 
of  pathogenic  bacteria  freely  exposed  to  the  air  in  laboratories  do  not 
endanger  the  health  of  those  who  work  over  them;  but  if  such  a  cul- 
ture is  spilled  upon  the  floor  and  allowed  to  remain  without  disin- 
fection, when  it  is  desiccated  the  bacteria 
contained  in  it  will  form  part  of  the  dust  of 
the  room  and  might  be  dangerous  to  its 
occupants.  Bacteria  do  not  escape  into  the 
air  from  the  surface  of  the  fluid  contents  of 
sewers  and  cesspools,  but  changes  of  level 
may  cause  a  deposit  upon  surfaces,  which 
is  rich  in  bacteria,  and  when  dried  this  ma- 
terial is  easily  carried  into  the  atmosphere 
by  currents  of  air. 

TyndalFs  experiments  (1869)  show  that 
in  a  closed  receptacle  in  which  the  air  is 
perfectly  still  all  suspended  particles  are  af- 
ter a  time  deposited  on  the  floor  of  the  closed 
air  chamber.  And  common  experience  de- 
monstrates the  fact  that  the  dust  of  the  at- 
mosphere is  carried  by  the  wind  from  ex- 
posed surfaces  and  again  deposited  when  the 
air  is  at  rest.  This  dust  as  deposited,  for 
example,  in  our  dwellings  contains  innu- 
merable bacteria  in  a  desiccated  condition, 
and  the  smallest  quantity  of  it  introduced 
into  a  sterile  organic  liquid  will  cause  it  to 
undergo  putrefactive  decomposition,  and 
by  bacteriological  methods  it  will  be  found 
to  contain  various  species  of  bacteria.  Such 
dust  also  contains  the  spores  of  various 
mould  fungi  which  are  present  in  the  atmo- 
sphere, usually  in  greater  numbers  than  the 
bacteria.  The  mould  fungi  are  air  plants 

which  vegetate  upon  the  surface  of  moist  organic  material  and  form 
innumerable  spores,  which  are  easily  wafted  into  the  air,  both  on 
account  of  their  low  specific  gravity  and  minute  size,  and  because  they 


FIG.  186.  —  Penicillum  glau- 
cum;  m,  mycelium,  from  which 
is  given  off  a  branching  pedicle 
bearing  spores.  X  150. 


BACTERIA   IX    THE   AIR. 

are  borne  upon  projecting  pedicles  by  which  they  are  removed  from 
the  moist  material  upon  which  and  in  which  the  mycelium  develops 
(Fig.  186),  and,  being  dry,  are  easily  carried  away  by  currents  of  air. 

Bacteriologists  have  given  much  attention  to  the  study  of  the  mi- 
croorganisms suspended  in  the  atmosphere,  with  especial  reference  to 
hygienic  questions.  The  methods  and  results  of  these  investigations 
will  be  considered  in  the  present  section. 

Pasteur  (1860)  demonstrated  the  presence  of  living  bacteria  in  the 
atmosphere  by  aspirating  a  considerable  quantity  of  air  through  a 
filter  of  gun-cotton  or  of  asbestos  contained  in  a  glass  tube.  By  dis- 
solving the  gun-cotton  in  alcohol  and  ether  he  was  able  to  demon- 
strate the  presence  of  various  microorganisms  by  a  microscopical  ex- 
amination of  the  sediment,  and  by  placing  the  asbestos  filters  in 
sterilized  culture  media  he  proved  that  living  germs  had  been  filtered 
out  of  the  air  passed  through  them. 


FIG.  187. 

A  method  employed  by  several  of  the  earlier  investigators  con- 
sisted in  the  collection  of  atmospheric  moisture  precipitated  as  dew 
upon  a  surface  cooled  by  a  freezing  mixture.  This  was  found  to  con- 
tain living  bacteria  of  various  forms.  The  examination  of  rain  water, 
which  in  falling  washes  the  suspended  particles  from  the  atmosphere, 
gave  similar  results. 

The  first  systematic  attempts  to  study  the  microorganisms  of  the 
air  were  made  by  Maddox  (1870)  and  by  Cunningham  (1873),  who 
used  an  aeroscope  which  was  a  modification  of  one  previously  de- 
scribed by  Pouchet.  In  the  earlier  researches  of  Miquel  a  similar 
aeroscope  was  used.  This  is  shown  in  Fig.  187.  The  opening  to  the 
cylindrical  tube  A  is  kept  facing  the  wind  by  means  of  a  wind  vane, 
and  when  the  wind  is  blowing  a  current  passes  through  a  small  aper- 
ture in  a  funnel-shaped  partition  which  is  properly  placed  in  the 
cylindrical  tube,  A  glass  slide,  upon  the  lower  surface  of  which  a 


544:  BACTERIA  IN  THE  AIR. 

mixture  of  glycerin  and  glucose  has  been  placed,  is  adjusted  near  the 
opening  of  the  funnel,  at  a  distance  of  about  three  millimetres,  so 
that  the  air  escaping  through  the  small  orifice  is  projected  against  it. 
By  this  arrangement  a  considerable  number  of  the  microorganisms 
present  in  the  air,  as  well  as  suspended  particles  of  all  kinds,  are  ar- 
rested upon  the  surface  of  the  slide  and  can  be  examined  under  the 
microscope  or  studied  by  bacteriological  methods.  But  an  aeroscope 
of  this  kind  gives  no  precise  information  as  to  the  number  of  living 
germs  contained  in  a  definite  quantity  of  air.  The  microscopical  ex- 
amination also  fails  to  differentiate  the  bacteria  from  particles  of 
various  kinds  which  resemble  them  in  shape,  and  the  microorgan- 
isms seen  are  for  the  most  part  spores  of  various  fungi  mingled  with 
pollen  grains,  vegetable  fibres,  plant  hairs,  starch  granules,  and 
amorphous  granular  material. 

Another  method,  which  has  been  employed  by  Cohn,  Pasteur, 
Miquel,  and  others,  consists  in  the  aspiration  of  a  definite  quantity  of 
air  through  a  culture  liquid,  which  is  then  placed  in  an  incubating 
oven  for  the  development  of  microorganisms  washed  out  of  the  air 
which  has  been  passed  through  it.  This  method  shows  that  bacteria 
of  different  species  are  present,  but  gives  no  information  as  to  their 
relative  number,  and  requires  further  researches  by  the  plate  method 
to  determine  the  characters  of  the  several  species  in  pure  cultures. 

A  far  simpler  method  consists  in  the  exposure  of  a  solid  culture 
medium,  which  has  been  carefully  sterilized  and  allowed  to  cool  on  a 
glass  plate  or  in  a  Petri's  dish,  for  a  short  time  in  the  air  to  be  ex- 
amined. Bacteria  and  mould  fungi  deposited  from  the  air  adhere  to 
the  surface  of  the  moist  culture  medium,  and  form  colonies  when  the 
plate,  enclosed  in  a  covered  glass  dish,  is  placed  in  the  incubating  oven. 
The  number  of  these  colonies  which  develop  after  exposure  in  the 
air  for  a  given  time  enables  us  to  estimate  in  a  rough  way  the  num- 
ber of  microorganisms  present  in  the  air  of  the  locality  where  the 
exposure  was  made  ;  and  the  variety  of  species  is  determined  by  ex- 
amining the  separate  colonies,  each  of  which  is,  as  a  rule,  developed 
from  a  single  germ.  By  exposing  a  number  of  plates  at  different 
times  this  method  enables  us  to  determine  what  species  are  most 
abundant  in  a  given  locality  and  the  comparative  number  in  dif- 
ferent localities,  as  determined  by  counting  the  colonies  after  ex- 
posure for  a  definite  time — e.g.,  ten  minutes.  Of  course  we  will  only 
obtain  evidence  of  the  presence  of  such  aerobic  bacteria  as  will 
grow  in  our  culture  medium.  The  anaerobic  bacteria  may  be  studied 
by  placing  plates  exposed  in  a  similar  way  in  an  atmosphere  of  hydro- 
gen. Bacteria  which  grow  slowly  and  only  under  special  conditions, 
like  the  tubercle  bacillus,  would  be  likely  to  escape  observation,  as 
the  mould  fungi  and  common  saprophytes  would  take  complete  pos- 


BACTERIA  IN   THE   AIR. 


545 


session  of  the  surface  of  the  culture  medium  before  the  others  had 
formed  visible  colonies.  Students  will  do  well  to  employ  this  simple 
and  satisfactory  method  for  the  purpose  of  making  themselves,  familiar 
with  the  more  common  atmospheric  organisms,  and  they  will  find 
the  shallow  glass  dishes  with  a  cover,  known  as  Petri's  dishes,  very 
convenient  for  the  purpose.  These  dishes  should  be  sterilized  in  the 
hot-air  oven  and  sufficient  sterile  nutrient  gelatin  or  agar  poured 
into  them  to  cover  the  bottom.  After  the  culture  medium  has  be- 
come solid  by  cooling,  the  exposure  may  be  made  by  simply  remov- 
ing the  cover  and  replacing  it  at  the  end  of  the  time  fixed  upon. 


FIG.  188. 

To  determine  in  a  more  exact  way  the  number  of  microorganisms 
contained  in  a  given  quantity  of  air  will  require  other  methods.  But 
we  may  say,  en  passant,  that  such  a  determination  is  usually  not  of 
great  scientific  importance.  The  number  is  subject  to  constant  fluc- 
tuations in  the  same  locality,  depending  upon  the  force  and  direction 
of  the  wind.  If  we  have  on  one  side  of  our  laboratory  a  dusty 
street  and  on  the  other  a  green  field,  more  bacteria  will  naturally  be 
found  when  the  wind  blows  from  the  direction  of  the  street  than 
when  it  comes  from  the  opposite  direction  ;  or,  if  the  air  is  filled  with 
dust  from  recently  sweeping  the  room,  we  may  expect  to  find  very 


546  BACTERIA  IX   THE   AIR. 

manj'  more  than  when  the  room  has  been  undisturbed  for  some  time. 
The  painstaking  researches  which  have  already  been  made  have  es- 
tablished in  a  general  way  the  most  important  facts  relating  to  the 
distribution  of  atmospheric  bacteria,  but  have  failed  to  show  any  de- 
finite relation  between  the  number  of  atmospheric  bacteria  and  the 
prevalence  of  epidemic  diseases.  In  the  apparatus  of  Hesse,  Fig. 
188,  a  glass  tube,  having  a  diameter  of  four  to  five  centimetres  and  a 
length  of  half  a  metre  to  a  metre,  is  employed.  In  use  this  is  sup- 
ported upon  a  tripod,  as  shown  in  the  figure,  and  air  is  drawn 
through  it  by  a  water  aspirator  consisting  of  two  flasks,  also  shown. 
The  upper  flask  being  filled  with  water,  this  flows  into  the  lower 
flask  by  siphon  action,  and  upon  reversing  the  position  of  the  flasks 
number  one  is  again  filled.  By  repeating  this  operation  as  many 
times  as  desired  a  quantity  of  air  corresponding  with  the  amount  of 
water  passed  from  the  upper  to  the  lower  flask  is  slowly  aspirated 
through  the  horizontal  glass  tube.  The  microorganisms  present  are 
deposited  upon  nutrient  gelatin  previously  allowed  to  cool  upon  the 
lower  portion  of  the  large  glass  tube.  The  air  enters  through  a  small 
opening  in  a  piece  of  sheet  rubber  which  is  tied  over  the  extremity 
of  the  horizontal  tube,  and  before  the  aspiration  is  commenced  this 
opening  is  covered  by  another  piece  of  sheet  rubber  tied  over  the 
first.  Experience  shows  that  when  the  air  is  slowly  aspirated  most 
of  the  germs  contained  in  it  are  deposited  near  the  end  of  the  tube 
through  which  it  enters.  The  colonies  which  develop  upon  the  nu- 
trient gelatin  show  the  number  and  character  of  living  microorgan- 
isms contained  in  the  measured  quantity  of  air  aspirated  through  the 
apparatus.  The  method  with  a  soluble  filter  of  pulverized  sugar,  to 
be  described  hereafter,  is  preferable  when  exact  results  are  desired; 
and  for  the  purpose  of  determining  the  relative  abundance  and  the 
variety  of  microorganisms  present  in  the  atmosphere  of  a  given  lo- 
cality the  exposure  of  nutrient  gelatin  in  Petri's  dishes  is  far  simpler, 
and,  as  a  rule,  will  furnish  all  the  information  that  is  of  real 
value. 

In  his  extended  researches  made  at  the  laboratory  of  Montsouri, 
in  Paris,  Miquel  has  used  various  forms  of  apparatus  and  has  ob- 
tained interesting  results  ;  but  his  method  of  ensemencements  frac- 
tionnes  requires  a  great  expenditure  of  time  and  patience,  and  the 
more  recent  method  with  soluble  filters  is  to  be  preferred. 

In  his  latest  modification  of  the  method  referred  to  Miquel  used  a 
flask  like  that  shown  in  Fig.  189.  From  twenty  to  forty  cubic  cen- 
timetres of  distilled  water  are  introduced  into  this  flask.  The  cap  A 
contains  a  cotton  air  filter  and  is  fitted  to  the  neck  of  the  flask  by  a 
ground  joint.  This  is  removed  during  the  experiment.  The  tube  C 
is  connected  with  an  aspirator.  It  contains  two  cotton  or  asbestos 


BACTERIA    IN   THE    AIR. 


547 


FIG.  189. 


filters,  c  and  6.  The  cap  being  removed  and  the  aspirator  attached, 
the  air  is  drawn  through  the  water,  by  which  suspended  germs  are 
arrested  ;  or  if  not  they  are  caught  by  the  inner  cotton  plug  b.  The 
sealed  point  of  the  tube  B  is  now  broken  off,  and  the  contents  of  the 
flask  equally  divided  in  thirty  to  forty  tubes  containing  bouillon, 
which  are  placed  in  the  incubating  oven. 
Twenty-five  cubic  centimetres  of  bouillon 
are  also  introduced  into  the  flask,  and  the 
cotton  plug  b  is  pushed  into  it  so  that  any 
bacteria  arrested  by  it  may  develop.  If 
one-fourth  or  one-fifth  of  the  bouillon  tubes 
show  a  development  of  bacteria  it  is  in- 
ferred that  each  culture  originated  from 
a  single  germ,  and  the  number  present  in 
the  amount  of  air  drawn  through  the  flask 
is  estimated  from  the  number  of  tubes  in 
which  development  occurs. 

The  method  adopted  by  Straus  and  Wiirtz  is  more  convenient  and 
more  reliable  in  its  results.  This  consists  in  passing  the  air  by  means 
of  an  aspirator  through  liquefied  nutrient  gelatin  or  agar.  The  ap- 
paratus shown  in  Fig.  190  is  used  for  this  purpose.  Two  cotton 
plugs  are  placed  in  the  tube  B,  to  which  the  aspirator  is  attached, 
and  after  the  determined  quantity  of  air  has  been  passed  through  the 
liquefied  medium  the  inner  plug  is  pushed  down  with  a  sterilized 
platinum  needle  so  as  to  wash  out  in  the  culture 
medium  any  germs  arrested  by  it.  Finally  the 
gelatin  or  agar  is  solidified  upon  the  walls  of 
the  tube  A  by  rotating  it  upon  a  block  of  ice  or 
under  a  stream  of  cold  water.  It  is  now  put 
aside  for  the  development  of  colonies,  which  are 
counted  to  determine  the  number  of  germs  pre- 
sent in  the  quantity  of  air  passed  through  the 
liquefied  culture  medium.  The  main  difficulty 
with  this  apparatus  is  found  in  the  fact  that  the 
nutrient  gelatin  foams  when  air  is  bubbled 
through  it ;  for  this  reason  an  agar  medium  is 
to  be  preferred.  In  using  this  it  will  be  neces- 
sary to  place  the  liquefied  agar  in  a  bath  main- 
tained at  40°  C.  Foaming  of  the  gelatin  is  pre- 
vented by  adding  a  drop  of  olive  oil  before  ster- 
ilization in  the  steam  sterilizer.  But  this  inter- 
feres with  the  transparency  of  the  medium. 
In  the  earlier  experiments  upon  atmospheric  organisms  Pasteur 
used  a  filter  of  asbestos,  which  was  subsequently  washed  out  in  a 


Fio.  190. 


548 


BACTERIA   IN   THE   AIR. 


culture  liquid.     A  filter  of  this  kind  washed  out  in  liquefied  gelatin 
or  nutrient  agar  would  give  more  satisfactory  results,  as  the  culture 
medium  could  be  poured  upon  plates  or  spread  upon  the  walls  of  a 
test  tube  and  the  colonies  counted  in  the  usual  way.     Petri  prefers 
to  use  a  filter  of  sand,  which  he  finds  by  experiment  arrests  the  mi- 
croorganisms suspended  in  the  atmosphere,  and  which  is  subsequently 
distributed  through  the  culture  medium.     The  sand  used  is  such  as 
has  been  passed  through  a  wire  sieve  having 
openings  of  0.5  millimetre  in  diameter.     This  is 
sterilized  by  heat,  and  is  supported  in  a  cylin- 
drical glass  tube  by  small  wire-net  baskets.    The 
complete  arrangement  is  shown  in  Fig.    191. 
Two  sand  filters,  c,  and  C2,  are  used,  the  lower 
one  of  which  serves  as  a  control  to  prove  that 
all  microorganisms  present  in  the  air  have  been 
arrested  by  the  upper  one.     The  upper  filter  is 
protected,  until  the  aspirator  attached  to  the 
tube  h  is  put  in  operation,  by  a  sterile  cotton 
plug,  not  shown  in  the  figure  which  represents 
the  filter  in  use.    Petri  uses  a  hand  air  pump  as 
an  aspirator,  and  passes  one  hundred  litres  of 
air  through  the  sand  in  from  ten  to  twenty 
minutes.     The  sand  from  the  two  filters  is  then 
distributed  in  shallow  glass  dishes  and  liquefied 
gelatin  is  poured  over  it ;  this  is  allowed  to  sol- 
idify and  is  put  aside  for  the  development  of 
colonies.    The  principal  objection  to  this  method 
is  the  presence  of  the  opaque  particles  of  sand 
in  the  culture  medium.    This  objection  has  been 
overcome  by  the  use  of  soluble  filters,  a  method 
first  employed  by  Pasteur  and 'since  perfected 
by  Sedgwick  and  by  Miquel.     The  most  useful 
material  for  the  purpose  appears  to  be  cane 
sugar,  which  can  be  sterilized  in  the  hot-air  oven 
at  150°  C.  without  undergoing  any  change  in 
its  physical  characters.     Loaf  sugar  is  pulver- 
ized in  a  mortar  and  passed  through  two  sieves 
in  order  to  remove  the  coarser  grains  and  the 
very  fine  powder,  leaving  for  use  a  powder  having  grains  of  about 
one-half  millimetre  in   diameter.     This  powdered  sugar   is  placed 
in  a  glass  tube  provided  with  a  cap  having  a  ground  joint  and  a  cot- 
ton plug  to  serve  as  an  air  filter  (A,  Fig.  192),  or  in  a  tube  such  as  is 
shown  at  B,  having  the  end  drawn  out  and  hermetically  sealed.     Two 
cotton  plugs  are  placed  at  the  lower  portion  of  the  tube,  at  a  and  at  b. 


FIG.  191. 


BACTERIA   IN   THE   AIR. 


Glass  tubing  having  a  diameter  of  about  five  millimetres  is  used  in 
making  these  tubes,  and  from  one  to  two  grammes  of  powdered  sugar 
is  a  suitable  quantity  to  use  as  a  filter.  The  whole  apparatus  is  steril- 
ized for  an  hour  at  150°  C.  in  a  hot-air  oven  after  the  pulverized 
sugar  has  been  introduced.  Before  using  it  will  be  necessary  to 
pack  the  sugar  against  the  supporting  plug  a  by  gently  striking  the 
lower  end  of  the  tube,  held  in  a  vertical  position,  upon  some  horizon- 
tal surface ;  and  during  aspiration 
the  tube  must  remain  in  a  vertical 
position,  or  nearly  so,  in  order  that 
the  sugar  may  properly  fill  its  entire 
calibre.  The  aspirator  is  attached  to 
the  lower  end  of  the  tube  by  a  piece 
of  rubber  tubing.  When  the  tube  B 
is  used  the  sealed  extremity  is  broken 
off  at  the  moment  that  the  aspirator 
is  set  in  action,  and  it  is  again  sealed 
in  a  flame  after  the  desired  amount 
of  air  has  been  passed  through  the 
filter.  The  next  step  consists  in  dis- 
solving the  sugar  in  distilled  water 
or  in  liquefied  gelatin.  To  insure 
the  removal  of  all  the  sugar  the  cot- 
ton plug  a  may  be  pushed  out  with  a 
sterilized  glass  rod,  after  removing  b 
with  forceps.  From  fifty  to  five  hun- 
dred cubic  centimetres  of  distilled 
water,  contained  in  an  Erlenmeyer 
flask  and  carefully  sterilized,  may  be 
used,  the  amount  required  depending 
upon  circumstances  relating  to  the 
conditions  of  the  experiment.  By 
adding  five  or  ten  cubic  centimetres 
of  this  water,  containing  the  sugar 
and  microorganisms  arrested  by  it, 
to  nutrient  gelatin  or  agar  liquefied  by  heat,  and  then  making  Es- 
march  roll  tubes,  the  number  of  germs  in  the  entire  quantity  is  easily 
estimated  by  counting  the  colonies  which  develop  in  the  roll  tubes. 

Sedgwick  and  Tucker,  in  a  communication  made  to  the  Boston 
Society  of  Arts,  January  12th,  1888,  were  the  first  to  propose  the  use 
of  a  soluble  filter  of  granulated  sugar  for  collecting  atmospheric 
germs.  Their  complete  apparatus  consists  of  an  exhausted  receiver, 
from  which  a  given  quantity  of  air  is  withdrawn  by  means  of  an  air 
pump.  A  vacuum  gauge  is  attached  to  the  receiver,  which  is  coupled 
47 


FIG.  192. 


FIG.  193. 


550  BACTERIA   IN   THE   AIR. 

with  the  glass  tube  containing  the  granulated -sugar  filter  by  a  piece 
of  rubber  tubing.  Instead  of  transferring  the  soluble  filter  to  gela- 
tin in  test  tubes,  they  use  a  large  glass  cylinder  having  a  slender 
stem,  in  which  the  sugar  is  placed  (Fig.  193).  After  the  aspiration 
liquefied  gelatin  is  introduced  into  the  large  glass  cylinder,  which  is 
held  in  a  horizontal  position  ;  the  sterilized  cotton  plug  is  then  re- 
placed in  the  mouth  of  the  cylinder,  the  sugar  is  pushed  into  the 
liquefied  gelatin  and  dissolved,  and  by  rotating  the  cylinder  upon  a 
block  of  ice  the  gelatin  is  spread  upon  its  walls  as  in  an  Esmarch  roll 
tube.  For  convenience  in  counting  the  colonies  lines  are  drawn  upon 
the  surface  of  the  cylinder,  dividing  it  into  squares  of  uniform  di- 
mensions. 


GENERAL  RESULTS   OF  RESEARCHES   MADE. 

As  already  stated,  the  presence  of  bacteria  in  the  atmosphere  de- 
pends upon  their  being  wafted  by  currents  of  air  from  surfaces  where 
they  are  present  in  a  desiccated  condition.  That  they  are  not  carried 
away  from  moist  surfaces  is  shown  by  the  fact  that  expired  air  from 
the  human  lungs  does  not  contain  microorganisms,  although  the  in- 
spired air  may  have  contained  considerable  numbers,  and  there  are 
always  a  vast  number  present  in  the  salivary  secretions.  The  moist 
mucous  membrane  of  the  respiratory  passages  constitutes  a  germ 
trap  which  is  much  more  efficient  than  the  glass  slide  smeared  with 
glycerin  used  in  some  of  the  aeroscopes  heretofore  described,  for  it 
is  a  far  more  extended  surface.  As  a  matter  of  fact,  most  of  the  sus- 
pended particles  in  inspired  air  are  deposited  before  the  current  of 
air  passes  through  the  larynx. 

Air  which  passes  over  large  bodies  of  water  is  also  purified  of  its 
germs  and  other  suspended  particles.  The  researches  of  Fischer 
show  that  at  a  considerable  distance  from  the  land  no  germs  are 
found  in  the  atmosphere  over  the  ocean,  and  that  it  is  only  upon  ap- 
proaching land  that  their  presence  is  manifested  by  the  development 
of  colonies  upon  properly  exposed  gelatin  plates. 

Uffelmann  found,  in  his  researches,  that  in  the  open  fields  the 
number  of  living  germs  in  a  cubic  metre  of  air  averaged  two  hundred 
and  fifty,  on  the  sea  coast  the  average  was  one  hundred,  in  the  court- 
yard of  the  University  of  Rostock  four  hundred  and  fifty.  The  num- 
ber was  materially  reduced  after  a  rainfall  and  increased  when  a 
dry  land  wind  prevailed. 

Frankland  found  that  fewer  germs  were  present  in  the  air  in 
winter  than  in  summer,  and  that  when  the  earth  was  covered  with 
snow  the  number  was  greatly  reduced,  as  also  during  a  light  fall  of 
snow ;  the  air  of  towns  was  found  to  be  more  rich  in  germs  than  the 


BACTERIA    IN   THE   AIR.  551 

air  of  the  country ;  the  lower  strata  of  the  atmosphere  contained 
more  than  the  air  of  elevated  localities. 

Von  Freudenreich  also  found  that  the  air  of  the  country  contained 
fewer  germs  than  that  of  the  city.  Thus  in  the  city  of  Berne  a  cubic 
metre  of  air  often  contained  as  many  as  two  thousand  four  hundred 
germs,  while  the  maximum  in  country  air  was  three  hundred.  His  re- 
sults corresponded  with  those  of  Miquel  in  showing  that  the  number 
of  atmospheric  organisms  is  greater  in  the  morning  and  the  evening, 
between  the  hours  of  6  and  8,  than  during  the  rest  of  the  day.  Neu- 
mann, whose  researches  were  made  in  the  Moabite  Hospital,  found 
the  greatest  number  of  bacteria  in  the  air  in  the  morning  after  the 
patients  able  to  sit  up  had  left  their  beds  and  the  wards  had  been 
swept.  The  number  of  germs  was  then  from  eighty  to  one  hundred 
and  forty  in  ten  litres  of  air,  while  in  the  evening  the  number  fell  to 
four  to  ten  germs  in  ten  litres. 

Miquel  has  given  the  following  summary  of  results  obtained  in 
his  extended  experiments,  made  in  Paris  during  the  years  1881, 1882, 
and  1883  : 


Average  for 

1880  

Number  of  Germs  in  a  Cubic  Metre  of  Air. 

Air  of  Laboratory, 
Montsouri. 

Air  of  Park,  Mont 
souri. 

215 
348 
550 

71 
62 
51 

1881  

1882.  . 

Rue  de  Rivoli,  average  for  one  year,  750  ;  summit  of  Pantheon,  28  ; 
Hotel-Dieu,  1880,  average  for  four  months,  male  ward  6,300,  female 
ward  5,120  ;  La  Piete  Hospital,  average  of  fifteen  months,  11,100. 

It  must  be  remembered  that  the  figures  given  relate  both  to  bac- 
teria and  to  the  spores  of  mould  fungi,  and  that  the  latter  are  com- 
monly the  most  numerous  when  the  experiment  is  made  in  the  open 
air.  Petri  has  shown  that  when  gelatin  plates  are  exposed  in  the  air 
the  relative  number  of  spores  of  mould  fungi  deposited  upon  them  is 
less  than  is  obtained  in  aspiration  experiments. 

The  number  of  colonies  which  develop  on  exposed  plates  does  not 
represent  the  full  number  of  bacteria  deposited,  for  these  colonies 
very  frequently  have  their  origin  in  a  dust  particle  to  which  several 
bacteria  are  attached,  or  in  a  little  mass  of  organic  material  contain- 
ing a  considerable  number. 

It  is  generally  conceded  that  sea  air  and  country  air  are  more 
wholesome  than  the  air  of  cities,  and  especially  of  crowded  apart- 
ments, in  which  the  number  of  bacteria  has  been  shown  to  be  very 
much  greater.  But  it  would  be  a  mistake  to  ascribe  the  sanitary 
value  of  sea,  country,  and  mountain  air  to  the  relatively  small  num- 


553  BACTERIA   IX   THE   AIR. 

ber  of  bacteria  present  in  such  air.  There  are  other  important  fac- 
tors to  be  considered,  and  we  have  no  satisfactory  evidence  that  the 
number  of  saprophytic  bacteria  present  in  the  air  has  an  important 
bearing  upon  the  health  of  those  who  respire  it.  We  do  know  that 
the  confined  air  of  crowded  apartments,  and  especially  of  factories 
in  which  a  large  quantity  of  dust  is  suspended  in  the  air,  predisposes 
those  breathing  such  air  to  pulmonary  diseases  and  lowers  the  gen- 
eral standard  of  health.  But  it  has  not  been  proved  that  this  is  due 
to  the  presence  of  bacteria.  Infectious  diseases  may,  under  certain 
circumstances,  be  communicated  by  way  of  the  respiratory  passages 
as  a  result  of  breathing  air  containing  in  suspension  pathogenic  bac- 
teria ;  but  there  is  reason  to  believe  that  this  occurs  less  frequently 
than  is  generally  supposed. 

Kruger  has  shown  that  the  dust  of  a  hospital  ward  in  which  pa- 
tients with  pulmonary  consumption  expectorated  occasionally  upon 
the  floor  contained  tubercle  bacilli.  This  was  proved  by  wiping  up 
the  dust  on  a  sterilized  sponge,  washing  this  out  in  bouillon,  and  in- 
jecting this  into  the  cavity  of  the  abdomen  of  guinea-pigs.  Two 
animals  out  of  sixteen  injected  became  tuberculous.  In  pulmonic 
anthrax,  which  occasionally  occurs  in  persons  engaged  in  sorting 
wool — "wool-sorters'  disease" — infection  occurs  as  a  result  of  the 
respiration  of  air  containing  the  spores  of  the  anthrax  bacillus. 

Among  the  non-pathogenic  saprophytes  found  in  the  air  certain 
aerobic  micrococci  appear  to  be  the  most  abundant,  and,  as  a  rule, 
bacilli  are  not  found  in  great  numbers  or  variety.  In  some  localities 
various  species  of  sarcinsB  are  especially  abundant.  The  following 
is  a  partial  list  of  the  species  which  have  been  shown  by  the  researches 
of  various  bacteriologists  to  be  occasionally  present  in  the  air.  But, 
as  heretofore  remarked,  their  presence  is  to  be  regarded  as  acci- 
dental, and  so  far  as  we  know  there  is  no  bacterial  flora  properly  be- 
longing to  the  atmosphere  : 

Micrococcus  ureae  (Pasteur),  Diplococcus  roseus  (Bumm),  Diplococcus 
citreus  conglomerates  (Bumm),  Micrococcus  radiatus  (Fliigge),  Micrococcus 
flavus  desidens  (Fliigge),  Micrococcus  flavus  liquefaciens  (Fliigge),  Micro- 
coccus  tetragen  us  versatilis  (Stern berg),  Micrococcus  pyogenes  aureus  (Rosen- 
bach),  Micrococcus  pyogenes  citreus  (Passet),  Micrococcus  cinnabareus 
(Fliigge),  Micrococcus  flavus  tardigradus  (Fliigge),  Micrococcus  versicolor 
(Fliigge),  Micrococcus  viticulosus  (Katz),  Micrococcus  candidans  (Fliigge), 
Pediococcus  cerevisiae  (Balcke),  Sarcina  lutea  (SchrOter),  Sarcina  rosea 
(Schroter),  Sarcina  aurantiaca,  Sarcina  alba,  Sarcina  Candida  (Reinke), 
Bacillus  tumescens  (Zopf),  Bacillus  subtilis  (Ehrenberg),  Bacillus  multipedi- 
culosus  (Fliigge),  Bacillus  mesentericus  fuscus  (Fliigge),  Bacillus  mesenteri- 
cus  ruber  (G-lobig),  Bacillus  inflatus  (A.  Koch),  Bacillus  mesentericus  vul- 
gatus,  Bacillus  prodigiosus,  Bacillus  aerophilus  (Liborius),  Bacillus  pestifer 
(Frankland),  Spirillum  aureuni  (Weasel),  Spirillum  flavescens  (Weibel),  Spi- 
rillum flavum  (Weibel),  Bacillus  Havaniensis  (Sternberg). 

In  the  recent  researches  of  Welz,  made  in  the  vicinity  of  Freiburg, 
twenty-three  different  micrococci  and  twenty-two  bacilli  were  obtained 
from  the  air. 


II. 

BACTERIA  IN  WATER. 

THE  water  of  the  ocean,  of  lakes,  ponds,  and  running  streams 
necessarily  contains  bacteria,  as  they  are  constantly  being  carried 
into  it  by  currents  of  air  passing  over  the  neighboring  land  surfaces, 
and  by  rain  water  which  washes  suspended  microorganisms  from 
the  atmosphere ;  and,  as  such  water  contains  more  or  less  organic 
material  in  solution,  many  of  the  saprophytic  bacteria  multiply  in  it 
abundantly.  It  is  only  in  the  water  of  springs  and  wells  which 
comes  from  the  deeper  strata  of  the  soil  that  they  are  absent.  The 
number  and  variety  of  species  present  in  water  from  any  given 
source  will  depend  upon  conditions  relating  to  the  amount  of  organic 
pabulum,  the  temperature,  the  depth  of  the  water,  the  fact  of  its 
being  in  motion  or  at  rest,  its  pollution  from  various  sources,  etc. 
The  comparatively  pure  water  of  lakes  and  running  streams  contains 
a  considerable  number  of  bacteria  which  find  their  normal  habitat 
in  such  waters  and  which  multiply  abundantly  in  them,  notwith- 
standing the  small  quantity  of  organic  matter  and  salts  which  they 
contain.  The  water  of  stagnant,  shallow  pools,  and  of  sluggish 
streams  into  which  sewage  is  discharged,  contains  a  far  greater 
number  and  a  greater  variety  of  species. 

The  study  of  these  bacteria  in  water  has  received  much  attention 
on  account  of  the  sanitary  questions  involved,  relating  to  the  use  of 
water  from  various  sources  for  drinking  purposes.  In  the  present 
section  we  shall  first  give  an  account  of  the  methods  of  bacteriologi- 
cal water  analysis,  and  then  a  condensed  statement  of  results  ob- 
tained in  the  very  numerous  investigations  which  have  been  made. 

A  very  important  point  to  be  kept  in  view  is  the  fact  that  a  great 
increase  in  the  number  of  bacteria  present,  in  samples  of  water  col- 
lected for  investigation,  is  likely  to  occur  if  these  samples  are  kept 
for  some  time.  A  water  which,  for  example,  contains  only  two 
hundred  to  three  hundred  bacteria  per  cubic  centimetre  when  the  ex- 
amination is  made  at  once,  may  contain  several  thousand  at  the  end 
of  twenty-four  hours,  and  at  the  end  of  the  second  or  third  day 
twenty  thousand  or  more  may  be  present  in  the  same  quantity. 


554  BACTERIA   IN   WATER. 

Later,  on  account  of  the  exhaustion  of  organic  pabulum,  the  num- 
ber is  again  reduced  as  the  bacteria  present  gradually  lose  their 
vitality.  Under  these  circumstances  it  is  evident  that  an  estimate  of 
the  number  of  bacteria  present  in  water  from  a  given  source  can 
have  no  value,  unless  a  sample  is  'tested  by  bacteriological  methods 
within  a  short  time  after  it  has  been  collected.  Not  more  than  an 
hour  or  two  should  be  allowed  to  elapse,  especially  in  warm  weather. 
By  placing  the  water  upon  ice  the  time  may  be  extended  somewhat, 
but  Wolffhugel  has  shown  that  the  number  of  germs  is  gradually 
diminished  when  water  is  preserved  in  this  way,  and  it  will  be  safest 
to  make  an  immediate  examination  when  this  is  practicable. 

The  collection  may  be  made  in  a  sterilized  Erlenmeyer  flask  pro- 
vided with  a  cotton  air  filter,  or  in  a  bottle  having  a  ground-glass 
stopper  which  has  been  wrapped  in  tissue  paper  and  sterilized  for  an 
hour  or  more  at  150°  C.  in  the  hot-air  oven.  Or  the  small  flasks  with 
a  long  neck  may  be  used,  as  first  recommended  by  Pasteur.  These 
are  prepared  as  follows  :  The  bulb  is  first  gently  heated,  and  the  ex- 
tremity of  the  tube  dipped  into  distilled  water,  which  mounts  into 


FIG.  194. 


the  bulb  as  it  cools ;  the  water  is  then  made  to  boil,  and  when  all 
but  a  drop  or  two  has  escaped  and  the  bulb  is  filled  with  steam  the 
extremity  of  the  tube  is  hermetically  sealed.  When  the  steam  has 
condensed  by  the  cooling  of  the  bulb  a  partial  vacuum  is  formed, 
and  the  tube  is  ready  for  use  at  any  time.  It  is  filled  with  water  by 
breaking  off  the  sealed  extremity  under  the  surface  of  the  water  of 
which  a  sample  is  desired.  This  is  done  with  sterilized  forceps,  and 
care  must  be  taken  that  the  exterior  of  the  tube  is  properly  sterilized 
before  the  collection  is  made.  The  end  is  immediately  sealed  in  the 
flame  of  a  lamp.  A  difficulty  with  these  vacuum  tubes  is  that  they 
are  so  completely  filled  with  water  that  this  cannot  be  readily  drawn 
from  them  again  in  small  quantities.  The  writer  therefore  prefers 
to  make  the  collection  in  a  tube  shaped  as  shown  in  Fig.  194,  in  which 
a  partial  vacuum  is  formed  just  before  the  collection  by  heating  the 
air  in  the  bulb.  The  water  mounts  into  the  tube  as  the  air  in  the 
bulb  cools,  and  is  readily  forced  out  again  for  making  cultures  by 
applying  gentle  heat  to  the  bulb.  As  a  lamp  is  needed  to  seal  the  end 
of  the  tube  in  either  case,  there  is  110  special  advantage  in  having  a 
vacuum  formed  in  advance,  and,  as  stated,  the  vacuum  tubes  are  So 


BACTERIA    IN   WATER. 


555 


nearly  filled  with  water  that  it  is  not  so  simple  a  matter  to  obtain  the 
contents  for  our  culture  experiments  without  undue  exposure  to  at- 
mospheric germs.  In  practice  small  glass  bottles  with  ground-glass 
stoppers  will  be  found  most  convenient,  and,  when  properly  steril- 
ized, are  unobjectionable.  They  should  be  filled  at  a  little  distance 
below  the  surface,  as  there  is  often  a  deposit  of  dust  upon  the  surface 
of  standing  water,  and  sometimes  a 
delicate  film  made  up  of  aerobic  bac- 
teria. When  water  is  to  be  obtained 
from  a  pump  or  a  hydrant  it  should 
be  allowed  to  flow  for  some  time  before 
the  collection  is  made.  To  collect 
water  at  various  depths  the  apparatus 
shown  in  Fig.  195  is  recommended  by 
Lepsius.  An  iron  frame  supports  an 
inverted  flask,  A,  filled  with  sterilized 
mercury  and  containing  about  three 
hundred  cubic  centimetres.  The  flask 
B  is  intended  to  receive  the  mercury 
when,  at  the  desired  depth,  it  is  al- 
lowed to  flow  through  the  capillary 
tube  b.  This  is  sealed  at  the  extremity 
and  bent  as  shown  in  the  figure.  By 
pulling  upon  the  cord  c  this  tube  is 
broken,  and  as  the  mercury  flows  from 
the  flask  this  is  filled  with  water 
through  the  tube  a.  The  extremity 
of  the  broken  tube  b  is  closed  by  the 
mercury  in  the  flask  B  when  A  is  full 
of  water,  and  the  apparatus  can  be 
brought  to  the  surface  with  only  such 
water  as  was  collected  at  the  depth 
from  which  a  sample  was  desired. 

The  bacteriological  analysis  is 
made  by  adding  a  definite  quantity 
of  the  water  under  investigation  to 
liquefied  gelatin  or  agar-gelatin,  and 
making  a  plate  or  Esmarch  roll  tube,  which  is  put  aside  for  the  devel- 
opment of  colonies.  Miquel  and  others  have  preferred  to  use  liquid 
cultures  and  the  method  of  fractional  cultivation  described  in  the 
previous  section.  The  use  of  a  solid  culture  medium  has,  however, 
such  obvious  advantages  that  we  do  not  consider  it  necessary  to  do 
more  than  refer  to  the  other  method  as  one  which,  when  applied 
with  skill  and  patience,  may  give  sufficiently  accurate  results. 


FIG.  195. 


556  BACTERIA   IN   WATER. 

The  amount  of  water  which  should  be  added  to  the  usual  quan- 
tity of  liquefied  flesh-peptone-gelatin  in  a  test  tube,  in  order  that  the 
colonies  which  develop  may  be  well  separated  from  each  other  and 
easily  counted,  can  only  be  determined  by  experiment.  If  the  water 
is  from  an  impure  source  a  single  drop  may  be  too  much,  and  it  will 
be  necessary  to  dilute  it  with  distilled  water  recently  sterilized.  But 
for  ordinary  potable  water  it  will  usually  be  best,  in  a  first  experi- 
ment, to  make  two  trials,  one  with  one  cubic  centimetre  and  one 
with  one-half  cubic  centimetre  added  to  the  liquefied  nutrient  gelatin. 
The  water  in  the  collecting  bottle  should  be  shaken,  to  distribute  the 
bacteria  which  may  have  settled  to  the  bottom,  before  drawing  off  by 
means  of  a  sterilized  pipette  the  amount  used  for  the  experiment,  and 
the  germs  present  in  it  are  to  be  distributed  through  the  liquefied 
gelatin  by  gently  moving  the  tube  to  and  fro. 

Koch's  method  of  preparing  a  gelatin  plate  is  illustrated  in  Fig. 
196.  A  glass  dish,  containing  ice  water  and  covered  with  a  large 


Fio.  196. 

plate  of  glass,  is  supported  upon  a  levelling  tripod.  By  means  of  a 
spirit  level  this  is  adjusted  to  a  horizontal  position,  so  that  when  the 
liquefied  gelatin  is  poured  upon  the  smaller  sterilized  glass  plate,  seen 
in  the  centre  of  the  large  plate  of  glass,  it  will  not  flow,  but  may  be 
evenly  distributed  over  the  surface  by  means  of  a  sterilized  glass  rod. 
The  glass  cover  resting  against  the  side  of  the  apparatus  is  placed 
over  the  gelatin  plate  while  it  is  cooling,  to  protect  it  from  atmo- 
spheric germs,  and  when  the  gelatin  is  hard  the  plate  is  transferred 
to  a  shallow  glass  dish,  which  is  kept  at  a  temperature  of  about 
20°  C.  for  several  days  for  the  development  of  colonies.  It  is  difficult 
to  count  colonies  when  more  than  five  thousand  develop  upon  a  plate 
of  the  usual  size,  and  for  this  reason  it  will  be  best  to  repeat  the  ex- 
periment with  a  smaller  quantity  of  water  from  the  same  source,  if 
this  is  at  hand,  rather  than  to  attempt  to  count  an  overcrowded 
plate.  Before  pouring  the  gelatin  upon  the  plate  the  lip  of  the  test 
tube  containing  it  should  be  sterilized  by  passing  it  through  a  flame. 
The  liquefied  gelatin  should  ba  carefully  distributed  to  cover  a  rect- 


BACTERIA   IN   WATER.  557 

angular  surface  and  leaving  a  margin  of  about  one  centimetre  around 
the  edge  of  the  plate.  The  Koch's  dish  in  which  the  gelatin  plate  is 
placed  for  the  development  of  colonies  should  be  carefully  sterilized 
by  heat  or  by  washing  it  out  with  a  sublimate  solution.  A  circular 
piece  of  filtering  paper,  saturated  with  sublimate  solution  or  distilled 
water,  is  placed  at  the  bottom  of  the  lower  dish  to  keep  the  air  in  a 
moist  condition  and  prevent  drying  of  the  gelatin.  Usually  two  or 
three  plates  made  at  the  same  time  are  placed  one  above  the  other  on 
glass  supports  made  for  this  purpose.  If  many  liquefying  organisms 
are  present  it  will  be  necessary  to  count  the  colonies  before  these  run 
together — usually  on  the  second  day  ;  but  in  the  absence  of  liquefy- 
ing colonies  it  is  best  to  wait  until  the  third,  or  even  the  fifth  day,  as 
the  number  of  visible  colonies  and  the  ease  of  counting  them  will  be 
greater  than  at  an  earlier  date.  The  development  of  a  few  scattered 
liquefying  colonies  which  threaten  to  spoil  the  plate  may  be  arrested 
by  taking  up  the  liquefied  gelatin  from  each  with  a  bit  of  filtering 
paper,  and  then,  by  means  of  a  camel's-hair  brush,  applying  a  solu- 
tion of  potassium  permanganate  to  the  margin  of  the  colony.  The 
growth  of  colonies  of  mould  fungi,  which  have  developed  from  spores 
from  the  atmosphere  falling  upon  the  plate  while  it  is  exposed,  can 
be  checked  by  the  application  of  collodion  containing  bichloride  of 
mercury. 

Counting  of  the  colonies  is  a  simple  matter  when  they  are  few 
in  number ;  when  they  are  numerous  it  is  customary  to  place  the 
plate  over  a  dark  background,  and  to  place  above  it  a  glass  plate 
divided  into  square  centimetres  by  lines  ruled  with  a  diamond.  By 
means  of  a  lens  of  low  power  the  colonies  in  a  certain  number  of 
squares  are  counted  and  the  average  taken.  This  multiplied  by  the 
number  of  square  centimetres  in  the  gelatin-covered  surface  gives 
approximately  the  entire  number  of  colonies  which  have  developed 
from  the  amount  of  water  used  in  the  experiment. 

Instead  of  using  Koch's  original  plate  method,  as  above  described, 
the  shallow,  covered  glass  dishes  recommended  by  Petri  may  be 
employed.  These  are  from  one  to  one  and  one-half  centimetres  high 
and  from  ten  to  fifteen  centimetres  in  diameter.  The  liquefied  gel- 
atin is  poured  into  the  lower  dish  and  the  cover  at  once  placed  over 
it.  The  gelatin  does  not  dry  out  very  soon,  but,  if  necessary,  several 
of  these  Petri's  dishes  may  be  placed  in  a  larger  jar,  which  serves  as 
a  moist  chamber. 

The  roll  tubes  of  Esmarch  may  also  ba  used,  and  have  the  ad- 
vantage that  accidental  colonies  from  air-borne  germs  are  excluded. 
The  counting  of  colonies  is  not  quite  as  easy,  but  by  the  use  of  a 
mounted  lens  especially  designed  for  the  purpose  it  is  attended  with 
no  great  difficulty.  The  surface  of  the  tube  is  divided  into  squares 


558  BACTERIA   IN   WATER. 

by  colored  lines,  and  the  number  of  colonies  in  several  squares  is 
counted  in  order  to  obtain  an  average  and  estimate  the  entire 
number. 

Water  which  contains  numerous  liquefying  bacteria  had  better 
be  examined  by  the  use  of  nutrient  agar  instead  of  gelatin;  and  in 
very  warm  weather  it  will  be  necessary  to  use  an  agar  medium,  as 
ten-per-cent  gelatin  is  likely  to  melt  if  the  temperature  goes  above 
22°  C.  A  difficulty  in  the  use  of  agar  for  plates  consists  in  the  lia- 
bility of  the  film  to  slip  from  the  glass.  This  may  be  remedied  to 
some  extent  by  adding  a  few  drops  of  a  concentrated  solution  of  gum 
acacia  to  the  liquefied  agar  medium.  Petri's  dishes  are  well  adapted 
for  the  use  of  the  agar  medium,  as  the  objection  referred  to  does  not 
apply  to  them.  The  gelatin-agar  medium,  containing  5  per  cent 
of  gelatin  and  0. 75  per  cent  of  agar,  may  also  be  used  with  advan- 
tage in  the  bacteriological  analysis  of  water.  Much  stress  was  at 
one  time  laid  upon  the  enumeration  cf  liquefying  colonies,  upon 
the  supposition  that  the  liquefying  bacteria  were  especially  harmful 
as  compared  with  the  non-liquefying,  and  that  a  water  containing 
many  liquefying  colonies  was  to  be  looked  upon  with  suspicion.  We 
now  know,  however,  that  there  are  many  common  and  harmless 
saprophytes  which  cause  the  liquefaction  of  gelatin,  and  that  some 
of  the  most  dangerous  pathogenic  bacteria  do  not  liquefy  gelatin. 
This  distinction  has  therefore  no  special  value,  and  the  question  for 
bacteriologists  to-day  is  not  how  large  is  the  comparative  number  of 
liquefying  colonies,  but  what  species  are  represented  by  the  colonies 
present,  liquefying  and  non-liquefying,  and  what  are  the  special 
pathogenic  properties  of  each.  The  answer  to  these  questions,  in 
the  case  of  any  particular  water  supply,  calls  for  special  knowledge 
and  great  patience  and  care  in  the  isolation  in  pure  cultures,  and 
careful  study  of  the  various  species  present. 

It  is  now  generally  recognized  that  a  mere  enumeration  of  the 
number  of  colonies  which  develop  from  a  water  under  investigation 
is  not  a  sufficient  indication  upon  which  to  found  an  opinion  as  to  its 
potability.  An  excessive  number  of  bacteria  is  an  indication  that 
the  water  contains  a  large  amount  of  the  organic  material  which 
serves  as  pabulum  for  these  microorganisms.  But  the  chemists  are 
able  to  determine  the  amount  of  organic  matter  present  in  water 
with  greater  precision  ;  and,  as  we  have  seen,  the  number  of  bacteria 
may  increase  many-fold  in  water  which  is  kept  standing  in  the  labo- 
ratory for  two  or  three  days  in  a  well-corked  bottle.  As  a  matter  of 
fact,  the  enumeration  of  bacteria  in  water,  although  it  has  given  us 
results  of  scientific  interest,  has  not  materially  added  to  the  methods 
previously  applied  for  estimating  the  sanitary  value  of  water  ob- 
tained from  various  sources  for  drinking  purposes.  But  the  bacte- 


BACTERIA   IX   WATER. 

riological  examination  may  prove  to  be  of  great  value  if  it  succeeds 
in  demonstrating  the  presence  of  certain  pathogenic  bacteria  and  in 
thus  preventing  the  use  of  a  dangerous  water.  We  do  not  mean  to 
say,  however,  that  an  enumeration  of  the  bacteria  present  in  drink- 
ing water  has  no  practical  value.  An  excessive  number  indicates  an 
excessive  amount  of  organic  pabulum,  which  may  have  come  from 
a  dangerous  source;  and  the  dangerous  pathogenic  bacteria  are  not 
only  more  likely  to  be  present  in  such  water,  but  they  can  more 
readily  multiply  in  it,  while  in  a  pure  water  they  would  fail  to  in- 
crease in  number,  and,  as  has  been  shown  by  experiment,  would  die 
out  within  a  short  time. 

The  number  of  bacteria  present  in  rain  water,  or  in  snow  which 
has  recently  fallen,  varies  greatly  at  different  times.  Naturally  the 
number  is  greater  when  the  surface  of  the  earth  is  dry  and  the  at- 
mosphere loaded  with  dust  by  currents  of  wind  passing  over  it,  and 
less  when  the  surface  is  moist  and  the  atmosphere  has  been  purified 
by  recent  rains. 

In  snow  from  the  surface  of  a  glacier  in  Norway,  Schmelck  found 
two  bacteria  and  two  spores  of  mould  fungi  per  cubic  centimetre  of 
water  from  the  melted  snow.  Ganowski,  in  experiments  made  with 
freshly  fallen  snow  collected  in  the  vicinity  of  Kiew,  obtained  the  fol- 
lowing results  :  February  3d,  1888  :  temperature  of  the  air,  7.2°  C. ; 
snowfall,  0. 1  millimetre ;  number  of  bacteria  in  1  cubic  centimetre 
of  water  from  melted  snow,  34  in  one  sample  and  38  in  another. 
February  20th,  1888  :  temperature,  11.1°  C.  ;  snowfall,  1.1  milli- 
metres ;  number  of  bacteria  in  one  sample,  203,  in  another  384. 

Miquel  obtained  from  rain  water  collected  at  Montsouri  during  a 
rainy  season  4. 3  germs  per  cubic  centimetre  ;  in  rain  water  collected 
in  the  centre  of  the  city  of  Paris,  10  per  cubic  centimetre. 

Hail  has  also  been  shown  to  contain  bacteria  in  considerable  num- 
bers. Bujwid  found  in  hailstones  which  fell  at  Warsaw  21,000 
bacteria  in  1  cubic  centimetre  ;  but  this  is  exceptional,  and  is  supposed 
to  be  due  to  the  fact  that  surface  water  had  been  carried  into  the  air 
by  the  storm  and  frozen.  Fontin  examined  hail  which  fell  in  St. 
Petersburg,  and  obtained  an  average  of  729  bacteria  per  cubic  centi- 
metre of  water  from  the  melted  hail. 

River  water  has  been  carefully  examined  by  numerous  bacterio- 
logists in  various  localities  and  at  different  seasons  of  the  year.  We 
give  below  some  of  the  results  reported  : 

Water  of  the  Seine  at  Choisy,  before  reaching  Paris,  300  ;  at 
Bercy,  1,200  ;  at  Saint-Denis,  after  receiving  the  sewer  water  from 
the  city,  200,000  germs  per  cubic  centimetre  (Miquel). 

Water  of  the  Spree  beyond  Kopenick,  82,000  ;  two  hundred  steps 
below  the  mouth  of  the  Wuhle,  118,000  ;  in  Berlin  above  the  mouth 


560  BACTERIA  IX   WATER. 

of  the  Panke,  940,000;  below  the  mouth  of  the  Panke,  1,800,000 
(Koch). 

Water  of  the  Main  above  the  city  of  Wiirzburg,  in  the  month  of 
February,  520  ;  below  the  city,  15,500  (Rosenberg). 

Water  of  the  Potomac,  at  Washington,  in  1886  :  January,  3,774  ; 
February,  2,536  ;  March,  1,210 ;  April,  1,521  ;  May,  1,064 ;  June, 
348  ;  July,  255  ;  August,  254 ;  September,  178 ;  October,  75  ;  No- 
vember, 116  ;  December,  967  (Theobald  Smith). 

The  Thames,  in  the  autumn  of  1885,  in  the  vicinity  of  London 
Bridge  two  hours  after  high  water,  contained  45,000  germs  per  cubic 
centimetre ;  the  water  of  the  Lea  at  Lea  Bridge,  4,200,000  (Bisch- 
off). 

The  Neva  inside  the  city  of  St.  Petersburg,  in  September,  1883, 
contained  1,500  in  one  sample  and  1,040  in  another  ;  in  November 
(20th),  6,500  (Poehl). 

The  water  of  the  Oder,  collected  within  the  limits  of  the  city  of 
Stettin,  was  found  by  Link  to  contain  from  5,240  to  15,000  bacteria 
per  cubic  centimetre  ;  that  of  the  Limmat,  at  Zurich,  346  in  one 
specimen  and  508  in  another  (Cramer). 

Lake  ivater,  as  a  rule,  contains  fewer  bacteria  than  river  water. 

Wolffhugel,  in  researches  extending  from  July,  1884,  to  July, 
1885,  obtained  from  the  water  of  the  Tegeler  Lake  an  average  of  396 
bacteria  per  cubic  centimetre.  Cramer  obtained  an  average  of  168 
per  cubic  centimetre  during  the  months  of  October,  December,  and 
January,  1884,  from  the  water  of  Lake  Zurich  ;  in  June  of  the  same 
year  the  average  of  42  examinations  gave  71  per  cubic  centimetre. 
In  Lake  Geneva,  Fol  and  Dunant  obtained  from  water  collected  some 
distance  from  the  shore  an  average  of  38  bacteria  per  cubic  centi- 
metre. 

Ice  which  is  usually  collected  from  lakes  and  rivers  contains  a 
greater  or  less  number  of  bacteria,  according  to  the  depth  and  purity 
of  the  water.  The  ice  used  in  Berlin,  collected  from  the  surface  of 
lakes  and  rivers  in  the  vicinity  of  the  city,  contains  from  a  few  hun- 
dred to  25,000  bacteria  to  the  cubic  centimetre  (Friinkel).  In  the  ex- 
periments of  Heyroth  samples  of  ice  from  the  same  source  gave  less 
than  100  per  cubic  centimetre  in  three,  from  100  to  500  in  eight,  from 
500  to  1,000  in  six,  from  1,000  to  5,000  in  seven,  and  14,400  in  one. 

Prudden  obtained  from  Hudson  River  ice,  put  up  six  miles  below 
the  city  of  Albany,  an  average  of  398  bacteria  per  cubic  centimetre 
from  transparent  ice,  and  in  the  superficial  "snow  ice"  9,187.  Ice 
collected  lower  down  the  river  contained  an  average  of  189  in  the 
transparent  and  3,693  in  the  snow  ice. 

Ice  from  the  Dora  at  Turin  was  found  by  Bordoni-Uffreduzzi  to 
contain  from  120  to  3,546  bacteria  per  cubic  centimetre. 


BACTERIA   IN   WATER.  561 

Hydrant  water,  as  supplied  to  cities,  has  received  the  attention 
of  numerous  investigators.  The  water  supply  of  Berlin  was  ex- 
amined by  Plagge  and  Proskauer  at  intervals  of  a  week  from  June, 
1885,  to  April,  1886.  Their  tabulated  results  show  considerable 
variations.  We  give  the  figures  for  a  single  day,  June  30th,  1885  : 
Stralauer  works,  water  of  the  Spree,  unfiltered  4,400,  filtered  53  ; 
Tegeler  works,  water  of  the  lake,  unfiltered  880,  filtered  44  ;  high  re- 
servoir at  Charlottenberg,  71  ;  75  W.  Wilhelmstrasse,  121  ;  Fried- 
richstrasse,  41-42  S.  W.,  160  ;  Schmidstrasse,  165  E.,  51  ;  Friedrich- 
strasse,  126  N.,  151  ;  Weinmeisterstrasse,  15  C.,  63. 

Wells  which  are  supplied  by  water  from  deep  strata  contain  few 
bacteria,  unless  contaminated  by  surface  water  in  which  they  are 
usually  very  abundant.  Roth  examined  the  water  of  sixteen  surface 
wells  in  Belgard,  which  has  a  very  porous  subsoil,  and  found  from 
4,500  to  5,000  bacteria  in  three,  from  7,800  to  15,000  in  six,  from 
18,000  to  35,000  in  six,  and  130,000  per  cubic  centimetre  in  one. 

Forty-seven  wells  in  Stettin,  the  water  of  which  was  examined  by 
Link,  gave  the  following  results  :  Less  than  100  in  six,  100  to  500  in 
twenty-one,  and  in  the  remainder  (sixteen)  from  1,000  to  18,000. 

Sixty-four  wells  in  Mainz  examined  by  Egger,  and  53  in  Gotha 
by  Becker,  gave  more  favorable  results  ;  the  number  of  wells  in  the 
former  city,  in  which  less  than  100  colonies  developed  from  1  cubic 
centimetre,  was  34,  and  in  the  latter  the  same  (34).  Bolton  examined 
the  water  of  13  wells  in  Gottingen,  and  found  but  1  in  which  the 
number  of  colonies  from  1  cubic  centimetre  was  less  than  100  ;  in  12 
the  number  varied  from  180  to  4,940. 

The  water  of  deep  wells  and  springs  may  be  entirely  free  from 
bacteria,  or  nearly  so.  Egger  found  in  the  water  of  an  artesian  well 
at  Mainz  4  bacteria  per  cubic  centimetre,  and  the  same  number  was 
found  by  Hueppe  in  the  deep  well  at  the  Wiesbaden  slaughter-house. 
The  artesian  well  at  the  gasworks  of  Kiel  was  found  by  Brennig  to 
contain  from  6  to  30  bacteria  per  cubic  centimetre.  In  a  spring  at 
Batiolettes,  Fol  and  Dunant  found  57  bacteria  per  cubic  centimetre. 
Furbringer  obtained  from  springs  at  Jena  156  from  one,  51  from 
another,  32  from  another,  and  109  from  another.  The  water  supplied 
to  Danzig  from  the  Prangenaur  Spring  was  found  in  several  experi- 
ments to  be  free  from  bacteria  (Freimuth). 

In  a  summary  of  results  obtained  in  various  German  cities  Tie  • 
mann  and  Gartner  find  that  sixty-nine  per  cent  of  the  wells  from 
which  samples  of  water  were  examined  contained  less  than  500  bac- 
teria per  cubic  centimetre. 

The  water  of  sewers  is  naturally  rich  in  bacteria.  Miquel  found 
that  at  Clichy  the  sewer  water  contained  6,000,000  bacteria  per  cubic 
centimetre.  Bischoff  found  in  water  from  London  sewers  7,500.000, 


562  BACTERIA   IN   WATER. 

and  numerous  observations  show  that  the  number  of  bacteria  in  river 
water  is  greatly  increased  in  the  vicinity  of  and  below  the  mouths 
of  city  sewers. 

We  conclude  from  the  experimental  data  recorded  that  water 
containing  less  than  100  bacteria  to  the  cubic  centimetre  is  presum- 
ably from  a  deep  source  and  uncontaminated  by  surface  drainage, 
and  that  it  will  usually  be  safe  to  recommend  such  water  for  drink- 
ing purposes,  unless  it  contains  injurious  mineral  substances. 
Water  that  contains  more  than  500  bacteria  to  the  cubic  centimetre, 
although  it  may  in  many  cases  be  harmless,  is  to  be  looked  upon 
with  some  suspicion,  and  water  containing  1,000  or  more  bacteria  is 
presumably  contaminated  by  sewage  or  surface  drainage  and  should 
be  rejected  or  filtered  before  it  is  used  for  drinking  purposes.  But, 
as  heretofore  stated,  the  danger  does  not  depend  directly  upon  the 
number  of  bacteria  present,  but  upon  contamination  with  pathogenic 
species  which  are  liable  to  be  present  in  surface  water  and  sewage. 
In  swallowing  a  glassful  of  pure  spring  water  a  number  of  bacteria 
from  the  buccal  cavity  are  washed  away  and  carried  into  the  stomach, 
which,  if  enumerated,  would  doubtless  far  exceed  in  numbers  those 
found  in  the  most  impure  river  water. 

The  number  of  bacteria  does  not  depand  alone  upon  the  amount 
of  organic  pabulum  contained  in  a  water,  and  cannot  be  depended 
upon  in  forming  an  estimate  of  this ;  for,  as  has  been  shown  by 
Bolton,  certain  water  bacteria  multiply  abundantly  in  water  con- 
taining comparatively  little  organic  matter,  while  other  species  fail 
to  grow  unless  the  quantity  is  greater.  In  a  water  containing  con- 
siderable nutrient  material  the  water  bacteria  may  be  restrained  in 
their  development  by  other  species  present  until  the  amount  of  pabu- 
lum is  reduced  so  that  these  no  longer  thrive,  when  the  common 
water  bacteria  will  take  the  precedence,  and  an  enumeration  may 
show  a  greater  number  of  colonies  than  at  first.  But,  in  general, 
water  rich  in  organic  material  contains  a  greater  number  of  bacteria 
and  a  greater  variety  of  species  than  that  which  is  comparatively 
pure. 

That  certain  bacteria  may  multiply  in  water  which  has  been 
carefully  sterilized  has  been  shown  by  Bolton  and  others.  Two  com- 
mon water  bacteria — Micrococcus  aquatilis  and  Bacillus  erythrospo- 
rus — multiplied  abundantly  in  doubly  distilled  water,  and  when 
this  water  was  again  sterilized  and  re-inoculated  with  one  of  these 
species  the  same  abundant  increase  occurred.  This  was  repeated  six 
times  with  the  same  result  (Bolton).  Computing  the  number  of 
these  water  bacteria  in  ten  cubic  centimetres  of  distilled  water  at 
twenty  millions,  and  estimating  their  specific  gravity  at  one,  and  the 
diameter  of  the  individual  cells  at  one  /<,  the  total  weight  of  the  entire 


BACTERIA  IN  WATER.  563 

number,  according  to  Bolton,  would  be  less  than  one-hundredth 
of  a  milligramme,  and  at  least  three-fourths  of  this  must  consist  of 
water.  The  organic  material  represented  by  this  number  of  bacteria 
would  therefore  be  so  minute  that  it  might  be  supplied  by  dust  par- 
ticles accidentally  falling  into  the  distilled  water. 

Rosenberg  has  shown  that  while  many  of  the  species  which  he 
obtained  in  pure  cultures  from  the  water  of  the  river  Main  multiplied 
in  sterilized  distilled  water,  other  species  quickly  died  out  in  such 
water.  The  growth  of  certain  bacteria  depends  not  only  upon  the 
quantity  of  nutritive  material  present,  but  upon  its  quality,  the  con- 
ditions in  this  regard  being  widely  different  for  different  species. 

In  view  of  the  facts  heretofore  stated  bacteriologists  are  now  giv- 
ing more  attention  to  a  careful  study  of  the  kinds  of  bacteria  pre- 
sent in  their  examinations  of  water.  Rosenberg,  in  his  examinations 
of  the  water  of  the  Main  in  the  vicinity  of  Wiirzburg  (1886),  found 
that  before  the  river  reached  the  city  the  water  contained  more 
micrococci  than  bacilli,  but  that  after  receiving  the  sewage  of  the 
city  the  number  of  bacilli  was  greatly  in  excess. 

Adametz  (1888)  has  described  eighty-seven  species  obtained  by 
him  from  water  in  the  vicinity  of  Vienna  ;  Maschek  found  fifty-five 
different  species  in  the  drinking  water  used  at  Leitmeritz;  and  Tils 
(1890)  has  described  fifty-nine  species  obtained  by  him  from  the  city 
water  supply  at  Freiburg. 

Among  the  pathogenic  bacteria  which  are  liable  to  find  their 
way  into  water  used  for  drinking  purposes,  the  most  important,  from 
a  sanitary  point  of  view,  are  the  bacillus  of  typhoid  fever  and  the 
spirillum  of  Asiatic  cholera.  Both  of  these  microorganisms  are  pre- 
sent in  great  numbers  in  the  excreta  of  persons  suffering  from  the 
specific  forms  of  disease  to  which  they  give  rise,  and  are  consequently 
liable  to  contaminate  wells  and  streams  which  receive  surface  water, 
when  such  excreta  are  thrown  upon  the  surface  or  into  sewers,  etc. 
Epidemics  of  these  diseases  have  frequently  been  traced  to  the  use 
of  such  contaminated  water,  and  in  a  few  instances  the  presence  of 
these  specific  disease  germs  in  water  has  been  demonstrated  by  bac- 
teriological methods.  Laboratory  experiments  indicate,  however, 
that  an  increase  of  these  pathogenic  bacteria  in  drinking  water  is  not 
likely  to  occur,  except  under  special  conditions,  and  that  they  die 
out  after  a  time,  being  at  a  disadvantage  in  the  struggle  for  exist- 
ence constantly  going  on  among  the  numerous  species  which  have 
their  normal  habitat  in  water. 

Bolton,  Frankland,  and  others  have  shown  that  the  anthrax  ba- 
cillus, not  containing  spores,  dies  out  in  hydrant  water  within  five  or 
six  days.  In  the  experiments  of  Kraus  the  anthrax  bacillus  added 
to  well  water,  not  sterilized,  at  a  temperature  of  10.5°  C.,  was  still 


50-4  BACTERIA   IN   WATER. 

present  in  a  living  condition  on  the  second  day,  but  no  colonies  de- 
veloped after  the  third  day ;  the  typhoid  bacillus  died  out  between 
the  fifth  and  seventh  days  ;  the  cholera  spirillum  was  no  longer  found 
on  the  second  day.  In  the  meantime  the  common  water  bacteria 
had  increased  in  numbers  enormously.  Similar  results  have  been 
reported  by  Hochstetter  and  others.  Hueppe,  in  ten  experiments  in 
which  the  typhoid  bacillus  was  added  to  well  water  of  a  bad  quality, 
found  that  in  two  no  development  of  this  bacillus  occurred  after  the 
fifth  day,  while  a  few  colonies  developed  in  the  other  experiments  as 
late  as  the  tenth  day.  In  these  experiments  the  temperature  was 
comparatively  low  (10.5°  C.).  At  a  higher  temperature  the  experi- 
ments of  Wolffhugel  and  Riedel  show  that  an  increase  may  take 
place.  At  the  room  temperature  (about  20°  C. )  the  typhoid  bacillus 
added  to  distilled  water,  to  well  water,  and  to  Berlin  hydrant  water 
was  still  present,  in  some  instances,  at  the  end  of  thirty-two  days. 
And  it  was  found  that  in  some  cases  a  decrease  in  the  number 
occurred,  then  a  notable  increase,  and  finally  a  second  diminution. 

Koch  found  the  cholera  spirillum  in  a  water  tank  at  Calcutta 
during  a  period  of  fourteen  days,  and  in  his  experiments  showed  that 
it  preserved  its  vitality  in  well  water  for  thirty  days,  in  Berlin  sewer 
water  for  six  to  seven  days,  and  in  the  same  mixed  with  faeces  for 
twenty-seven  hours  only.  In  the  experiments  of  Nicati  and  Rietsch 
the  cholera  spirillum  preserved  its  vitality  in  distilled  water  for 
twenty  days,  in  sewer  water  (of  Marseilles)  thirty-eight  days,  in 
water  of  the  harbor  for  eighty-one  days.  The  numerous  experiments 
recorded  by  the  observers  named,  and  by  Bolton,  Hueppe,  Hoch- 
stetter, Maschek,  Kraus,  and  others,  show  that  while  the  cholera 
spirillum  may  sometimes  quickly  die  out  in  distilled  water,  in  other 
experiments  it  preserves  its  vitality  for  several  weeks  (Maschek),  and 
that  it  lives  still  longer  in  water  of  bad  quality,  such  as  is  found  in 
sewers,  harbors,  etc.  Bolton  found  that  for  its  multiplication  a 
water  should  contain  at  least  40  parts  in.  100,000  of  organic  material, 
while  the  typhoid  bacillus  grew  when  the  proportion  was  considerably 
less  than  this— 6.7  parts  in  100,000. 

Russell  has  recently  (1891)  studied  the  bacterial  flora  of  the 
Gulf  of  Naples,  and  of  the  mud  at  the  bottom  of  this  gulf,  col- 
lected at  various  depths  up  to  eleven  hundred  metres.  His  inves- 
tigations show  that  sea  water  does  not  contain  as  many  bacteria  as 
an  equal  volume  of  fresh  water ;  that  bacteria  are  found  in  about 
equal  numbers  in  water  from  the  surface  and  in  that  from  various 
depths  ;  that  the  mud  at  the  bottom  constantly  contains  large  num- 
bers of  bacteria ;  that  some  of  the  species  isolated  grow  best  in  a 
culture  medium  containing  sea  water. 

At  a  depth  of  50  metres  the  water  contained  121  bacteria  per  cubic 


BACTERIA    IN   WATER.  565 

centimetre,  and  the  mud  from  the  bottom  245,000  ;  at  100  metres  the 
water  contained  10  and  the  mud  200,000  per  cubic  centimetre ;  at 
500  metres  the  water  contained  22  and  the  mud  12,500  per  cubic 
centimetre  ;  at  1,100  metres  the  mud  contained  24,000. 

The  following  new  species  were  obtained  by  Russell  from  the 
source  mentioned :  Bacillus  thalassophilus,  Cladothrix  intricata, 
Bacillus  granulosus,  Bacillus  limosus,  Spirillum  marinum,  Bacillus 
litoralis,  Bacillus  halophilus. 

The  bacterial  flora  of  fresh  and  sea  water  is  very  extensive,  as 
will  be  seen  by  the  following  list  of  species  which  have  been  described 
by  various  bacteriologists  who  have  given  their  attention  to  its 
study  : 

NON-PATHOGENIC   MICROCOCCI. 

Micrococcus  aurantiacus  (Colin),  Micrococcus  luteus  (Cohn),  Micrococcus 
violaceus  (Cohn),  Micrococcus  flavus  liquefaciens  (Fliigge),  Micrococcus  fla- 
vus  desideiis  (Fliigge),  Micrococcus  radiatus  (Fliigge),  Micrococcus  cinnaba- 
reus  (Fliigge),  Micrococcus  flavus  tardigradus  (Fliigge),  Micrococcus  versi- 
color  (Fliigge),  Micrococcus  agilis  (Ali-Cohen) ,  Micrococcus fuscus  (Maschek), 
Diplococcus  luteus  (Adametz),  Pediococcus  albus  (Lindner),  Micrococcus 
cerasinus  siccus  (List),  Micrococcus  citreus  (List),  Micrococcus  aquatilis 
(Bolton),  Micrococcus  fervidosus  (Adametz),  Micrococcus  plumosus  (Brauti- 
gam),  Micrococcus  viticulosus  (Katz),  Micrococcus  cremoides  (Zimmermann), 
Micrococcus  carneus  (Zimmermann),  Mici'ococcus  concentricus  (Zimmer- 
mann), Micrococcus  rosettaceus  (Zimmermann),  Micrococcus  ureae  (Pasteur), 
Weisser  Streptococcus  (Maschek),  Wurmformiger  Streptococcus  (Maschek), 
Micrococcus  aerogenes  (Miller),  Sarcina  alba,  Sarcina  Candida  (Reinke), 
Sarcina  lutea. 

PATHOGENIC   MICROCOCCI. 

Staphylococcus  pyogenes  aureus  (Rosenbach),  Micrococcus  of  Heydeii- 
reich — "  Micrococcus  Biskra." 

NON-PATHOGENIC   BACILLI. 

Bacillus  arborescens  (Frankland),  Bacillus  viscosus  (Frankland),  Bacil- 
lus aquatilis  (Frankland),  Bacillus  liquidus  (Frankland),  Bacillus  nubilis 
(Frankland),  Bacillus  vermicularis  (Frankland),  Bacillus  aurantiacus 
(Frankland),  Bacillus  cceruleus  (Smith),  Bacillus  glaucus  (Maschek),  Bacil- 
lus albus  putidus  (Maschek),  Bacillus  fluorescens  liquefaciens,  Bacillus  flup- 
rescens  nivalis  (Schmolck),  Bacillus  lividus  (Plagge  and  Prpskauer),  Bacil- 
lus rubidus  (Eisenberg),  Bacillus  sulfureum  (Holschewnikoff),  Bacillus 
violaceus,  Bacillus  gasoformans  (Eisenberg),  Bacillus  liquefaciens  (Eisen- 
berg), Bacillus  phosphorescens  indicus  (Fischer),  Bacillus  phosphorescens 
indigenus  (Fischer),  Bacillus  phosphorescens  gelidus  (Katz),  Bacillus  sma- 
ragdino-phosphoresceiis  (Katz),  Bacillus  argenteo-phosphorescens  Nos.  I., 
II.,  and  III.  (Katz),  Bacillus  cyaneo-phosphorescens  (Katz),  Bacillus  ar- 
genteo-phosphorescens liquefaciens  (Katz),  Bacillus  ramosus,  Bacillus  sub- 
tilis  (Ehrenberg),  Proteus  sulfureus  (Linden born),  Bacillus  aureus  (Ada- 
metz), Bacillus  brunneus  (Adametz),  Bacillus  flavocoriaceus  (Adametz), 
Bacillus  fluorescens  noii-liquefaciens,  Bacillus  latericeus  (Adametz),  Bacillus 
stolonatus  (Adametz),  Bacillus  berolinensis  indicus  (Classen),  Bacillus  ery- 
throsporus  (Eidam),  Bacillus  luteus  (List),  Bacillus  aquatilis  sulcatus  Nos. 
1,  2,  3,  4,  and  5  (Weichselbaum),  Bacillus  albus  (Eisenberg),  Bacillus  multi- 
ped iculosus(  Fliigge),  Bacillus  Ziirnianum  (List),  Bacillus  fulvus  (Zimmer- 
mann), Bacillus  helvolus  (Zimmermann),  Bacillus  ochraceus  (Zimmer- 

48 


566  BACTERIA   IN  WATER. 

mann),  Bacillus plicatus,  Bacillus  devorans  (Zimmermann),  Bacillus gracilis 
(Zimmermann),  Bacillus  guttatus  (Zimmermann),  Bacillus  implexus  (Zim- 
mermann), Bacillus  punctatus  (Zimmermann),  Bacillus  radiatus  aquatilis 
(Zimmermann),  Bacillus  vermiculosus  (Zimmermann),  Bacillus  constrictus 
(Zimmermann),  Bacillus  fluorescens  aureus  (Zimmermann),  Bacillus  fluo- 
rescens  longus  (Zimmermann),  Bacillus  fluorescens  tenuis  (Zimmermann), 
Bacillus  fuscus  (Zimmermann),  Bacillus  rubefaciens  (Zimmermann),  Bacil- 
lus subflavus  (Zimmermann),  Bacillus  janthinus  (Zopf),  Bacillus  mycoides 
(Fliigge),  Bacillus  tremelloides  (Tils),  Bacillus  cuticularis  (Tils),  Bacillus 
filiformis  (Tils),  Bacillus  ubiquitus  (Jordan),  Bacillus  circulans  (Jordan), 
Bacillus  superficialis  (Jordan),  Bacillus  reticularis  (Jordan),  Bacillus  ru- 
bescens  (Jordan),  Bacillus  hyalinus  (Jordan),  Bacillus  cloacae  (Jordan), 
Bacillus  delicatulus  (Jordan),  Bacillus  violaceus  laurentius  (Jordan). 

PATHOGENIC  BACILLI. 


bilis  (Hauser),  Bacillus  canalis  capsulatus  (Mori),  Bacillus  canalis  parvus 
(Mori),  Spirillum  cholerae  Asiaticse  ("  Comma  bacillus,"  Koch),  Bacillus  coli 
commums  (Escherich),  Bacillus  hydrophilus  _  fuscus  (Sanarelli),  Bacillus 
venenosus  (Vaughan),  Bacillus  yenenosus  bre vis  (Vaughan),  Bacillus  vene- 
nosus  invisibilis  (Vaughan),  Bacillus  venenosus  liquefaciens  (Vaughan). 


3USU11 


III. 

BACTERIA    IN  THE  SOIL. 

SURFACE  soil,  and  especially  that  which  is  rich  in  organic  matter, 
contains  very  numerous  bacteria  of  many  different  species.  Some  of 
these  are  of  special  interest  on  account  of  their  pathogenic  power. 
Thus  the  bacillus  of  malignant  oedema  and  the  bacillus  of  tetanus 
have  been  shown  to  be  widely  distributed  species,  which  have  been 
obtained  by  investigators  in  various  parts  of  the  world  by  inoculating 
susceptible  animals — guinea-pigs  or  mice — with  a  little  rich  surface 
soil.  Other  species  are  interesting  because  of  their  action  in.  nitrifi- 
cation and  in  the  destructive  decomposition  of  organic  material  by 
which  it  is  fitted  for  assimilation  by  the  higher  plants.  Many  of  the 
bacteria  present  in  the  soil  are  strictly  anaerobic,  and  in  attempts  to 
estimate  the  number  and  kind  of  microorganisms  present  in  a  given 
sample  this  fact  must  be  kept  in  view. 

The  simplest  method  of  studying  the  bacteria  in  the  soil  consists 
in  introducing  a  small  quantity  into  liquefied  gelatin  in  test  tubes, 
and,  after  carefully  crushing  it  with  a  sterilized  glass  rod  and  thor- 
oughly mixing  it  with  the  gelatin,  making  roll  tubes  in  the  usual 
way.  Some  of  these  should  be  put  up  for  anaerobic  cultures — i.e., 
the  tube  should  be  filled  with  an  atmosphere  of  hydrogen  according 
to  Frankel's  method.  If  the  object  in  view  is  to  estimate  the  num- 
ber of  bacteria  in  a  given  sample  of  soil  the  difficulty  is  encountered 
that,  however  finely  crushed,  the  little  masses  of  earth  are  likely  to 
contain  numerous  bacteria,  and  we  cannot  safely  assume  that  each 
colony  originates  from  a  single  germ.  Thoroughly  washing  a  small 
quantity  of  soil,  by  agitation,  in  a  considerable  quantity  of  distilled 
water,  and  then  adding  a  definite  quantity  of  the  water  to  nutrient 
gelatin  and  making  roll  tubes  or  plates,  as  in  water  analysis,  sug- 
gests itself  as  a  simple  method  ;  but  Frankel  has  shown  that  it  is  far 
from  being  reliable  when  the  object  is  to  estimate  the  number  of 
bacteria.  He  obtained  more  uniform  and  accurate  results  by  intro- 
ducing the  earth  at  once  into  liquefied  gelatin  and  crushing  it  as 
thoroughly  as  possible  with  a  strong  platinum  wire,  after  which  as 
thorough  a  mixture  as  possible  was  effected  by  tilting  the  tube  up 


568  BACTERIA   IN   THE   SOIL. 

and  down.  But  for  the  purpose  of  obtaining  pure  cultures  from  sin- 
gle colonies  of  the  various  species  present,  we  should  prefer  to  wash 
the  earth  in  distilled  water  and  to  allow  the  sediment  to  settle  before 
taking  a  portion  of  the  water  to  add  to  the  nutrient  medium. 

In  some  experiments  made  in  1881  Koch  ascertained  that  in  soil 
which  had  not  been  disturbed  but  few  bacteria  were  to  be  found  at 
the  depth  of  a  metre;  and  this  fact  has  since  been  established  by  the 
extended  researches  of  Frankel,  who  devised  a  special  boring  instru- 
ment for  obtaining  samples  of  earth  from  different  depths.  Miquel, 
in  1879,  estimated  the  number  of  bacteria  in  one  gramme  of  earth 
collected  in  the  park  of  Montsouri,  Paris,  at  a  depth  of  twenty  centi- 
metres, at  700,000;  and  in  a  cultivated  field  which  had  been  treated 
with  manure,  at  900,000.  The  following  results  were  obtained  by 
Adametz  :  One  gramme  of  earth  from  a  sandy  soil  contained  at  the 
surface  380,000,  at  a  depth  of  twenty  to  twenty-five  centimetres 
400,000 ;  the  same  quantity  of  clayey  soil  contained  at  the  surface 
500,000,  at  a  depth  of  twenty  to  twenty-five  centimetres  460,000. 

In  experiments  made  by  Beumer  (1886)  and  by  Maggiora  (1887) 
considerably  greater  numbers  were  found,  but  the  last-named  ob- 
server, in  some  instances  at  least,  kept  the  earth  for  some  time  after 
collecting  it,  which  may  have  materially  influenced  the  result. 
Beumer  obtained  from  a  specimen  of  sandy  humus  taken  from  a 
depth  of  three  metres  45,000,000  to  the  gramme ;  at  four  metres, 
10,000,000;  at  five  metres,  8,000,000;  at  six  metres,  5,000,000. 
These  specimens  were  obtained  from  the  vicinity  of  hospitals  at 
Greifswald.  In  a  churchyard,  at  a  depth  of  four  metres,  the  num- 
ber in  one  experiment  was  1,152,000,  and  in  another  1,278,000. 

Frankel  has  given  special  attention  to  the  examination  of  undis- 
turbed soil  not  in  the  immediate  vicinity  of  dwellings.  In  samples 
from  a  fruit  orchard  near  Potsdam  he  found  that  the  superficial 
layers  contained  from  50,000  to  350,000  germs  per  cubic  centimetre. 
The  greatest  number  was  not  immediately  upon  the  surface,  but  at 
from  one-quarter  to  one-half  metre  below  the  surface.  The  num- 
ber was  found  to  be  greater  in  summer  than  in  winter,  the  maximum 
being  in  July  and  August.  At  a  depth  of  three-quarters  of  a  metre 
to  a  metre  and  a  half  there  was  a  very  great  and  abrupt  diminution  in 
the  number  of  germs.  From  200,000  atone-half  metre  the  number  fell 
to  2,000  at  a  depth  of  a  metre,  from  250,000  at  three-quarters  of  a 
metre  to  200  at  one  metre,  etc. ,  and  at  a  depth  of  one  and  one-half 
metres,  in  some  instances,  no  more  living  germs  were  obtained.  In 
other  experiments  a  few  colonies  developed  from  earth  obtained  at  a 
depth  of  three  or  four  metres,  but  these  were  slow  in  making  their 
appearance,  and  often  several  days,  or  even  Aveeks,  elapsed  before 
they  became  visible  in  Esmarch  roll  tubes.  In  experiments  with  sur- 


BACTERIA  IX  THE  SOIL.  569 

face  soil,  on  the  contran*,  a  multitude  of  colonies  developed  within 
twenty-four  to  forty-eight  hours,  and,  as  many  liquefying  bacteria 
were  present,  it  was  necessary  to  make  the  enumeration  on  the  first 
or  second  day,  at  which  time,  no  doubt,  many  of  the  bacteria  present 
had  not  yet  formed  visible  colonies.  The  results  obtained  have, 
therefore,  only  a  relative  value. 

The  most  important  fact  developed  by  Frankel's  researches  is  that 
in  virgin  soil  there  is  a  dividing  line  at  a  depth  of  from  three-quarters 
to  one  and  one-half  metres,  below  which  very  few  bacteria  are  found, 
and  that,  consequently,  the  "  ground- water  region  "  is  free  from  micro- 
organisms, or  nearly  so,  notwithstanding  the  immense  numbers  pre- 
sent in  the  superficial  layers. 

The  extended  researches  of  Maggiora,  made  in  the  vicinity  of 
Turin,  led  him  to  the  following  conclusions  : 

1.  The  number  of  germs  in  desert  and  forest  soil§  is  much  smaller,  other 
conditions  being  equal,  than  in  cultivated  lands,  and  in  these  it  is  less  than 
in  inhabited  localities. 

2.  In  desert  soils  the  number  of  germs  bears  a  relation  (a)  to  the  geologi- 
cal epoch  to  which  the  lands  belong,  and,  within  certain  limits,  to  the  heignt 
above  the  level  of  the  sea — the  older  the  soil  and  the  greater  the  altitude, 
other  things  being  equal,  the  fewer  the  germs  ;  (6)  to  the  compactness  and 
aeration  of  the  soil — the  more  compact  and  impermeable  to  air  the  smaller 
the  number  of  germs  capable  of  developing  in  gelatin  ;  (c)  to  the  nature  of 
the  soil — sandy  soils  contain  fewer  germs  than  soils  rich  in  clay  and  in 
humus. 

3.  In  cultivated  lands  the  number  of  germs  augments  with  the  activity 
of  cultivation  and  the  strength  of  the  fertilizers  used. 

4.  In  inhabited  localities  the  number  of  germs  in  the  superficial  layers  is 
very  great.     In  the  deep  layers  it  usually  diminishes  rapidly,  as  is  the  case 
in  all  other  soils. 

As  to  the  kinds  of  bacteria  present,  and  their  biological  characters 
and  functions  in  preparing  organic  material  for  assimilation  by  the 
plants  whose  roots  penetrate  the  soil,  we  have  yet  much  to  learn. 
Frankel  remarks  that  the  species  most  frequently  encountered  in  the 
deeper  strata  of  the  soil  were  three  bacilli  which  also  abound  in  the 
superficial  layers — viz.,  the  "  hay  bacillus,"  the  "wurzel  bacillus," 
and  the  "hirnbacillus."  In  all  eleven  bacilli  were  isolated  and  cul- 
tivated. Micrococci  were  only  found  four  times,  and  spirilla  not  at 
all.  Mould  fungi  were  more  abundant,  and  especially  one  previously 
obtained  from  the  air  by  Hesse  and  called  by  him  "brauner  Schim- 
melpilz."  Anaerobic  bacilli,  contrary  to  expectation,  were  not  ob- 
tained in  FrankeFs  researches,  and  no  pathogenic  species  were  found 
in  the  deeper  layers  of  the  soil.  We  have  already  referred  to  the 
fact  that  the  bacillus  of  malignant  oedema  and  the  bacillus  of  tetanus, 
two  pathogenic,  anaerobic  species,  are  common  in  rich  surface  soil  in 
various  parts  of  the  world. 


570  BACTERIA   IN   THE   SOIL. 

The  results  obtained  in  the  researches  referred  to,  in  which  nutri- 
ent gelatin  was  used  as  a  culture  medium,  are  no  doubt  very  in- 
complete, not  only  on  account  of  the  liquefaction  of  the  gelatin  by 
common  liquefying  bacilli  before  other  species  present  have  formed 
visible  colonies,  but  also  because  this  is  not  a  favorable  culture  me- 
dium for  some  of  the  species  present  in  the  soil.  Thus  Prankland  has 
succeeded  in  isolating  a  nitrifying  ferment  which  he  calls  "  Bacillo- 
coccus,"  which  grows  abundantly  in  bouillon,  but  fails  to  grow  in 
nutrient  gelatin.  Winogradski  has  also  obtained  in  pure  cultures  a 
nitrifying  ferment  from  the  soil  in  the  vicinity  of  Zurich,  which  he 
has  called  "  Nitromonas." 

Comparatively  few  micrococci  are  found  in  the  soil,  while  in  the 
air  they  are  usually  found  to  be  more  abundant  than  bacilli.  This 
is  perhaps  due  to  the  fact  that  the  bacilli  are  more  promptly  destroyed 
by  desiccation  and  the  action  of  sunlight. 

Several  bacteriologists  have  made  investigations  relating  to  the 
duration  of  vitality  of  pathogenic  bacteria  in  the  soil.  Frankel  found 
that  in  Berlin  the  bacillus  of  anthrax,  in  Esmarch  roll  tubes,  when 
buried  m  the  soil  at  a  depth  of  two  metres,  only  occasionally  gave 
evidence  of  growth,  and  at  three  metres  no  development  occurred. 
The  comparatively  low  temperature  at  this  depth  was  no  doubt  an 
important  factor  in  influencing  the  result.  The  cholera  spirillum  in 
the  months  of  August,  September,  and  October  grew  at  a  depth  of 
three  metres,  but  in  the  remaining  months  of  the  year  failed  to  grow 
at  two,  while  growth  occurred  at  one  and  one-half  metres.  The 
bacillus  of  typhoid  fever  grew  at  three  metres  during  the  greater 
portion  of  the  year. 

Giaxa  has  made  extended  and  interesting  experiments  with  the 
cholera  spirillum,  cultures  of  which  he  added  to  different  kinds  of 
soil  (garden  earth,  clay,  sand)  and  placed  at  different  depths  below 
the  surface — one-quarter,  one-half,  and  one  metre.  Some  of  the  earth 
was  sterilized  and  some  was  not.  In  the  unsterilized  earth  he  found 
the  cholera  spirillum  in  considerable  numbers  at  the  end  of  twenty- 
four  hours  at  the  greatest  depth  tested  (one  metre),  but  at  the  end  of 
forty- eight  hours  it  had  disappeared  in  five  experiments  out  of  seven 
— the  lowest  temperature  at  this  depth  was  20°  C.  In  the  sterilized 
soil  the  result  was  different ;  the  cholera  spirillum  was  present  in 
enormous  numbers  at  the  end  of  four  days  at  a  depth  of  a  metre, 
and  was  still  found  in  smaller  numbers  at  the  end  of  twelve  days, but 
had  disappeared  at  the  end  of  twenty-one  days.  These  results  indicate 
that  the  presence  of  common  saprophytes  in  the  soil  is  prejudicial  to 
the  development  of  the  cholera  spirillum,  and  that  under  ordinary 
circumstances  it  succumbs  in  the  struggle  for  existence  with  these 
more  hardy  microorganisms. 


BACTERIA    IN    THE    SOIL.  571 

The  recently  published  researches  of  Proskauer  (1891)  confirm 
those  of  Frankel  and  others  as  to  the  rapid  diminution  in  the  number 
of  bacteria  in  the  deeper  layers  of  the  soil.  They  also  agree  with 
those  of  Gartner  in  showing  that  in  the  soil  of  churchyards  the 
number  of  bacteria  diminishes  greatly  in  the  soil  beneath  the  layer 
containing  coffins.  In  general  the  influence  of  dead  bodies  upon  the 
bacteria  in  the  soil  in  the  vicinity  of  coffins  was  very  slight ;  in  the 
subsoil  of  the  graveyard  there  were  not  many  more  bacteria  than  in 
similar  soil  outside  of  this.  Reimers  had  previously  shown  that 
samples  of  earth  from  two  graves,  in  one  of  which  the  body  had  been 
buried  for  thirty-five  years  and  in  the  other  for  one  and  one- 
half  years,  gave  similar  results  when  examined  by  bacteriological 
methods. 

Manfredi  has  recently  (1892)  published  the  results  of  his  extended 
investigations  relating  to  the  dust  in  the  streets  of  Naples.  The 
number  of  bacteria  varied  greatly  in  different  parts  of  the  city.  In 
streets  where  the  traffic  was  least  and  hygienic  conditions  the  best 
the  average  number  was  10,000,000  per  gramme.  In  dirty  and  busy 
thoroughfares  the  average  was  1,000,000,000,  and  in  certain  localities 
the  number  was  even  five  times  as  great  as  this.  Injections  into 
guinea-pigs  gave  a  positive  result  in  seventy-three  per  cent  of  the 
animals  experimented  upon.  Among  the  known  pathogenic  bacteria 
obtained  in  this  way  were  the  pus  cocci  (in  eight),  the  Bacillus  tuber- 
culosis (in  three),  the  bacillus  of  malignant  oedema,  and  the  tetanus 
bacillus. 

In  the  recently  published  memoir  of  Fiilles  (1891)  the  following 
species  are  described  as  having  been  found  by  him  in  the  soil  at 
Freiburg,  Germany: 

MICROCOCCI. 

(a)  Non-liquefying. — Micrococcus  aurantiacus  (Colin),  Micrococcus  can- 
didus  (Cohn),  Micrococcus  luteus  (Cohn),  Micrococcus  candicans  (Flugge), 
Micrococcus  versi color  (Flugge),  Micrococcus  cirftiabareus  (Fliigge),  Micro- 
coccus  cereus  albus  (Passet),  Micrococcus  fervitosus  (Adametz),  Rother  coc- 
cus (Maschek). 


(6)  Liquefying. — Micrococcus  flavus  liquefaciens  (Flugge),  Micrococcus 
vus  desidens  (Flugge),  Diplococc 


flavus  desidens  (Flugge),  Diplococcus  luteus  (Adametz),  Sarcina  lutea. 


NON-PATHOGENIC   BACILLI. 

(a)  Non-liquefying.— Bacillus  fluorescens  putidus  (Flugge),  Bacillus  mus- 
coides  (Liborius),  Bacillus  scissus  (Frankland),  Bacillus  candicans,  Bacillus 
diffusus  (Frankland),  Bacillus  filiformis  (Tils),  Bacillus  luteus  (Fliigge), 
Fluorescent  water  bacillus  (Eisenberg),  Bacillus  viridis  pallescens  (Frick), 
Bluish-green  fluorescent  bacillus  (Adametz),  Bacillus  stolonatus  (Adametz), 
Bacillus  Ziirnianum  (List),  Bacillus  aerogenes  (Miller),  Bacillus  No.  1  and 
Bacillus  No.  2  (Fiilles). 

(6)  Liquefying. — Bacillus  ramosus  liquefaciens  (Fliigge),  Bacillus  liqui- 
dus  (Frankland),  Bacillus  ramosus — "wurzel  bacillus,"  Bacillus  subtilis 


572  BACTERIA   IN  THE   SOIL. 

(Ehrenberg),  Bacillus  mesentericus  fuscus  (Fliigge),  Bacillus  mesentericus 
vulgatus  (Fliigge),  Bacillus  fluorescens  liquefaciens  (Fliigge),  Lemon-yellow 
bacillus  (Maschek),  Green  yellow  bacillus  (Eisenberg),  Gas-forming  bacillus 
(Eisenberg),  Gray  bacillus  (Maschek),  Bacillus  prodigiosus  (Ehrenberg), 
Proteus  mirabilis  (Hauser),  Proteus  vulgaris  (Hauser),  Bacillus  mesentericus 
vulgatus,  Bacillus  cuticularis  (Tils),  "  Weisser  bacillus"  (Eisenberg). 

(c)  Pathogenic. — Bacillus  cedematis  maligni  (Koch). 

In  addition  to  the  above  the  following  species  have  been  described  by 
other  authors:  Bacillus  liquefaciens  magnus  (Liideritz),  Bacillus  radiatus 
(Liideritz),  Bacillus  solidus  (Liideritz),  Bacillus  mycoides  roseus  (Scholl), 
Bacillus  viscpsus  (Frankland),  Bacillus  candicans  (Frankland),  Bacillus 
poliformis  (Liborius),  Clostridiutn  fcetidum  (Liborius). 

Pathogenic  species. — Staphylococcus  pyogenes  aureus  (Eosenbach),  Ba- 
cillus tetani(Nicolaier),  Streptococcus  septicus  (Nicolaier),  Pseudo-oedema  ba- 
cillus (Liborius),  Bacillus  septicus  agrigenus  (Nicolaier),  Bacillus  of  Utpadel. 


IV. 

BACTERIA  OF  THE   SURFACE  OF  THE  BODY  AND  OF 
EXPOSED  MUCOUS  MEMBRANES. 

GREAT  numbers  of  bacteria  of  various  species  multiply  upon  the 
surface  of  the  human  body,  where  they  find  the  necessary  pabulum 
in  the  excretions  from  the  skin  and  the  exfoliated  epithelium.  Evi- 
dently the  number  will  be  largely  influenced  by  the  clothing  worn, 
the  atmospheric  conditions  as  to  heat  and  moisture,  personal  habits, 
etc.  The  writer  has  frequently  inoculated  culture  media  with  a  drop 
of  sterilized  fluid  which  had  been  placed  upon  the  surface  of  the  body 
of  patients  in  hospitals  and  of  healthy  persons.  By  friction  with  a 
platinum  needle  at  the  point  where  the  drop  of  fluid  is  applied  the 
surface  is  washed  and  a  little  epithelium  detached.  Cultures  may 
always  be  obtained  by  inoculating  nutrient  media  from  a  drop  of  fluid 
applied  in  this  way.  Micrococci  of  various  species,  including  the  pus 
cocci,  are  very  commonly  encountered  ;  sarcinaB  and  various  bacilli 
are  also  frequently  met  with.  Even  the  hands,  which  by  reason  of 
their  exposure  and  frequent  ablutions  are  freer  from  exfoliated  epi- 
thelium than  portions  of  the  body  covered  with  clothing,  have  con- 
stantly attached  to  their  surface  a  considerable  number  of  bacteria. 
This  is  shown  by  the  experiments  of  Kummel  and  Forster,  of  Fiir- 
bringer  and  others,  with  reference  to  the  disinfection  of  the  hands. 
Forster  found  that  after  the  most  careful  cleaning  of  the  hands  with 
soap,  water,  and  a  brush,  contact  of  the  fingers  with  nutrient  gelatin 
always  resulted  in  the  development  of  a  greater  or  less  number  of 
colonies. 

Bordoni-Uffreduzzi,  in  his  researches  relating  to  the  bacteria  of 
the  skin,  obtained  in  pure  cultures  five  different  species  of  micrococci 
and  two  bacilli.  Pure  cultures  of  his  Bacterium  graveolens,  which 
was  usually  found  between  the  toes,  gave  off  a  disagreeable  odor  like 
that  observed  from  this  locality  in  certain  individuals.  In  his  re- 
searches made  in  Havana  the  writer  frequently  encountered  in  cul- 
tures from  the  surface,  associated  with  various  micrococci,  his  Micro- 
coccus  tetragenus  versatilis. 

Fiirbringer  found  quite  frequently  in  the  spaces  beneath  the  fin- 


574  BACTERIA  OF  THE  SURFACE  OF  THE  BODY 

ger  nails  Staphylococcus  pyogenes  aureus  associated  with  various 
other  microorganisms.  A  similar  result  had  previously  been  reported 
by  Bockhart. 

In  his  examinations  of  water  from  various  sources  Miquel  found 
that  "wash- water"  from  the  floating  laundries  on  the  Seine  con- 
tained more  bacteria  than  water  from  any  other  source,  even  than 
the  water  of  the  Paris  sewers.  His  enumeration  gave  twenty-six 
million  germs  per  cubic  centimetre. 

Hohein  has  enumerated  the  colonies  developing  from  undercloth- 
ing worn  for  various  lengths  of  time  and  made  of  different  kinds  of 
material.  A  piece  of  the  goods  to  be  tested  was  sewed  fast  to  the 
underclothing,  so  as  to  come  in  immediate  contact  with  the  body  ;  at 
the  end  of  a  given  time  a  fragment  one-quarter  of  a  centimetre  square 
was  cut  up  as  fine  as  possible  and  distributed  in  nutrient  gelatin. 
Plates  were  made  and  the  colonies  counted  at  the  end  of  five  or  six 
days. 

In  an  experiment  in  which  sterilized  woven  goods  were  worn  next 
to  the  skin  of  the  upper  arm  the  following  results  were  obtained  : 
Linen  goods,  at  the  end  of  one  day  28,  two  days  4,180  colonies  ;  cot- 
ton goods,  end  of  one  day  105,  end  of  two  days  1,870  ;  woollen  goods, 
end  of  one  day  606,  end  of  two  days  6,799.  When  the  material  had 
been  in  contact  with  the  skin  for  four  days  the  colonies  which  devel- 
oped were  so  numerous  that  they  could  not  be  counted. 

Maggiora  isolated  twenty-two  species  of  bacteria  from  his  cultures 
inoculated  with  epidermis  from  the  foot.  None  of  these  proved  to 
be  pathogenic  for  mice,  rabbits,  or  guinea-pigs.  Several  gave  off  a 
strong  odor  of  trimethylamin,  similar  to  that  of  sweating  feet. 

The  following  species  have  been  found  upon  the  surface  of  the 
body : 

Non-pathogenic. — Diplococcus  albicans  tardus  (Unna  and  Tommasoli), 
Diplococcus  citreus  liquefaciens  (Unna  and  Tommasoli),  Diplococcus  flavus 
liquefaciens  tardus  (Unna  and  Tommasoli).  Staphylococcus  viridis  flaves- 
cens  (Gruttmanti),  Bacillus  graveolens  (Bordoni-Uffreduzzi),  Bacillus  epider- 
midis  (Bprdoni),  Ascobacillus  citreus  (Unna  and  Tommasoli),  Bacillus  fluo- 
rescens  liquefaciens  minutissimus  (Unna  and  Tommasoli),  Bacillus  aureus 
(Unna  and  Tommasoli),  Bacillus  ovatus  minutissimus  (Unna  and  Tomma- 
soli), Bacillus  albicans  pateriformis  (Unna  and  Tommasoli),  Bacillus  spini- 
ferus  (Unna  and  Tommasoli),  Bacillus  of  Scheurlen,  Micrococcus  tetragenus 
versatilis  (Sternberg),  Bacillus  Havaniensis  liquefaciens  (Stern berg). 

Pathogenic. — Staphylococcus  pyogenes  albus,  Staphylococcus  pyogenes 
aureus,  Streptococcus  pyogenes,  Diplococcus  of  Demme,  Bacillus  of  Uemme, 
Bacillus  of  Schimmelbusch,  Bacillus  of  Tommasoli,  Bacillus  saprogenes  II. 
(Rosenbach),  Bacillus  parvus  ovatus  (Loffler). 

SURFACE   OF   MUCOUS   MEMBRANES. 

Cultures  made  from  the  conjunctives,  of  healthy  persons  usually 
show  the  presence  of  various  micrococci,  and  sometimes  of  bacilli. 


AXD  OF  EXPOSED  MUCOUS  MEMBRANES.  575 

In  diseased  conditions  these  are  more  numerous  than  in  health,  but 
the  pus  cocci  are  not  infrequently  found  in  healthy  eyes. 

As  bacteria  are  constantly  present  in  the  air,  they  are  necessarily 
deposited  upon  the  moist  mucous  membrane  of  the  nose  during  in- 
spiration. Indeed,  it  would  appear  as  if  an  important  function  of 
this  extended  mucous  membrane  is  to  purify  the  air  from  suspended 
particles,  and  it  has  been  shown  by  experiment  that  expired  air  is 
practically  free  from  bacteria.  The  greater  number  of  those  con- 
tained in  inspired  air  are  deposited  upon  the  mucous  membrane  of 
the  anterior  and  posterior  nares.  In  culture  experiments  made  by 
Von  Besser,  Wright,  and  others  the  nasal  mucus  was  found  to  con- 
tain a  great  variety  of  bacteria;  among  others  the  pus  cocci  were 
frequently  found  by  both  of  the  observers  mentioned.  In  eighty-one 
cases  Von  Besser  found  the  "diplococcus  pneumonise"  fourteen 
times,  Staphylococcus  pyogenes  aureus  fourteen  times,  Streptococ- 
cus pyogenes  seven  times,  and  Friedlander's  bacillus  twice.  Twenty- 
eight  of  the  cases  examined  were  convalescents  in  hospital ;  among 
these  the  pathogenic  species  mentioned  were  found  less  frequently 
than  in  other  individuals.  The  following  non-pathogenic  species 
were  isolated  :  Micrococcus  liquefaciens  albus  in  twenty-two  cases, 
Micrococcus  albus  in  nine  cases,  Micrococcus  cumulatus  tenuis  in 
fourteen  cases,  Micrococcus  flavus  liquefaciens  in  three  cases,  Bacil- 
lus striatus  albus  in  ten  cases,  etc. 

Paulsen  (1890)  made  thirty-one  cultures  in  nutrient  gelatin  from 
sixteen  persons  and  thirty-three  in  nutrient  agar  from  twenty-two 
persons,  with  the  following  result :  Eleven  remained  sterile,  nine- 
teen showed  not  more  than  ten  colonies,  sixteen  less  than  one  hun- 
dred, twelve  more  than  one  hundred,  and  in  six  the  number  was  so 
great  that  they  could  not  be  counted.  Micrococci  were  more  nu- 
merous than  bacilli ;  of  these  a  "  sulphur-yellow  coccus"  in  tetrads 
was  found  in  eight  individuals.  Various  species  of  liquefying  cocci, 
resembling  the  pus  cocci,  were  isolated,  but  the  conclusion  was 
reached  that  none  of  these  were  identical  with  the  staphyloccoci 
of  pus,  which  Von  Besser  and  Wright  both  found  in  a  considerable 
proportion  of  the  culture  experiments  made  by  them. 

Very  extended  researches  have  been  made  with  reference  to  the 
bacteria  present  in  the  human  mouth,  which  show  that  numerous 
species  are  constantly  present  in  the  buccal  secretions  and  upon  the 
surface  of  the  moist  mucous  membrane.  Some  of  these  are  occa- 
sional and  accidental,  while  others  appear  to  have  their  normal  habi- 
tat in  the  mouth,  where  the  conditions  as  to  temperature,  moisture, 
and  presence  of  organic  pabulum  are  extremely  favorable  for  their 
development.  A  minute  drop  of  saliva  spread  upon  a  glass  slide, 
dried,  and  stained  with  one  of  the  aniline  colors,  will  always  be 


576  BACTERIA  OF  THE  SURFACE  OF  THE  BODY 

found  to  contain  an  immense  number  of  bacteria  of  various  forms. 
Some  of  these  are  attached  to  epithelial  cells  and  some  scattered  about 
singly  or  in  groups.  Among  those  seen  in  a  single  specimen  we  will 
usually  find  cocci  in  tetrads,  in  chains,  and  in  irregular  groups, 
bacilli  of  various  dimensions,  and  occasionally  spirilla.  According 
to  Prof.  Miller,  of  Berlin,  the  following  species  "almost  inva- 
riably occur  in  every  mouth :  Leptothrix  innominata,  Bacillus 
buccalis  maximus,  Leptothrix  buccalis  maxima,  lodococcus  vagina- 
tus,  Spirillum  sputigenum,  SpirochaBte  dentium.  All  of  these  fail 
to  grow  in  ordinary  culture  media.  Miller  has  made  extended  at- 
tempts to  obtain  cultures  by  varying  the  medium  used  and  attempt- 
ing to  imitate  as  nearly  as  possible  the  natural  medium  in  which  they 
are  found  ;  but  his  attempts  have  been  unsuccessful,  or  nearly  so — 
"  only  line  cultures  afforded  a  limited  growth,  but  the  colonies  never 
developed  more  than  fifteen  to  twenty  cells,  and  a  transference  to  a 
second  plate  proved  futile,  no  further  growth  taking  place/' 

Up  to  the  year  1885  Miller  had  isolated  twenty -two  different  spe- 
cies of  bacteria  from  the  human  mouth.  Ten  of  these  were  cocci, 
five  short  bacilli,  six  long  bacilli,  and  one  a  spirillum.  Later  the 
same  author  cultivated  eight  additional  species.  Vignal  has  iso- 
lated and  described  seventeen  species  obtained  by  him  in  pure  cul- 
tures from  the  healthy  human  mouth  ;  most  of  these  are  bacilli, 
and  Miller,  who  found  micrococci  to  be  more  numerous,  supposes 
the  difference  in  results  to  be  due  to  the  fact  that  many  of  the  cocci 
do  not  grow  in  nutrient  gelatin,  which  was  the  medium  employed 
by  Vignal.  In  the  researches  of  the  last-named  author  the  follow- 
ing species  were  obtained  most  frequently,  in  the  order  given  : 
1.  Bacterium  termo.  2.  Bacillus  e  (Bacillus  ulna  ?).  3.  Potato  ba- 
cillus. 4.  Coccus  a.  5.  Bacillus  b.  6.  Bacillus  d.  7.  Bacillus  c 
(Bacillus  alvei  ?).  8.  Bacillus  subtilis.  9.  Staphylococcus  pyogenes 
albus.  10.  Staphylococcus  pyogenes  aureus. 

Among  the  species  above  enumerated  we  find  two  of  the  most 
common  pus  cocci,  Staphylococcus  albus  and  aureus,  but  no  mention 
is  made  of  another  important  pathogenic  micrococcus  which  is  fre- 
quently found  in  the  healthy  human  mouth,  viz. ,  the  micrococcus  of 
sputum  septicaemia,  first  named  by  the  writer  Micrococcus  Pasteuri. 
This  does  not  grow  at  ordinary  temperatures,  and  consequently 
would  not  be  obtained  in  gelatin  plate  cultures.  Very  different  re- 
sults have  been  reported  by  different  observers  as  to  the  frequency 
with  which  these  pathogenic  cocci  are  found  in  the  buccal  cavity. 
Black  found  in  the  saliva  of  ten  healthy  individuals  the  Staphy- 
lococcus pyogenes  aureus  seven  times,  Staphylococcus  pyogenes  al- 
bus four  times,  and  Streptococcus  pypgenes  three  times.  On  the 
other  hand,  Netter  found  Staphj'lococcus  aureus  only  seven  times  in 


AND   OF   EXPOSED   MUCOUS   MEMBRANES.  577 

one  hundred  and  twenty-seven  individuals  examined.  Miller  also 
has  rarely  found  the  pus  cocci  in  the  mouths  of  healthy  persons. 
Streptococcus  pyogenes  was  not  found  by  Vignal  in  his  extended 
researches.  The  experiments  of  the  writer,  of  Vulpian,  Frankel, 
iSTetter,  Claxton,  and  others  show  that  the  micrococcus  which  in 
1885  I  named  Micrococcus  Pasteuri,  and  which  is  identical  with  the 
' '  diplococcus  pneumonise  "  of  German  authors,  is  frequently  present 
in  the  healthy  human  mouth— now  called  Micrococcus  pneumonise 
crouposse.  Netter  examined  the  saliva  of  one  hundred  and  sixty-five 
healthy  individuals  and  obtained  it  in  fifteen  per  cent  of  the  number 
examined. 

Another  pathogenic  micrococcus  which  is  frequently  present  in 
the  mouths  of  healthy  persons  is  the  Micrococcus  tetragenus  of  Koch. 
The  following  pathogenic  bacteria  have  also  been  isolated  and  de- 
scribed :  Bacillus  crassus  sputigenus  (Kreibohm),  Bacillus  salivarius 
septicus  (Biondi).  The  Streptococcus  septo-pyaemicus  of  Biondi  is 
described  as  having  characters  identical  with  those  of  the  Strepto- 
coccus pyogenes  of  Rosenbach.  Two  other  pathogenic  species  de- 
scribed by  Biondi  were  each  found  in  a  single  case  only.  Miller 
has  described  the  following  pathogenic  species  isolated  and  studied 
by  him  :  Micrococcus  gingivse  pyogenes,  Bacterium  gingivse  pyo- 
genes, Bacillus  dentalis  viridans,  Bacillus  pulpse  pyogenes. 

Vignal  has  tested  a  considerable  number  of  microorganisms,  ob- 
tained by  him  in  his  cultures  from  the  healthy  human  mouth,  with 
reference  to  their  peptonizing  action  upon  various  kinds  of  food,  with 
the  idea  that  some  of  them  may  have  an  important  physiological 
function  of  this  kind.  Out  of  nineteen  species  he  found  ten  which, 
after  a  longer  or  shorter  time,  dissolved  fibrin,  nine  which  dissolved 
gluten,  ten  which  dissolved  casein,  and  five  which  dissolved  albu- 
min ;  nine  changed  lactose  into  lactic  acid,  seven  inverted  cane  sugar, 
seven  caused  the  fermentation  of  glucose,  and  seven  coagulated 
milk. 

Recently  (1891)  Sanarelli  has  shown  that  normal  saliva  has  the 
power  of  destroying  the  vitality  of  a  limited  number  of  certain  patho- 
genic bacteria,  including  the  following  species  :  Staphylococcus  pyo- 
genes aureus,  Streptococcus  pyogenes,  Micrococcus  tetragenus, 
Bacillus  typhi  abdominalis,  Spirillum  choleras  Asiaticse.  When  to 
ten  cubic  centimetres  of  saliva,  sterilized  by  filtration  through  porce- 
lain, the  above-mentioned  pathogenic  bacteria  were  added  in  small 
numbers  by  means  of  a  platinum  needle  carried  over  from  a  pure 
culture,  no  development  oscurred,  and  at  the  end  of  twenty-four 
hours  the  bacteria  introduced  were  incapable  of  growth  in  a  suitable 
medium.  But  when  this  amount  of  filtered  saliva  was  inoculated 
with  a  large  platinum  loop — an  ose — a  certain  number  of  the  bacteria 


578  BACTTCRIA   OF   THE   SURFACE   OF   THE   BODY 

survived,  and  at  the  end  of  three  or  four  days  an  abundant  develop- 
opment  occurred.  At  first,  however,  the  number  of  living  cells  was 
considerably  diminished.  In  saliva  to  which  one  ose  of  a  culture  of 
Staphylococcus  aureus  was  added  thirteen  thousand  eight  hundred 
and  forty  colonies  developed  in  a  plate  made  immediately  after  inocu- 
lation, while  a  plate  made  at  the  end  of  twenty-four  hours  contained 
but  one  hundred  and  thirty-two  colonies,  and  one  at  the  end  of  forty- 
eight  hours  had  but  eight  colonies.  Subsequently  multiplication 
occurred,  and  a  plate  made  on  the  ninth  day  after  inoculation  con- 
tained so  many  colonies  that  they  could  not  be  counted. 

The  diphtheria  bacillus  was  not  destroyed  in  filtered  saliva,  but 
did  not  multiply  in  it.  On  the  other  hand,  it  proved  to  be  a  very 
favorable  medium  for  the  development  of  Micrococcus  pneumonise 
crouposse.  . 

Mucus  from  the  surface  of  the  meatus  urinarius  of  man  and 
woman,  or  from  the  vagina,  will  always  be  found  to  contain  various 
bacteria ;  but  the  bladder,  the  uterus,  and  Fallopian  tubes  in  healthy 
individuals  are  free  from  microorganisms.  Winter  has  isolated 
twenty-seven  different  species  from  vaginal  and  cervical  mucus,  and 
reports  that  he  found  Staphylococcus  pyogenes  albus  in  one-half  of 
the  cases  examined.  A  streptococcus  was  also  encountered  which 
resembled  Streptococcus  pyogenes,  although  not  positively  identified 
with  it.  Samschin,  on  the  other  hand,  failed  to  obtain  the  pus  cocci 
in  vaginal  mucus  from  healthy  women. 

Donderlein,  Von  Ott,  and  others  have  carefully  examined  the 
lochial  discharge  with  reference  to  the  presence  of  bacteria.  The 
first-named  author  found  that  in  healthy  women  the  lochial  discharge 
obtained  from  the  uterus  was  free  from  germs,  but  when  collected 
from  the*  vagina  various  microorganisms  were  obtained.  In  one  case 
in  which  some  fever  existed  Staphylococcus  pyogenes  aureus  was 
found  in  the  vagina,  while  the  discharge  from  the  uterus  was  free 
from  germs.  In  five  cases  of  puerperal  fever  Streptococcus  pyogenes 
was  obtained  in  the  lochial  discharge  from  the  uterus.  The  results 
of  Von  Ott  correspond  with  those  of  Donderlein.  Czerniewski,  in 
the  lochia  of  fifty-seven  healthy  women,  found  the  Streptococcus 
pyogenes  but  once,  while  in  the  lochial  discharge  of  fatal  cases  of 
puerperal  fever  it  was  always  present. 

Steffeck  (1892)  has  examined  the  vaginal  secretion  of  twenty-nine 
pregnant  females  who  had  not  been  subjected  to  digital  examina- 
tion, and  found  Staphylococcus  pyogenes  albus  in  nine,  Staphylo- 
coccus pyogenes  aureus  in  three,  and  Streptococcus  pyogenes  in  one. 
These  results  indicate  that  puerperal  septicaemia  from  self-infection 
may  occur  in  exceptional  cases.  In  seventeen  of  the  twenty-nine 
cases  examined  none  of  these  pyogenic  micrococci  were  found. 


AND  OF  EXPOSED  MUCOUS  MEMBRANES.  579' 

The  following  species  have  been  obtained  from  the  nasal  and 
buccal  secretions  : 

FROM   THE   NOSE. 

Non-pathogenic. — Micrococcus  nasalis  (Hajek),  Diplococcus  coryzae 
(Hajek),  Micrococcus  albus  liquefaciens  (Von  Besser),  Micrococcus  cumu- 
latus  tenuis  (Von  Besser),  Micrococcus  tetragenus  subflavus  (Von  Besser), 
Diplococcus  fluorescens  foetidus  (Klamann),  Micrococcus  totidus  (Klamanu), 
Vibrio  nasalis  (Weibel),  Bacillus  striatus  flavus  (Von  Besser),  Bacillus 
striatus  albus  (Von  Besser). 

Pathogenic. — Staphylococcus  pyogenes  aureus,  Staphylococcus  pyogenes 
albus,  Streptococcus  pyogenes,  Bacillus  of  Friedlander,  Bacillus  of  rhino- 
scleroma  (?),  Bacillus  foetidus  ozaenae  (Hajek),  Bacillus  mallei  (Loffler),  Ba- 
cillus smaragdinus  foetidus  (Reimannj. 

FROM   THE   MOUTH. 

Non-pathogenic. — Micrococcus  roseus  (Eisenberg),  Micrococcus  A,  B,  C, 
D,  E  of  Podbielskij,  Sarcinapulmonum  (Hauser),  Sarcina  lutea,  Micrococcus 
candicaiis  (Fliigge),  Bacillus  of  Miller,  Bacillus  virescens  (Frick),  Vibrio 
rugula,  Vibrio  lingualis  (Weibel),  Pseudo-diphtheria  bacillus  (Von  Hoff- 
mann), Bacillus  mesentericus  vulgatus,  Bacillus  subtilis,  Bacillus  a,  b,  c,  d, 
e,  f,  g,  h,  i,  and y  of  Vignal,  Bacillus  subtilis  similis,  Bacillus  radiciformis 
(Eisenberg),  Bacillus  luteus,  Bacillus  fluorescens  non-liquefaciens,  Bacillus 
ruber,  Bacillus  viridiflavus,  Proteus  Zenkeri,  Bacillus  G,  H,  I,  J,  K,  L,  M, 
N,  and  Vibrio  O  and  P  of  Podbielskij,  Vibrio  viridans  (Miller),  Micrococcus 
nexifer  (Miller),  lodococcus  magnus  (Miller),  Ascococcus  buccaljs  (Miller), 
Bacillus  fuscans  (Miller). 

Pathogenic. — Staphylococcus  pyogenes  albus,  Staphylococcus  pyogenes 
aureus,  Staphylococcus  salivarius  septicus(Biondi),  Streptococcus  pyogenes, 
Micrococcus  salivarius  septicus  (Biondi),  Micrococcus  tetragenus  (Gaffky), 
Micrococcus  gingivae  pyogenes  (Miller),  Streptococcus  septo-pysemicus  (Bi- 
ondi), Streptococcus  articulorum  (Loffler),  Micrococcus  of  Manfredi,  Micro- 
coccus  pneumoniae  crouposae — ' '  Micrococcus  Pasteuri "  (Sternberg) ;  Bacillus 
diphtherias  (Loffler),  Bacillus  tuberculosis  (Koch),  Bacillus  of  Friedlander, 
Bacillus  bronchitidse  putridae  (Lumnitzer),  Bacillus  septicaemias  haemorrha- 
gicae,  Bacillus  gingivae  pyogenes  (Miller),  Bacillus  pulpse  pyogenes  (Miller), 
Bacillus  dentalis  viridans  (Miller),  Bacillus  crassus  sputigenus  (Kreibohm), 
Bacillus  saprogenes  No.  1  (Rosenbach),  Bacillus  pneumoniae  agilis*  (Schou), 
Bacillus  pneumoniae  of  Klein,  Bacillus  pneumosepticus  (Babes). 


V. 
BACTERIA   OF  THE   STOMACH  AND   INTESTINE. 

As  the  secretions  of  the  mouth  contain  numerous  bacteria,  these 
must  constantly  find  their  way  to  the  stomach,  but  conditions  are 
not  favorable  for  their  development  when  the  stomach  is  in  a  healthy 
state  and  its  secretions  normal.  Under  certain  circumstances,  how- 
ever, there  may  be  an  abundant  development  in  the  stomach  of  spe- 
cies which  give  rise  to  various  fermentations,  and  no  doubt  dyspep- 
tic symptoms  are  frequently  due  to  this  cause.  In  the  present 
section  we  are,  however,  only  concerned  with  the  bacteria  of  the 
healthy  stomach.  Most  of  these,  we  think,  are  to  be  considered  as 
only  temporarily  and  accidentally  present  in  this  viscus  as  the  result 
of  the  swallowing  of  the  buccal  secretions  and  of  food  and  drink  con- 
taining them. 

The  experiments  of  Straus  and  Wiirtz  and  of  others  show  that 
normal  gastric  juice  possesses  decided  germicidal  power,  which  is 
due  to  the  free  hydrochloric  acid  contained  in  it.  Hamburger  (1890) 
found  that  gastric  juice  containing  free  acid  is  almost  always  free 
from  living  microorganisms,  and  that  it  quickly  kills  the  cholera 
spirillum  and  the  typhoid  bacillus,  but  has  no  effect  upon  anthrax 
spores.  Straus  and  Wiirtz  found  that  the  cholera  spirillum  is  killed 
by  two  hours'  exposure  in  gastric  juice  obtained  from  dogs,  the 
typhoid  bacillus  in  two  to  three  hours,  anthrax  bacilli  in  fifteen  to 
twenty  minutes,  and  the  tubercle  bacillus  in  from  eighteen  to  thirty- 
six  hours.  The  experiments  of  Kurlow  and  Wagner,  made  with 
gastric  juice  obtained  from  the  stomach  of  healthy  men  by  means  of 
a  stomach  sound,  gave  the  following  results  :  Anthrax  bacilli  with- 
out spores  failed  to  grow  after  exposure  to  the  action  of  human  gas- 
tric juice  for  half  an  hour,  but  spores  were  not  destroyed  in  twenty- 
four  hours ;  the  typhoid  bacillus  was  killed  in  one  hour ;  the 
cholera  spirillum,  the  bacillus  of  glanders,  and  Bacillus  pyocyanus 
were  all  destroyed  at  the  end  of  half  an  hour  ;  the  pus  cocci  showed 
greater  resisting  power.  Certain  bacteria  have  a  greater  resisting 
power  for  acids  than  any  of  those  above  mentioned,  and  some  of  them 
may  consequently  pass  through  the  healthy  stomach  to  the  intestine 


BACTERIA   OF   THE   STOMACH   AND    INTESTINE.  581 

in  a  living  condition,  but  there  is  good  reason  to  believe  that  the 
spirillum  of  cholera  or  the  bacillus  of  anthrax  would  not.  On  the 
other  hand,  the  tubercle  bacillus  and  the  spores  of  other  bacilli  can, 
no  doubt,  pass  through  the  stomach  to  the  intestine  without  losing 
their  vitality. 

Of  nineteen  species  isolated  by  Vignal  in  his  cultures  from  the 
healthy  human  mouth,  the  greater  number  resisted  the  action  of  the 
gastric  juice  for  more  than  an  hour,  and  six  species  which  did  not 
form  spores  were  found  to  retain  their  vitality  in  gastric  juice  for 
more  than  twenty-four  hours. 

In  making  a  bacteriological  analysis  of  the  contents  of  the  healthy 
stomach  the  more  resistant  microorganisms  and  those  which  form 
spores  will  naturally  be  found  in  greater  or  less  numbers,  inasmuch 
as  some  of  them  are  likely  to  be  present  in  food  and  water  ingested. 

Van  Puteren  (1888)  obtained  a  variety  of  microorganisms  in  very 
considerable  numbers  from  the  stomachs  of  infants  fed  upon  un- 
sterilized  cow's  milk,  but  in  healthy  nursing  infants  the  number  was 
much  smaller,  especially  when  the  mouth  was  washed  out  with  dis- 
tilled water  immediately  before  and  after  nursing.  In  18  per  cent 
of  the  cases  no  microorganisms  were  found  under  these  circum- 
stances, and  in  41  per  cent  the  number  fell  below  one  thousand  per 
cubic  centimetre.  Among  the  nursing  infants  examined  (eighty- 
five)  the  following  species  were  most  numerous  :  Monilia  Candida, 
Bacillus  lactis  aerogenes,  a  non-liquefying  coccus,  Staphylococcus 
pyogenes  aureus,  Bacillus  subtilis.  In  infants  fed  upon  cow's  milk 
(eleven)  Bacillus  lactis  aerogenes  was  present  in  45.4  per  cent  of 
the  cases,  and  Staphylococcus  pyogenes  aureus  in  27.2  per  cent,  non- 
liquefying  cocci  in  54.4  per  cent,  liquefying  cocci  in  72. 7  per  cent, 
Bacillus  subtilis  in  36.3  per  cent,  and  Bacillus  butyricus  (Hueppe) 
in  all  of  the  cases  ;  next  to  these  Bacillus  flavescens  liquefaciens 
was  the  most  abundant.  The  author  named  reaches  the  conclusion 
that  no  species  is  constant  and  that  the  presence  of  those  found  de- 
pends upon  accidental  circumstances. 

Abelous  (1889)  found  in  his  own  stomach,  washed  out  while  fast- 
ing, a  considerable  number  of  species  of  bacteria,  viz.  :  Sarcina 
ventriculi,  Bacillus  pyocyanus,  Bacillus  lactis  aerogenes,  Bacillus 
subtilis,  Bacillus  mycoides,  Bacillus  amylobacter,  Vibrio  rugula, 
and  eight  other  undescribed  bacilli  and  one  coccus.  All  of  these 
microorganisms  were  able  to  resist  the  action  of  hydrochloric  acid 
in  the  proportion  of  1.7  grammes  in  1,000  grammes  of  water. 
Several  were  found  to  be  facultative  anaerobics. 

The  action  of  the  bacteria  isolated  by  him  was  tested  by  Abelous 
upon  various  alimentary  substances.     The  time  required  to  effect 
changes,  such  as  the  digestion  of  fibrin,  the  changing  of  starch 
49 


582  BACTERIA   OF   THE   STOMACH  AND   INTESTINE. 

into  glucose,  etc.,  was  found  to  be  so  long  that  there  was  no  reason 
to  suppose  that  any  one  of  the  microorganisms  tested  was  con- 
cerned in  ordinary  stomach  digestion. 

In  the  intestine  conditions  are  favorable  for  the  development  of 
many  species  of  saprophytic  bacteria,  and  the  smallest  quantity  of 
excrementitious  material  from  the  bowels,  spread  upon  a  glass  slide 
and  stained  with  one  of  the  aniline  colors,  will  be  found  to  contain 
a  multitude  of  microorganisms  of  this  class,  of  various  forms. 
Among  these  are  certain  species  which  have  their  normal  habitat  in 
the  intestine,  and  which  may  always  be  obtained  in  cultures  from 
this  source,  while  others,  having  been  present  in  food  or  water  in- 
gested, and  having  escaped  destruction  in  the  acid  juices  of  the 
stomach,  are  accidentally  and  temporarily  present.  These  latter 
may  or  may  not  increase  in  the  organic  pabulum  which  abounds  in 
the  intestine,  according  as  the  conditions  are  favorable  or  otherwise. 
The  strictly  aerobic  bacteria  could  not  multiply  because  of  the  ab- 
sence of  oxygen,  and  the  species  encountered  are  for  the  most  part 
anaerobics  or  facultative  anaerobics.  The  Bacillus  coli  communis 
of  Escherich,  which  is  the  most  constant  and  abundant  species  found 
in  the  intestine  of  man  and  of  certain  of  the  lower  animals,  is  a  facul- 
tative anaerobic,  which  grows  readily  in  the  ordinary  culture  media, 
either  in  the  presence  of  oxygen  or  in  an  atmosphere  of  hydrogen. 
But  certain  other  bacteria  of  the  intestine  are  strictly  anaerobic  and 
do  not  grow  readily  in  the  media  commonly  employed  by  bacteri- 
ologists. 

Escherich  has  shown  that  in  new-born  infants  the  meconium  is 
free  from  bacteria.  At  the  end  of  twelve  to  eighteen  hours  after 
birth  bacteria  appear  in  the  alvine  discharges,  and  the  number  is 
already  considerable  at  the  expiration  of  the  first  twenty -four  hours 
of  independent  existence.  The  species  first  found  are  cocci  and  yeast 
cells  which  no  doubt  come  from  the  atmosphere,  having  been  de- 
posited upon  the  moist  mucous  membrane  of  the  mouth  and  swal- 
lowed with  the  buccal  secretions.  When  the  meconium  is  replaced 
by  "milk  faeces"  these  contain  in  large  numbers  the  Bacillus  coli 
communis,  heretofore  spoken  of  as  the  most  common  species  found  in 
the  intestine  of  adults.  Another  species  associated  with  this,  but 
not  so  abundant,  is  the  Bacillus  lactis  aerogenes  of  Escherich. 
Other  bacilli  and  cocci  are  found  occasionally  in  smaller  numbers. 
These  bacilli  do  not  liquefy  gelatin,  and,  as  a  rule,  the  microor- 
ganisms found  in  the  alvine  discharges  of  healthy  persons  are  non- 
liquefying  bacteria.  Escherich's  researches  led  him  to  the  conclu- 
sion that  the  Bacillus  lactis  aerogenes  is  constantly  present  in  the 
small  intestine  of  milk-fed  children  as  the  most  prominent  species, 
and  that  its  multiplication  there  is  favored  by  the  presence  of  milk 


BACTERIA   OF   THE   STOMACH  AND   INTESTINE.  583 

sugar,  and  that  Bacillus  coli  communis  finds  the  most  favorable 
conditions  for  its  growth  in  the  large  intestine. 

Brieger,  in  1884,  isolated  from  faeces  and  carefully  studied  two 
bacilli,  one  of  which  has  since  been  called  by  his  name.  This  is  a 
non-liquefying  bacillus  which  is  very  pathogenic  for  guinea-pigs, 
and  which  in  its  morphology  and  characters  of  growth  closely  re- 
sembles the  Bacillus  coli  communis  of  Escherich.  Indeed,  a  num- 
ber of  non-liquefying  bacilli,  differing  but  slightly  in  their  morpho- 
logical and  biological  characters,  have  been  obtained  by  various 
investigators  from  the  alimentary  canal  of  man  and  the  lower  ani- 
mals, and  it  is  still  a  question  whether  they  are  to  be  regarded  as 
distinct  species  or  as  varieties  of  the  "colon  bacillus  "  of  Escherich. 
The  bacillus  obtained  by  Emmerich  from  cholera  cadavers  in  Na- 
ples belongs  to  this  group,  and,  if  not  identical  with  the  colon  bacil- 
lus, resembles  it  so  closely  that  its  differentiation  is  extremely  diffi- 
cult. Brieger's  bacillus  forms  propionic  acid  in  solutions  containing 
grape  sugar.  A  second  bacillus  obtained  by  him  from  the  same 
source  resembles  the  "  pneumococcus  "  of  Friedlander  ;  this  causes 
the  fermentation  of  saccharine  solutions,  with  production  of  ethyl 
alcohol. 

Bienstock  (1883)  isolated  four  species  of  bacilli  from  normal  faeces, 
two  of  which  are  comparatively  large  and  resemble  Bacillus  sub- 
tilis  in  their  morphology  and  in  the  formation  of  spores.  A  third 
species  is  described  as  an  extremely  slender  pathogenic  bacillus,  re- 
sembling the  bacillus  of  mouse  septicaemia.  The  fourth  species  is  an 
actively  motile  bacillus  which  forms  end  spores,  causing  the  rods  to 
have  the  form  of  a  drumstick.  This  is  said  to  cause  the  decomposi- 
tion of  albumin,  with  production  of  ammonia  and  carbon  dioxide. 
Later  researches  do  not  sustain  Bienstock's  conclusion  that  the  ba- 
cilli described  by  him  are  the  principal  forms  found  in  normal  faeces. 

Among  the  species  encountered  by  Escherich,  in  addition  to  those 
.  mentioned  above  (Bacillus  coli  communis  and  Bacillus  lactis  aero- 
genes),  are  the  following :  Proteus  vulgaris,  found  three  times  in 
meconium,  and  constantly  in  the  faeces  of  dogs  fed  upon  flesh  ;  Strep- 
tococcus coli  gracilis,  found  in  meconium,  but  not  during  the  period 
of  nursing,  is  constantly  present  in  the  intestine  when  a  flesh  diet  is 
employed. 

The  intestine  of  carnivorous  and  omnivorous  animals  contains  a 
greater  number  of  bacteria  than  that  of  the  herbivora,  and  in  the 
large  intestine  they  are  far  more  numerous  than  in  the  small  intes- 
tine (De  Giaxa).  Sucksdorf  has  enumerated  the  colonies  developing 
from  one  milligramme  of  faeces  from  individuals  on  mixed  diet.  He 
obtained  an  average  of  380,000  from  a  series  of  observations  in  which 
the  maximum  was  2,300,000  and  the  minimum  25J300. 


584  BACTERIA   OF  THE   STOMACH   AND    INTESTINE. 

The  following  species  have  been  isolated  from  faeces  and  the  con- 
tents of  the  intestine  of  cadavers  : 

^  Non-pathogenic. — Streptococcus  coli  gracilis  (Escherich),  Micrococcus 
aerogenes  (Miller),  Micrococcus  tetragenus  versatilis  (Sternberg),  Micrococ- 
cus ovalis  (Escherich),  "Yellow  liquefying1  staphyiococcus  "  (Escherich), 
"  Porzellancoccus  "  (Escherich),  Bacillus  subtilis,  Bacillus  aerogenes  (Miller), 
Bacterium  aerogenes  (Miller),  Bacillus  lactis  erythrogenes  (Hueppe),  Clostri- 
dium  fcetidum  (Liborius),  Bacillus  nauscoides(Liborius),  Bacillus  putriflcus 
coli  (Bienstock),  Bacillus  subtilis  similis  I.  and  II.  (Bienstock),  Bacillus 
Zopfii,  Bacillus  liquefaciens  communis  (Stern berg),  Bacillus  in testinus  lique- 
faciens  (Sternberg),  Bacillus  intestinus  motilis  (Sternberg),  Bacillus  fluores- 
cens  liquefaciens  (Fliigge),  "Colorless  fluorescent  liquefying  bacillus'* 
(Escherich),  "Yellow  liquefying  bacillus"  (Escherich),  Bacillus  mesenteri- 
cus  vulgatus,  Bacilli  of  Booker,  A  to  T,  first  series ;  a  to  s,  second  series ; 
Bacilli  of  Jeffries  A  to  Z,  and  «,  /?. 

Pathogenic. — Staphyiococcus  pyogenes  aureus.  Bacillus  typhi  abdo- 
minalis,  Bacillus  septicaemise  haemorrhagicae,  Bacillus  of  Belfanti  and  Pas- 
carola,  Bacillus  enteritidis  (Gartner),  Bacillus  of  Lesage,  Bacillus  pseuclo- 
murisepticus  (Bienstock),  Bacillus  coli  communis  (Escherich),  Bacillus  lactis 
aerogenes  (Escherich),  Bacillus  cavicida  (Brieger),  Bacillus  of  Emmerich, 
Bacillus  coprogenesfcetidus(Schottelius),  Bacillus  of  Utpadel,  Bacillus  leporis 
lethalis  (Sternberg),  Bacillus  acidiformans  (Sternberg),  Bacillus  cuniculicida 
Havaniensis  (Sternberg),  Bacillus  cadaveris  (Sternberg),  Bacillus  cavicida 
Havaniensis  (Sternberg),  Proteus  vulgaris  (Hauser),  Bacillus  tuberculosis^ 
Spirillum  cholerse  Asiaticse,  Spirillum  of  Finkler  and  Prior. 


A  . 
t. 


VI. 

BACTERIA  OF    CADAVERS   AND    OF    PUTREFYING 
MATERIAL  FROM  VARIOUS  SOURCES. 

THE  putrefactive  changes  which  occur  so  promptly  in  cadavers, 
when  temperature  conditions  are  favorable,  result  chiefly  from  post- 
mortem invasion  of  the  tissues  by  bacteria  contained  in  the  alimen- 
tary canal.  But  it  is  probable  that  under  certain  circumstances 
microorganisms  from  the  intestine  may  find  their  way  into  the  cir- 
culation during  the  last  hours  of  life,  and  that  the  very  prompt  putre- 
factive changes  in  certain  infectious  diseases  in  which  the  intestine 
is  more  or  less  involved  are  due  to  this  fact.  The  writer  has  made 
numerous  experiments  in  which  a  portion  of  liver  or  kidney  re- 
moved from  the  cadaver  at  an  autopsy  made  soon  after  death — one 
to  six  hours — has  been  enveloped  in  an  antiseptic  wrapping  and  kept 
for  forty-eight  hours  at  a  temperature  of  25°  to  30°  C.  In  every  in- 
stance there  has  been  an  abundant  development  of  bacteria,  although 
as  a  rule  none  were  obtained  from  the  same  material  immediately  after 
the  removal  of  the  organ  from  the  body.  This  shows  that  a  few 
scattered  bacteria  were  present.  The  same  result  was  obtained  in 
cases  of  sudden  death  from  accident,  as  from  portions  of  liver  or 
kidney  removed  from  the  bodies  of  persons  dying  of  yellow  fever, 
tuberculosis,  and  other  diseases. 

Numerous  researches  show  that  the  blood  of  healthy  men  and 
animals  is  free  from  bacteria,  and  that  saprophytic  bacteria  injected 
into  a  vein  soon  disappear  from  the  circulation ;  and  recent  experi- 
ments show  that  blood  serum  has  decided  germicidal  power.  But  in 
spite  of  this  fact  the  experiments  of  Wyssokowitsch  show  that  cer- 
tain bacteria  injected  into  the  circulation  may  be  deposited  in  the 
liver,  the  spleen,  and  the  marrow  of  the  bones,  and  there  retain  their 
vitality  for  a  considerable  time.  The  spores  of  Bacillus  subtilis  were 
found  by  the  observer  named  to  preserve  their  vitality  in  the  liver  or 
spleen  of  animals  into  which  they  had  been  injected,  for  a  period  of 
two  or  three  months.  In  the  writer's  experiments  the  microorgan- 
isms which  first  developed  in  fragments  of  liver  preserved  in  an  an- 
tiseptic wrapping  were  certain  large  anaerobic  bacilli,  and  especially 


586 


BACTERIA   OF  CADAVERS   AND    OF 


my  Bacillus  cadaveris,  together  with  the  Bacillus  coli  communis 
of  Escherich,  my  Bacillus  hepaticus  fortuitus,  and  other  non-lique- 
fying bacilli  of  the  "colon  group." 

These  bacteria  did  not  give  rise  to  a  putrefactive  odor,  and  the 
fragment  of  liver  when  cut  into  had  a  fresh  appearance  and  a  very 
acid  reaction.  Later,  putrefactive  changes  occurred  and  Proteus 


FIG.  197.— Smear  preparation  from  liver  of  yellow-fever  cadaver,  kept  forty-eight  hours  in  an 
antiseptic  wrapping,    x  1,000.    From  a  photomicrograph.    (Sternberg.) 

vulgaris  and  other  putrefactive  bacteria  obtained  the  precedence. 
Evidently  all  of  these  species  must  have  been  present  in  the  liver  at 
the  time  it  was  removed  from  the  cadaver,  although  in  such  small 
numbers  that  they  were  rarely  seen  in  smear  preparations  or  ob- 
tained in  cultures  from  the  fresh  liver  tissue.  The  appearance  of  a 
smear  preparation  from  the  interior  of  a  fragment  preserved  for 
forty-eight  hours  in  an  antiseptic  wrapping  is  shown  in  Fig.  197. 

The  horribly  offensive  gases  which  are  given  off  from  dead  ani- 
mals in  a  state  of  putrefaction  appear  to  be  due  to  certain  large  an- 
aerobic bacilli  which  are  found  in  such  material, 
and  which  have  not  yet  been  thoroughly  studied 
owing  to  the  difficulty  of  cultivating  them  in  arti- 

VS        ficial  media ;  among  them  is  a  large  bacillus  with 
c-ff*         round  ends  which  forms  an  oval  spore  at  one  ex- 
^P  ^.       ^    tremity  of  the  rather  long  rod.     This  the  writer 
^  ^Sfc          has  described  under  the  name  of  Bacillus  cada- 

FIQ.  we.  veris  grandis,  Fig.  198. 

In  the  interior  of  a  putrefying  mass  of  this  kind 

only  those  bacteria  are  found  which  are  able  to  grow  in  the  absence 
of  oxygen,  but  aerobic  saprophytes  may  multiply  upon  the  surface  of 


PUTREFYING   MATERIAL   FROM   VARIOUS   SOURCES.  587 

such  a  mass,  or  in  organic  liquids  to  which  the  air  has  free  access. 
Among  the  most  common  putrefactive  bacteria  are  the  Proteus  vul- 
garis,  Proteus  mirabilis,  and  Proteus  Zenkeri  of  Hauser.  Formerly 
the  minute  motile  bacteria  found  in  putrefying  animal  infusions,  etc. , 
were  commonly  spoken  of  as  belonging  to  the  species  "  Bacterium 
termo,"  but  recent  researches  show  that  several  different  species  were 
included 'Under  this  name  by  those  whose  researches  were  made  be- 
fore the  introduction  of  Koch's  method  for  isolating  and  differentiat- 
ing microorganisms  of  this  class  by  the  use  of  solid'  culture  media. 
The  different  species  of  Proteus  are  all  facultative  anaerobics.  They 
are  more  or  less  pathogenic,  and  according  to  Hauser  produce  a  chem- 
ical poison  which,  when  injected  into  small  animals,  causes  death  with 
all  of  the  symptoms  of  putrid  intoxication.  The  bacillus  of  mouse 
septicaemia,  which  was  first  obtained  by  Koch  from  a  putrefying  meat 
infusion,  is  also  pathogenic,  as  are  the  writer's  Bacillus  cadaveris 
and  various  other  anaerobic  bacteria  found  in  putrefying  material. 

Some  account  of  the  various  products  of  putrefaction  and  the 
microorganisms  concerned  in  their  production  will  be  found  in  Sec- 
tion IV.,  Part  Second,  of  the  present  volume. 


VII. 

BACTERIA  IN  ARTICLES  OF  FOOD. 

Milk  always  contains  bacteria,  unless  drawn  with  special  precau- 
tions into  a  sterilized  flask.  In  the  healthy  udder  of  the  cow  it  is 
sterile,  but  in  tuberculous  cows,  when  the  milk  glands  are  involved, 
tubercle  bacilli  may  find  their  way  into  the  milk  in  considerable 
numbers.  Ag  ordinarily  obtained  and  preserved,  milk  is  greatly  ex- 
posed to  bacterial  contamination  from  various  sources  ;  desquamated 
cuticle  from  the  external  surface  of  the  udder  and  from  the  hands  of 
the  milker,  and  floating  particles  from  the  air  of  the  stable,  fall  into  it 
at  the  very  moment  it  is  drawn,  and  it  is  subsequently  contaminated 
by  bacteria  from  the  air,  and  from  water  used  in  washing  the  recep- 
tacles in  which  it  is  placed  or  added  to  it  by  the  thrifty  milkman. 
As  it  furnishes  an  excellent  nutrient  medium  for  many  of  the  bacteria 
which  are  thus  introduced  into  it,  under  favorable  conditions  of  tem- 
perature it'  quickly  undergoes  changes  due  to  the  multiplication  in  it 
of  one  or  more  of  these  microorganisms.  The  acid  fermentation  and 
coagulation  of  the  casein  which  so  constantly  occurs  is  completely 
prevented  by  sterilizing  fresh  milk  in  flasks  provided  with  a  close- 
fitting  cork  or  cotton  air  filter.  Numerous  researches  have  been 
made  with  reference  to  the  microorganisms  found  in  milk  and  the 
various  fermentations  to  which  they  give  rise.  Naturally  a  great 
variety  of  species  will  be  found  in  an  extended  research,  but  all  are 
accidentally  present,  and  only  those  demand  special  attention  which 
produce  the  various  fermentations  of  this  fluid  commonly  encoun- 
tered, or  which  have  special  pathogenic  properties. 

Several  different  bacteria  produce  an  acid  fermentation  and  con- 
sequent coagulation  of  milk,  but  the  usual  agent  in  producing  this 
fermentation  is  the  Bacillus  acidi  lactici,  which  is  identical  with  the 
"  ferment  lactique  "  of  Pasteur.  When  a  pure  culture  of  this  bacillus 
is  introduced  into  sterilized  milk  kept  at  a  temperature  of  25°  to  30°  C. , 
coagulation  occurs  in  from  fifteen  to  twenty-four  hours.  A  uniform, 
gelatinous  mass  is  produced  which  does  not  subsequently  become 
dissolved  (Adametz).  Various  other  bacteria  produce  a  similar 
change,  including  a  number  of  common  water  bacteria,  several  spe- 


BACTERIA  IN   ARTICLES   OF  FOOD.  589 

cies  of  sarcina,  Staphylococcus  pyogenes  aureus,  and  other  pus  cocci. 
Usually  coagulation  is  due  to  the  combined  action  of  several  bacteria, 
among  which  Bacillus  acidi  lactici  is  apt  to  be  the  most  prominent. 

Other  bacteria  produce  coagulation  without  the  lactic  acid  fer- 
mentation. This  appears  to  be  due  to  the  formation  of  a  soluble 
ferment  which  acts  like  rennet,  causing  the  coagulation  of  milk 
which  has  a  neutral  or  slightly  alkaline  reaction.  The  coagu- 
lated casein  in  this  case  is  subsequently  redissolved.  The  bacteria 
which  produce  this  change  for  the  most  part  form  spores,  while  the 
lactic  acid  ferments  do  not.  If,  therefore,  milk  is  heated  nearly  to  the 
boiling  point  the  acid-forming  bacteria  will  be  destroyed  and  the 
spores  of  the  other  species  surviving  will  give  rise  to  coagulation 
without  the  production  of  lactic  acid.  Among  the  more  common 
microorganisms  of  this  group  are  the  Bacillus  butyricus  (Hueppe), 
Bacillus  mesentericus  vulgatus,  Loffler's  "  white  milk-bacillus,"  and 
the  bacilli  described  by  Duclaux  under  the  generic  name  of  Tyrothrix. 

Other  fermentations  are  produced  by  certain  chromogenic  bacteria, 
and  these,  as  a  rule,  are  not  as  harmless  from  a  sanitary  point  of  view 
as  those  above  referred  to.  Blue  milk  is  produced  by  the  presence  of 
Bacillus  cyanogenus,  yellow  milk  by  Bacillus  synxanthus  (Schroter) 
and  by  a  species  obtained  by  List  from  the  faeces  of  a  sheep  and 
another  found  by  Adametz  in  cheese.  The  well-known  Bacillus 
prodigiosus  produces  its  characteristic  red  pigment  when  present  in 
milk,  and  a  bluish-red  color  is  caused  by  Bacterium  lactis  erythrogenes 
(Hueppe). 

Viscous  fermentation  in  milk  is  produced  by  several  different  bac- 
teria, among  others  by  a  micrococcus  studied  by  Schmidt-Muhlheim, 
and  a  short  bacillus  isolated  by  Adametz — Bacillus  lactis  viscosus. 
Milk  which  has  undergone  this  change  is  unwholesome  as  food  ;  it 
is  recognized  by  the  long  filaments  which  are  produced  when  it  is 
touched  with  any  object  and  this  is  slowly  withdrawn. 

The  Caucasian  milk  ferment,  Bacillus  Caucasicus,  produces  a 
special  fermentation,  which  has  been  referred  to  in  Section  IV. ,  Part 
Second  (page  132). 

Various  pathogenic  bacteria  have  occasionally  been  found  in  milk 
in  addition  to  the  tubercle  bacillus  already  referred  to.  Thus  Adametz 
found  Staphylococcus  pyogenes  aureus  in  two  samples  which  had 
been  submitted  to  him  for  examination,  one  of  which  had  given  rise 
to  vomiting  and  diarrhoea.  Wyssokowitsch  cultivated  from  milk 
which  had  been  standing  some  time  a  pathogenic  bacillus,  named  by 
him  Bacillus  oxytocus  perniciosus. 

The  special  microorganism  which  produces  the  poisonous  pto- 
maine called  by  Vaughan  tyrotoxicon  has  not  yet  been  isolated  ;  nor 
do  we  know  the  exact  cause  of  scarlet  fever,  although  there  is  evi- 


590  BACTERIA  IN  ARTICLES   OF   FOOD. 

dence  that  this  disease  has  been  spread  by  the  use  of  contaminated 
milk,  as  have  also  diphtheria  and  typhoid  fever,  which  diseases  are 
due  to  bacilli  now  well  known.  As  the  cholera  spirillum  grows 
readily  in  milk,  this  disease  could  110  doubt  also  be  transmitted  in  the 
same  way. 

Recently  (1892)  Sedgwick  and  Batchelder  have  examined  a  large 
number  of  specimens  of  milk  obtained  in  Boston  and  vicinity,  for  the 
purpose  of  determining  the  number  of  bacteria  present.  They  found, 
as  an  average  of  several  trials,  that  milk  obtained  in  a  clean  stable, 
from  a  well-kept  cow,  by  milking  in  the  usual  way  into  a  sterilized 
bottle,  contained  530  bacteria  per  cubic  centimetre.  . "  When,  however, 
the  milkman  used  the  ordinary  milk  pail  of  flaring  form,  seated 
himself  with  more  or  less  disturbance  of  the  bedding,  and  vigorously 
shook  the  udder  over  the  pail  during  the  usual  process  of  milking," 
the  numbers  were  very  much  higher — on  an  average  30,500  per  cubic 
centimetre  immediately  after  milking.  The  average  of  fifteen  samples 
taken  from  the  tables  of  persons  living  in  the  suburbs  of  Boston  was 
69,143  per  cubic  centimetre.  The  average  of  fifty-seven  samples  of 
Boston  milk,  obtained  directly  from  the  milk  wagons  and  plated  at 
once,  was  2,355,500  per  cubic  centimetre.  The  average  of  sixteen 
samples  from  groceries  in  the  city  of  Boston  was  4,577,000  per  cubic 
centimetre. 

Prof.  Renk  found  in  the  milk  supply  of  Halle  from  0,000,000 
to  30,000,000  bacteria  per  cubic  centimetre — a  number  considerably 
exceeding  that  usually  found  in  the  sewage  of  American  cities  (Sedg- 
wick). 

In  fresh  butter  of  good  quality  but  few  microorganisms  are  found, 
but  in  "  cheesy  butter"  having  a  disagreeable  odor  Kreuger  has 
found  a  great  number  of  bacteria.  Among  these  the  most  numerous 
were  an  oval  coccus,  Micrococcus  acidi  lactici  (Kreuger),  a  slender 
bacillus  closely  resembling,  and  possibly  identical  with,  the  Bacillus 
fluorescens,  and  the  Bacillus  acidi  lactici  of  Hueppe. 

Duclaux  (1887)  has  isolated  from  different  kinds  of  cheese  no 
less  than  eleven  different  species  of  bacteria,  which  he  believes  are 
concerned  in  the  "  ripening  process."  Seven  of  these  are  aerobic  and 
four  anaerobic  species.  Adametz  (1889)  has  also  isolated  and  studied 
a  number  of  species  to  which  he  attributes  the  ripening  of  cheese. 

Meats,  even  when  salted  and  smoked,  may  contain  living  patho- 
genic bacteria  which  were  present  prior  to  the  death  of  the  animal, 
and,  when  not  properly  preserved,  are  of  course  liable  to  be  invaded 
by  putrefactive  bacteria. 

The  researches  of  Foster  (1889)  show  that  the  typhoid  bacillus, 
the  pus  cocci,  the  tubercle  bacillus,  and  the  bacillus  of  swine  plague 
resist  the  action  of  a  saturated  solution  of  salt  for  weeks  and  even  for 


BACTERIA  IN  ARTICLES   OF   FOOD.  591 

months;  and  the  same  observer  found  that  the  ordinary  processes  of 
salting  and  smoking  did  not  destroy  the  tubercle  bacillus  in  the  flesh 
of  a  cow  which  had  succumbed  to  tuberculosis.  Beu  has  made  cul- 
tures from  a  large  number  of  specimens  of  fresh,  salted,  and  smoked 
meats  and  fish,  with  the  general  result  that  the  fresh  and  salted  meats 
were  found  to  contain  a  limited  number  of  bacteria  of  various  species, 
and  that  smoking  for  several  days  did  not  insure  the  destruction  of 
these  microorganisms.  In  specimens  of  sausage  six  days'  smoking 
did  not  destroy  a  liquefying  bacillus  which  was  present,  but  at  the 
end  of  six  weeks'  exposure  to  smoke  this  bacillus  no  longer  grew, 
while  a  non-liquefying  bacillus  present  in  the  same  specimen  had  not 
been  destroyed.  Fourteen  days'  smoking  sufficed  to  destroy  all  the 
microorganisms  in  a  specimen  of  bacon,  but  this  was  not  sufficient 
for  the  interior  portions  of  a  ham.  Among  the  bacteria  obtained  by 
Beu  from  smoked  meats  he  mentions  the  following  :  Staphylococcus 
cereus  albus,  Proteus  vulgaris,  Staphylococcus  pyogenes  aureus,  Ba- 
cillus liquefaciens  viridis,  etc.  The  number  of  colonies  which  de- 
veloped from  a  fragment,  the  size  of  a  mustard  seed  to  that  of  a  flax- 
seed,  taken  from  the  interior  of  the  meats  examined,  was  usually 
small;  and  the  presence  of  a  few  scattered  bacteria  of  these  common 
species  has  no  significance  from  a  sanitary  point  of  view,  except  as 
showing  that  pathogenic  bacteria  may  survive  in  infected  meats  after 
they  have  been  exposed  to  the  usual  processes  of  salting  and  smoking. 

Petri,  in  experiments  upon  the  bacillus  of  swine  plague  (Schweine- 
rothlauf),  arrived  at  the  following  results  : 

The  flesh  of  swine  which  died  of  this  disease  preserved  its  infec- 
tious properties  after  having  been  preserved  in  brine  for  several 
months,  and  the  same  flesh  salted  or  pickled  for  a  month  and  then 
smoked  for  fourteen  days  contained  the  rothlauf  bacillus  in  a  living 
and  unattenuated  condition.  At  the  end  of  three  months  virulent 
rothlauf  bacilli  were  still  obtained  from  a  smoked  ham,  but  they  were 
no  longer  found  at  the  end  of  six  months. 

Schrank  (1888)  has  made  cultures  from  both  the  albumin  and  the 
yolk  of  fresh  eggs,  and  finds  that  they  are  free  from  bacteria.  He 
thinks  that,  as  a  rule,  putrefactive  bacteria  obtain  access  to  the  inte- 
rior through  injured  places  in  the  shell,  although  exceptionally  the 
egg  may  be  infected  with  them  in  the  oviduct  of  the  fowl.  The  usual 
bacteria  concerned  in  the  putrefactive  changes  in  eggs  are,  according 
to  the  author  mentioned,  a  variety  of  Proteus  vulgaris  and  Bacillus 
fluorescens  putidus. 

Peters  (1889)  has  studied  the  flora  of  the  "  sauerteig "  used  in 
Germany  as  yeast  for  leavening  bread.  In  addition  to  the  numerous 
cells  of  three  species  of  Saccharomyces,  he  finds  that  bacilli  are  present 
in  great  numbers,  as  shown  by  direct  microscopical  examination  and 


592  BACTERIA  IN  ARTICLES  OF  FOOD. 

culture  experiments.  He  describes  five  species,  designated  Bacillus 
A,  B,  C,  D,  and  E,  which  are  commonly  present,  and  to  which  the 
acid  fermentation  of  the  dough  is  ascribed. 

In  Graham  bread  which  had  undergone  changes  making  it  unfit 
to  eat,  Kratschmer  and  Niemilowicz  have  found  the  Bacillus  mesen- 
tericus  vulgatus,  which  appears  to  have  been  the  cause  of  the  fer- 
mentation, which  was  produced  in  bread  having  a  slightly  alkaline 
reaction  by  inoculating  it  with  a  pure  culture  of  this  bacillus.  The 
infected  bread  has  a  brownish  color,  a  peculiar  odor,  and  becomes 
sticky  and  viscid. 

Uffelmann  (1890)  has  also  studied  the  bacteria  in  spoiled  rye  bread, 
and  obtained,  in  addition  to  common  mould  fungi,  Bacillus  mesente- 
ricus  vulgaris  and  Bacillus  liodermus. 

Bernheim  (1888)  has  examined  various  grains  used  as  food,  with 
reference  to  the  presence  of  bacteria,  and  claims  to  have  demon- 
strated their  presence  by  staining  thin  sections,  and  also  by  cultures, 
in  corn,  wheat,  rye,  barley,  and  peas.  He  supposes  that  they  find 
their  way  from  the  earth  through  the  roots  and  stems  of  plants. 
This  appears  to  be  very  doubtful,  in  view  of  the  researches  of  other 
observers,  and  further  researches  are  necessary  before  we  can  accept 
the  fact  as  demonstrated  that  they  are  usually  present  in  healthy 
kernels  of  the  grains  mentioned. 


VIII. 
NON-PATHOGENIC  MICROCOCCI. 

MANY  of  the  saprophytic  micrococci  and  bacilli  have  already  been 
described  in  the  sections  devoted  to  pathogenic  bacteria  (Part  Third). 
We  propose  at  present  to  give  an  account  of  the  morphological  and 
biological  characters  which  distinguish  those  microorganisms  which 
have  not  been  shown  to  possess  pathogenic  power.  But  it  must  be  re- 
membered that  in  many  instances  the  bacteria  described  in  this  and 
the  following  sections  have  not  been  tested  at  all,  or  only  very  im- 
perfectly tested,  with  reference  to  this  point ;  and  no  doubt  some  of 
them,  if  tested  upon  the  various  animals  usually  employed  in  experi- 
ments of  this  kind,  would  prove  to  be  more  or  less  pathogenic.  On 
the  other  hand,  many  of  the  saprophytes  heretofore  described  as 
pathogenic  only  produce  marked  morbid  phenomena  in  susceptible 
animals  when  they  are  injected  beneath  the  skin,  into  a  serous  cavity, 
or  into  the  circulation  in  considerable  quantities.  The  experiments 
of  Buchner  show  that  very  many  of  the  common  saprophytes  usually 
classed  as  non-pathogenic  give  rise  to  a  local  abscess  when  sterilized 
cultures  are  injected  subcutaneously  into  rabbits  or  guinea-pigs.  In 
short,  there  is  no  well-defined  dividing  line  between  the  pathogenic 
and  non-pathogenic  bacteria,  and  some  of  those  now  described  as 
non-pathogenic,  as  the  result  of  more  extended  experiments,  will  no 
doubt  eventually  be  transferred  to  the  list  of  pathogenic  bacteria. 

159.    MICROCOCCUS   FLAVUS   LIQUEFACIENS   (Flugge). 

Found  in  the  air  and  in  water. 

Morphology. — Tolerably  large  micrococci,  in  pairs  or  in  irregular  groups. 

Biological  Characters . — Anaerobic,  liquefying,  chromogenic  micrococ- 
cus.  Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  forms  small,  yellow  colonies,  which  under  a  low  power  are 
seen  to  be  spherical  or  oval,  with  a  finely  granular  surface  and  a  yellowish- 
brown  color;  lines  radiate  from  the  centre  through  a  zone  of  transparent 
liquefied  gelatin  to  the  sharply  defined  border,  and  later  the  colonies,  which 
have  a  diameter  of  four  to  six  millimetres,  resemble  a  wagon  wheel.  In 
gelatin  stick  cultures  smooth,  spherical,  yellow  colonies  form  upon  the  sur- 
face ;  these  become  confluent  and  form  a  yellow  layer,  which  by  the  slow 
liquefaction  of  the  gelatin  becomes  depressed ;  at  the  end  of  five  days  the 
gelatin  is  liquefied  to  a  depth  of  about  two  millimetres  and  a  yellowish, 
flocculent  deposit  is  seen  at  the  bottom  of  the  yellowish-white  fluid.  Upon 
potato  a  deep-yellow  layer  with  irregular  margins  is  quickly  developed. 


594  NON-PATHOGENIC   MICROCOCCI. 

160.    MICROCOCCUS   FLAVUS   DESIDENS    (Fltigge). 

Found  in  air  and  water. 

Morphology. — Small  micrococci,  usually  in  pairs,  but  sometimes  seen  in 
groups  of  three  or  in  short  chains. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micro- 
coccus.  Grows  slowly  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  the  deep  colonies  appear  as  white  or  yellow  points; 
under  a  low  power  they  are  seen  as  oval,  yellowish-brown,  finely  granular 
discs.  The  superficial  colonies  are  circular,  with  irregular  margins,  and  are 
not  elevated  above  the  level  of  the  gelatin ;  by  the  fourth  day  they  may 
attain  a  diameter  of  five  to  ten  millimetres ;  they  have  a  brownish-yellow 
color  ;  the  gelatin  is  gradually  liquefied,  and  the  colony  which  sinks  below 
the  surface  is  surrounded  by  a  ring  of  liquefied  gelatin  from  one  to  four 
millimetres  broad.  In  gelatin  stick  cultures  a  slimy,  yellowish- brown  layer 
of  limited  extent  is  formed  upon  the  surface,  and  a  confluent,  porcelain- 
white  mass  along  the  line  of  puncture ;  at  the  end  of  eight  days  liquefac- 
tion has  occurred  under  the  superficial  layer  to  a  depth  of  three  to  four  mil- 
limetres, forming  a  cylinder  filled  with  a  thick  fluid,  to  the  bottom  of  which 
the  surface  growth  gradually  sinks.  Upon  potato  a  slimy,  yellowish-brown 
layer  with  irregular  outlines  is  slowly  developed. 

161.  MICROCOCCUS  AGILIS  (Ali-Cohen). 

Found  in  water. 

Morphology. — Micrococci,  one  n  in  diameter,  usually  in  pairs,  oc- 
casionally in  tetrads  or  in  chains ;  have  extremely  slender  flagella,  which 
are  four  to  five  IJL  in  length. 

Biological  Characters. — An  aerobic,  liquefying  (very  slowly),  motile, 
chromogenic  micrococcus.  Grows  at  the  room  temperature  in  the  usual  cul- 
ture media — not  in  the  incubator  at  37°  C.  This  micrococcus  is  distinguished 
by  its  active  movements  and  by  the  presence  of  a  longflagellum.  which  may 
be  demonstrated  by  Loffler's  method  of  staining.  In  gelatin  stick  cultures 
growth  occurs  along  the  line  of  inoculation,  and  liquefaction  commences  at 
the  end  of  three  to  four  weeks ;  sometimes  only  a  dry,  funnel-shaped  cavity 
is  formed.  Upon  agar  and  upon  potato  a  pink  layer  is  slowly  developed. 

162.  MICROCOCCUS  FUSCUS  (Maschek). 

Found  in  water. 

Morphology. — Micrococci,  which  are  often  elliptical,  or  even  in  the  form 
of  short  rods  (bacilli  ?). 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micrococ- 
cus. Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  forms  spherical  colonies  which  under  a  low  power  present  the 
appearance  of  being  finely  cleft  and  vary  in  color  from  pale-brown  to  black; 
liquefaction  quickly  occurs.  In  gelatin  stick  cultures  but  scanty  growth 
occurs  along  the  line  of  puncture ;  upon  the  surface  a  sepia-brown  layer  is 
formed  and  the  gelatin  is  quickly  liquefied.  Gelatin  cultures  have  a  strong 
putrefactive  odor.  Upon  potato  a  slimy,  brown  layer  is  formed,  which  be- 
comes almost  black. 

163.    DIPLOCOCCUS   CITREUS   CONGLOMERATUS   (Bumm). 

Obtained  from  gonorrhceal  pus  and  from  the  air — in  dust. 

Morphology. — Diplococci,  consisting  of  two  hemispherical  elements  sepa- 
rated by  a  narrow  cleft,  and  closely  resembling  the  Micrococcus  gonorrhoeas ; 
about  1.5  jj.  in  diameter;  frequently  in  tetrads,  usually  united  in  conglomerate 
masses. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 


NON-PATHOGENIC   MICROCOCCI.  595 

ing,  chromogenic  micrococcus.  Grows  in  the  usual  culture  media  at  the 
room  temperature.  Upon  gelatin  plates  forms  lemon-yellow  colonies,  which 
throw  out  tongue-like  projections  upon  the  surface  of  the  gelatin  and  have 
wave-like  margins ;  the  surface  is  at  first  moist  and  shining,  later  cleft  and 
scaly  In  gelatin  stick  cultures  development  occurs  along  the  line  of  punc- 
ture and  on  the  surface;  liquefaction,  beginning  near  the  surface,  progresses 
slowly ;  a  yellowish  layer  floats  upon  the  surface,  and  later  settles  to  the 
bottom  of  the  tube. 

164.    DIPLOCOCCUS   CITREUS   LIQUEFACIENS    (Unna). 

Found  on  the  skin  of  persons  suffering  from  eczema  seborrhoeicum. 

Morphology. — Small,  oval  cocci,  in  pairs  or  in  tetrads,  often  in  irregular 
groups  or  in  short  chains  ;  the  diameter  of  a  single  element  in  a  pair  is 
from  0.4  to  0.1  >«. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micrococ- 
cus. Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates,  at  the  end  of  four  days,  the  superficial  colonies  are  grayish- 
white,  flat,  circular  discs  the  size  of  a  mustard  seed ;  at  the  end  of  eight  days 
they  are  grayish-yellow,  opaque,  and  about  one  to  two  millimetres  in  dia- 
meter; at  the  end  of  two  weeks  they  are  lemon -yellow,  concave,  and  begin 
to  sink  into  a  shallow  funnel  of  liquefied  gelatin  ;  under  a  low  power  they 
are  seen  to  be  finely  granular.  The  deep  colonies  appear  at  first  as  white 
points;  under  the  microscope  they  are  seen  to  be  spherical  or  oval,  brownish- 
yellow,  and  have  sharply  defined  outlines.  In  gelatin  stick  cultures,  at  the 
end  of  six  days,  a  thin,  shining,  yellowish  layer  has  formed  on  the  surface; 
at  the  end  of  two  weeks  the  gelatin  is  softened  and  a  thick,  yellowish- white, 
flocculent  deposit  is  seen,  "while  upon  the  surface  of  the  liquefied  medium 
is  an  irregular,  plate-shaped,  deep  lemon-yellow  layer ;  at  the  end  of  three 
weeks  the  liquefaction  has  extended  to  a  depth  of  about  six  millimetres ;  the 
liquefied  gelatin  is  opaque  and  of  a  yellow  color.  Upon  the  surface  of  agar 
a  yellowish-brown  layer  with  irregular  margins  is  quickly  developed;  upon 
potato,  at  the  end  of  two  weeks,  a  grayish-yellow  layer. 

165.    DIPLOCOCCUS  FLAVUS  LIQUEFACIENS  TARDUS    (Unna). 

Found  upon  the  skin  of  individuals  suffering  from  eczema  seborrhoeicum. 

Morphology. — Biscuit-formed  diplococci,  resembling  the  "  gonococcus" ; 
each  element  in  a  pair  is  from  0.5  to  0.8  /^  in  diameter. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, chromogenic  micrococcus.  Grows  in  the  usual  culture  media  at  the 
room  temperature— very  slowly  upon  gelatin  and  potato,  more  rapidly  on 
agar.  Upon  gelatin  plates,  at  the  end  of  eight  days,  the  superficial  colonies 
are  very  small,  circular,  shining,  pale  grayish-yellow  discs;  at  the  end  of 
three  weeks  they  are  as  large  as  a  hempseed  and  of  a  chrome-yellow  color; 
later  they  become  greenish-yellow  and  float  in  a  circular  zone  of  transparent, 
liquefied  gelatin.  The  deep  colonies  are  at  first  punctiform ;  later  they  are 
small,  opaque  spheres  of  an  olive  brownish-yellow  color.  In  gelatin  stick 
cultures  a  thin,  yellowish-white,  slimy  layer  is  slowly  developed  upon  the 
surface ;  at  the  end  of  three  weeks  this  is  from  three  to  four  millimetres 
in  diameter  and  irregular  in  outline ;  as  it  becomes  older  the  color  is  dark- 
yellow  or  greenish-yellow ;  a  thin,  yellowish  growth  develops  along  the  line 
of  puncture ;  at  the  end  of  four  weeks  the  surface  is  depressed  without  being 
really  liquefied ;  in  eight  weeks  about  half  of  the  gelatin  in  the  tube  is  lique- 
fied and  ti'anspareiit.  The  surface  growth  first  floats  upon  the  liquefied  me- 
dium ;  later  it  settles  to  the  bottom  as  a  thick,  flocculent,  yellow  deposit, 
and  the  gelatin  acquires  a  yellow  color.  Upon  the  surface  of  agar  a  thick, 
slimy,  yellowish  white  layer  with  wavy  margins  is  developed ;  later  this  has 
a  greenish-yellow  color.  Upon  potato  a  sulphur-yellow  layer  is  formed. 


500  NON-PATHOGENIC   MICROCOCCI. 

166.   DIPLOCOCCUS  FLUORESCENS  FCETIDUS  (Klamann). 

Obtained  from  the  posterior  nares. 

Morphology. — Diplococci,  about  1.4  n  in  diameter  (the  pair),  often  ar- 
ranged in  chains  containing  from  six  to  ten  elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, chromogenic  micrococcus.  Grows  in  the  usual  culture  media  at  the 
room  temperature — better  at  37°  C.  Upon  gelatin  plates  the  superficial 
colonies  are  at  first  gray  or  brownish  circular  masses,  which  soon  sink  be- 
low the  surface  of  the  liquefying  gelatin  and  later  form  a  crater-like  de- 
pression, in  the  centre  of  wnich  is  seen  a  brownish-gray  sediment,  while 
the  surrounding  gelatin  has  a  grass-green  or  violet  color.  In  gelatin  stick 
cultures  a  circular,  shallow,  pale-gray,  saucer-shaped  cavity  forms  at  the 
surface,  and  a  purse-like  pouch  along  the  line  of  puncture  ;  a  shining,  iri- 
descent film  floats  upon  the  surface  of  the  liquefied  gelatin,  and  a  greenish- 
gray  sediment  accumulates  at  the  bottom  ;  finally  the  gelatin  is  completely 
liquefied  and  has  a  green  color  above,  while  a  violet-colored  film  floats  upon 
the  surface.  Upon  agar  a  granular,  brownish-gray  layer  is  quickly  devel- 
oped. Upon  potato  a  finely  granular  layer,  which  after  a  time  acquires  a 
dark,  bluish-green  color,  while  the  potato  around  it  is  colored  blue.  The 
color  is  changed  to  red  by  acids. 

167.  DIPLOCOCCUS  LUTEUS  (Adametz). 

Found  in  water, 

Morphology. — Micrococci,  usually  in  pairs,  of  1.2  to  1.3  fit  in  diameter  ; 
sometimes  observed  in  chains  of  eight  to  ten  elements  or  in  irregular  groups. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
micrococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
This  micrococcus  is  described  by  Adametz  as  actively  motile.  Upon  gelatin 
plates,  at  the  end  of  three  days,  circular,  pale-yellow,  viscous  colonies  are 
developed,  which  have  a  diameter  of  about  one  millimetre.  Under  a  low 
power  they  are  seen  to  be  granular  and  brownish-yellow  in  the  centre,  while 
the  margins  are  pale-yellow ;  at  the  end  of  six  days  the  colonies  are  of  an  in- 
tense yellow  color  and  about  three  millimetres  in  diameter.  In  gelatin 
stick  cultures  growth  occurs  rapidly  upon  the  surface  only,  at  first  as  a  cir- 
cular, lemon-yellow  layer  marked  with  concentric  circles;  at  the  end  of 
about  ten  days  the  gelatin  at  the  surface  acquires  an  intense  brownish-red 
color,  which  extends  downward  in  a  cloud-like  manner,  gradually  dimin- 
ishing in  intensity  ;  liquefaction  commences  at  the  end  of  several  weeks. 
Upon  the  surface  of  agar  a  viscid  yellow  layer  is  formed  along  the  impf- 
strich,  and  the  medium  acquires  a  brownish-red  color.  Upon  potato  a  dirty- 
yellow  layer,  which  subsequently  has  a  brownish  color,  is  developed ;  this 
gives  off  the  characteristic  odor  of  penicillum  cultures.  In  milk  coagula- 
tion of  the  casein  is  produced  in  about  five  days. 

168.  DIPLOCOCCUS  ROSEUS  (Bumm). 

Found  in  the  air. 

Morphology.— Diplococci  resembling  the  "  gonococcus, "  the  elements  of 
a  pair  being  hemispherical  and  separated  by  a  tolerably  broad  cleft;  the 
diameter,  measured  from  pole  to  pole,  is  from  1  to  1.5  n. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, chromogenic  micrococcus.  Grows  in  nutrient  gelatin  at  the  room 
temperature.  Upon  gelatin  plates  slightly  elevated,  pink  colonies  are  de- 
veloped, which  under  the  microscope  are  seen  to  be  finely  granular  and  ir- 
regular in  outline.  In  gelatin  stick  cultures  an  abundant  development  oc- 
curs upon  the  surface  and  along  the  line  of  puncture ;  this  has  a  pink  color ; 
the  gelatin  is  slowly  liquefied  after  a  considerable  time. 


NON-PATHOGEXIC   MICROCOCCI.  597 

169.  MICROCOCCUS  CREMOIDES  (Zimmermann). 

Found  in  water. 

Morphology. — Micrococci,  about  0.8  n  in  diameter,  arranged  in  grape-like 
masses. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micrococ- 
cus.  Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  the  deep  colonies  are  small  and  yellowish- white  in  color; 
under  a  low  power  they  are  seen  to  be  spherical,  granular,  and  yellow  or 
brownish-gray.  Superficial  colonies  have  an  irregular,  ' '  gnawed  "  margin, 
and  cause  a  saucer-like  liquefaction  of  the  gelatin,  at  the  bottom  of  which  a 
yellowish- white  mass,  arranged  in  concentric  rings,  may  be  seen ;  around 
the  margin  delicate  outgrowths  into  the  unliquefied  gelatin  may  be  seen.  In 
gelatin  stick  cultures  liquefaction  occurs  along  the  line  of  puncture  in  three 
or  four  days;  an  air  bubble  is  usually  seen  near  the  surface,  and  below  this 
an  accumulation  of  a  yellowish-white  color;  the  liquefied  gelatin  below  this 
is  transparent  for  some  distance,  and  the  bottom  of  the  narrow  channel  is 
again  filled  with  a  yellowish-white  mass  of  micrococci ;  at  the  end  of  a  week 
the  liquefied  channel  measures  about  eleven  millimetres  at  the  surface  and 
a  yellowish- white  film  floats  upon  the  liquefied  gelatin.  Upon  the  surface  of 
agar  a  yellowish- white  layer  with  irregular  margins  and  a  lustre  like  that 
of  amber  is  developed.  Upon  potato  a  tolerably  abundant,  cream-colored 
layer  extends  over  the  surface. 

170.  MICROCOCCUS  ROSEUS  (Eisenberg). 

Found  in  sputum  of  a  patient  with  influenza. 

Morphology. — Micrococci  of  0.8  to  1  n  in  diameter,  solitary  or  in  irregular 
groups. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, chromogenic  micrococcus.  Grows  in  the  usual  culture  media  at  the 
room  temperature,  and  at  37°  C.  without  production  of  color.  Upon  gelatin 
plates,  at  the  end  of  three  to  four  days,  minute  pink  colonies  are  formed ; 
later  liquefaction  commences  about  the  colonies  and  progresses  slowly.  In 
gelatin  stick  cultures  development  occurs  slowly  both  upon  the  surface  and 
along  the  line  of  puncture ;  the  growth  is  at  first  colorless ;  after  three  to 
four  days  a  small,  round,  pink  layer  is  formed,  which  is  depressed  in  the 
centre ;  at  the  end  of  a  week  the  color  resembles  that  of  a  red  azalea  blossom, 
and  liquefaction  commences ;  at  the  end  of  three  weeks  the  gelatin  is  about- 
half -liquefied  and  a  pink  sediment  is  seen.  Upon  the  surface  of  agar,  at 
the  room  temperature,  a  soft,  dark-pink  layer  is  formed  along  the  impfstrich 
in  two  days ;  at  37°  C.  a  similar  development  occurs  in  twenty-four  hours, 
but  without  color.  Upon  potato,  at  the  end  of  three  to  four  days,  a  cherry- 
red  streak  is  seen  along1  the  impfstrich ;  this  gradually  becomes  darker  and 
covers  the  entire  surface ;  the  growth  then  resembles  that  of  Bacillus  pro- 
digiosus. 

171.    MICROCOCCUS   AURANTIACUS   (Cohn). 

Found  in  water. 

Morphology. — Spherical  or  slightly  oval  cocci,  1.3  to  1.5  >«  in  diameter, 
solitary,  in  pairs,  or  in  irregular  groups. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus. Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  spherical  or  elliptical  colonies  of  an  orange-yellow  color 
and  smooth,  shining  surface.  In  gelatin  stick  cultures  a  small,  button-like, 
yellow  growth  develops  upon  the  surface,  and  after  a  considerable  time  mi- 
nute yellow  colonies  are  seen  along  the  line  of  puncture.  Upon  agar  an 
orange-yellow  layer  is  formed,  and  upon  potato  a  slimy,  yellow  growth. 

50 


598  NON-PATHOGENIC   MICROCOCCI. 

172.    MICROCOCCUS  CERASINUS   SICCUS   (List). 

Found  in  water. 

Morphology. — Micrococci,  from  0.25  to  0.32  /*  in  diameter,  solitary  or  in 
pairs. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus.  Grows  best  at  37  C.  Does  not  grow  well  in  nutrient  gelatin. 
Upon  the  surface  of  agar  a  dry,  cherry-red  layer  is  quickly  developed. 
Upon  potato  the  surface  is  quickly  covered  with  a  cherry-red  layer.  The 
pigment  is  not  soluble  in  water,  alcohol,  or  ether,  and  is  not  changed  by 
acids  or  alkalies. 

173.   MICROCOCCUS  VERSICOLOR  (Fliigge). 

Found  in  water. 

Morphology. — Micrococci,  in  pairs  or  in  irregular  groups. 

Biological  Characters. — Anaerobic,  non-liquefying,  chromogenic  micro- 
coccus.  Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  the  deep  colonies  are  at  first  white  points;  later  yellow, 
opaque,  finely  granular  spheres.  The  superficial  colonies  are  irregular  in 
outline,  slimy,  and  have  a  pear]y  lustre;  they  may  attain  a  diameter  of  two 
to  ten  millimetres.  In  gelatin  stick  cultures  small,  spherical,  yellow  colonies 
develop  along  the  line  of  puncture,  and  a  layer  with  irregular,  "gnawed  " 
margins  and  a  pearly  lustre  upon  the  surface.  Upon  agar  a  slimy,  opaque 
layer  of  a  yellowish-brown  color.  Upon  potato  a  slimy  layer  is  quickly  de- 
veloped. 

174.    MICROCOCCUS   OF  DANTEC. 

Obtained  by  Dantec  (1891)  from  salted  codfish  which  had  undei'gone 
changes  characterized  by  a  red  color  and  an  offensive  odor. 

Morphology. — Micrococci,  from  three  to  five  n  in  diameter,  often  marked 
by  a  line  of  commencing  binary  division. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  micro- 
coccus.  Forms  a  red  pigment.  In  gelatin  plates  small,  disc-shaped  colo- 
nies of  a  red  color  are  slowly  developed ;  these  rarely  measure  more  than  a 
millimetre  in  diameter.  In  gelatin  stick  cultures  development  is  slow ; 
along  the  line  of  puncture  the  growth  has  a  yellowish  color ;  on  the  surface 
it  is  of  a  pale-red,  and  later  of  deeper-red  color.  Upon  agar  the  development 
is  more  rapid  than  upon  gelatin.  It  grows  upon  dried  codfish  without  pro- 
duction of  pigment,  except  when  it  is  associated  with  other  microorganisms — 
especially  a  liquefying  coccus  which  is  often  found  with  it. 

Not  pathogenic. 

175.  MICROCOCCUS  CARNEUS  (Zimmermann). 

Found  in  water. 

Morphology. — Micrococci,  having  a  diameter  of  about  0.8  y«,  united  in 
irregular,  grape-like  masses. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus.  Grows  best  at  the  room  temperature  ;  very  scanty  develop- 
ment at  30°  to  33°  C.  Upon  gelatin  plates  the  deep  colonies  are  small, 
spherical,  and  grayish-white  in  color.  Superficial  colonies  are  but  slightly 
elevated,  circular  in  outline,  and  of  a  grayish-red  to  pale-red  color  ;  under 
the  microscope  they  are  seen  as  circular  discs  with  a  more  opaque,  reddish- 
gray  centre  surrounded  by  a  somewhat  more  transparent  zone,  and  this  by 
a  second,  still  paler  zone ;  in  older  cultures  the  distinct  zones  are  no  longer 
to  be  distinguished,  but  the  reddish-brown  color  fades  out  from  the  centre 
towards  the  margin  of  the  colonies.  In  gelatin  stick  cultures,  at  the  end  of 
five  days,  a  thin,  circular,  pale-pink  layer,  with  irregular  outlines  and  about 


NON-PATHOGENIC   MICROCOCCI.  599 

3.5  millimetres  in  diameter,  is  developed  upon  the  surface,  and  a  finely 
granular,  white  growth  along  the  line  of  puncture.  Upon  the  surface  of 
gelatin  a  flesh-red  layer,  which  later  acquires  a  violet  hue,  is  formed  along 
the  impfstrich.  Upon  agar  the  growth  is  similar  but  more  abundant,  and 
the  margins  are  coarsely  toothed.  Upon  potato  an  abundant  red  layer  is  de- 
veloped. 

176.  MICROCOCCUS   CINNABAREUS   (Flligge). 

Found  in  air  and  in  water. 

Morphology. — Large,  spherical  cocci,  frequently  associated  in  pairs  or  in 
tetrads. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  the  deep  colonies  are  first  seen  as  minute  points  at  the 
end  of  four  days ;  under  a  low  power  they  are  seen  to  be  oval  or  lenticular, 
with  a  well-defined  contour  and  of  a  dark  reddish-brown  color.  The  super- 
ficial colonies,  at  the  end  of  four  days,  are  from  0. 5  to  1  millimetre  in  dia- 
meter and  brick- red ;  at  the  end  of  eight  days  they  project  from  the  gelatin  in 
button-shape  and  are  cinnabar-red.  In  gelatin  stick  cultures  isolated  white 
colonies  are  seen  along  the  line  of  puncture  at  the  end  of  four  to  five  days, 
and  upon  the  surface  a  button-like  mass  of  moderate  dimensions  is  de- 
veloped, which  is  first  pink  and  later  cinnabar-red.  Upon  potato  a  cinnabar- 
red  layer  is  slowly  developed. 

177.  MICROCOCCUS  CEREUS  ALBTis  (Passet). 

Obtained  by  Passet  (1885)  in  the  pus  of  acute  abscesses  (two  cases  out  of 
thirty-three  examined),  and  by  Tils  (1890)  from  the  Freiburg  water  supply. 

Morphology. — Large  cocci,  *1. 16  n  in  diameter,  solitary  or  associated  in 
irregular  groups. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  forms  superficial  colonies,  which  attain  a  diameter  of  one  to  two  mil- 
limetres and  resemble  drops  of  stearin  or  white  wax.  In  gelatin  stick  cul- 
tures grows  upon  the. surface  as  a  grayish- white  layer  with  irregular,  thick- 
ened margins,  resembling  a  drop  of  stearin;  scanty  growth  along  the  line  of 
puncture.  Upon  potato  a  dirty-white  layer  of  moderate  thickness  is  de- 
veloped. 

178.  MICROCOCCUS  CEREUS  FLAVus  (Passet). 

Obtained  by  Passet  (1885),  in  a  single  case  out  of  thirty-three  examined, 
from  the  pus  of  an  acute  abscess. 

Morphology. — Micrococci  of  irregular  dimensions,  associated  in  irregular 
groups  and  occasionally  in  chains. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  micro- 
coccus.  Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  lemon-yellow  colonies  are  developed,  which  attain  a  diameter 
of  one  to  two  millimetres.  In  gelatin  stick  cultures  the,  growth  around  the 
•point  of  inoculation  resembles  a  drop  of  stearin  or  wax  with  elevated  mar- 
gins and  has  a  yellow  color ;  a  scanty  yellow  streak  is  developed  along  the 
line  of  puncture.  Upon  potato  a  citron-yellow  layer  is  formed. 

179.    MICROCOCCUS   CITREUS. 

Synonym. — Cremefarbiger  micrococcus  (List). 
Found  in  water. 

Morphology. — Large,  spherical  cocci,  from  1.5  to  2.2/*in  diameter,  soli- 
.ary,  in  pairs,  or  in  chains  of  eight  or  more  elements. 

Biological  Characters. — Anaerobic,  non-liquefying,  chromogenic  micro- 


600  NON-PATHOGENIC    MICROCOCCI. 

coccus.  Grows  in  the  usual  culture  media  at  the  room  temperature — better 
at  37°  C.  Upon  gelatin  plates  forms  upon  the  surface  dirty  pale-yellow  or 
cream-colored  colonies,  which  after  several  days  have  a  diameter  of  0.5  to 
0.8  centimetre  and  are  about  0.5  millimetre  thick;  these  have  usually  irre- 
gular outlines  and  a  moist,  shining  appearance.  In  gelatin  stick  cultures 
very  scanty  growth  occurs  along  the  line  of  puncture.  Upon  agar  a  pale- 
yellow  layer  is  formed.  Upon  potato,  at  37°  C.,  an  abundant  growth  occurs, 
forming  a  yellow  layer. 

180.  MICROCOCCUS  FERVIDOSUS  (Adametz). 

Found  in  water. 

Morphology, — Small,  round  cocci,  0.6  n  in  diameter,  in  pairs  or  in  ir- 
regular groups. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  media  at  the  room  temperature.  Upon  gelatin  plates,  at  the  end 
of  four  to  five  days,  the  deep  colonies  appear  as  white  points,  which  under  a 
low  power  have  a  pale-yellow  color  and  resemble  dewdrops;  upon  the  sur- 
face transparent,  yellow  colonies  with  irregular,  jagged  edges  are  devel- 
oped ;  later  these  are  granular  in  the  centre  and  have  a  brownish  color, 
while  the  marginal  zone  is  yellowish  and  slightly  wrinkled.  In  gelatin 
stick  cultures  a  thin,  circular  layer  with  finely  toothed  margins  forms  upon 
the  surface,  and  a  granular  growth  along  the  line  of  puncture.  In  glycerin- 
gelatin  numerous  gas  bubbles  of  various  sizes  are  developed  in  the  medium. 
Upon  agar  a  circular,  milk-white,  slimy  layer  is  formed,  which  later  has  a 
pearly  lustre.  Upon  potato  a  dirty- white  layer  with  irregular  margins. 

181.    MICROCOCCUS  FLAVUS  TARDIGRADUS    (Fliigge). 

'Found  in  the  air  and  in  water. 

Morphology. — Large,  spherical  cocci,  usually  associated  in  irregular 
groups ;  sometimes  have  peculiar  dark  poles. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus. Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  the  deep  colonies  are  spherical  or  oval,  dark  chrome- 
yellow,  and  from  0.4  to  0.6  millimetre  in  diameter;  under  a  low  power 
they  appear  to  have  a  dark  olive-green  color.  The  superficial  colonies  are 
from  0.5  to  1  millimetre  in  diameter,  have  a  smooth,  varnished-looking  sur- 
face, and  are  slightly  elevated  above  the  surface  of  the  gelatin  at  the  mid- 
dle ;  under  a  low  power  the  centre  is  grayish-yellow  and  the  margin  paler. 
In  gelatin  stick  cultures,  at  the  end  of  eight  days,  a  row  of  small,  spherical, 
isolated  yellow  colonies  is  developed  along  the  line  of  puncture. 

182.   MICROCOCCUS  LUTEUS   (Cohn). 

Found  in  water. 

Morphology. — Oval  cocci,  from  1  to  1.2  /*  in  diameter,  associated  in  zo- 
oglcea  masses  ;  the  intercellular  substance  is  easily  soluble  in  water. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus. The  yellow  pigment  produced  is  not  soluble  in  water,  ether,  or 
alcohol,  and  is  not  changed  by  acids  or  alkalies.  Grows  in  the  usual  cul- 
ture media  at  the  room  temperature.  Upon  gelatin  plates  sulphur-yellow, 
superficial  colonies  are  developed,  which  have  irregular  outlines  and  may 
attain  a  diameter  of  4  millimetres  and  a  thickness  of  0. 5  millimetre ;  under 
a  low  power  they  are  seen  to  be  granular.  In  gelatin  stick  cultures  a  yel- 
low layer  forms  about  the  point  of  puncture  and  a  granular  growth  along 
the  line  of  inoculation.  Upon  agar  a  yellow,  slimy  layer.  Upon  potato  an 
intensely  yellow  layer  with  irregular  margins,  which  after  a  time  has  a 
wrinkled  surface. 


NON-PATHOGENIC   MICROCOCCI.  601 

183.   MICROCOCCTJS  VIOLACEUS  (Cohn). 

Found  in  water. 

Morphology. — Elliptical  cocci,  frequently  united  in  chains. 

Biological  Characters. — An  aerobic,  non -liquefy ing,  chromogenic  mi- 
crococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  forms  superficial  colonies  of  hemispherical  form  and 
violet  color.  In  gelatin  stick  cultures  scanty  growth  along  the  line  of 
puncture,  and  upon  the  surface  a  hemispherical  mass  of  violet-blue  color. 
Upon  agar  a  violet -blue  layer.  Upon  potato  a  violet-colored  streak  is 
formed  along  the  impfstrich. 

184.    STAPHYLOCOCCUS  VIRIDIS  FLAVESCENS   (Guttmann). 

Found  in  the  vesicles  of  varicella. 

Morphology. — Micrococci  of  irregular  dimensions,  solitary,  in  pairs,  or 
in  irregular  groups;  does  not  differ  in  morphology  from  Staphylococcus 
pyogenes  aureus. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  mi- 
crococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates,  at  the  end  of  two  days,  small,  greenish-yellow  colo- 
nies become  visible ;  under  a  low  power  these  are  seen  to  be  spherical  and 
slightly  granular  upon  the  surface — less  so  at  a  later  date.  In  gelatin  stick 
cultures  growth  occurs  both  upon  the  surface  and  along  the  line  of  punc- 
ture, of  a  grayish-yellow  color.  Upon  agar,  at  the  end  of  twenty- four 
hours  at  37°  C.,  a  greenish-yellow  growth  occurs  along  the  line  of  puncture. 
An  abundant  development  occurs  upon  potato  in  twenty-four  hours  at 
37°  C. 

185.    MICROCOCCUS  OCHROLEUCUS   (Prove). 

Found  in  urine  of  man. 

Morphology. — Micrococci,  from  0.5  to  0.8  /*  in  diameter,  solitary,  in 
pairs,  or  in  short  chains. 

Biological  Characters. — An  aerobic,  non- liquefy  ing,  chromogenic  micro- 
coccus.  The  pigment  is  soluble  in  alcohol,  insoluble  in  water,  and  is  decol- 
orized by  acids.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates,  at  the  end  of  twenty-four  hours,  small,  colorless  colo- 
nies are  developed,  surrounded  by  a  somewhat  elevated  and  wavy  border ; 
later  branching  offshoots  are  given  off  from  the  margin  and  the  centre  ac- 
quires a  sulphur-yellow  color.  In  gelatin  stick  cultures  a  thin,  colorless, 
superficial  layer  is  quickly  developed ;  this  in  three  or  four  days  acquires  a 
sulphur-yellow  color.  The  growth  upon  potato  is  scanty  and  is  scarcely 
visible  before  the  fifth  day.  Old  gelatin  cultures  give  off  a  peculiar  odor. 

186.    MICROCOCCUS  ACIDI  LACTICI  LIQUEFACIENS   (Kreuger). 

Found  in  "  cheesy  butter." 

Morphology. — Oval  cocci,  from  1  to  1.5  ft  in  diameter,  frequently  associ- 
ated in  pairs  or  in  tetrads. 

Biological  Characters.—  An  aerobic  smd  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  best  at  the  room  temperature.  Upon  gelatin 
plates  small,  white  colonies  are  developed  at  the  end  of  three  days,  which 
under  the  microscope  are  seen  to  have  deeply  cleft  margins ;  the  gelatin 
about  the  colonies  is  gradually  liquefied.  In  gelatin  stick  cultures  a  white, 
granular  growth  occurs  along  the  line  of  puncture,  and  a  funnel-shaped 
liquefaction  of  the  gelatin  occurs  by  the  third  day ;  liquefaction  progresses 
rapidly,  and  a  dirty-white,  slightly  wrinkled  layer  forms  upon  the  surface, 
while  the  gelatin  below  is  clouded.  In  milk  coagulation  occurs  in  three 
days  at  20°  to  25°  C.,  and  lactic  acid  is  formed;  a  clear  layer  of  serum  is 
seen  above  the  homogeneous  coagulated  mass  of  casein,  which  is  not  subse- 
quently peptonized. 


602  NON-PATHOGENIC   MICROCOCCI. 

187.    MICROCOCCUS  AEROGENES   (Miller). 

Found  in  the  alimentary  canal. 

Morphology. — Large  oval  cocci. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. Upon  gelatin  plates  forms  spherical  colonies  of  dark  color  and  smooth 
contour.  In  gelatin  stick  cultures  development  occurs  along  the  line  of 
puncture,  with  a  brownish-yellow  color,  and  a  flat,  button-like,  grayish- 
white,  soft  mass  is  formed  upon  the  surface ;  slight  liquefaction  occurs  after 
some  days.  Upon  the  surface  of  agar  a  yellowish-white,  pap-like  layer  is 
formed.  The  growth  upon  potato  is  similar  to  that  upon  agar.  Possesses  a 
great  resistance  against  the  action  of  acids. 

188.    MICROCOCCUS  ALBUS  LIQUEFACIENS   (Von  BeSSer). 

Very  common  in  the  nasal  mucus  of  healthy  persons. 

Morphology. — Micrococci,  about  twice  as  large  as  Staphylococcus  pyo- 
genes  albus,  spherical  or  elliptical ;  in  irregular  groups  or  in  chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  produces  a  stocking-shaped  pouch  of  lique- 
fied gelatin,  and  after  a  time  complete  liquefaction— sometimes  only  pai'tial 
and  very  tardy  liquefaction.  Upon  agar  plates  white,  shining  colonies 
with  an  elevation  at  the  centre  and  of  the  margin,  with  a  depression  be- 
tween, 0.5  centimetre  or  more  in  diameter;  under  a  low  power  the  centre 
appears  brownish  and  is  surrounded  by  a  dark  zone,  this  py  a  more  trans- 
parent, grayish-brown  zone,  and  finally  by  an  opaque  marginal  ring.  Upon 
potato  a  shining,  white  layer  is  developed. 

189.  MICROCOCCUS  FCETIDUS  (Klamann). 

Found  in  the  posterior  nares  of  man. 

Morphology. — Micrococci  of  irregular  dimensions,  solitary,  in  pairs,  in 
short  chains,  or  in  irregular  groups;  the  diplococci  measure  1.4/*  in  dia- 
meter. 

Biological  Characters. — An  aerobic,  liquefying  micrococcus.  Grows  at 
the  room  temperature  in  the  usual  culture  media — not  so  well  in  the  incu- 
bating oven.  Upon  gelatin  plates  oval  or  spherical  white  colonies  are  slowly 
developed.  In  gelatin  stick  cultures  a  milk-white,  shining,  elevated  mass, 
with  a  knobby  surface,  is  developed  about  the  point  of  puncture ;  later  this 
presents  a  central  prominence  surrounded  by  concentric  circles  and  acquires 
a  brownish  color ;  liquefaction  occurs  slowly  and  the  cultures  develop  a 
disagreeable  odor  like  that  of  ozaena.  Upon  the  surface  of  agar  a  whitish, 
irregular  layer  is  slowly  developed  and  extends  over  the  entire  surface. 
Upon  potato  a  slimy,  irregular  growth,  of  a  pale  reddish-gray  color  and  a 
knobby  surface,  which  gives  off  an  intense  and  disagreeable  odor  like  that 
of  oza3na. 

190.    MICROCOCCUS  RADIATUS  (Fliigge). 

Found  in  the  air  and  in  water. 

Morphology. — Micrococci,  from  0.8  to  1  /*  in  diameter,  solitary,  in  short 
chains,  or  in  irregular  groups. 

Biological  Characters. — An  aerobic,  liquefying  micrococcus.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates,  at 
the  end  of  two  days,  white  colonies  with  a  yellowish-green  shimmer,  about 
one  millimetre  in  diameter,  are  developed ;  under  a  low  power  these  appear 
yellowish-brown  and  have  starfish-like  outgrowths ;  at  the  end  of  four  days 
a  delicate,  regularly -arranged,  radiating  aureole  surrounds  the  colonies,  out- 


NON-PATHOGENIC  MICROCOCCI.  603 

side  of  which  a  second  and  finally  a  third  similar  "  Strahlenkranz  "  is 
often  developed;  liquefaction  progresses  slowly  about  the  colonies.  In 
gelatin  stick -cultures  feathery  outgrowths  occur  at  intervals  along  the  line 
of  puncture,  radiating  horizontally  into  the  gelatin ;  liquefaction  commences 
near  the  surface  as  a  pointed  funnel  and  gradually  extends  downward. 
Upon  potato  a  yellowish-brown  layer  is  quickly  developed. 

191.   DIPLOCOCCUS  ALBICANS  AMPLUS. 

Synonym. — Gray- white  micrococcus  (Bumm). 

Found  in  mucus  from  the  healthy  vagina. 

Morphology. — Diplococci  resembling  the  "  gonococcus  "  inform,  but  con- 
siderably larger,  from  2  to  2.8  ft  in  diameter;  the  diplococci  are  usually  soli- 
tary, but  sometimes  are  in  groups  of  three  or  four. 

"Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  at  the  room  temperature  in  the  usual  culture  me- 
dia. Upon  gelatin  plates  slightly  elevated,  grayish-white  colonies  are 
formed.  In  gelatin  stick  cultures  growth  occurs  upon  the  surface  and  along 
the  line  of  puncture  as  a  grayish-white  stripe ;  after  a  time  liquefaction  com- 
mences under  the  surface  growth. 

192.    MICROCOCCUS  CANDICANS  (Flugge). 

Very  common  in  the  air  and  in  water. 

Morphology. — Spherical  cocci,  from  1  to  1.2  M-  in  diameter,  associated  in 
irregular  groups. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates, 
at  the  end  of  two  days,  the  deep  colonies  are  spherical  and  white  or  yellow- 
ish in  color,  of  from  0.4  to  0.5  millimetre  in  diameter  ;  under  the  micro- 
scope they  are  seen  to  be  finely  granular,  dark-brown  spheres.  Upon  the 
surface  milk-white,  shining  colonies  with  irregular  outlines,  which  under 
the  microscope  are  seen  to  be  finely  granular  and  to  have  jagged  margins. 
In  gelatin  stick  cultures  a  confluent  white  growth  forms  along  the  line  of 
puncture,  and  a  button-like  mass  upon  the  surface.  Upon  potato  a  slimy, 
white  layer  is  quickly  developed. 

193.    MICROCOCCUS   CANDIDUS   (Cohn). 

Found  in  water. 

Morphology. — Small,  perfectly  spherical  cocci,  from  0.5  to  0.7  n  in  diame- 
ter, united  in  zoo'gloea  masses — the  intercellular  zooglcea  substance  is  soluble 
in  water. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  snow-white  colonies  with  irregular  outlines,  which  under  the  micro- 
scope are  seen  to  be  slightly  granular.  In  gelatin  stick  cultures  a  flat,  milk- 
white  layer  is  formed  about  the  point  of  puncture;  very  scanty  development 
along  the  line  of  inoculation.  Upon  agar  the  same  as  on  gelatin. 

194.  MICROCOCCUS  ACIDI  LACTICI  (Marpmann). 

Found  in  cow's  milk. 

Morphology. — Large  cocci,  solitary  or  in  pairs. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  at  the  end  of  twenty-four  hours  punctiform,  yellowish-white,  lustre- 
less colonies.  In  gelatin  stick  cultures  a  thin,  yellowish  layer  forms  upon 
the  surface,  which  is  thickest  in  the  middle,  thin  and  transparent  at  the 


604  NON-PATHOGENIC  MICROCOCCI. 

margin,  and  without  lustre.  In  miflc,  at  the  end  of  twelve  hours,  a  red 
color  is  developed,  which  disappears  at  the  end  of  twenty-four  hours,  when 
coagulation  has  occurred  as  a  result  of  the  formation  of  lactic  acid. 

195.    MICROCOCCUS  LACTIS  VISCOSUS. 

Synonym. — Micrococcus  of  bitter  milk  (Conn). 

Found  in  cream  which  had  a  bitter  taste. 

Morphology. — Micrococci  of  moderate  dimensions,  frequently  united  in 
pairs ;  in  agar  cultures  forms  short  chains. 

Biological  Characters. — Anaerobic  and  facultative  anaerobic,  liquefying 
micrococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature — 
more  rapidly  at  35°  C.  Upon  gelatin  plates  forms  small,  spherical  colonies, 
which,  as  liquefaction  commences,  spread  out  upon  the  surface  as  a  thin, 
granular  mass.  In  gelatin  stick  cultures  liquefaction  commences  at  the  sur- 
face, forming  a  shallow  cavity,  and  rapidly  progresses  until  the  gelatin  is 
entirely  liquefied ;  the  liquefied  gelatin  is  extremely  viscid.  Upon  agar  a 
shining,  homogeneous  white  layer  is  developed.  Upon  potato  white,  shining 
masses,  which  are  more  or  less  separated  from  each  other.  In  bouillon  an 
abundant  development  occurs  and  a  thin  film  is  formed  upon  the  surface ; 
the  bouillon  becomes  very  viscous.  In  milk  growth  is  rapid  and  the  milk 
acquires  a  bitter  taste;  at  35°  C.  coagulation  occurs  in  twenty-four  hours  and 
the  milk  has  an  acid  reaction ;  the  coagulum  is  soft  and  soon  commences  to 
dissolve  from  the  peptonizing  action  of  the  ferment,  but  solution  is  not  com- 
plete. Cultures  in  gelatin  and  bouillon  are  especially  viscid,  and  may  be 
drawn  out  into  threads  which  are  scarcely  visible  and  are  as  much  as  three 
metres  long.  The  acid  formed  by  the  growth  of  this  micrococcus  in  milk  is 
butyric. 

196.  SPHJEROCOCCUS  ACIDI  LACTICI  (Marpmann). 

Found  in  fresh  cow's  milk. 

Morphology. — Very  small,  oval  cocci,  in  pairs  or  in  short  chains. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  porcelain-white  colonies,  the  size  of  a  pin's  head,  upon  the  surface  of 
the  gelatin.  In  gelatin  stick  cultures  growth  is  scanty  along  the  line  of 
puncture ;  upon  the  surface  a  layer  is  developed  which  has  sloping,  toothed 
margins,  and  at  the  end  of  six  weeks  acquires  a  pale-yellow  color.  Milk  ac- 
quires a  reddish  color,  and  is  coagulated  at  the  end  of  twenty-four  hours, 
with  formation  of  lactic  acid. 

197.    MICROCOCCUS  AQUATILIS  (Bolton). 

Very  common  in  water. 

Morphology. — Small  cocci,  associated  in  irregular  groups. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  circular,  porcelain- white,  slightly  elevated  colonies;  under  a  low 
power  the  deep  colonies  are  seen  to  be  mulberry-like  in  form,  with  roughly 
toothed  contour  and  a  pale-yellowish  color;  the  superficial  colonies  are  cir- 
cular and  are  surrounded  by  a  narrow,  homogeneous  marginal  zone,  while 
the  interior  is  peculiarly  marked,  resembling  a  schematic  drawing  of  a  sec- 
tion of  a  liver  acinus.  In  gelatin  stick  cultures  growth  occurs  both  on  the 
surface  and  along  the  line  of  puncture,  of  a  white  color.  Upon  the  surface 
of  agar  a  white  layer  is  formed. 

198.  MICROCOCCUS  CONCENTRICUS  (Zimmermann). 

Found  in  water. 

Morphology. — Micrococci,  0.9  /*  in  diameter,  associated  in  irregular 
masses. 


NON-PATHOGENIC  MICROCOCCI.  605 

Biological  Characters. — Anaerobic,  non-liquefyingmicrococcus.  Grows 
in  the  usual  culture  media — best  at  the  room  temperature.  Upon  gelatin 
plates  the  deep  colonies  appear  as  small,  bluish-gray  points;  the  superficial 
colonies  are  at  first  small,  bluish-gray  discs,  which  later  are  irregular  in  out- 
line ;  at  the  end  of  five  days  they  are  about  three  millimetres  broad  and  con- 
sist of  a  central  grayish- white  disc  surrounded  by  a  bluish-gray  ring  with  ir- 
regular outlines.  Under  a  low  power  the  deep  colonies  are  seen  to  be  spherical 
and  granular,  of  a  pale-brown  or  yellowish-green  color,  and  in  the  interior 
usually  several  concentric  rings  are  observed;  the  superficial  colonies  show 
in  the  interior  a  darker  disc  with  irregular  margins  and  marked  by  fine  ra- 
diating fissures ;  around  this  is  an  irregular  marginal  zone  of  a  pale-brown 
color  and  granular  in  appearance,  and  this  is  enclosed  in  a  white,  shining 
border.  In  gelatin  stick  cultures  a  thin,  bluish-gray  layer  forms  upon  the 
surface,  which  consists  of  a  number  of  concentric  rings  of  growth  arranged 
around  the  point  of  puncture  as  a  centre.  Upon  agar  a  broad,  smooth,  shin- 
ing layer  with  toothed  margins  and  of  bluish-gray  white  color.  Oil  potato 
a  thin,  slimy,  yellowish-gray  layer. 

199.  MICROCOCCUS  CUMULATUS  TENUis  (Von  Besser). 

Very  common  in  nasal  mucus  of  man. 

Morphology. — Large  oval  cocci,  associated  in  masses. 

Biological  Characters. — Anaerobic  and  facultative  anaerobic,  non-lique- 
fying micrococcus.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  grows  along  the  line  of  puncture  as  a  delicate 
white  stripe  composed  of  small  colonies ;  upon  the  surface  as  a  flat,  trans- 
parent layer  with  slightly  elevated  margins.  Upon  agar  plates  as  thick, 
transparent  drops  about  0.2  millimetre  in  diameter;  under  a  low  power 
these  are  seen  to  have  a  large  brown  nucleus  surrounded  by  a  grayish-brown 
zone  having  wrinkled  margins ;  later  the  colonies  attain  a  diameter  of  0. 5 
centimetre,  and  appear  as  flat,  transparent  discs  with  a  large  central  nucleus. 
Scarcely  any  growth  upon  potato.  In  bouillon  a  considerable  deposit  accu- 
mulates at  the  bottom  of  the  tube,  and  the  liquid  is  nearly  transparent 
above. 

200.  MICROCOCCUS  PLUMOSUS  (Brautigam). 

Found  in  water. 

Morphology. — Micrococci,  0.8  n  in  diameter,  associated  in  zoogloea. 

Biological  Characters. — Anaerobic,  non-liquefying  micrococcvis.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
yellowish- white  colonies  are  developed,  which  send  out  tongue-like  processes 
and  the  margins  of  which  are  abruptly  thickened.  In  gelatin  stick  cultures, 
from  along  the  line  of  puncture,  at  certain  points,  long,  delicate,  white  off- 
shoots are  given  off  into  the  gelatin,  which  resemble  needle- like  crystals; 
similar  offshoots  from  the  layer  upon  the  surface  of  the  gelatin  are  also 
seen ;  these  consist  of  cocci  in  masses,  arranged  like  chains  of  pearls.  Upon 
potato  an  irregular,  yellowish- white  layer  with  tongue-like  offshoots. 

201.  MICROCOCCUS  ROSETTACEUS  (Zimmermaiin). 

Found  in  water. 

Morphology. — Spherical  or  elliptical  cocci,  from  0.7  to  1  ft  in  diameter, 
associated  in  grape-like  masses. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
the  deep  colonies  are  small,  grayish-white,  and  usually  spherical  in  form ; 
under  a  low  power  they  are  sometimes  seen  to  be  lenticular  or  mussel  - 
shaped.  The  superficial  colonies  are  rather  broad,  shining,  yellowish-gray 
drops,  with  more  or  less  irregular  outlines.  In  gelatin  stick  cultures  a  thin, 


606  NON-PATHOGENIC   MICROCOCCI. 

gray,  rosette-like  layer  of  irregularly  circular  contour  develops  upon  the 
surface;  very  scanty  growth  along  the  line  of  puncture.  Upon  aoar  a 
smooth,  shining,  gray  layer  with  finely  toothed  margins.  Upon  potato  a 
yellowish-gray  layer  is  quickly  formed. 

202.  MICROCOCCUS  URE.E  (Pasteur). 

Found  in  the  air  and  in  ammoniacal  urine. 

Morphology.—  Micrococci,  from  0.8  to  1  /f  in  diameter,  solitary,  in  pairs, 
in  tetrads,  or  in  short  chains ;  also  in  zoogloea  masses. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  in  the  usual  culture  media  at  the  room  tem- 
perature—better at  30°  to  35°  C.  Upon  gelatin  plates  forms,  at  the  end  of 
twenty-four  hours,  small,  white,  pearly,  shining  colonies  of  smooth  surface 
and  sharply  defined  outline ;  at  the  end  of  ten  days  these  are  large,  flat  colo- 
nies resembling  a  drop  of  stearin.  In  gelatin  stick  cultures  development  oc- 
curs along  the  line  of  puncture  in  form  of  a  thin,  tenacious  thread.  Old  cul- 
tures have  a  paste- like  odor. 

According  to  Von  Jaksch,  a  very  favorable  medium  for  the  growth  of  this 
micrococcus  is  made  by  adding  to  one  litre  of  water,  magnesia  sulphate 
one-sixteenth  gramme,  potassium  hypophosphite  one-eighth  gramme,  potas- 
sium sodium  tartrate  five  grammes,  urea  five  grammes.  In  urine  and  solu- 
tions containing  urea  carbonate  of  ammonia  is  formed  during  the  develop- 
ment of  this  micrococcus — ammoniacal  fermentation. 

203.    MICROCOCCUS  URE.E  LIQUEFACIENS  (Flugge). 

Found  in  ammoniacal  urine. 

Morphology. — Spherical  cocci,  from  1.25  to  2  n  in  diameter,  solitary,  in 
chains  of  three  to  ten  elements,  or  in  irregular  groups. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefying 
micrococcus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  forms,  at  the  end  of  twenty-four  hours,  small,  white, 
punctiform  colonies,  which  under  a  low  power  appear  as  well-defined,  dark- 
gray  spheres;  after  they  reach  the  surface  of  the  gelatin  the  colonies  become 
considerably  larger,  have  a  yellowish-brown  color  and  a  central  nucleus 
consisting  of  the  original  deep  colony ;  the  surface  of  the  superficial  colo- 
nies is  granular,  the  outline  becomes  gradually  wavy ;  liquefaction  of  the 
gelatin  around  the  colonies  occurs  gradually.  In  gelatin  stick  cultures  a 
confluent,  white  growth  develops  along  the  line  of  puncture,  and  liquefac- 
tion quickly  occurs  and  extends  to  the  walls  of  the  tube;  finally  one-half 
or  more  of  the  gelatin  is  liquefied  and  has  a  whitish,  clouded  appearance^ 
while  a  thick,  yellowish- white  deposit  is  seen  at  the  bottom. 

204.   MICROCOCCUS  VITICULOSUS  (Katz). 

Found  in  the  air  and  in  water. 

Morphology. — Oval  micrococci,  from  1  to  1.2  n  in  diameter;  forms  thick 
zoogloea  masses. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  rapidly  in  the  usual  culture  media  at  the 
room  temperature.  Upon  gelatin  plates  the  deep  colonies  are  seen  to  con- 
sist of  hair-like  branches  given  off  from  a  centre,  and  which  for  some  dis- 
tance form  a  delicate  network ;  under  a  low  power  these  branches  are  seen 
to  be  made  up  of  zoogloea  masses  of  various  dimensions  united  in  chaplets. 
The  superficial  colonies  extend  rapidly  as  a  thin,  jelly-like,  clouded  white 
layer,  from  which  fine  threads  are  given  off  into  the  deeper  layers  of  the 
gelatin.  In  gelatin  stick  cultures  growth  occurs  along  the  line  of  puncture 
as  a  delicate  network  of  threads ;  upon  the  surface  a  feathery  growth  occurs 
along  the  line  of  inoculation.  Upon  potato  a  dry,  dirty-white  layer  is. 
quickly  developed. 


NON-PATHOGENIC  MICROCOCCI.  607 

205.  DIPLOCOCCUS  ALBICANS  TARDissiMUS  (Eisenberg). 

Synonym. — Milk-white  micrococcus  (Bumm). 

Found  in  secretions  from  the  vagina  and  cervix,  especially  in  the  vaginal 
secretions  of  puerperal  women. 

Morphology. — Diplococci  resembling  the  "  gonococcus, "  and  consisting 
of  two  biscuit-shaped  halves  separated  by  a  cleft  which  is  not  as  broad  as 
that  seen  in  Micrococcus  gonorrhcese;  the  diameter,  from  pole  to  pole, 
averages  about  1.25  fi.  In  unstained  preparations  the  cleft  is  not  seen  and 
the  diplococci  appear  as  spherical,  highly  refractive  bodies. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  very  slowly  at  the  room  temperature  in  the 
usual  culture  media.  Upon  gelatin  plates  forms  extremely  small,  puncti- 
form  colonies,  which  under  a  low  power  are  seen  to  be  spherical,  opaque, 
and  brownish-green  in  color;  at  the  end  of  two  weeks  they  may  attain  a  dia- 
meter of  two  millimetres.  In  gelatin  stick  cultures  small,  isolated,  gray- 
ish-white colonies  are  developed,  after  some  days,  along  the  line  of  puncture, 
and  a  thin,  whitish,  stearin-like  layer  with  irregularly  dentate  margins  is 
slowly  developed  upon  the  surface.  Upon  the  surface  of  agar  a  thin, 
moist,  grayish-white  layer  with  dentate  margins  is  slowly  developed. 

206.  DIPLOCOCCUS  ALBICANS  TAKDUS   (Unna). 

Found  upon  the  surface  of  the  body  in  individuals  having  eczema  se- 
borrhoeicum. 

Morphology. — Diplococci  consisting  of  two  oval  elements,  with  the  long 
diameters  in  parallel  planes,  from  0.7  to  0.8  /*  long  and  0.6  /*  broad;  often 
associated  in  short  chains  or  in  irregular  groups. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
slowly  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  the  deep  colonies  are  usually  oval,  dark-yellow,  and  at  the  end  of 
eight  days  are  as  large  as  a  mustard  seed.  The  superficial  colonies  are  cir- 
cular in  outline,  with  well-defined  margins,  elevated,  grayish-yellow,  and 
at  the  end  of  eight  days  one  to  two  millimetres  in  diameter ;  under  a  low 
power  they  are  seen  to  be  granular,  grayish-yellow,  with  shining  margins ; 
at  the  end  of  five  weeks  they  are  gray  and  present  two  or  three  zones  of  dif- 
ferent dimensions,  with  an  elevated  circular  centre  and  finally  with  thin, 
slimy,  dentate  margins ;  under  the  microscope  finely  granular  projections 
are  seen  upon  the  sm-face.  In  gelatin  stick  cultures,  at  the  end  of  three 
weeks,  a  thin,  waxy-looking,  yellowish-white  layer  with  finely  dentate  mar- 
gins develops  upon  the  surface  and  a  scanty  growth  has  occurred  along  the 
line  of  puncture.  At  the  end  of  five  weeks  this  superficial  layer  may  have 
a  diameter  of  one  centimetre.  Upon  the  surface  of  agar,  at  the  end  of  five 
weeks,  a  yellowish-gray  streak  with  irregular,  dentate  margins  and  a  dull 
lustre  is  formed  along  the  line  of  inoculation. 

207.  STAPHYLOCOCCUS    ALBUS    LIQUEFACIENS. 

Synonym. — White  liquefying  staphylococcus  (Escherich). 

Found  occasionally  in  the  alvine  discharges  of  healthy  infants. 

Morphology. — Micrococci  of  from  0.8  to  1.2  M  in  diameter,  occasionally 
oval  in  form  and  three  V-  in  long  diameter ;  associated  in  irregular  groups 
— considerably  larger  than  Staphylococcus  pyogenes  albus. 

Biological  Characters. — An  aerobic,  liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  spherical,  white  colonies,  which  after  some  time  cause  a  gradual 
liquefaction  of  the  surrounding  gelatin.  In  gelatin  stick  cultures  a  scanty 
development  is  seen  along  the  line  of  puncture  at  the  end  of  three  to  four 
days,  and  gradual  liquefaction  of  the  gelatin  occurs  in  funnel  form ;  the 
liquefied  gelatin  is  viscid,  of  syrupy  consistence,  and  slightly  clouded;  £he 


608  NON-PATHOGENIC  MICROCOCCI. 

surface  is  covered  by  a  white  layer  of  micrococci ;  development  usually 
ceases  before  complete  liquefaction  has  occurred.  Upon  agar  and  upon 
blood  serum  a  white  layer  is  developed,  which  presents  nothing  characteris- 
tic ;  blood  serum  is  not  liquefied.  Upon  potato  a  very  scanty,  thin,  color- 
less layer,  which  later  appears  as  a  collection  of  white,  button-like  masses. 

208.  MICROCOCCUS  OVALIS  (Escherich). 

Found  frequently  in  meconium  and  faeces  of  milk-fed  infants. 

Morphology. — Micrococci  of  from  0.2  to  0.3  n  in  diameter,  frequently 
seen  as  oval  cells  0.6  to  0.7  n  long  and  0.3  /*  broad,  in  the  middle  of  which 
a  commencing  line  of  division  may  sometimes  be  seen ;  sometimes  in  short 
chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Upon  gelatin  plates  forms  very  small  colonies  which  are  in 
no  way  characteristic.  In  gelatin  stick  cultures  small,  white  colonies  are 
developed  along  the  line  of  puncture,  and  no  development  occurs  upon  the 
surface,  or  a  scanty,  colorless  ring  of  growth  surrounds  the  point  of  punc- 
ture. Upon  potato  a  tolerably  abundant  growth  occurs,  consisting  of  a 
small,  white  layer.  In  milk  it  causes  an  acid  reaction,  and  coagulation  after 
several  days. 

209.  DIPLOCOCCUS  CORYZ^E  (Hajek). 

Found  in  nasal  mucus  in  acute  nasal  catarrh. 

Morphology. — Large  diplococci,  flattened  along  the  line  of  contact;  re- 
semble short  bacilli  with  round  ends. 

Biological  Characters. — Anaerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  white,  glass-like,  slightly  elevated  colonies.  In  gelatin  stick  cultures 
the  growth  resembles  that  of  Friedliinder's  bacillus  at  first,  but  the  super- 
ficial growth  is  flatter  after  some  days.  Upon  the  surface  of  agar  forms  a 
diffuse  layer. 

210.  MICROCOCCUS  FINLAYENSIS  (Sternberg). 

Obtained  by  Finlay  in  cultures  from  the  liver  and  spleen  of  a  yellow- 
fever  cadaver. 

Morphology. — Micrococci,  from  0.5  to  0.7/*  in  diameter,  solitary,  in 
paii*s,  or  occasionally  in  groups  of  four;  also  in  irregular  masses.  Like 
other  staphylococci,  the  cocci  are  seen,  in  properly  stained  preparations,  to 
be  made  up  of  two  hemispherical  portions. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  micro- 
coccus.  Grows  slowly  at  the  room  temperature  in  the  usual  culture  media. 
In  gelatin  stick  cultures  growth  occurs  along  the  line  of  puncture  and  lique- 
faction near  the  surface;  the  cup  shaped  cavity  which  is  slowly  formed  is 
lined  with  a  very  viscid,  opaque,  pale- yellow  layer  of  cocci.  Upon  the  sur- 
face of  agar  a  viscid  layer  having  a  pale-yellow  color  is  formed.  Not  path- 
ogenic for  rabbits  or  guinea-pigs. 

211.    MICROCOCCUS  OP  FREIRE. 

Presented  to  the  writer,  at  the  time  of  his  visit  to  Brazil  (1887),  by  Dr. 
Domingos  Freire,  as  his  yellow-fever  germ — so-called  Cryptococcus  xantho- 
geuicus. 

Morphology. — Micrococci,  from  0.5  to  0.8 n  in  diameter,  solitary,  in  pairs, 
or  in  irregular  agglomerations ;  like  other  staphylococci,  groups  of  four  and 
chains  of  three  or  four  elements  are  occasionally  formed. 


NON-PATHOGENIC  MICROCOCCI. 


609 


Stains  with  the  aniline  colors  usually  employed  and  by  Gram's  method. 

Biological  Characters. — An  aerobic,  liquefying  staphylococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Is  killed  by  exposure 
to  a  temperature  of  60°  C.  for  ten  minutes.  Vitality  not  destroyed  by  long 
exposure  to  a  freezing  temperature.  Development  occurs  at  a  comparatively 
low  temperature — 10°  to  15°  C.  Preserves  its  vitality  for  several  months  in 
cultures.  In  gelatin  stick  cultures  development  occurs  along  the  line  of 
puncture  and  liquefaction  in  cup  shape  near  the  surface ;  the  cocci  accumu- 
late at  the  bottom  of  the  cup  as  a  milk-white  deposit;  later  the  gelatin  may 
be  completely  liquefied  at  the  upper  part  of  the  tube  for  half  an  inch  or 
more,  and  the  non -liquefied  gelatin  forms  a  horizontal  floor  upon  which  a 
milk-white  deposit  is  seen.  In  agar  stick  cultures  an  irregular,  white,  opaque 
growth  is  seen  along  the  line  of  puncture,  and  a  soft,  milk-white  layer, 
with  irregular  outlines,  forms  upon  the  surface.  Upon  potato  a  milk-white 
layer,  from  three  to  five  millimetres  wide,  is  developed  along  the  line  of  in- 
oculation at  the  end  of  forty-eight  hours  at  37°  C.  Does  not  coagulate  milk. 


FIG.  199.  FIG.  200. 

FIG.  199.—  Micrococcus  of  Freire,  from  a  gelatin  culture,  x  1,000.  From  a  photomicrograph. 
(Sternberg.) 

Fm.  200.— Culture  of  Freire's  micrococcus  in  nutrient  gelatin,  end  of  eight  dayg  at  28°  C.  From 
a  photograph.  (Sternberg.) 

In  the  writer's  experiments  this  micrococcus  has  not  proved  to  be  patho- 
genic for  guinea-pigs.  According  to  Freire,  it  is  not  pathogenic  for  these 
animals  in  the  winter  months,  but  in  summer,  at  Rio  de  Janeiro,  it  is  fatal 
to  guinea-pigs  and  to  small  birds. 

212.    STREPTOCOCCUS  COLI  GRACILIS   (Escherich). 

Found  in  the  faeces  of  healthy  children  on  flesh  diet— not  during  the 
period  of  nursing  (Escherich). 

Morphology.—  Micrococci,  from  0.2  to  0.4  n  in  diameter,  usually  in  S- 
shaped  chains  containing  from  six  to  twenty  elements.  In  agar  cultures  the 
chains  are  shorter,  and  upon  potato  they  are  rarely  seen;  the  elements  in  a 
chain  are  often  elongated  and  show  indications  of  commencing  transverse 
division. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing streptococcus.  Grows  rapidly  in  the  usual  culture  media  at  the  room 
temperature.  Upon  gelatin  plates  the  colonies  are  at  first  small,  spherical, 
and  well  defined,  later  bulging  and  lying  at  the  bottom  of  a  funnel  of  Hque- 


610  NON-PATHOGENIC  MICROCOCCI. 

fied  gelatin ;  by  reflected  light  the  colonies  are  of  a  whitish  lustre.     In  gela- 
tin stick  cultures  development  occurs  along  the  line  of  puncture,  and  lique- 
faction commences  on  the  second  day  along  the  entire  line,  forming  a  tube 
of  rather  uniform  dimensions ;  the  liquefied  gelatin  is  slightly 
clouded,  and  a  very  slight  deposit  of  a  white  color  is  seen  at 
j^jjP  the  bottom  of  the  tube ;.  by  the  eighth  to  tenth  day  liquefac- 

MB»    ^&      tioii  is  complete ;  in  older  cultures  a  finely  granular,  whitish 

>*       •       deposit  is  seen,  while  the  gelatin  above  is  quite  transparent 
»**       and  has  an  acid  reaction.     Upon  agar  a  very  scanty  super- 
^^    f          ficial  growth  occurs.      Blood  serum  is  not  liquefied,   but 
vW»  /  small,  shining  scales  are  developed  upon  the  surface.     Upon 

FIG.  201.—  Str.  young  potato  a  thin  layer  of  white,  button  like  colonies  de- 
coli graciiis,from  velops  upon  the  surface;  no  growth  occurs  on  old  potato, 
a  liquefied  geia-  Milk  is  coagulated  and  acquires  an  acid  reaction  after  a  con- 
tin  culture,  x  siderable  time. 

970.  (Escherich.) 

213.  STREPTOCOCCUS  ACIDI  LACTICI  (Grotenf eld) . 

Found  in  coagulated  milk  in  Finnland. 

Morphology. — Spherical  or  oval  cocci,  from  0.5  to  1  jj.  long  and  0.3  to  0.6 
H  thick,  associated  in  long  chains. 

Biological  Characters. — An  anaerobic  (not  strict),  non-liquefying  strep- 
tococcus. Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  forms  spherical,  white  colonies — best  when  the  plate  is  cov- 
ered with  a  layer  of  gelatin  to  exclude  the  air.  In  gelatin  stick  cultures  an 
abundant  development  along  the  line  of  puncture  only.  In  milk  causes  co- 
agulation of  the  casein  and  an  acid  reaction. 

214.    STREPTOCOCCUS  GIGANTEUS  URETHRA   (Lustgarten). 

Found  in  the  normal  human  urethra. 

Morphology. — Spherical  cocci,  0.8  to  1  n  in  diameter,  associated  in  chains 
which  often  contain  many  hundred  elements,  and  are  often  united  in  thick, 
tangled  masses. 

Biological  Characters. — An  aerobic  micrococcus.  Grows  slowly  in  nu- 
trient agar  at  37°  C. ;  does  not  grow  at  the  room  temperature.  Upon  agar 
plates  elongated,  drop-like  colonies  are  slowly  formed,  which  are  not  ele- 
vated above  the  surface  ;  these  are  easily  overlooked  in  reflected  light,  and 
in  transmitted  light  are  iridescent;  the  colonies  are  often  shaped  like  a  clover 
leaf ;  they  never  become  confluent,  and  attain  their  greatest  development  by 
the  eighth  day ;  transplantation  to  other  agar  tubes  is  rarely  successful.  In 
streak  cultures  upon  agar  development  occurs  for  the  most  part  in  the  con- 
densation water  as  a  flocculeiit  deposit. 

215.   STREPTOCOCCUS  ALBUS. 

Synonym.—  Weisser  Streptococcus  (Maschek). 

Found  in  Freiburg  water  by  Tils. 

Morphology. — Streptococci,  which  show  independent  movements  when 
undergoing  binary  division  (Tils). 

Biological  Characters. — An  aerobic,  liquefying  streptococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
superficial  colonies  are  developed,  which  are  flat,  circular  in  outline,  and 
bounded  by  a  white  margin ;  saucer-shaped  liquefaction  quickly  occurs,  and 
under  a  low  power  a  pale-brown  cloud  is  seen  in  the  centre.  Upon  agar 
the  disc-shaped  colonies  have  a  darker  interior.  In  gelatin  stick  cultures 
the  development  is  chiefly  upon  the  surface ;  liquefaction  progresses  rapidly, 
and  a  white  deposit  is  formed.  Upon  potato  a  slimy,  white  layer  is  quickly 
developed. 


NON-PATHOGENIC    MICROCOCCI.  611 

216.    STREPTOCOCCUS   VERMIFORMIS. 

Synonym. — Wurmformiger  Streptococcus  (Maschek). 

Found  in  Freiburg  water  by  Tils. 

Morphology.—  Streptococci,  which  show  slow,  vermiform,  progressive 
movements ;  the  juxtaposition  of  sevei'al  cocci  in  a  chain  gives  the  appearance 
of  bacilli,  which  are  again  united  in  chains  (Tils). 

Biological  Characters. — An  aerobic,  liquefying  streptococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates 
forms  yellowish-white  colonies,  which  sink  into  the  gelatin  as  liquefaction 
occurs;  about  the  more  transparent  interior  a  darker  liquefied  ring  is  seen, 
which  is  bounded  by  a  white  border ;  under  a  low  power  the  interior  is  seen 
to  be  finely  granular  and  pale-brown  in  color ;  the  margin  has  a  radiate  ap- 
pearance. In  gelatin  stick  cultures  growth  occurs  upon  the  surface  and 
along  the  line  of  puncture,  causing  rapid  liquefaction  of  the  gelatin;  a  dirty- 
yellow  deposit  accumulates  at  the  Dottom  of  the  tube.  Upon  potato  a  dirty- 
yellow  layer  is  slowly  developed ;  later  this  becomes  somewhat  darker. 

217.  STREPTOCOCCUS  «REVis  (Von  Lingelsheim). 

Obtained  from  normal  human  saliva,  and  differentiated  from  Streptococ- 
cus pyogenes  by  Von  Lingelsheim  (1891). 

Morphology. — Micrococci,  solitary,  in  pairs,  or  in  short  chains— seldom 
as  many  as  eight  to  ten  elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  streptococcus.  Grows  in  the  usual  culture  media  at  the  room 
temperature —more  rapidly  than  Streptococcus  pyogenes.  Bouillon  is  uni- 
formly clouded  by  the  growth  of  this  streptococcus,  while  the  streptococci 
which  form  long  chains  leave  the  bouillon  transparent  and  form  conglo- 
merate masses.  In  blood  serum  of  the  ox  the  growth  of  this  streptococcus 
exactly  resembles  that  of  Streptococcus  pyogenes,  long  chains  being  formed 
which  are  associated  in  conglomerate  masses.  Upon  gelatin  plates,  at  the 
end  of  twenty -four  hours,  forms  punctiform  colonies,  which  under  the  mi- 
croscope are  usually  seen  to  be  spherical  in  form  with  an  even  contour. 
Upon  the  surface  ofagar  a  thin,  homogeneous,  yellowish-gray  layer  is  de- 
veloped along  the  impf strich — not  composed  of  separate  colonies ;  along  the 
line  of  puncture  in  nutrient  agar  the  colonies  are  largest  below  and  are  fre- 
quently flattened  or  irregular  in  corm.  In  gelatin  stick  cultures  the  devel- 
opment at  first  resembles  that  of  "Streptococcus  longus  "  (Streptococcus 
pyogenes) ,  but  after  three  days  a  funnel-like  cavity  forms  near  the  surface 
of  the  gelatin,  which  finally  extends  downward  for  a  distance  of  four  to  five 
millimetres,  while  below  this,  usually  separated  by  a  space  in  which  there  is 
no  evidence  of  growth,  colonies  the  size  of  a  pin's  head  are  developed  along 
the  line  of  puncture  in  rows.  Upon,  potato,  at  37°  C.,  an  abundant  develop- 
ment occurs  within  forty-eight  hours,  in  the  form  of  a  confluent,  white 
layer,  easily  stripped  from  the  surface. 

STREPTOCOCCUS  CADAVERIS  (Sternberg). 

Possibly  identical  with  Streptococcus  brevis,  described  above.  Found 
by  the  writer  in  the  liver  of  a  yellow-fever  cadaver. 

Morphology. — Micrococci,  in  pairs,  or  in  short  chains  which  are  usually 
made  up  of  cocci  in  pairs,  or  oval  elements  which  show,  more  or  less  dis- 
tinctly, commencing  binary  division;  diameter  about  0.5  //. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  streptococcus.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Grows  readily  in  a  decidedly  acid  medium.  In.  gelatin  stick 
cultures  opaque,  spherical  colonies  are  formed  along  the  line  of  puncture — 
larger  and  more  opaque  than  in  similar  cultures  of  Streptococcus  pyogenes 


612 


NON-PATHOGENIC  MICROCOCCI. 


made  at  the  same  time ;  later  the  isolated  colonies  at  the  bottom  of  the  line 
of  puncture  are  coarsely  granular  and  irregular  in  outline ;  no  growth  upon 
the  surface  of  gelatin.  Upon  the  surface  of  agar,  in  Havana,  a  white  mass 


FIG.  202.— Streptococcus  cadaveris,  from  a  culture  in  agua  coco,    x  1,000.    From  a  photo- 
micrograph.   (Sternberg.) 

formed  about  the  point  of  puncture ;  later,  in  Baltimore,  a  thin,  translucent 
layer  developed  upon  the  surface  of  agar  cultures.  Very  thin,  white  growth 
upon  potato  at  the  end  of  twelve  days.  In  bouillon  and  agua  coco  it  forms 


FIG.  203.— Streptococcus  Havaniensis,  from  acid  vomit  of  yellow-fever  patient,  kept  twenty 
four  hours  in  a  collecting  tube,     x  1,000.    From  a  photomicrograph.    (Sternberg.) 

little  flocculi  made  up  of  chains.  In  old  agar  cultures  it  is  very  small  and 
not  in  chains.  In  veal  broth,  long  chains,  in  which  the  cocci  are  larger  than 
usual;  the  elements  vary  considerably  in  size  in  the  same  chain. 

218.  STREPTOCOCCUS  HAVANIENSIS  (Sternberg). 

Found  in  acid  vomit  of  a  yellow-fever  patient  in  military  hospital,  Ha- 
vana. 


NON-PATHOGENIC  MICROCOCCI. 


613 


Morphology. — Micrococci,  from  0.6  to  0.9  n  in  diameter,  associated  in  long 
chains  which  are  made  up  of  cocci  in  pairs  or  of  oval  elements  showing 
commencing  transverse  division. 

Biological  Characters  not  determined. 

219.  STREPTOCOCCUS  LIQUEFACIENS  (Sternberg). 

Obtained  from  liver  of  yellow-fever  cadavers,  also  from  contents  of  in- 
testine. 

Morphology. — Spherical  or  short  oval  micrococci,  from  0.4  to  0.6  n  in 
diameter,  solitary,  in  pairs,  or  in  short  chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing streptococcus.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  liquefaction  occurs  rapidly  along  the  entire- 


FIG.  205. 

FIG.  204.— Streptrococcus  liquefaciens,  from  anaerobic  culture  in  nutrient  gelatin,  x  1,000.. 
From  a  photomicrograph.  (Sternberg.) 

FIG.  205.— Streptococcus  liquefaciens  ;  culture  in  nutrient  gelatin,  end  of  seven  days  at  22°  C. 
(Sternberg.) 

line  of  puncture,  and  by  the  end  of  a  week  the  gelatin  is  completely  lique- 
fied ;  it  is  but  slightly  opalescent,  and  a  scanty  white  deposit  forms  at  the 
bottom  of  the  tube.  In  agar  stick  cultures  a  scanty  growth  occurs  at  the 
point  of  puncture,  and  closely  crowded  colonies  are  developed  along  the 
line  of  inoculation.  Upon  potato  a  thin  and  limited,  dry,  white  layer  is 
formed  along  the  line  of  inoculation  in  four  to  five  days.  Not  pathogenic 
for  rabbits  or  guinea-pigs. 

220.    MICROCOCCUS  TETRAGENUS  VERSATILIS  (Sternberg). 

Synonym. — Micrococcus  tetragenus  febris  flavae  (Finlay). 

Obtained  by  Dr.   Finlay,  of  Havana,  from  his  ' '  mosquito  cultures  "- 
from  the  excrement  of  mosquitoes  which  he  had  allowed  to  draw  blood  from 
yellow-fever  patients ;  by  the  writer  from  cultures  from  the  surface  of  the 
body  of  patients  in  hospital  in  Havana,  and  from  the  air. 

Morphology.  — Micrococci,  in  tetrads,  or  in  irregular  groups  containing  three 
or  more  united  elements ;  varies  greatly  in  the  size  and  grouping  of  the  ele- 
ments, which  are  sometimes  less  than  0.5/<  in  diameter  and  may  measure 
1.5  p.  This  micrococcus  would  probably  be  classed  as  a  sarcina  by  somebac- 

51 


614 


NON-PATHOGENIC  MICROCOCCI. 


•teriologists,  but  division  in  three  directions,  forming  packets,  has  not  been 
•observed. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters.—  An  aerobic,  liquefying,  chromogenic  micro- 
coccus.  Grows  in  the  usual  culture  media  at  the  room  temperature.  Colo- 
nies in  gelatin  roll  tubes  are  spherical,  opaque,  at  first  of  a  pale-yellow  and 
later  of  a  lemon-yellow  color ; .  liquefaction  around  the  colony  usually  does 
not  commence  for  several  days  and  progresses  slowly.  In  gelatin  stick  cul- 
tures very  scanty  development  occurs  along  the  line  of  puncture,  and  the 
gelatin  is  liquefied  in  cup  shape  by  the  surface  growth ;  at  the  bottom  of  the 
liquefied  gelatin  a  viscid,  pale-yellow  mass  accumulates.  Upon  the  surface 
of  agar  a  thick,  viscid,  yellow  layer  is  formed  along  the  impfstrich,  which 


Fio.  206.  Fia.  207. 

FIG.  206.— Micrococcus  tetragenus  versatilia,  from  a  single  colony  in  nutrient  gelatin.  X  1,000. 
From  a  photomicrograph.  (Steinberg.) 

FIG.  207.— Micrococcus  tetragenus  versatilis;  culture  in  nutrient  gelatin,  end  of  two  weeks  at 
22°  C.  (Sternberg.) 


gradually  extends  over  the  entire  surface ;  the  color  varies  from  cream-yellow 
to  lemon-yellow,  and  the  surface  is  moist  and  shining.  The  growth  upon 
potato  is  similar  to  that  upon  agar.  Not  pathogenic  for  rabbits  or  guinea- 
pigs. 

221.  PEDIOCOCCUS  ALBUS  (Lindner). 

Found  in  well  water. 

Morphology. — Micrococci,  solitary,  in  pairs,  or  in  tetrads;  frequently  in 
pseudo-sarcina — accidental — groups. 

Biological  Characters. — An  aerobic,  liquefying  micrococcus.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Is  destroyed  by  a  tem- 
perature of  CO0  C.  in  eight  minutes.  Upon  gelatin  plates  forms  spherical 
•colonies,  around  which  liquefaction  rapidly  occurs,  allowing  the  colonies  to 
fall  to  the  bottom  of  the  liquefied  gelatin,  where  they  form  irregular  flocculi. 
In  gelatin  stick  cultures,  at  the  end  of  twenty-four  hours,  a  deep  channel  of 
liquefaction  has  already  formed,  at  the  bottom  of  which  a  white,  loose  sedi- 
ment collects ;  by  the  fourth  day  a  pale-orange  color  is  developed.  Upon 
the  surface  of  agar  a  broad,  dry  layer  forms  along  the  impfstrich ;  old  cul- 
tures have  an  orange  color.  Upon  potato  a  dirty-white  layer  is  developed. 
Produces  an  acid  reaction  in  culture  media.  , 


NON-PATHOGENIC  MICROCOCCI.  615 

222.  PEDIOCOCCUS  ACIDI  LACTICI  (Lindner). 

Found  by  Lindner  in  mash  from  malt  and  in  hay  infusion. 

Morphology. — Micrococci,  from  0.6  to  1  M  in  diameter,  solitary,  in  pairs, 
or  in  tetrads — division  in  two  directions. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  very  slowly  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin  plates  small  colonies  are  developed, 
which  are  first  colorless  and  later  yellowish-brown.  In  agar  stick  cultures 
a  moist,  thin,  colorless  layer  is  slowly  developed  upon  the  surface.  Upon 
potato  a  scanty,  scarcely  visible  growth.  Lactic  acid  is  produced  by  the 
growth  of  this  tetragenus  in  saccharine  solutions. 

223.  PEDIOCOCCUS  CEREVISIJE  (Balcke). 

Found  in  beer  and  in  the  air  of  breweries. 

Morphology. — Micrococci,  solitary,  in  pairs,  or  in  tetrads. 

Biological  Characters^ — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  micrococcus.  Grows  slowly  in  the  usual  culture  media  at  the 
room  temperature.  Is  killed  by  a  temperature  of  60°  C.  maintained  for 
eight  minutes.  Upon  gelatin  plates  forms  small,  colorless  colonies,  which 
later  are  yellowish-brown.  In  gelatin  stick  cultures  a  white,  leaf- like  layer 
is  formed  on  the  surface  and  a  grayish-white  growth  along  the  line  of  punc- 
ture. Upon  agar  a  moist,  grayish-white,  iridescent  layer  with  smooth  mar- 
gins. Upon  potato  a  scanty,  scarcely  visible  growth. 

224.    MICROCOCCUS    TETRAGENUS   MOBILIS    VENTRICULI    (Mendoza). 

Found  in  the  contents  of  the  stomach. 

Morphology. — Micrococci,  in  tetrads,  enclosed  in  a  transparent  capsule. 

Biological  Characters.  —  An  aerobic,  non-liquefying,  motile  (?)  tetrage- 
nus. Grows  slowly  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  forms  superficial  colonies  which  are  circular  in  outline, 
with  well-defined  margins,  and  dirty -white  in  color ;  under  a  low  power  they 
are  seen  to  be  finely  granular,  both  on  the  surface  and  in  the  interior.  In 
gelatin  stick  cultures  grows  upon  the  surface  as  a  dirty-white  layer ;  old 
cultures  have  a  "  sugar  color  "  and  give  off  an  odor  like  that  of  skatol.  The 
growth  upon  agar  is  similar  to  that  upon  gelatin. 

225.    MICROCOCCUS   TETRAGENUS  SUBPLAVUS  (Von  BeSSer). 

Found  in  nasal  mucus. 

Morphology. — Spherical  or  oval  cocci  of  medium  size,  usually  associated 
in  tetrads. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic  tetra- 
genus. Does  not  grow  in  nutrient  gelatin.  Grows  at  the  room  temperature 
in  nutrient  agar.  Upon  agar  plates  forms  flat,  dirty -white  colonies,  0.5 
cubic  centimetre  in  diameter,  with  shining  surface  and  somewhat  wrinkled 
margins ;  under  a  low  power  these  are  seen  to  have  a  small  brown  nucleus 
surrounded  by  a  grayish-brown,  irregularly  striped  zone,  around  which  is  a 
wrinkled  margin.  The  deep  colonies  are  dark-green  and  punctiform,  of  very 
irregular  form.  Upon  the  surface  of  agar  a  broad,  flat,  grayish-white  layer 
is  formed,  which  in  three  or  four  days  commences  to  turn  brown  at  the  mar- 
gins, and  at  the  end  of  four  weeks  has  the  color  of  cultures  of  Staphylococcus 
Eyogenes  aureus.  Upon  potato  a  pale-brown  layer  is  developed  along  the 
ne  of  inoculation. 

226.    SARCINA  AURANTIACA. 

Found  in  the  air  and  in  water. 

Morphology. — Micrococci, in  pairs,  with  hemispherical  elements,  in  tetrads,. 


c616 


NON-PATHOGENIC  MICROCOCCI. 


or  in  packets  containing  eight  or  more  elements,  as  a  result  of  division  in 
three  directions.     The  cells  are  smaller  than  those  of  Sarcina  lutea. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  sarcina. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  forms  small,  spherical,  granular  colonies  of  an  orange-yellow  color. 
In  gelatin  stick  cultures  liquefaction  occurs  slowly  along  the  line  of  inocula- 
tion, and  in  old  cultures  a  yellow  deposit  is  seen  at  the  bottom  of  the  trans- 
parent, liquefied  gelatin.  Upon  the  surface  of  agar  an  abundant,  shining, 
golden-yellow  layer  is  formed.  Upon  potato  development  is  scanty  and 
slow,  being  limited  to  the  line  of  inoculation. 

227.  SARCINA  LUTEA  (Schroter). 

Found  in  the  air. 

Morphology.  —  Micrococci,  1  //  or 
more  in  diameter,  associated  in  pairs,  in 
groups  of  four,  or  in  packets  containing 
eight  or  more  elements. 

Biological  Characters. — An  aero- 
bic, liquefying,  chromogenic  sarcina. 
Grows  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin 
plates  small,  spherical,  yellow  colonies 
are  slowly  developed.  In  gelatin  stick 
cultures  development  occurs  only  on 
the  surface  in  the  form  of  a  coarsely 
granular,  yellow  layer  of  moderate  di- 
mensions; liquefaction  of  the  gelatin 
occurs  in  old  cultures  and  progresses 
slowly.  Upon  the  surface  of  agar  a 
rather  thick,  canary-yellow  layer  is 
quickly  developed.  Upon  potato  a  sul- 
phur-yellow streak  is  slowly  developed 
along  the  line  of  inoculation. 


FIG.  208.— Sarcina  lutea,  from  an  agar 
culture.  X  1,000.  From  a  photomicro- 
graph. •  (Frankel  and  Pfeiffer.) 


228.  SARCINA  FLAVA  (De  Bary). 

Found  by  Lindner  in  beer. 

Morphology. — Small  micrococci  in  packets  of  sixteen  to  thirty-two  ele- 
ments, which  may  be  associated  in  irregular  masses  or  united  in  larger 
packets  of  cubical  form. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  sarcina. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  spherical,  yellow  colonies  are  developed,  and  liquefaction  of  the  gel- 
atin around  them  commences  in  about  four  days.  Upon  the  surface  of  agar 
forms  a  yellow  layer.  Upon  potato  the  growth  is  scanty  and  limited  to  the 
impfstrich,  yellow  in  color. 

229.  SARCINA  ROSE  A  (Schroter). 

Found  in  the  air. 

Morphology. — Large  cocci  in  cubical  packets  with  rounded  corners,  and 
about  eight  p  thick. 

Biological  Characters.— An.  aerobic,  liquefying,  chromogenic  sarcina. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  In  gelatin 
stick  cultures  liquefaction  occurs  rapidly,  and  old  cultures  acquire  a  red 
color,  which  by  the  addition  of  sulphuric  acid  is  changed  to  bluish-green. 
Uponograr  growth  is  slow,  and  small,  cartilaginous-looking  masses  are  de- 
veloped. Upon  potato  an  abundant,  intensely  red  layer  is  quickly  de- 
veloped. In  bouillon  development  is  rapid  and  a  red  sediment  is  deposited. 


NON-PATHOGENIC   MICROCOCCI.  617 

230.  SARCINA  ALBA  (Eisenberg). 

Found  in  the  air  and  in  water. 

Morphology. — Small  cocci,  associated  in  pairs  or  in  tetrads. 

Biological  Characters. — An  aerobic,  liquefying  (very  slightly)  sarcina. 
Grows  very  slowly  at  the  room  temperature  in  the  usual  culture  media. 
Upon  gelatin  plates  forms  small,  round,  white  colonies.  In  gelatin  stick 
cultures  forms  a  white,  button-like  mass  at  point  of  puncture ;  scanty 
growth  along  line  of  inoculation.  Upon  potato  grows  very  slowly  in  the 
form  of  a  yellowish- white  layer  limited  to  the  line  of  inoculation. 

231.  SARCINA  CANDIDA  (Reinke). 

Found  in  the  air  about  breweries. 

Morphology. — Micrococci  of  1.5  to  1.7  n  in  diameter,  solitary,  in  pairs,  or 
in  tetrads;  under  certain  circumstances,  as  for  example  in  hay  infusion, 
multiplication  occurs  in  three  directions,  forming  sarcina-like  packets. 

Biological  Characters. — Anaerobic,  liquefying  sarcina.  Grows  slowly 
at  the  room  temperature  in  the  usual  culture  media.  Upon  gelatin  plates 
forms  shining  white,  spherical  colonies,  which  later  have  a  yellowish  color 
and  are  surrounded  by  liquefied  gelatin.  In  gelatin  stick  cultures  causes 
rapid  liquefaction  along  the  line  of  puncture.  Upon  the  surface  of  agar 
forms  a  white,  moist,  shining  layer  with  smooth  margins. 

232.  SARCINA  PULMONUM  (Hauser). 

Found  in  the  sputum  of  patients  with  phthisis. 

Morphology. — Micrococci,  from  1  to  1.5  /a  in  diameter;  usually  associated 
in  tetrads,  but  may  form  cubical  groups  of  eight  cells. 

Biological  Characters. — An  aerobic,  non-liquefying  sarcina.  Grows 
slowly  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  in  three  days  white,  puiictiform  colonies  are  seen ;  later  these  still  re- 
main small;  under  a  low  power  they  are  seen  to  be  coarsely  granular.  In 
gelatin  stick  cultures  the  development  is  very  scanty  along  the  line  of  punc- 
ture ;  upon  the  surface  a  round,  sharply  denned  layer  of  a  pearl -gray  color 
is  developed ;  later  this  becomes  tolerably  thick,  is  grayish-brown  in  color, 
glistening,  and  has  more  or  less  folded  and  irregular  margins.  The  growth 
upon  potato  is  very  scanty  and  is  confined  to  the  line  of  inoculation. 

This  sarcina  is  said  by  Hauser  to  form  endogenous  spores  which  may  be 
demonstrated  by  Neisser's  method  of  staining,  and  which  have  great  resistance 
to  heat.  When  cultivated  in  urine  it  causes  ammoniacal  decomposition  of 
the  urea. 

233.  SARCINA  VENTRICULI  (Goodsir). 

Found  in  the  contents  of  the  stomach  of  man  and  animals. 

Morphology. — Spherical  or  slightly  oval  cells,  about  2.5  jit  in  diameter; 
united  in  cubical  groups  with  rounded  corners,  containing  eight  elements, 
and  then  associated  in  larger  "packets." 

Biological  Characters. — An  aerobic,  non-liquefying  sarcina.  Grows 
rapidly  at  the  room  temperature  in  suitable  media.  Upon  gelatin  plates,  at 
the  end  of  thirty-six  to  forty-eight  hours,  hemispherical,  yellowish  colonies 
are  developed  upon  the  surface ;  these  contain  cocci  in  pairs  and  tetrads, 
but  not  in  cubical  packets.  In  hay  infusion  development  occurs  upon  the 
surface  in  the  form  of  small,  brownish  scales,  while  a  brownish,  flocculent 
deposit  is  seen  at  the  bottom  of  the  tube ;  the  sarcina  form  is  well  developed. 
Upon  potato  a  dry,  colorless  strip  develops  along  the  impfstrich  in  twenty- 
four  hours;  later  this  acquires  a  chrome-yellow  color.  Upon  the  surface  of 
blood  serum  flat,  round,  pale  yellow  colonies  are  formed  along  the  line  of 
inoculation. 


618 


NON-PATHOGENIC   MICROCOCCI. 


234.  MICROCOCCUS  AMYLOVORUS  (Burrill). 

Synonym. — Micrococcus  of  pear  blight. 

Found  in  the  diseased  branches  of  pear  trees  affected  with  ' '  blight " — 
"fire  blight."  Discovered  by  Burrill  (1878)  and  carefully  studied  by  Ar- 
thur (1886). 

Morphology.— Oval  cells,  from  1  to  1.25  n  long  and  0.5  to  0.75  n  broad; 
usually  solitary,  often  in  pairs,  and  occasionally  in  a  linear  series  of  four. 
In  fluid  culture  media  form  zooglcea,  which  are  spherical  or  oblong  and  may 
be  from  thirty  to  forty  /f  long  and  twenty  to  thirty  /j.  broad ;  these  zoogloea 
masses  may  be  solitary,  or  united  in  pairs  or  short  chains ;  they  are  found  es- 
pecially upon  the  surface  of  the  culture  medium,  and  after  a  time  present  a 
wrinkled  appearance,  giving  some  resemblance  to  the  external  surface  of 
the  brain. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  micrococcus 
(bacillus?).  Grows  in  various  media  at  the  room  temperature.  According  to 
Arthur,  this  micrococcus  exhibits  active  "swarming  movements"  when 
undergoing  rapid  multiplication  in  a  favorable  medium :  ' '  The  bacteria  move 
rapidly  back  and  forth,  in  and  out,  among  each  other,  but  never  in  a  straight 
line  to  any  distance. "  An  infusion  of  potato  constitutes  a  favorable  cul- 
ture medium.  In  this  medium,  at  a  temperature  of  25°  to  30°  C.,  turbidity 
commences  in  twenty-four  hours  and  bubbles  of  carbon  dioxide  are  given 
off ;  in  forty -eight  hours  the  liquid  is  entirely  turbid  and  a  thin,  whitish  pel- 
licle has  formed  on  the  surface,  at  the  same  time  a  sediment  commences  to 
form  at  the  bottom  of  the  tube.  Upon  the  surface  of  nutrient  gelatin  de- 
velopment is  very  scanty  and  scarcely  perceptible.  In  the  interior  small, 
punctif  orm  colonies  are  developed ;  these  are  spherical  or  oval,  and  may  at- 
tain a  diameter  of  0.5  millimetre.  Upon  slices  of  unripe  pear,  in  two  or 
three  days,  fine  milky  drops  like  beads  of  dew  are  developed.  Upon  potato 
a  thin,  moist,  somewhat  yellowish  layer  is  developed. 

The  experiments  of  Bun-ill  and  o'f  Arthur  show  that  the  disease  known 
as  pear  blight  is  produced  by  applying  cultures  of  this  ' '  micrococcus  "  to 
healthy  branches  of  the  pear  tree. 


235.    ASCOCOCCUS  BILLROTHII. 

Found  by  Billroth   in  putrefying 
flesh  infusion. 

Morphology. — Small  cocci,  united 
in  peculiar  colonies.  Upon  the  sur- 
face of  liquid  media  form  a  cream- 
like  layer  in  which  numerous  small, 
spherical  or  oval  masses  are  seen. 
Under  the  microscope  these  are  seen 
to  consist  of  a  jelly-like,  cartilaginous, 
extremely  resistant  envelope  from 
ten  to  fifteen  ju.  thick ;  in  the  interior 
of  this  one  or  more  spherical  or  oval 
masses  of  cocci  are  enclosed,  which 
are  from  twenty  to  seventy  n  or  more 
in  diameter;  the  cocci  are  closely 
crowded  and  united  by  an  unusually 
firm  and  scanty  intercellular  sub- 
stance. 

Biological  Characters. — Aerobic.  Grows  at  the  room  temperature. 
Produces  a  strongly  alkaline  reaction  in  culture  media,  due  to  the  develop- 
ment of  ammonia.  According  to  Cohn,  a  greenish- white,  slimy  mass  is  de- 
veloped upon  slices  of  beet,  and  in  the  juice  of  the  sugar  beet  it  produces  a 
slimy  fermentation. 


FIG.  209.— ASCOCOCCUS  Billrothii. 


NON-PATHOGENIC  MICROCOCCI.  619 

236.   LETJCONOSTOC  MESENTEROIDES   (Cienkowski). 

Synonyms. — Froschlaichpilz ;  Pilz  der  Dextrangarung. 

Found  upon  the  beet  juice  and  the  molasses  of  sugar  factoi'ies,  where  it 
develops  as  large,  jelly-like  masses  resembling  frog  spawn ;  also  upon  raw 
or  cooked  carrots  or  sugar  beets. 

Morphology.  — The  reproductive  elements  are  spherical  or  oval,  and  from 
1.8to2ju  in  diameter;  they  consist  of  a  firm,  membranous  envelope  with 
shining  contents.  When  these  germinate — according  to  Van  Tieghem — the 
external  layer  of  the  cell  wall  is  ruptured  in  an  irregular  way  and  a  middle 
layer  is  extruded  to  form  a  thick,  jelly-like  envelope,  while  the  inner  layer 
remains  in  contact  with  the  protoplasmic  contents  of  the  cell ;  the  cell  and 
its  envelope  then  become  elongated  and  binary  division  of  the  reproductive 
element  occurs;  this  process  is  repeated  in  the  segments,  and  as  a  result  a 
chain  of  spherical  elements  enclosed  in  a  sausage-shaped  mass  of  jelly  is  de- 
veloped ;  later  the  chains  become  curved  and  break  up  into  longer  or  shorter 
fragments,  which  are  enclosed  in  an  irregular  gelatinous  mass ;  these  zoog- 
Icea  crowded  together  form  small  masses  having  a  parenchymatous  struc- 
ture ;  these  adhere  to  each  other  when  they  come  in  contact,  and  when  dis- 
tributed in  a  liquid  may  be  brought  together  by  shaking  to  form  a  large, 
Jelly-like  mass  which  ha's  apparently  been  developed  by  the  process  of  shak- 
ing, as  the  smaller  masses  suspended  in  the  fluid  could  not  readily  be  seen. 
The  zoogloea  masses  have  a  cartilage-like  consistence  and  can  be  cut  into 
sections  with  a  razor.  The  jelly  is  hyaline,  but  in  beet  juice  often  has  a  gray- 
ish color  from  the  presence  of  impurities  attached  to  its  surface.  When 
treated  with  a  solution  of  haematoxylon  it  acquires  a  brown  color.  After 
some  time  the  jelly  is  dissolved,  and  the  cocci  are  set  free  and  in  a  suitable 
medium  again  develop  zooglcea.  Van  Tieghem  has  demonstrated  the  forma- 
tion of  spores.  These  are  formed  when  conditions  are  no  longer  favorable 
for  the  development  of  the  vegetative  cells ;  here  and  there  a  cell  in  a  chain  is 
seen  to  increase  in  dimensions,  and  in  the  interior  of  this  mother  cell  a  con- 
siderable number  of  refractive  spores  are  developed. 

Biological  Characters.  —This  coccus  is  aerobic.  It  is  readily  cultivated 
in  liquid  media  containing  glucose.  According  to  Van  Tieghem,  it  appro- 
priates grape  sugar  directly  and  cane  sugar  indirectly — i.e.,  after  it  has  been 
changed  into  grape  sugar  by  a  ferment  produced  by  the  coccus.  Development 
is  very  rapid  under  favorable  conditions.  Thus  Durin  reports  that  a  wooden 
tub  in  which  beet  juice  had  been  kept,  and  upon  the  walls  of  which  a  thin, 
slimy  mass  of  this  microorganism  remained  attached,  was  filled  with  a  neu- 
tral solution  of  molasses  containing  ten  per  cent  of  sugar.  At  the  end  of 
twelve  hours  the  entire  contents  of  the  tub  had  been  changed  into  a  compact, 
jelly-like  mass  by  the  development  of  Leuconostoc  mesenteroides.  The 
chemical  formula  for  the  jelly  is  CnHioOio. 


IX. 

NON-PATHOGENIC  BACILLI. 
A.   Chroinogenic,  Non-Liquefying  Bacilli. 

237.    BACTERIUM  LUTEUM  (List). 

Found  in  water. 

Morphology. — Elliptical  cells  from  1.1  to  1.3  //  long. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic  bacillus.  Produces  an  orange-yellow  pigment  soluble  in  water, 
alcohol,  and  ether;  not  changed  by  alkalies,  but  at  once  destroyed  by  acids. 
Grows  at  the  room  temperature  in  the  usual  culture  media.  Upon  gelatin 
plates  forms  irregular  colonies  upon  the  surface,  of  slimy  consistence  and 
orange-yellow  in  color  ;  under  a  low  power  these  are  seen  to  consist  of  many 
club-shaped,  coarsely  granular,  zpoglcea  masses,  each  one  of  which  is  made 
up  of  several  segments.  In  gelatin  stick  cultures  development  occurs  slowly 
along  the  line  of  puncture  and  an  orange-yellow  layer  forms  on  the  surface. 
In  milk,  at  30°  C.,  a  layer  forms  upon  the  surface  in  from  twenty-four  to 
thirty  hours,  and  the  milk  below  has  a  pale-yellow  color ;  later  coagulation 
of  the  casein  occurs. 

238.  BACILLUS  AURANTIACUS  (Frankland). ' 

Found  in  well  water. 

Morphology.—  Short,  thick  bacilli  which  vary  greatly  in  their  dimensions ; 
sometimes  associated  in  pairs ;  often  grow  out  into  long  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  slightly  motile, 
chromogenic  bacillus.  Forms  an  orange-colored  pigment.  Grows  at  the 
room  temperature  in  the  usual  culture  media.  Upon  gelatin  plates  the  super- 
ficial colonies  are  homogeneous,  opaque,  elevated  masses  of  a  pale-orange 
color ;  the  deep  colonies  spherical  and  granular.  In  gelatin  stick  cultures 
scarcely  any  development  occurs  along  the  line  of  puncture ;  upon  the  sur- 
face a  shining,  orange-colored  layer  is  formed.  Upon  agar  a  similar  devel- 
opment occurs.  Upon  potato  the  growth  is  limited  to  the  line  of  inoculation 
and  is  of  shining,  oimtge-red  color. 

239.  BACILLUS  BRUNNEUS  (Adametz). 

Found  in  water. 

Morphology. — Small,  slender  bacilli. 

Biological  Characters.— An.  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Forms  a  brown  pigment.  Forms  spores. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  the  superficial  colonies  appear  as  little  drops  of  slimy  consistence,  but 
not  viscid ;  under  a  low  power  they  are  at  first  white  and  opaque,  with  circu- 
lar contour ;  later,  in  ten  to  fourteen  days,  they  are  gray,  and  a  brown  color 
is  given  off  from  the  lower  surface.  In  gelatin  stick  cultures  development 


XON-PATHOGENIC   BACILLI.  621 

occurs  chiefly  along  the  line  of  puncture ;  upon  the  surface  a  milk-white, 
slimy  growth  is  seen  about  the  point  of  puncture ;  this  becomes  about  one 
millimetre  thick  and  changes  to  a  gray  color,  while  a  brown  pigment  is 
given  off  from  its  lower  surface  and  also  along  the  line  of  inoculation. 

240.  BACILLUS  AUREUS  (Adametz). 

Found  in  water  and  also  upon  the  surface  of  the  body  in  cases  of  eczema 
seborrhceicum — by  Unna  and  Tommasoli. 

Morphology. — Slender  bacilli,  straight  or  slightly  curved,  from  1.5  to  4  n 
long  and  0.5  /f  broad ;  often  arranged  in  groups  in  which  the  bacilli  lie  paral- 
lel to  each  other;  frequently  in  pairs  or  in  long  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  slightly  motile, 
chromogenic  bacillus.  Forms  a  golden-yellow  pigment.  Spore  production 
not  observed.  Grows  slowly  at  the  room  temperature  in  the  usual  culture 
media.  Upon  gelatin  plates  forms  small  superficial  colonies  of  irregular 
form,  which  at  the  end  of  eight  days  still  appear  as  small  white  points ;  these 
later  become  pale-yellow  and  finally  chrome-yellow  in  color ;  they  are  opaque, 
have  well-defined  outlines,  and  may  attain  a  diameter  of  one  to  four  milli- 
metres; they  vary  in  form,  being  round  or  elliptical,  and  later  sometimes 
sausage-shaped.  In  gelatin  stick  cultures  development  occurs  slowly  upon 
the  surface  in  the  form  of  small,  hemispherical  colonies  crowded  together  to 
form  an  irregular,  dull-shining,  dark  chrome-yellow  layer  ;  very  scanty 
growth  occurs  along  the  line  of  puncture.  Upon  potato  broad,  glistening, 
hemispherical  colonies  are  formed,  which  gradually  become  confluent  and 
form  a  dark  chrome-yellow  layer  which  in  old  cultures  acquires  a  deep  red- 
dish-brown color. 

241.  BACILLUS  FLAVOCORIACEUS  (Eisenberg). 

Synonym. — Sulphur-yellow  bacillus  (Adametz). 

Found  in  water. 

Morphology. — Very  small  bacilli. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic bacillus.  Produces  a  sulphur-yellow  pigment.  Spore  formation 
not  observed.  Grows  at  the  room  temperature.  Upon  gelatin  plates  forms 
small,  round,  sulphur-yellow  colonies,  which  under  a  low  power  are  seen  to 
be  coarsely  granular  and  have  a  brownish-yellow  centre  surrounded  by  a 
pale-yellow  marginal  zone ;  older  colonies  are  irregular  in  outline.  In  gela- 
tin stick  cultures  a  scanty,  granular,  grape-like  growth  occurs  on  the  sur- 
face and  along  the  line  of  puncture. 

242.    BACILLUS  BEROLINENSIS  INDICUS   (Classen). 

Found  in  water — of  the  Spree. 

Morphology. — Slender  bacilli  with  round  ends,  resembling  the  typhoid 
bacillus  in  form  and  dimensions ;  usually  solitary,  sometimes  united  in  pairs 
or  in  chains  of  three.  The  rods  are  surrounded  by  a  delicate,  transparent 
envelope. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile,  chromo- 
genic bacillus.  Forms  an  indigo-blue  pigment  which  is  insoluble  in  water, 
alcohol,  or  chloroform,  soluble  in  cold  concentrated  hydrochloric  acid ;  is 
decolorized  by  ammonia.  Spore  formation  not  demonstrated.  Grows  rap- 
idly at  the  room  temperature  in  the  usual  culture  media.  Upon  gelatin 
plates,  at  the  end  of  three  days,  grayish-white  colonies  the  size  of  a  pin's 
head  are  developed ;  by  the  fourth  day  these  commence  to  acquire  an  indigo- 
blue  color,  the  deep  colonies  around  the  margin  and  the  superficial  colonies 
more  in  the  centre ;  the  uncolored  margins  of  the  superficial  colonies  are  ir- 
regularly bulged  and  have  a  pearly  lustre.  In  gelatin  stick  cultures  a  small, 
indigo-blue  mass  develops  at  the  point  of  puncture  at  the  end  of  twenty- 

52 


622  NON-PATHOGENIC   BACILLI. 

four  hours  •  in  the  course  of  three  or  four  days  this  becomes  a  regular  wall, 
and  then  extends  slowly  over  the  surface  of  the  gelatin,  forming  a  layer 
with  irregular  outlines.  Upon  the  surface  of  agar  the  growth  is  very  charac- 
teristic ;  at  the  room  temperature  an  indigo-blue  streak  is  seen  at  the  end  of 
twenty-four  hours,  and  in  four  or  five  days  this  becomes  a  tolerably  thick 
layer,  which  gradually  thins  out  at  the  edges  and  which  has  a  deep  indigo- 
blue  color ;  the  surface  is  covered  up  to  within  two  or  three  millimetres  of 
the  margin  with  a  thin,  shining  layer  of  pigment  similar  to  that  seen  upon 
a  saturated  solution  of  gentian  violet.  Upon  potato,  at  the  end  of  three  or 
four  days,  an  abundant  layer,  thickest  in  the  middle  and  with  well-defined 
margins,  is  formed ;  this  has  a  deep  indigo-blue  color,  and  also  has  a  thin 
film  of  pigment  on  the  surface  when  the  potato  has  an  acid  reaction;  when 
alkaline  a  thin,  dirty-green  layer  is  formed  without  the  film  of  pigment  on 
the  surface, 

243.  BACILLUS  CONSTRICTUS  (Zimmermann). 

Found  in  water. 

Morphology. — Bacilli  with  round  ends,  from  1.5  to  6.5  ju  in  length  and 
0.75  a  thick;  the  rods  are  constricted  at  intervals  so  as  to  form  two  to  six  or 
more  segments,  which  in  stained  preparations  are  separated  by  an  unstained 
interval. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile,  chromogenic  bacillus.  Forms  a  Naples-yellow  pigment. 
Spore  formation  not  observed.  Grows  slowly  at  the  room  temperature  in  the 
usual  culture  media — no  development  at  30°  C.  and  above.  Upon  gelatin 
plates  forms,  in  four  to  five  days,  small,  shining  drops  of  a  Naples-yellow 
color;  the  deep  colonies  under  a  low  power  are  spherical,  granular,  and 
yellowish-gray  in  color;  they  have  well-defined  outlines,  but  the  margins 
are  irregularly  dentate.  In  gelatin  stick  cultures  development  occurs  along 
the  line  of  puncture,  and  upon  the  surface  a  layer  is  developed  which  con- 
sists of  irregular  masses  closely  crowded  together  and  which  have  a  Naples- 
yellow  color.  Upon  the  surface  of  agar  a  tolerably  thick,  shining,  Naples- 
yellow  streak  is  developed  along  the  impfstrich.  Upon  potato  after  a  time 
a  thin  layer  of  a  cadmium-yellow  color  is  developed. 

244.  BACILLUS  FLUORESCENS  AUREUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Short  bacilli,  about  1.9  n  long  and  0.74  /*  broad,  usually 
in  pairs  and  associated  in  longer  or  shorter  groups;  have  long  terminal 
flagella. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile, 
chromogenic  bacillus.  Forms  an  ochre-yellow  pigment.  Spore  formation 
not  observed.  Grows  in  the  usual  culture  media — best  at  the  room  tempera- 
ture. Upon  gelatin  plates  the  deep  colonies  are  small,  yellowish- white,  and 
spherical ;  the  superficial  colonies  are  glistening,  yellowish-gray,  and  have 
ill-defined  margins ;  under  the  microscope  they  are  seen  to  be  thickest  in  the 
middle  and  have  irregular  outlines,  while  the  deep  colonies  are  sphei'ical, 
pale-yellow,  and  granular.  In  gelatin  stick  cultures  a  scanty  development 
occurs  along  the  line  of  puncture,  which  after  a  time  acquires  a  brownish 
color;  upon  the  surface  a  thin  layer  is  developed,  which  later  becomes 
thicker  at  the  centre  and  extends  to  the  walls  of  the  tube ;  it  has  a  yellow 
color.  Upon  the  surf  ace  of  agar  an  abundant  ochrous  or  golden-yellow 
layer  is  developed.  Upon  potato  the  growth  is  similar  but  more  scanty. 

245.  BACILLUS  FLUORESCENS  LONGUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology.— Straight  or  slightly  curved  bacilli,  about  0.83  n  broad,  and 
varying  greatly  in  length — from  1.45  to  14  u  and  more. 


NON-PATHOGENIC   BACILLI.  623 

Biological  Characters. — An  aerobic,  non-liquefying,  motile,  chromo- 
genic  bacillus.  Forms  a  grayish-yellow  pigment.  Spore  formation  not 
positively  determined,  but  unstained  bodies  resembling  spores  are  seen  in 
the  rods.  The  short  bacilli  only  are  motile,  the  longer  filaments  not.  Upon 
gelatin  plates  the  deep  colonies  are  small,  spherical,  and  white  with  a  green- 
ish lustre;  under  a  low  power  they  are  seen  to  be  yellowish,  sharply  de- 
fined, and  the  interior  is  marked  by  contorted  stripes.  The  superficial 
colonies  are  at  first  quite  thin,  nearly  circular  in  form,  and  with  a  pearly 
lustre ;  they  increase  rapidly  in  size,  and  at  the  end  of  three  days  appear  as 
yellowish-green  patches  which  may  be  as  much  as  nine  millimetres  in  dia- 
meter ;  the  margins  are  very  thin  and  appear  to  be  permeated  with  yellow- 
ish-white threads ;  under  a  low  power  the  superficial  colonies  are  seen  to  be 
striped  by  broad,  convoluted  bands  resembling  the  intestine  of  a  small  ani- 
mal. In  gelatin  stick  cultures  a  very  thin  layer  first  forms,  which  later  be- 
comes thicker  at  the  centre  and  soon  reaches  the  walls  of  the  test  tube ;  at 
first  it  has  a  blue  and  later  bluish-green  fluorescence.  Upon  the  surface  of 
agar  a  rather  thin  layer  is  developed  and  the  agar  acquires  a  greenish-yellow 
color.  Upon  potato  a  thin,  gray  layer  with  a  yellowish  reflection  and 
moist,  shining  surface  extends  over  the  surface. 

246.  BACILLUS  FLUORESCENS  TENUIS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

.  Morphology. — Short,  thick  bacilli  with  round  ends,  from  1  to  1.85  fit  long 
and  about  0.8  M  thick;  one  or  both  ends  are  somewhat  pointed ;  the  rods 
are  associated  in  irregular  groups,  and  in  old  cultures  often  in  chains  con- 
taining four  to  six  elements. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile,  chromo- 
genic  bacillus.  Forms  a  greenish-yellow,  fluorescent  pigment.  Spore  for- 
mation not  determined.  Grows  rather  rapidly  in  the  usual  culture  media 
at  the  room  temperature.  Upon  gelatin  plates  thin,  shining  superficial 
colonies  are  developed,  which  are  irregularly  circular  in  outline  and  have  a 
radiate-cleft  margin  ;  the  gelatin  acquires  a  green  color  far  beyond  their 
boundary.  In  gelatin  stick  cultures  a  thin  layer  is  formed  upon  the  surface, 
which  afterwards  becomes  thicker,  of  a  grayish-white  color,  and  extends  to 
the  walls  of  the  test  tube  in  about  four  days ;  the  gelatin  acquires  a  beautiful 
yellow  color  near  the  surface ;  by  reflected  light  the  surface  growth  is  at 
first  blue  and  later  bluish-green;  the  line  of  puncture  is  marked  by  a  scanty 
development  which  does  not  become  any  more  pronounced.  Upon  the  sur- 
face of  agar  a  smooth,  gray,  shining,  and  rather  scanty  layer  is  developed; 
the  agar  gradually  acquires  a  greenish  color.  Upon  potato  a  thin,  grayish- 
yellow,  shining  layer  is  developed  along  the  impfstrich;  later  this  acquires 
a  reddish-brown  color. 


247.   BACILLUS  FLUORESCENS  NON-LIQUEFACIENS. 

Found  in  water. 

Morphology. — Short,  slender  rods  with  round  ends. 

Biological .  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic  bacillus.  Forms  a  greenish-yellow,  fluorescent  pigment.  Spore 
formation  not  observed.  Grows  in  the  usual  culture  media  at  the  room 
temperature — not  in  the  incubating  oven.  Upon  gelatin  plates  forms  fern- 
shaped  superficial  colonies,  around  which  the  gelatin  has  a  pearly  lustre. 
In  gelatin  stick  cultures  very  scanty  growth  occurs  along  the  line  of  punc- 
ture ;  the  superficial  growth  has  a  fluorescent  shimmer.  Upon  the  surface  of 
agar  a  layer  is  formed  having  a  greenish  color.  Upon  potato  a  rapidly  de- 
veloped, diffuse,  brownish  layer  is  formed,  and  the  surface  of  the  potato 
acquires  a  grayish-blue  color. 


624  NON-PATHOGENIC   BACILLI. 

248.    BACILLUS  FLUORESCENS   PUTIDUS   (Flugge). 

Found  in  water. 

Morphology.— Short  bacilli  with  round  ends. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile, 
chromogenic  bacillus.  Produces  a  greenish,  fluorescent  pigment.  Does  not 
form  spores.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  the  superficial  colonies  are  small,  and  under  a  low  power 
they  are  seen  to  be  finely  granular  discs  with  a  dark  centre  surrounded  by 
a  yellow  zone,  and  a  pale-gray  margin  which  is  serpentine  in  outline;  older 
colonies  are  dentate  and  have  a  greenish  shimmer ;  the  gelatin  around  ac- 
quires a  fluorescent  green  color ;  an  odor  of  trimethylamin  is  given  off.  In 
gelatin  stick  cultures  development  occurs  upon  the  surface  only,  as  a  thin, 
dirty- white  layer ;  in  the  course  of  a  few  days  the  gelatin  commences  to 
acquire  a  greenish,  fluorescent  color,  most  intense  near  the  surface  and 
gradually  fading  out  below.  Upon  potato  a  thin,  slimy,  gray  or  brownish 
layer  is  developed. 

249.   BACILLUS   ERYTHROSPORUS   (Eidam). 

Found  in  water,  in  putrefying  flesh  infusion,  etc. 

Morphology. — Slender  bacilli  with  round  ends ;  often  grow  out  into  short 
filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile,  chromo- 
genic bacillus.  Forms  a  greenish-yellow,  fluorescent  pigment.  Forms  oval 
spores — from  two  to  eight  in  each  filament.  Grows  at  the  room  temperature 
in  the  usual  culture  media — not  in  the  incubating  oven.  Upon  gelatin  plates 
forms  whitish  colonies,  which  spread  out  over  the  surface  of  the  gelatin  as  a 
wrinkled  and  furrowed  layer,  around  which  the  gelatin  acquires  a  greenish- 
yellow,  fluorescent  color;  under  a  low  power  the  colonies  are  seen  to  have  an 
opaque,  brownish  centre  surrounded  by  a  transparent,  greenish-yellow  mar- 
ginal zone,  an  irregular  outline,  and  the  surface  is  marked  by  indistinct,  ra- 
diating lines.  In  gelatin  stick  cultures  an  abundant  growth  occurs  along 
the  line  of  puncture  and  upon  the  surface ;  the  gelatin  throughout  gradually 
acquires  a  fluorescent  green  color  by  transmitted,  and  a  yellow  color  by  re- 
flected light.  Upon  potato  a  layer  of  limited  dimensions  is  formed,  which  is 
at  first  reddish  in  color  and  later  nut-brown . 

250.   BACILLUS  VIRIDIS   PALLESCENS   (Frick). 

Morphology. — Bacilli  which  are  somewhat  longer  and  more  slender  than 
the  typhoid  bacillus ;  form  long  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile, 
chromogenic  bacillus.  Produces,  in  presence  of  oxygen,  a  pale  bluish-green 
pigment,  which  later  becomes  yellowish-brown  with  a  green  fluorescence. 
Grows  best  at  the  room  temperature.  Spore  formation  not  observed.  Upon 
gelatin  plates  the  deep  colonies  are  small  and  spherical;  superficial  colonies 
flat,  with  irregular,  well-defined  margins  and  a  granular  surface — similar  to 
Bacillus  virescens,  but  larger  and  of  more  rapid  development ;  the  colonies  are 
green  in  color  at  first,  but  fade  out  to  a  pale  bluish-green ;  they  are  fre- 
quently slightly  iridescent.  In  gelatin  stick  cultures  growth  occurs  upon 
the  surface  only,  of  a  green  color  which  quickly  fades  out  to  a  bluish-green. 
Upon  the  surface  of  agar  the  growth  is  the  same  as  on  gelatin.  Upon  potato 
a  nut-brown,  moist  layer  is  formed,  and  the  potato  around  it  acquires  a  dirty- 
violet  color. 

251.    BACILLUS  VIRESCENS   (Frick). 

Found  in  green  sputum. 

Morphology. — Bacilli  of  about  the  size  of  the  typhoid  bacillus,  three  to 
four  times  as  long  as  broad ;  frequently  grow  out  iiito  long  filaments. 


NOX-PATHOGENIC   BACILLI.  625 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile, 
fhromogenic  bacillus.  Forms  a  green  pigment,  which  after  several  weeks 
becomes  yellowish-brown  and  then  dark-green  and  fluorescent.  Spore 
formation  not  observed.  Grows  best  at  the  room  temperature— rather  slowly. 
Upon  gelatin,  plates  the  deep  colonies  are  small  and  spherical ;  the  superficial 
colonies  are  flat,  with  irregular  but  well-defined  margins  and  a  finely  gran- 
ular surface;  at  the  end  of  two  to  three  days  the  colony  and  the  surrounding 
gelatin  have  an  intensely  green  color ;  later  the  colony  becomes  thicker,  softer, 
and  of  a  still  deeper  green  color.  In  gelatin  stick  cultures  growth  occurs  on 
the  surface  only ;  the  gelatin  acquires  a  decided  green  color.  Upon  agar  an 
abundant  development  occurs  upon  the  surface.  Upon  potato  a  nut-brown, 
moist  layer  is  formed,  and  the  potato  around  it  acquires  a  dirty-violet  color. 
In  bouillon  forms  a  layer  upon  the  surface,  which  is  with  difficulty  made  to 
sink  to  the  bottom,  and  not  until  it  is  broken  up  by  shaking ;  the  upper  por- 
tion of  the  bouillon  has  a  green  color. 

252    BACILLUS  IRIS  (Frick). 

Morphology. — Very  small,  slender  bacilli. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chromo- 
genic  bacillus.  Produces  a  fluorescent  green  color,  which  later  becomes 
yellowish-brown,  and  finally  dark-green  and  fluorescent.  Spore  formation 
not  observed.  Grows  best  at  the  room  temperature.  Upon  gelatin  plates 
forms  prominent,  whitish,  round,  sharply  defined  superficial  colonies  with 
a,  smooth,  shining  surface ;  a  green  color  is  slowly  developed.  In  gelatin 
stick  cultures  a  prominent  mass  develops  about  the  point  of  puncture ;  no 
growth  along  the  line  of  puncture.  Upon  potato  a  dry,  pale-brown  layer  is 
formed.  In  bouillon  no  layer  is  formed  upon  the  surface,  and  the  bouillon 
is  not  colored 

253.  BACILLUS  FUSCUS  (Zimmermann). 

Found  in  water. 

Morphology.—  Straight  or  curved  bacilli  with  round  ends,  an  irregular 
contour,  here  and  there  slightly  bulging ;  about  0.63yu  in  diameter  and  of 
various  lengths. 

Biological  Characters.  —An  aerobic,  non-liquefying,  non-motile,  chromo- 
genic  bacillus.  Forms  a  dark  chrome-yellow  pigment.  Spore  formation 
not  observed.  Grows  slowly  at  the  room  temperatm-e  in  the  usual  culture 
media — best  at  30°  C.  Upon  gelatin  plates  the  deep  colonies  are  punctiform 
-and  yellowish-brown  in  color ;  later  they  project  from  the  surface  in  button 
form,  and  often  have  an  irregular,  knobby  form ;  under  the  microscope  such 
colonies  are  seen  to  be  made  up  of  smaller,  spherical  masses.  The  deep  col- 
onies, under  a  low  power,  are  spherical  or  irregular  in  form,  granular,  and 
grayish-yellow  or  brownish -yellow  in  color ;  the  superficial  colonies  have  a 
brownish-yellow  central  portion  surrounded  by  a  highly  refractive  marginal 
zone.  In  gelatin  stick  cultures  a  button-like  mass  develops  at  the  point  of 
puncture;  later  the  growth  extends  over  the  surface,  forming  a  thick, 
wrinkled  layer,  at  first  pale-yellow  and  then  chrome-yellow  in  color.  The 
growth  upon  agar  is  similar  to  that  upon  gelatin.  Upon  potato  a  dark 
chrome-yellow,  friable  layer  is  developed. 

254.  BACILLUS  RUBEFACIENS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  with  round  ends,  from  0.75  to  1.65 /*  long  and  about 
0.32  n  thick;  united  in  pairs,  or  in  chains  consisting  of  several  elements. 

Biological  Characters.—  An  aerobic,  non-liquefying,  actively  motile, 
chromogenic  bacillus.  Produces  a  pale-pink  pigment.  Grows  best  at  the 
room  temperature.  Upon  gelatin  plates  the  deep  colonies  are  spherical  or 
lenticular  in  form,  and  white  with  a  shade  of  yellowish-red ;  the  superficial 


620  NON-PATHOGENIC   BACILLI. 

colonies  are  flat,  gray  with  a  reddish  tint ;  under  the  microscope  the  deep 
colonies  are  seen  to  be  granular,  spherical,  and  yellowish  or  brownish  in 
color.  In  gelatin  stick  cultures  development  occurs  along  the  line  of  punc- 
ture, and  upon  the  surface  a  tolerably  thick,  grayish-white  layer  is  formed, 
which  later  has  a  yellowish  tint,  while  the  gelatin  around  it  has  a  bluish- 
white  lustre.  In  old  cultures  the  gelatin  frequently  acquires  a  pale  wine 
color.  Upon  agar  a  smooth,  rather  thick,  bluish-gray  layer  is  formed. 
Upon  potato  an  abundant,  yellowish-gray  layer  is  developed,  which  later 
has  a  reddish-brown  color,  while  the  potato  around  it  after  forty -eight  hours 
acquires  a  pink  color. 

255.  BACILLUS  STRIATUS  FLAVUS  (Von  Besser). 

Found  in  nasal  mucus — rare. 

Morphology.— Small,  thick  rods,  often  curved,  of  about  the  dimensions 
of  the  diphtheria  bacillus.  In  preparations  stained  with  methylene  blue,  has 
a  striated  appearance.  In  old  preparations  various  involution  forms  are 
seen. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  bacil- 
lus. Forms  a  sulphur- yellow  pigment.  Grows  at  the  room  temperature  in 
the  usual  culture  media.  Spore  formation  not  observed.  Upon  gelatin 
plates  forms  thick,  dry,  granular  colonies  of  a  yellowish  color.  Upon  agar 
plates  projecting  milk-white  colonies  of  about  0.5  centimetre  in  diameter 
are  developed ;  later  these  acquire  a  sulphur-yellow  color.  Upon  the  sur- 
face of  agar  a  white,  thick  layer  develops  along  the  impfstrich ;  after  some 
days  this  acquires  a  sulphur-yellow  color.  Upon  potato  a  narrow,  yellow 
stripe  is  developed  along  the  impfstrich. 

256.  BACILLUS  SUBPLAVUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  with  round  ends,  from  1.5  to  3;*  long  and  about 
0.77  n  broad  ;  united  in  chains  of  several  elements. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile,  chromo- 
genic bacillus.  Forms  a  pale-yellow  pigment.  Grows  best  at  the  room  tem- 
perature. Spore  formation  not  observed.  Upon  gelatin  plates  the  deep  colo- 
nies are  small,  yellowish-white,  and  spherical;  these  break  through  the 
surface  and  form  hemispherical,  yellowish-white,  shining  masses,  which 
later  extend  over  the  surface  and  have  an  irregular  outline;  under  a  low 
power  the  surface  is  seen  to  have  a  pearly  lustre ;  they  gradually  acquire  a 
dirty-yellow  color.  In  gelatin  stick  cultures  a  thin,  yellowish-gray  layer 
with  finely  dentate  margins  forms  about  the  point  of  puncture.  Upon  the 
surface  of  agar  a  pale-yellow  layer  gradually  extends  over  the  entire  sur- 
face; the  color  gradually  becomes  darker  and  is  finally  between  a  pale 
chrome-yellow  and  yellow  ochre.  Upon  potato  a  scanty,  dull,  clay-yellow 
layer  is  formed. 

257.   BACILLUS  CYANOGENUS   (Hueppe). 

Synonyms. — Bacterium  syncyanum;  Bacillus  lactis  cyanogenus;  Bacil- 
lus of  blue  milk. 

Found  in  milk. 

Morphology. — Bacilli  with  slightly  rounded  corners,  from  1.4  to  4  n  long 
and  from  0.3  to  0.5  n  broad. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile, 
chromogenic  bacillus.  Produces  a  grayish-blue  pigment.  Forms  spores, 
which  are  located  at  the  extremities  of  the  rods,  giving  them  a  club  shape. 
Grows  rapidly  at  the  room  temperature  or  in  the  indicating  oven.  Upon 
gelatin  plates,  at  the  end  of  two  days,  small,  punctiform,  grayish -white 
colonies  are  developed ;  the  superficial  colonies  appear  as  slimy  drops  which 


NON-PATHOGEXIC   BACILLI.  627 

attain  a  diameter  of  one  to  two  millimetres ;  they  are  finely  granular,  have  a 
dirty- white  color  and  circular,  smooth  outline ;  the  gelatin  around  them  ac 
quires  a  steely  grayish-blue  shimmer.     Under  a  low  power  the  deep  colonies 
are  seen  as  round  discs  with  a  dark  centre  and  a  brownish,  granular  mar- 
ginal zone  with  a  sharply  defined  dark  contour ;  the  superficial  colonies  have 
a  dark-brown  centre  surrounded  by  a  grayish-brown,   and  outside  of  this  a 
narrow,   yellowish,  finely  granular  marginal  zone 
with  a  sharply  denned  contour.     In  gelatin  stick         •„  t ,  v 
cultures  a  white  mass  develops  around  the  point       -^f/^L      \L  )  '^  />\!  *// 
of  puncture,  and  around  it  the  gelatin  acquires  a      ^  wr    /}, 
dark  steel-blue  color.     Upon  agar  a  grayish  layer 
is  developed  and  the  culture  medium  acquires  a 

dark-brown  color  near  the  surface.     Upon  potato         FIG.  210.— Bacillus   cyano- 
a  slimy,  yellowish  layer  is  developed,    limited  to      genus;  at  a  the  rods  contain 
the  vicinity  of  the  impf strich ;  around  this  the  po-      spores,    x  TOO.   (Flugge.) 
tato  acquires  a  diffused  grayish-blue  color.     Upon 

blood  serum  development  occurs  without  the  formation  of  pigment.  In 
milk  a  slightly  alkaline  reaction  is  produced  by  the  growth  of  this  bacillus ; 
the  casein  is  not  coagulated ;  at  the  surface  and  gradually  extending  down- 
ward a  slate-blue  color  is  developed,  and  upon  the  addition  of  an  acid  this 
changes  to  an  intense  blue.  In  milk  which  has  not  been  sterilized  and  which 
contains  acid-forming1  bacteria  a  sky-blue  color  is  produced  without  the  ad- 
dition of  an  acid.  The  pigment  is  produced  most  abundantly  at  a  tempera- 
ture of  15°  to  18°  C. ;  at  25"  G.  it  is  less  abundant,  and  at  37°  C.  is  not  formed 
at  all. 

Note. — Jordan  gives  an  account  of  Bacillus  cyanogenus  which  differs 
materially  from  that  above  given  by  Fliigge,  and  which  leads  to  the  belief 
that  two  or  more  different  bacilli  have  been  described  under  this  name. 
Jordan's  description  agrees  tolerably  well,  however,  with  that  of  Heim.  The 
bacillus  described  by  him  was  quite  frequently  found  in  Lawrence  sewers 
and  is  described  as  follows : 

"Morphology. — Small  bacilli  with  rounded  ends,  often  oval  in  form. 
Occur  in  chains  in  all  media,  isolated  individuals  being  quite  the  exception. 
The  chain  is  usually  long  and  its  members  cohere  quite  firmly.  On  no  me- 
dium has  there  been  observed  anything  resembling  spore  formation.  The 
individuals  are  about  1.3  /*  long  and  0.8  ju  broad.  Motility :  There  is  a  slight 
independent  movement  to  be  observed  in  hanging  drops.  We  have  certainly 
ncD  found  this  species  to  be  '  very  motile.'  Temperature:  Does  not  grow  as 
well  at  37°  as  at  21°  C.  Need  of  oxygen :  Grows  very  scantily  under  the 
mica  plate.  Plate  cultures :  The  young  colonies  below  the  surface  of  the 
gelatin  are  usually  slightly  oval,  with  a  coarsely  granular  interior  and  an 
even,  regular  edge.  Often,  however,  the  colonies  have  a  frayed,  irregular 
appearance  to  the  naked  eye,  and  with  the  microscope  show  fine  branchings 
from  the  centre.  On  coming  to  surface  the  colonies  always  spread  out  into 
a  dull,  dry  expansion  with  irregularly  hacked  edges.  Sometimes  the  colo- 
nies are  surrounded  by  a  light  blue-green  haze,  which  soon  changes  to  a 
faint  brown ;  and  this  becomes  deeper  and  deeper  till  the  whole  plate  is 
colored  an  intense  dark -brown.  More  often,  however,  in  our  experience,  the 
brown  color  comes  without  a  previous  development  of  the  blue.  In  slightly 
acid  gelatin  the  blue  color  comes  more  surely  and  constantly  than  in  the 
ordinary  alkaline  medium.  The  gelatin  is  not  liquefied.  Tubes — gelatin  : 
In  about  three  days  there  is  a  thin  surface  growth,  smooth  and  faintly  lus- 
trous. The  contour  is  at  first  quite  regular,  with  the  edges  only  slightly 
toothed.  There  is  only  a  slight  growth  along  the  inoculation  line.  The 
gelatin  near  the  surface  soon  takes  on  a  brown  tint,  and  eventually  the  whole 
tube  of  gelatin  is  colored  dark-brown.  The  blue  coloration  is  not  observed 
as  well  in  tubes  as  on  plates.  This  species  grows  fairly  well  in  acid  gelatin, 
but  not  so  well  as  in  alkaline.  In  the  former  the  brown  color  invariably  comes 
more  slowly.  Tubes— agar :  In.  three  days  there  is  a  good  surface  growth, 
white  and  lustrous.  The  agar  is  colored  dark-brown.  The  growth  itself 


G28  NON-PATHOGENIC  BACILLI. 

also  assumes  a  brownish  cast.  Potato  culture .'  A  very  rapid  growth  on  po- 
tato. In  twenty-four  hours  the  potato  is  colored  a  deep-brown  color  over 
nearly  its  whole  surface.  We  have  in  no  case  observed  a  previous  blue  color- 
ation. The  growth  is  brownish,  thin,  spreading-,  and  dry.  Milk:  The  milk 
very  slowly  becomes  a  light-chocolate  color.  The  reaction  is  slightly  alka- 
line. Bouillon:  In  three  days  the  bouillon  has  become  slightly  turbid. 
Month-old  cultures  are  a  deep  brown,  with  a  tough,  thick  skin  on  the  sur- 
face. Effect  upon  nitrates  :  Nitrates  are  slowly  reduced." 

Jordan  remarks :  "This  is  undoubtedly  the  'bacillus  of  blue  milk'  de- 
scribed originally  by  Hueppe." 

258.  BACILLUS  FUSCUS  LIMBATUS  (Scheibenzuber). 

Obtained  from  rotten  eggs. 

Morphology.  — Short  rods,  occasionally  united  into  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile,  chromogenic  bacillus.  Produces  a  brown  pig- 
ment. Spore  formation  not  observed.  Grows  at  the  room  temperature  in 
the  usual  culture  media.  Upon  gelatin  plates  colonies  are  developed  in  the 
form  of  small  brown  masses  of  circular  outline  and  often  surrounded  by  a 
paler  marginal  zone  which  is  two  to  three  times  as  broad  as  the  brown  in- 
terior. In  gelatin  stick  cultures  a  branching  growth  is  seen  along  the  line 
of  puncture,  and  the  short  branches  are  beset  with  small  projections ;  the 
gelatin  in  the  vicinity  of  the  line  of  growth  acquires  a  brown  color.  Upon 
the  surface  a  scanty  development  occurs.  Upon  the  surface  of  agar  a  super- 
ficial layer,  beneath  which  the  medium  acquires  a  dark-brown  color,  Upon 
potato  a  brown  layer  is  developed. 

259.  BACILLUS  LATERICEUS  (Eisenberg). 

Synonym.—  Ziegelroter  bacillus  (Adametz). 

Found  in  water. 

Morphology. — Bacilli,  from  three  to  five  times  as  long  as  broad;  grow  out 
into  short  curved  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic bacillus.  Forms  a  brick-red  pigment.  Grows  very  slowly  at  the 
room  temperature.  Spore  formation  not  observed.  Upon  gelatin  plates 
forms  punctiform,  brick- red  colonies ;  under  a  low  power  these  are  seen  to 
be  spherical,  finely  granular,  and  brownish-red  in  color ;  the  opaque  centre 
is  surrounded  by  a  more  transparent  marginal  zone.  In  gelatin  stick  cultures 
a  tolerably  thick,  slimy,  brick-red  layer  is  developed ;  very  scanty  growth 
along  the  line  of  puncture.  Upon  potato  a  brick-red  layer, 

260.  BACILLUS  SPINIFERUS  (Unna). 

Found  upon  the  surface  of  the  body  in  cases  of  eczema  seborrhceicum. 

Morphology. — Straight  or  slightly  curved  bacilli,  2  /*  long  and  0.8  to 
1  f-t  broad ;  solitary  or  in  pairs,  frequently  seen  in  irregular  groups  or  lying 
parallel  to  each  other  in  bundles. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  ba- 
cillus. Forms  a  grayish-yellow  pigment.  Spore  formation  not  observed. 
Grows  rather  slowly  at  the  room  temperature.  Upon  gelatin  plates,  at  the 
end  of  eight  days,  the  superficial  colonies  are  prominent,  shining,  skin- 
colored,  and  circular  in  outline,  from  one  to  two  millimetres  in  diameter ; 
under  a  low  power  they  are  seen  to  be  irregular  in  outline,  covered  with 
coarse  projections ;  later  finely  granular,  with  a  margin  surrounded  by  small, 
thorn-like  projections,  which  after  a  time  form  a  radiating  aureole  and 
give  the  colony  a  porcupine-like  appearance.  In  gelatin  stick  cultures,  at 
the  end  of  six  days,  an  irregular,  wrinkled  layer  about  two  millimetres  broad 
is  formed  upon  the  surface;  this  is  grayish-yellow  upon  the  folds  and  bluish 


NON-PATHOGENIC   BACILLI.  029 

in  the  furrows;  as  this  extends  the  folds  become  more  prominent  and  more 
decidedly  yellow  in  color,  the  margins  are  irregular,  dentate,  and  thin; 
along  the  line  of  inoculation  very  small,  yellowish,  punctiform  colonies  are 
developed.  Upon  the  surface  of  agar  the  growth  is  similar  to  that  upon 
gelatin.  Upon  potato  development  is  very  slow;  first  as  a  glistening,  yel- 
lowish-white line  along  the  impfstrich;  at  the  end  of  three  weeks  here  and 
there  along1  this  line  small,  grayish-yellow,  glistening  masses  are  seen. 

261.  BACILLUS  KUBESCENS  (Jordan). 

Found  in  sewage  at  Lawrence,  Mass. 

Morphology. — Bacilli  with  round  ends,  about  4  jn  long  and  0.9  n  broad, 
often  slightly  curved ;  solitary,  in  pairs,  or  in  short  chains. 

Biological  Characters. — An  aerobic,  non- liquefy  ing,  motile,  chromoge- 
nic  bacillus.  Forms  a  pale-pink  pigment.  Spore  formation  not  observed. 
Movements  slow.  Grows  best  at  the  room  temperature.  Upon  gelatin 
plates  the  deep  colonies  are  spherical  or  oval ;  on  coming  to  the  surface  they 
form  a  projecting,  porcelain- white  drop;  they  slowly  increase  in  size,  and 
after  a  time  have  a  slight  brownish  color.  In  gelatin  stick  cultures  a  pro- 
minent porcelain-white  mass  is  formed  upon  the  surface  at  the  point  of  in- 
oculation; very  scanty  growth  along  line  of  puncture;  grows  in  slightly  acid 
gelatin.  Upon  the  surface  of  agar  a  white  and  lustrous  layer  is  quickly  de- 
veloped, which  is  at  first  smooth,  but  later  becomes  wrinkled ;  in  cultures 
about  three  weeks  old  a  slight  pinkish  tinge  is  seen.  Upon  potato  the 
growth  is  rapid  and  abundant;  it  is  at  first  light-brown  in  color,  and  this 
gradually  changes  to  pink;  at  the  end  of  three  weeks  there  is  a  projecting 
growth  which  has  a  delicate  flesh-pink  color ;  the  potato  itself  is  not  coloi'ed. 
Milk  is  not  coagulated  and  has  an  alkaline  reaction  ;  in  old  cultures  a  slight 
pinkish  tinge  is  observed  near  the  surface.  Bouillon  becomes  slightly  tur- 
bid and  a  heavy  white  precipitate  is  formed.  At  the  end  of  several  weeks 
a  thick,  tenacious  film  forms  upon  the  surface. 

262.  BACILLUS  ALLII  (Griffiths). 

Synonym. — Bacterium  allii. 

Found  upon  the  surface  of  putrefying  onions. 

Morphology. — Bacilli  with  round  ends,  from  5  to  7  /« long  and  about 
2. 5  p  broad ;  solitary  or  in  pairs ;  form  zooglcea. 

Biological  Characters. — An  aerobic,  chromogenic  bacillus.  Produces  a 
green  pigment  which  is  soluble  in  alcohol.  Grows  tolerably  well  on  nu- 
trient agar,  and  produces  a  bright  green  pellicle  on  the  surface  of  this  me- 
dium. Sulphuretted  hydrogen  is  given  off  by  the  cultures  in  small  quan- 
tities. 

B.  Chromogenic,  Liquefying  Bacilli. 

263.  BACILLUS  FULVUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Short  bacilli  with  round  ends,  from  0.88  to  1.3  ju  in  length 
and  0.77  //  broad ;  solitary,  in  pairs,  or  in  chains  containing  several  elements. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile,  chromoge- 
nic bacillus.  Grows  slowly  at  the  room  temperature — best  at  30°  C.  Spore 
formation  not  observed.  Forms  a  gamboge-yellow-colored  pigment.  Upon 
gelatin  plates  the  deep  colonies  are  irregularly  spherical,  oval,  or  elliptical, 
granular,  and  yellowish -gray  in  color;  they  are  usually  surrounded  by  pale- 
yellow  patches.  The  superficial  colonies  are  reddish-yellow,  drop-like,  and 
at  the  end  of  eight  days  measure  about  one  millimetre  in  diameter.  In  gela- 
tin stick  cultures  a  prominent,  arched  mass  of  irregularly  circular  contour 
and  of  the  color  of  gamboge  is  formed  about  the  point  of  puncture ;  a  scanty 

53 


630  NON-PATHOGENIC   BACILLI. 

growth  occurs  along  the  line  of  inoculation,  which  has  a  slightly  yellowish 
color;  liquefaction  commences  after  some  weeks.  Upon  the  surface  of 
agar  an  abundant,  glistening  layer  of  a  gamboge-yellow  color.  Upon 
potato  development  occurs  slowly  along  the  impfstrich;  the  growth  has 
at  first  an  india-yellow  color,  which  later  becomes  ochre  yellow. 

264.  BACILLUS  HELVOLUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  from  1.5  to  4.5 // in  length  and  about  0.5  n  broad; 
usually  in  pairs,  but  also  in  chains  of  four  or  more  elements  and  in  long 
filaments. 

Biological  Characters.—  An  aerobic,  liquefying,  motile  (rotary  motion 
only),  chromogenic  bacillus.  Forms  a  Naples-yellow  pigment.  Spore  for- 
mation not  observed.  Grows  rather  rapidly  at  the  room  temperature.  Upon 
gelatin  plates  the  deep  colonies  are  small,  spherical,  and  of  a  pale-yellow 
color ;  when  they  come  to  the  surface  they  form  a  prominent  pale-yellow 
drop,  which  lies  in  a  shallow  cavity.  The  superficial  colonies  for  some  time 
have  a  sharply  defined  contour  and  an  irregular  outline ;  by  transmitted 
light  they  have  a  dark-brown  color.  In  gelatin  stick  cultures  a  button-like 
mass  of  a  Naples-yellow  color  forms  about  the  point  of  puncture ;  this  gradu- 
ally extends  until  it  nearly  reaches  the  walls  of  the  test  tube ;  in  the  n.ean- 
time  the  gelatin  below  is  slowly  liquefied  and  a  saucer-shaped  depression  is 
formed ;  liquefaction  progresses  very  slowly.  Upon  the  surface  of  agar 
an  abundant  layer  of  a  Naples-yellow  color  is  developed.  Upon  potato  a 
tolerably  thick  and  abundant,  shining,  yellow  layer,  which  frequently  has 
a  shade  of  green. 

265.  BACILLUS  OCHRACEUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  with  round  ends,  from  1.25  to  4.5  /*  long  and  from 
0.65  to  0.75  /f  broad;  usually  in  pairs,  or  in  chains  containing  several  ele- 
ments, also  in  long  jointed  filaments.  In  stained  preparations  a  capsule-like 
envelope  may  often  be  seen. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  an  ochre- yellow  pigment.  Spore  formation  not  observed. 
Motions  slow  and  serpentine.  Grows  rather  slowly — best  at  the  room  tem- 
perature. Upon  gelatin  palates  forms  small,  pale-yellow,  spherical  colonies, 
which  gradually  increase  in  size  and  cause  the  gelatin  above  them  to  become 
liquefied,  so  that  they  lie  at  the  bottom  of  a  saucer-shaped  cavity ;  here  the 
color  is  more  intense  and  becomes  a  golden  ochrous  yellow ;  later  the  yel- 
low mass  extends  in  diameter,  and  is  of  a  paler  yellow  color  at  the  mar- 
gin than  at  the  centre.  Under  a  low  power  the  colonies  are  seen  at  first  as 
granular,  yellowish-brown  discs  ;  later  they  are  covered  with  wart-like  pro- 
jections. ID  gelatin  stick  cultures  liquefaction  occurs  at  first  in  funnel 
form,  and  when  it  extends  to  the  walls  of  the  tube  it  gradually  progresses 
downward ;  a  pale-yellow  deposit  is  seen  at  the  bottom  of  the  liquefied  gela- 
tin, which  later  acquires  an  ochrous-yellow  tint.  Upon  the  surface  of  agar 
an  ochrous-yellow  layer  is  formed,  which  at  the  end  of  four  to  six  weeks 
has  a  breadth  of  about  six  millimetres  at  the  lower  portion  of  the  impfstrich. 
Upon  potato  a  thin,  ochrous-yellow  layer  is  developed. 

266.  BACILLUS  PLICATUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology.—  Small,  thin  bacilli  with  rounded  ends,  about  0.48/*  (?)  in 
length  and  0.45  /*  broad;  usually  in  pairs,  but  also  in  chains  of  four  or  more 
elements. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile,  chromo- 
genic bacillus.  Forms  a  grayish-yellow  pigment.  Spore  formation  on 


NON-PATHOGENIC  BACILLI.  631 

observed.  Grows  best  at  the  room  temperature.  Upon  gelatin  plates  small, 
yellowish-white  colonies  of  irregular  form  are  developed  beneath  the  surface, 
which  under  a  low  power  are  seen  to  present  hemispherical  projections ; 
when  they  break  through  the  surface  they  have  a  mulberry -like  appearance 
and  yellowish-white  color.  In  gelatin  stick  cultures  a  wrinkled,  yellowish- 
white  layer  with  irregular  contour  is  developed;  at  the  end  of  one  or  two 
weeks  it  is  depressed  and  the  gelatin  gradually  undergoes  liquefaction :  an 
abundant  development  of  small,  granular,  yellowish- white  colonies  occurs 
along  the  line  of  puncture.  Upon  potato  a  thin  layer  is  formed,  which 
soon  becomes  dry  and  friable  and  has  a  grayish-yellow  color. 

267.    BACILLUS  JANTHINUS   (Zopf). 

Synonym. — Yiolet  bacillus. 

Found  in  water  and  in  sewage  (at  Lawrence,  Mass.). 

Morphology. — Very  small,  slender  bacilli,  often  associated  in  short  fila- 
ments; about  2  n  long  and  0.5  to  0.6  ft  broad. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  a  bluish-violet  pigment.  Spore  formation  not  observed. 
Grows  best  at  the  room  temperature.  Upon  gelatinplates  the  deep  colonies 
are  spherical  or  oval,  with  an  even  contour ;  upon  coming  to  the  surface 
they  spread  out  as  a  broad,  irregular  expansion  with  deeply  notched  edges ; 
these  superficial  colonies  are  at  first  thin,  but  later  increase  in  thickness ;  a 
deep-violet  color  soon  appears,  sometimes  near  the  centre  of  the  colony, 
sometimes  around  its  edges;  the  gelatin  is  very  slowly  liquefied.  In  gelatin 
stick  cultures  a  scanty  growth,  without  color,  is  developed  along  the  line  of 
puncture,  and  a  thin,  violet-colored  layer  upon  the  surface.  The  gelatin  is 
slowly  liquefied,  and  an  abundant  violet-colored  precipitate  is  seen  at  the 
bottom  of  the  liquefied  gelatin  in  old  cultures.  Upon  the  surface  of  agar  a 
rather  tough  and  coherent  layer  is  developed,  which  has  a  dark-violet  color. 
Upon  potato  the  development  is  rapid  and  covers  the  entire  surface ;  the 
growth  frequently  has  a  beaded  appearance,  and  the  membranous  growth  is 
with  difficulty  detached  from  the  surface;  it  has  a  black-violet  color.  In 
milk  an  abundant  development  occurs  without  producing  coagulation,  and 
causing  it  to  acquire  a  violet  color.  Reduces  nitrate  to  nitrite  very  rapidly 
and  completely.  (Above  characters  given  by  Jordan.) 

268.    BACILLUS  VIOLACEUS  LAURENTIUS   (Jordan). 

"  Found  in  large  numbers  in  the  effluent  of  Tank  1 "  at  Lawrence,  Mass. 

Morphology. — Bacilli  with  round  ends,  from  3  to  3. 6  /*  long  and  0.7  ft 
broad;  often  in  pairs,  and  sometimes  in  chains  of  four  or  five  elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Produces  a  dark- violet  pigment.  Spore  for- 
mation not  observed.  Grows  best  at  the  room  temperature.  Upon  gelatin 
plates  the  deep  colonies,  at  the  end  of  two  days,  are  small,  spherical,  and 
coarsely  granular ;  they  usually  have  a  radiating  margin,  and  a  dark  centre ; 
upon  coming  to  the  surface  a  thin,  irregular  expansion  occurs  and  the  gela- 
tin is  quickly  liquefied  in  the  vicinity  of  the  colony ;  at  the  centre  a  violet- 
colored  spot  is  seen,  and  around  this  a  zone  of  slightly  clouded  liquid  gelatin ; 
liquefaction  progresses  rapidly,  but  the  central  violet  mass  does  not  mate- 
rially increase  in  size.  In  gelatin  stick  cultures  liquefaction  occurs  rapidly 
along  the  line  of  inoculation;  the  liquefied  gelatin  is  clouded  and  of  a  violet 
color,  and  an  abundant  dark- violet  precipitate  accumulates  at  the  bottom  of 
the  tube.  Upon  agar  an  abundant  development  occurs,  which  at  first  has  a 
dark-violet  color  and  later  becomes  jet-black.  Upon  potato  an  abundant 
growth  of  a  dark- violet  color  spreads  over  the  entire  surface;  this  soon  be- 
comes jet-black,  except  near  the  edge.  In  milk  the  bacillus  develops  rapidly 
and  abundantly,  causing  rapid  coagulation  of  the  casein  and  an  acid  reac- 
tion; the  milk  acquires  a  deep  blue- violet  color.  In  ordinary  bouillon  the 


C32  NOX-PATHOGENIC   BACILLI. 

violet  color  is  not  developed,  but  when  nitrates  are  added  the  growth  is  more 
luxuriant  and  a  rich  violet  color  is  produced.  Nitrates  are  reduced  to-  ni- 
trites by  this  bacillus,  rather  slowly. 

269.    BACILLUS  TREMELLOIDES   (Schottelius). 

Found  in  the  Freiburg  water  supply  by  Tils. 

Morphology. — Bacilli  with  round  ends,  from  0.75  to  1  n  long  and  0.25  n 
broad,  associated  in  friable  masses. 

Biological  Characters. — An  aerobic,  liquefying,  chromoqenic  bacillus. 
Forms  a  golden -yellow  pigment.  Spore  formation  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  the 
deep  colonies  appear  as  yellow  points ;  at  the  end  of  forty-eight  nours  the 
superficial  colonies  appear  as  prominent  yellow  masses  and  the  plate  looks 
as  if  it  were  covered  with  coarse  sand ;  at  the  end  of  a  few  days  the  colonies 
measure  several  millimetres  in  diameter  and  do  not  subsequently  increase 
in  size ;  under  a  low  power  these  are  seen  £o  be  made  up  of  cloud-like  masses 
and  have  a  yellow  or  yellowish-brown  color,  the  contour  is  smooth  or  irre- 
gularly bulging;  at  the  end  of  eight  days  the  margin  is  surrounded  by  a 
golden-yellow,  slimy  layer  and  the  colony  commences  slowly  to  sink  into 
the  gelatin.  In  gelatin  stick  cultures  isolated,  punctiform,  yellow  colonies 
are  developed  along  the  line  of  inoculation,  and  upon  the  surface  a  colony 
which  resembles  those  upon  gelatin  plates ;  at  the  end  often  to  fourteen  days 
the  superficial  layer  is  slowly  depressed  as  a  result  of  liquefaction  of  the 
underlying  gelatin.  Upon  the  surface  of  agar  a  layer  is  developed  which 
is  at  first  dry  and  granular,  later  slimy  and  of  a  golden-yellow  color.  Upon 
potato  a  yellow  layer  is  developed  which  may  attain  a  thickness  of  several 
millimetres;  after  a  long  time  the  growth  is  surrounded  by  a  golden-yellow, 
slimy  zone,  and  no  further  extension  occurs  upon  the  surface  of  the  potato. 
In  milk,  at  the  end  of  thirty-six  hours,  a  strongly  acid  reaction  is  produced 
and  the  fluid  becomes  viscid. 

270.    BACILLUS   CUTICULARIS    (Tils). 

Found  in  water. 

Morphology. — Bacilli  from  2  to  3  n  long  and  0.3  to  0.5/f  broad;  may 
grow  out  into  short  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Spore  formation  not  observed.  Forms  a  yellow  pigment.  The 
shorter  rods  are  slightly  motile,  the  longer  filaments  not.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  the  deep 
colonies  appear  under  the  microscope  as  brownish  discs  with  an  irregular 
but  smooth  contour.  The  superficial  colonies  are  yellowish-brown  in  color, 
with  well-defined  contour;  after  several  days  the  centre  commences  to  be 
depressed  and  the  gelatin  is  quickly  liquefied ;  the  colony  then  consists  of  a 
membranous  film  surrounded  by  a  well-defined  zone  of  liquefied  gelatin; 
finally  the  gelatin  of  the  plate  is  entirely  liquefied  and  these  membranous 
colonies  float  upon  the  surface.  In  gelatin  stick  cultures,  at  the  end  of  two 
days,  liquefaction  commences  near  the  surface  and  progresses  rapidly;  a 
membranous  layer  is  formed  on  the  surface.  Upon  potato  development  is 
slow,  in  the  form  of  a  pale-yellow  layer,  which  later  becomes  slimy  and 
dark-yellow.  In  milk  a  pale-yellow,  membranous  layer  is  formed  upon  the 
surface  in  from  twenty-four  to  thirty-six  hours,  and  an  odor  of  sulphuretted 
hydrogen  is  developed. 

271.    FLESH-COLORED   BACILLUS   (Tils). 

Found  in  water. 

Morphology.—  Bacilli  of  2  j*  in  length  and  0.5  t*  broad ;  in  hanging-drop 
cultures  always  seen  solitary  and  in  active  motion. 


NON-PATHOGENIC   BACILLI. 


633 


FIG.  211.— Bacillus  arbores- 
cens,  from  a  gelatin  culture. 
X  1,000.  (Frankland.) 


Biological  Characters.— An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  a  dark  flesh-colored  pigment.  Spore  formation  not  ob- 
served. Grows  at  the  room  temperature  in  the  usual  culture  media.  Upon 
gelatin  plates,  at  the  end  of  two  days,  circular  cavities  with  well-defined 
margins  and  filled  with  liquefied  gelatin  are  seen;  under  a  low  power  the 
centre  of  the  colonies  is  seen  to  be  more  opaque  and  is  surrounded  by  con- 
centric rings,  alternately  of  lighter  and  darker  color,  while  the  marginal 
zone  is  colorless  and  appears  finely  granular.  In  gelatin  stick  cultures 
liquefaction  occurs  rapidly  along  the  line  of  puncture,  in  funnel  shape;  at 
the  lower  part  of  the  funnel  a  deposit  of  a  pale-pink  color  accumulates  and 
the  liquefaction  ceases  to  extend.  Upon  the  surface  of  agar  it  grows  rapidly 
and  forms  a  thick,  slimy,  pale-pink  layer.  Upon  potato  a  layer  is  formed 
which  is  first  pale  and  later  dark  flesh-colored. 

272.  BACILLUS  ARBORESCENS  (Frankland). 

Found  in  the  London  water  supply. 

Morphology.— Bacilli  with  round  ends,  about  2.5  ^  long  and  0.5  /^  broad; 
often  united  in  pairs,  or  in  chains  of  three  or  four  ^^_ 

elements ;  also  form  long,  flexible  filaments.  /^^^    -^ 

Biological  Characters. — An  aerobic,   liquefy-  — -S. 

ing,  chromogenic  bacillus.  Spore  formation  not 
observed.  Oscillating  movements  only.  Grows 
in  the  usual  culture  media  at  the  room  tempera- 
ture. Upon  gelatin  plates  the  colonies,  at  the  end 
of  twenty-four  hours,  consist  of  a  thin  axial  trunk 
with  root-like  offshoots  at  both  ends;  later  the  body  becomes  thicker  and  the 
branching  extremities  are  so  strongly  developed  that  the  whole  has  the  ap- 
pearance of  a  sheaf  of  wheat ;  the  naked-eye  appearance,  in  this  stage,  is  also 
peculiar,  and  the  colony  is  seen  as  an  iridescent  bundle,  constricted  in  the 
middle  and  with  the  ends  striped  in- a  radial  direction;  later  the  gelatin  is 

liquefied  slowly  and  the  central  part  of  the 
colony  acquires  a  yellow  color,  while  the 
periphery  is  beautifully  iridescent.  In*  ge- 
latin stick  cultures,  by  the  second  day,  an 
iridescent  layer  is  seen  on  the  surface;  in 
the  middle  of  this  the  gelatin  is  slightly 
depressed  and  filled  with  a  semi-fluid,  yel- 
lowish mass;  along  the  line  of  puncture  a 
transparent,  grayish  cloudiness  is  seen ; 
liquefaction  progresses  slowly  at  the  sur- 
face, and  a  funnel  is  formed,  at  the  bottom 
of  which  the  yellow  deposit  gradually  in- 
creases; along  the  line  of  puncture  no 
further  changes  occur.  Upon  the  surface 
of  agar  a,  rather  thin,  dirty  orange  colored 
layer  is  formed,  the  margins  of  which  are 
slightly  iridescent  and  striped  in  a  radial  direction.  Upon  potato  a  thick, 
glistening  stripe  of  a  deep  orange-red  color  is  formed  along  the  line  of  in- 
oculation ;  the  surface  of  this  is  covered  with  irregular  protuberances. 

273.  BACILLUS  CITREUS  CAD  AVERTS  (Strassmann). 

Found  in  a  cadaver  fifty  hours  after  death  from  accidental  shooting — in 
blood  from  a  vein. 

Morphology. — Oval  bacilli,  0.9  ju.  long  and  0.6  /^  broad,  usually  united  in 
chains. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile,  chromogenic 
bacillus.  Forms  a  yellow  pigment.  Spore  formation  not  observed.  Grows 
slowly  at  the  room  temperature.  Upon  gelatin  plates  forms  small,  pale- 


FIG.  212.— Colony  of  Bacillus  arbo- 
escens.    X  100.    (Frankland.) 


634  NON-PATHOGENIC  BACILLI. 

yellow  colonies,  around  which  the  gelatin  is  liquefied  in  circular  form.  In 
gelatin  stick  cultures  liquefaction  occurs  at  the  surface,  with  formation  of  an 
air  bubble  at  the  surface,  a  scanty,  yellow  deposit  at  the  bottom  of  this,  clear 
liquefied  gelatin  below,  and  a  yellow  deposit  on  the  concave  floor  of  the 
liquefied  gelatin;  below  this,  along  the  line  of  puncture,  small  colonies 
are  seen.  The  cultures  give  off  an  odor  of  sulphuretted  hydrogen.  Upon 
the  surface  of  agar  a  narrow,  yellow  layer  forms  along  the  impfstrich. 
Upon  potato  a  dry,  lemon-yellow,  slightly  granular  layer  is  developed. 

274.    BACILLUS   MEMBRANACEUS   AMETHYSTINUS   (Eisenberg). 

Found  in  a  specimen  of  well  water  from  Spalato. 

Morphology.  — Short  bacilli  with  round  ends,  from  1  to  1.4  ju  long  and  0.5 
to  0.8/*  broad;  in  irregular  groups;  some  of  the  rods  in  stained  preparations 
show  end  staining. 

Biological  Characters . — An  aerobic,  liquefying,  non-motile,  chrpmogenic 
bacillus.  Produces  a  dark-violet  pigment  which  has  a  metallic  lustre. 
Spore  formation  not  determined.  Grows  at  the  room  temperature  in  the 
usual  culture  media — no  development  at  37. 5°  C.  Upon  gelatin  plates,  at 
the  end  of  two  to  three  days,  colonies  are  developed  the  size  of  a  poppy-seed, 
which  have  a  homogeneous,  dark- violet  color ;  later  a  ring  of  liquefied  gela- 
tin forms  around  each  colony,  which  gradually  extends,  and  at  the  end  of 
one  to  two  weeks  the  entire  gelatin  is  liquefied  and  the  colonies  are  seen 
floating  upon  its  surface,  not  much  larger  than  when  liquefaction  com- 
menced. When  the  colonies  are  not  so  closely  crowded  superficial  colonies 
are  seen  at  the  end  of  three  to  four  days,  which  resemble  those  of  the  typhoid 
bacillus ;  they  have  a  yellowish- white  color  and  a  dentate  margin ;  at  the 
end  of  ten  to  fourteen  days  the  gelatin  around  these  colonies  commences  to 
soften  and  a  dark- violet  color  extends  from  the  centre  to  the  periphery ;  at 
the  end  of  three  to  four  weeks  the  colonies  are  seen  floating  upon  the  surface 
of  the  scarcely  liquefied  gelatin,  as  large  violet  layers.  In  gelatin  stick  cul- 
tures a  yellowish-white  layer  with  dentate  borders  develops  upon  the 
surface,  which  at  the  end  of  ten  to  fourteen  days  begins  to  acquire  a  violet 
color  at  the  centre,  which  gradually  extends  to  the  periphery;  liquefaction 
occurs  slowly,  so  that  at  the  end  of  about  four  weeks  a  thick,  violet-colored 
layer  rests  upon  the  softened  and  depressed  surface  of  the  culture  medium; 
at  the  end  of  three  to  four  months  the  gelatin  in  the  tube  is  completely 
liquefied.  Upon  the  surface  of  agar  a  yellowish- white,  milky,  thick  layer 
is  formed,  which  commences  to  acquire  a  violet  color  at  the  end  of  eight  to 
ten  days,  and  at  the  end  of  three  to  four  weeks  is  seen  as  a  wrinkled,  dark- 
violet  layer  with  a  metallic  lustre,  which  is  easily  lifted  entire  from  the  sur- 
face of  the  culture  medium.  Upon  potato  a  dirty-yellow  or  olive-green  layer 
is  slowly  formed  and  gradually  extends  from  the  line  of  inoculation.  In 
bouillon  development  is  very  slow ;  at  the  end  of  several  weeks  the  dark- 
brown  bouillon  is  seen  to  have  a  violet  film  upon  the  surface  and  a  deposit 
of  the  same  color  at  the  bottom  of  the  tube. 

275.  ASCOBACILLUS  CITREUS  (Unna  and  Tommasoli). 

Found  upon  the  surface  of  the  body  of  individuals  with  eczema  sebor- 
rhoeicum. 

Morphology. — Straight  or  curved  bacilli,  1.3  jtt  long  and  0.3 1*  broad,  soli- 
tary, in  pairs,  or  in  irregular  groups. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Produces  a  lemon-yellow  pigment.  Spore  formation  not  observed. 
Grows  in  the  usual  media  at  the  room  temperature — slowly  in  gelatin,  rapidly 
upon  agar  and  potato.  Upon  gelatin  plates,  at  the  end  of  two  weeks,  promi- 
nent, opaque,  yellow,  punctiform  colonies  are  developed  upon  the  surface, 
while  the  deep  colonies  are  scarcely  visible  with  the  naked  eye ;  under  a 
low  power  they  are  seen  to  be  grayish-yellow,  opaque,  sometimes  like  little 


NOX-PATHOGEXIC   BACILLI.  635 

drops  of  oil  and  sometimes  a  conglomeration  of  minute  spherical  masses. 
Later  the  deep  colonies  are  oval,  dark,  sharply  defined,  and  as  large  as  a 
pea ;  those  nearer  the  surface  are  conglomerate ;  those  upon  the  surface  are 
partly  homogeneous,  pale-yellow,  and  round;  some  show  an  opaque,  con- 
glomerate mass  in  the  centre,  with  a  more  transparent,  yellowish-green 
marginal  zone ;  some  have  a  form  resembling  that  of  Saturn  with  its  rings. 
In  gelatin  stick  cultures  a  slimy,  thick,  lemon-yellow  layer  develops  upon 
the  surface ;  this  is  gradually  depressed  in  the  middle,  while  the  margins  re- 
main elevated  and  granular ;  along  the  line  of  puncture  small  colonies  are 
developed  which  form  a  funnel  above ;  at  the  end  of  five  to  six  weeks  the 
gelatin  in  the  funnel,  when  shaken,  appears  pap-like,  and  the  layer  floats 
upon  its  surface,  while  some  greenish  flocculi  are  seen  below.  Upon  the 
surface  ofagar  development  is  rapid  and  the  entire  surface  is  covered  within 
a  few  days;  below,  the  layer  consists  of  an  abundant  jelly-like  growth, 
covered  with  protuberances  resembling  drops  of  honey ;  above,  it  has  an 
orange  color  and  creamy  consistence,  and  is  covered  with  numerous  small, 
spherical  or  oval  masses.  Upon  potato  a  slimy,  lemon-yellow  layer  is 
quickly  developed  and  extends  over  the  entire  surface ;  at  the  margins  this 
is  more  transparent  and  albuminous  in  appearance ;  at  the  end  of  two  weeks 
the  central  portion  has  a  greenish-yellow  color,  distributed  like  the  veins  of 
a  grape  leaf,  with  smaller,  pale-yellow  veins. 

276.    BACILLUS   CCERULEUS   (Smith). 

Found  in  water  of  the  Schuylkill  River. 

Morphology. — Bacilli  from  2  to  2.5  p  long  and  0.5  u  broad,  frequently  as- 
sociated in  chains. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  bacillus. 
Produces  a  beautiful  blue  pigment.  Spore  formation  not  observed.  Grows 
slowly  at  the  room  temperature.  Upon  gelatin  plates  forms  superficial  colo- 
nies having  a  blue  color,  around  which  the  gelatin  is  liquefied.  In  gelatin 
stick  cultures  cup-shaped  liquefaction  occurs  at  the  surface  and  a  blue  color 
is  developed,  while  below  a  scanty,  colorless  growth  occurs  along  the  line  of 
puncture.  Upon  the  surface  ofagar  a  bluish  layer  is  formed.  Upon  po- 
tato at  first  a  beautiful  dark-blue  layer,  which  later  acquires  an  intense 
blue-black  color. 

277.    BACILLUS   FLUORESCENS   LIQUEFACIENS. 

Found  in  water  and  in  various  putrefying  infusions — very  common. 

Morphology. — Short  bacilli,  in  pairs  with  a  constriction  at  the  point  of 
junction. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  a  greenish-yellow,  fluorescent  pigment.  Spore  formation 
not  observed.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  whitish  colonies  are  developed  upon  the  surface,  which 
may  attain  a  diameter  of  three  millimetres;  a  ring  of  liquefied  gelatin  forms 
around  each ;  under  a  low  power  the  colonies  are  seen  to  have  a  sharp  con- 
tour and  irregularly  circular  outline,  a  dark-brown,  finely  granular  centre 
surrounded  by  a  finely  granular  marginal  zone  of  a  yellow  color,  which  be- 
comes more  transparent  and  grayish- white  toward  the  edge;  the  gelatin 
gradually  acquires  a  greenish  tint.  In  gelatin  stick  cultures  a  whitish 
growth  occurs  along  the  line  of  puncture ;  a  small  funnel  of  liquefied  gelatin 
is  first  seen  near  the  surface,  and  this  has  an  air  bubble  above;  gradually  the 
liquefaction  extends  to  the  walls  of  the  test  tube  and  also  in  a  downward 
direction,  forming  a  superficial  layer  of  liquefied  gelatin,  upon  the  floor  of 
which  a  thick  white  deposit  is  formed;  the  gelatin  below  this  has  a  green- 
ish-yellow fluorescence  and  the  liquefied  gelatin  also,  although  less  pro- 
nounced. Upon  potato  an  abundant  brownish  layer  is  developed  along  the 
line  of  inoculation. 


630  NON-PATHOGENIC   BACILLI. 

278.    BACILLUS  FLUORESCEXS   LIQUEFACIENS   MIXUTISSIMUS 

(Unna  and  Tommasoli). 

Found  upon  the  surface  of  the  body  in  cases  of  eczema  seborrhoeicuin. 
Possibly  identical  with  the  previously  described  species. 

Morphology. — Bacilli  with  round  ends,  usually  constricted  in  the  middle, 
from  1.5  to  2  u  long  and  0.3  u  broad ;  often  united  to  form  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile,  chromogenic  bacillus.  Forms  a  greenish-yellow,  slightly  fluo- 
rescent pigment.  Forms  spherical  spores.  Grows  rapidly  in  the  usual  cul- 
ture media  at  the  room  temperature.  Upon  gelatin  plates,  at  the  end  of 
three  to  four  days,  the  colonies  consist  of  an  outer  yellowish- white  zone  of 
transparent,  liquefied  gelatin  and  a  thick,  pale-brown  centre  which  is  made 
up  of  grayish  granular  material.  In  gelatin  stick  cultures,  at  the  end  of 
three  days,  a  broad  funnel  of  liquefied  gelatin  is  formed  above,  which  is 
about  one  centimetre  deep  and  five  millimetres  in  diameter  at  the  surface; 
the  liquefied  gelatin  is  clouded,  greenish-yellow,  and  contains  some  whitish 
nocculi,  while  a  thick  whitish  deposit  accumulates  at  the  bottom ;  at  the 
end  of  eight  days  the  gelatin  is  entirely  liquefied  and  a  thick,  opaque,  gray- 
ish-yellow, fluorescent  layer  floats  upon  the  surface.  Upon  the  surface  of 
agar  a  slimy,  moist,  smooth,  pale-brown  layer  is  developed.  Upon  potato 
a  broad,  compact,  flat  layer  is  quickly  developed;  this  has  a  pale-brown 
color  and  elevated,  sharply  defined  margins;  the  potato  acquires  a  dark 
color. 

279.    BACILLUS   FLUORESCENS   NIVALIS    (Sclimolck). 

Found  in  ice  water  and  snow  from  Norwegian  glaciers.  (Probably  iden- 
tical with  No.  277.) 

Morphology. — Short  bacilli,  often  united  in  chains. 

Biological  Characters. — An  aerobic  liquefying,  motile,  chromogenic 
bacillus.  Forms  a  bluish-green,  fluorescent  pigment.  Spore  formation  not 
observed.  Upon  gelatin  plates  whitish,  punctiform  colonies  are  formed, 
which  spread  out  upon  the  surface  as  round  discs  and  cause  liquefaction  of 
the  surrounding  gelatin ;  the  non-liquefied  gelatin  in  the  vicinity  acquires  a 
bluish-green  fluorescence.  In  gelatin  stick  cultures  liquefaction  occurs  in 
funnel  form,  and  the  liquefied  gelatin  acquires  a  greenish  fluorescence  like 
that  of  Bacillus  liquefaciens  fluorescens.  Upon  the  surface  of  agar  a 
whitish  layer  is  formed  and  the  culture  medium  acquires  a  fluorescent  color. 
Upon  potato  a  brownish  layer  is  developed. 

280.    BACILLUS   LACTIS   ERYTHROGENES    (Hueppe). 

Synonym. — Bacillus  of  red  milk. 

Found  in  red  milk,  and  by  Baginsky  in  the  faeces  of  a  child. 

Morphology. — Short  bacilli  with  round  ends,  from  1  to  1.4^  long  and 
from  0.3  to  0.5  /f  thick;  in  bouillon  cultures  may  grow  out  into  short  fila- 
ments. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile,  chromogenic 
bacillus.  Produces  a  yellow  pigment  which  is  destroyed  by  acids  and  is 
developed  either  in  the  presence  or  absence  of  light;  and  a  red  pigment 
which  is  absorbed  by  the  culture  medium  and  is  produced  most  abundantly 
in  an  alkaline  or  neutral  medium  in  the  absence  of  light.  Does  not  form 
spores.  The  cultures  give  off  an  intense  and  disagreeable  odor.  Grows  at 
the  room  temperature  in  the  usual  culture  media — more  rapidly  at  28°  to 
35°  C.  \Jpongelatinplates  small,  spherical  colonies  are  developed,  Avhich 
are  at  first  grayish- white  and  later  yellow  in  color;  after  a  time  the  sur- 
rounding gelatin  is  liquefied  in  saucer  shape  and  acquires  a  pale-pink  color. 
In  gelatin  stick  cultures  a  rather  thin,  round  layer  is  developed  upon  the 
surface,  which  is  at  first  whitish  and  later  yellow  in  color;  the  gelatin 


XOX-PATHOGENIC   BACILLI.  637 

around  it  acquires  a  pale-pink  color,  and  after  a  time  liquefaction  occurs ; 
along-  the  line  of  puncture  the  development  is  scanty ;  at  the  end  of  ten  to 
twelve  days  a  slightly  clouded,  pink  liquid  is  seen  at  the  upper  part  of  the 
test  tube,  ia  which  well-defined  yellow  colonies  are  suspended,  while  the 
unliquefied  gelatin  below  has  a  pink  color.  Upon  the  surface  of  agar  a 
glistening,  yellowish  layer  is  slowly  developed.  Upon  potato  development 
is  more  rapid  and  an  extended  layer  is  formed,  which  is  first  grayish-white 
and  later  yellow  in  color;  the  potato  acquires  a  dark  color  which  later 
becomes  yellowish -red ;  at  37°  C. ,  at  the  end  of  six  to  eight  days,  an  intense 
golden-yellow  color  is  developed.  In  bouillon  development  is  rapid  and 
yellowish  cloudiness  of  the  culture  medium  is  seen.  In  milk  the  casein  is 
slowly  precipitated  and  later  is  peptonized,  with  a  neutral  or  alkaline  re- 
action of  the  medium ;  a  stratum  of  blood-red  serum  is  seen  above  the  pre- 
cipitated casein,  and  above  this  a  yellowish-white  layer  of  cream. 

281.  BACILLUS  GLAUCUS  (Maschek). 

Found  in  water. 

Morphology. — Slender  bacilli  of  various  lengths. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile,  chromogemc 
bacillus.  Produces  a  gray  pigment.  Spore  formation  not  observed.  Grows 
rapidly  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  forms  round,  gray  colonies  wTith  sharply  defined  outlines;  on  the 
fourth  day  the  centre  becomes  intensely  gi*ay,  th'e  margin  brown  and  folded 
in  a  radial  direction ;  on  the  eighth  day  liquefaction  has  occurred  and  the 
colony  sinks  beneath  the  surface.  In  gelatin  stick  cultures  development  is 
rapid  both  upon  the  surface  and  along  the  line  of  puncture ;  the  entire  gela- 
tin is  quickly  liquefied  and  a  gray  deposit  is  seen  at  the  bottom  of  the  tube. 
Upon  the  surface  of  agar  a  gray  layer  is  quickly  developed.  Upon  potato 
the  growth  is  at  first  of  a  dirty- white;  later  a  slimy,  dark-gray  layer  is 
formed. 

282.  BACILLUS  LIVIDUS  (Plagge  and  Proskauer). 

i 

Found  in  the  Berlin  water  supply. 

Morphology. — Slender  bacilli  of  medium  size. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile,  chromogenic  bacillus.  Produces  an  intense  blue-black  pigment. 
Spore  formation  not  observed.  Grows  slowly  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin  plates  the  colonies  at  first  resemble 
drops  of  ink ;  the  gelatin  around  them  is  slowly  liquefied  and  a  bluish- violet 
deposit  is  seen  at  the  bottom  of  the  liquefied  gelatin.  In  gelatin  stick  cultures 
a  colorless  growth  is  seen  along  the  line  of  puncture  and  a  violet  layer  upon 
the  surface ;  liquefaction  occurs  very  slowly.  Upon  the  surface  of  agar  a 
beautiful  blue-black  layer  is  developed.  Upon  potato  an  abundant  layer  of 
a  violet  color  is  formed  along  the  line  of  inoculation. 

283.    BACILLUS  INDICUS  (Koch). 

Found  in  the  contents  of  the  intestine  of  a  monkey,  by  Koch,  while  pur- 
suing his  cholera  investigations  in  India. 

Morphology. — A  short  and  slender  bacillus  with  round  ends. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile,  chromogenic  bacillus.  Spore  formation  not  observed.  Produces 
a  brick-red  pigment.  Grows  rapidly  in  the  usual  culture  media — best  in  the 
incubating  oven.  Upon  gelatin  plates  the  deep  colonies  are  white  and 
punctiform ;  under  a  low  power  they  are  seen  to  be  granular,  irregular  in 
form,  and  of  a  greenish-brown  color.  The  superficial  colonies  quickly  cause 
liquefaction  of  the  gelatin  and  form  circular  depressions  with  a  well-defined 
outline  and  grayish  contents,  which  under  the  microscope  appear  as  dense, 
finely  granular,  grayish-yellow  masses,  the  edges  of  which  appear  to  be 

54 


038  NON-PATHOGENIC   BACILLI. 

fringed  with  short  fibres ;  later  the  gelatin  acquires  a  pale-red  color,  which 
gradually  becomes  more  intense.  In  gelatin  stick  cultures  liquefaction  is 
rapid  along  the  entire  line  of  inoculation ;  a  wrinkled,  red  film  forms  upon 
the  surface  and  grayish- white  flocculi  accumulate  at  the  bottom  of  the  lique- 
fied medium.  Upon  the  surface  of  agar  an  abundant  layer,  covering  the 
entire  surface,  is  quickly  developed  in  the  incubator ;  this  usually  acquires 
a  brick -red  color,  but  the  margins  of  the  layer,  or  even  the  entire  growth, 
may  remain  colorless,  especially  in  cultures  kept  in  the  incubating  oven. 
Upon  potato  development  occurs  very  rapidly  along  the  line  of  inoculation; 
this  soon  acquires  the  characteristic  color.  Blood  serum  is  liquefied  by  this 
bacillus.  Large  quantities  (twenty  cubic  centimeti'es)  of  a  pure  culture  in- 
jected into  a  vein  or  into  the  peritoneal  cavity  of  a  rabbit  or  guinea-pig 
cause  the  death  of  the  animal  in  from  three  to  twenty  hours;  at  the  autopsy 
an  intense  gastro-enteritis  is,  found. 

284.    BACILLUS   PRODIGIOSUS. 

Synonyms.-' ^Micrococcus  prodigiosus;  Monas  prodigiosa. 

This  bacillus  has  long  been  known,  having  attracted  attention  because  of 
the  blood-red  stains  which  it  causes  upon  farinaceous  substances,  such  as 
boiled  potatoes,  moist  bread,  etc.  It  was  described  by  Ehrenberg  under  the 
name  of  Monas  prodigiosa.  At  times,  in  certain  parts  of  Europe,  it  has 
been  exceptionally  abundant,  and  the  bloody-looking  patches  produced  by 
its  rapid  development  upon  favorable  media  have  been  regarded  with  ap- 
prehension, by  the  superstitious. 

Morphology. — Short  bacilli  with  rounded  ends,  which  are  sometimes  so 
short  as  to  be  scarcely  distinguishable  from  micrococci,  but  also  occur  as 
rod-shaped  cells  and  short  filaments ;  frequently  in  pairs  and  occasionally  in 
chains  containing  ten  or  more  elements — especially  in  acid  media. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, usually  non-motile,  chromogenic  bacillus.  Although  usually  described 
as  non-motile,  this  bacillus  is  said  under  certain  circumstances  to  be  capable 
of  spontaneous  movements.  According  to  Schottelius,  these  are  best  seen 
when  it  is  cultivated  in  strongly  diluted  liquid  media  and  under  urifavoiv 
able  conditions  of  growth.  Forms  a  red  pigment  which  is  soluble  in  alcohol 
and  ether,  but  not  in  water;  this  is  only  formed  in  presence  of  oxygen;  it  is 
changed  to  a  pale-red  color  by  the  action  of  acids,  and  the  deep- red  color  is 
restored  by  ammonia  and  other  strong  alkalies.  The  pigment  is  not  seen  in 
the  interior  of  the  bacterial  cells,  but  the  chromogenic  substance  formed  by 
them  develops  the  color  outside  of  the  cells,  where  it  is  seen  in  the  form  of 
granules.  The  formation  of  pigment  is  influenced  not  only  by  the  presence 
of  oxygen,  which  is  essential  to  its  production,  but  also  by  conditions  re- 
lating to  temperature,  constitution  of  the  culture  medium,  etc.  By  continu- 
ous cultivation  in  the  incubating  oven  a  non-chromogenic  variety  may  be 
obtained,  and  the  same  result  is  obtained  by  continuous  cultivation  in  acid 
bouillon.  But  under  favorable  conditions  color  production  again  returns 
after  a  few  successive  transplantations  upon  potato  or  nutrient  agar,  if  the  cul- 
tures are  kept  at  the  room  temperature  and  freely  exposed  to  the  air.  Spore 
formation  has  not  been  observed,  but  this  bacillus  retains  its  vitality  for  a 
long  time  in  a  desiccated  condition.  Cultures  give  off  a  strong  odor  of  tri- 
methylamm;  and  in  culture  media  containing  sugar,  fermentation  occurs 
with  production  of  alcohol  and  carbon  dioxide.  This  bacillus  grows  rapidly 
in  the  ordinary  culture  media — best  at  the  room  temperature  or  a  little 
above  (25°  C.).  Upon  gelatin  plates  small,  white,  punctiform  colonies  are 
developed  below  the  surface,  and  upon  the  surface  round,  granular  colonies 
which  quickly  cause  liquefaction  of  the  gelatin;  saucer-like  depressions  are 

Eroduced,  at  the  bottom  of  which  the  colony  is  seen  as  a  whitish  mass  which 
iter  acquires  a  deep-red  color,  first  appearing  at  the  centre.     In  gelatin 
stick  cultures  liquefaction  quickly  occurs  along  the  entire  line  of  inoculation 
and  rapidly  extends  until  the  medium  is  completely  liquefied ;  pigment  for- 


NON-PATHOGENIC  BACILLI.  639 

mation  occurs  at  the  surface  only,  but  after  a  time  the  entire  medium  is 
colored  red  by  the  deposition  of  granular,  colored  masses  from  the  surface 
growth.  Upon  the  surface  of  agar  an  abundant  purplish-red  layer  is 
formed,  but  the  color  is  not  absorbed  by  the  culture  medium.  Upon  potato 
very  rapid  and  abundant  development  occurs  at  the  room  temperature, 
forming  a  thick,  purplish-red  layer  which  after  some  days  has  the  color  of 
undissolved  fuchsiii  and  a  metallic  lustre.  Blood  serum  is  liquefied  by  this 
bacillus.  In  milk  the  development  of  Bacillus  prodigiosus  causes  a  precipi- 
tation of  the  casein  and  a  deep-red  color  of  the  medium.  When  cul- 
tivated for  some  time  in  acid  media  the  peptonizing  (liquefying)  power  of  the 
bacillus  is  greatly  reduced,  as  well  as  its  chromogenic  power.  It  has  been 
showji  by  Roger  that  animals  which  are  not  susceptible  to  the  disease 
known  as  malignant  oedema,  become  infected  and  die  when  inoculated  with 
the  malignant-oedema  bacillus  and  at  the  same  time  with  one  or  two  cubic 
centimetres  of  a  culture  of  Bacillus  prodigiosus.  But  this  bacillus  alone  has 
no  decided  pathogenic  power.  An  interesting  discovery  made  by  Pawlowsky 
is  the  fact  that  when  rabbits  are  inoculated  simultaneously  with  a  virulent 
culture  of  the  anthrax  bacillus  and  with  a  culture  of  Bacillus  prodigiosus 
they  recover  from  the  inoculation,  the  chemical  products  of  one  bacillus 
having  apparently  the  power  to  neutralize  the  toxic  substances  to  which  the 
other  owes  its  pathogenic  potency. 

285.  BACILLUS   MESENTERICUS  RUBER. 

Synonym.  —  Rothen  Kartoffelbacillus  (G-lobig). 

Found  upon  potatoes. 

Morphology. — Slender  bacilli  with  round  ends,  united  in  pairs,  in  chains 
of  four,  or  in  long  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Produces  a  reddish-yellow  or  pink  pigment.  Forms  oval  spores 
which  have  a  great  resistance  against  high  temperatures  and  germicidal 
agents.  Grows  rapidly,  especially  at  a  temperature  of  45°  C. ;  also  at  the 
room  temperature  in  the  usual  culture  media.  Upon  gelatin  plates,  at  15° 
to  20°  C.,  at  the  end  of  two  days  deep  colonies  are  formed  wnich  are  spheri- 
cal and  of  a  yellow  color;  when  these  come  to  the  surface  they  spread  out 
as  a  fine  network,  around  the  margins  of  which  projecting  points  are  seen ; 
liquefaction  commences  on  the  fom-th  day  and  this  network  vanishes,  leav- 
ing a  grayish-brown,  friable  mass  at  the  bottom  of  the  liquefied  medium.  In 
gelatin  stick  cultures,  at  the  end  of  three  or  four  days,  a  cloudy  white 
growth  is  developed  along  the  line  of  puncture,  and  liquefaction  occurs  in 
funnel  shape  near  the  surface ;  this  soon  exends  to  the  walls  of  the  tube  and 
downward,  and  a  thin  film  is  formed  on  the  surface.  Upon  potato,  at 
15°  C.,  at  the  end  of  three  days  the  surface  is  covered  by  a  thin,  viscid, 
slimy,  yellowish,  finely  wrinkled  layer;  at  37°  C.  the  entire  surface  is 
covered  in  twenty-four  hours  with  a  reddish-yellow  or  pink  layer;  in  forty- 
eight  hours  this  extends  over  the  lower  surface  of  the  potato  also,  except 
where  it  is  in  contact  with  the  receptacle  in  which  it  is  placed. 

286.  BACILLUS  PYOCYANUS  ft  (Ernst). 

Found  in  pus  from  bandages  colored  green. 

Morphology. — Slender  bacilli  from  2  to  4  u  long — occasionally  5  to  6  // — 
and  from  0.5  to  0.75  n  broad;  sometimes  united  in  pairs,  or  chains  of  three 
elements. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile,  chromo- 
genic bacillus.  Produces  a  yellowish-green  pigment;  when  old  cultures 
are  shaken  up  with  chloroform  and  this  is  allowed  to  stand,  three  layers  are 
formed— an  upper,  clouded,  dirty-yellow  layer;  below  this  is  a  milky,  pale- 
green  layer;  and  at  the  bottom  a  transparent,  azure-blue  layer.  Spore  for- 
mation has  not  been  demonstrated.  Grows  in  the  usual  culture  media  at  the 


640  NON-PATHOGENIC  BACILLI. 

room  temperature — more  rapidly  at  35°  C.  Upon  gelatin  plates  colonies  are 
formed  resembling  those  of  the  well-known  Bacillus  pyocyanus,  but  lique- 
faction is  more  rapid.  In  gelatin  stick  cultures  funnel-shaped  liquefaction 
occurs  at  the  upper  part  of  the  line  of  puncture  by  the  third  day,  and  pro- 
gresses more  rapidly  than  is  the  case  with  Bacillus  pyocyanus  under  the 
same  circumstances ;  on  the  fifth  day  a  bluish-green  color  is  developed ;  by 
the  twelfth  day  liquefaction  has  obliterated  the  entire  line  of  growth  and 
extends  to  the  margins  of  the  tube;  the  liquefied  gelatin  for  a  depth  of 
about  one  centimetre  has  a  dark  emerald-green  color,  and  a  film  consisting 
of  bacilli  is  seen  upon  the  surface.  Upon  the  surface  of  agar  a  flat,  green- 
ish-white, dry  layer  is  formed  along  the  line  of  inoculation,  and  the  agar 
around,  at  the  end  of  a  week,  acquires  a  bluish-green  color.  Upon  potato, 
at  the  end  of  three  days,  an  abundant  dry  layer  of  a  fawn-brown  color  has 
developed ;  this  is  surrounded  by  a  pale-green  coloration  of  the  potato,  and 
at  points  where  the  surface  is  fissured  an  intense  dark-green  color  is  de- 
veloped; the  growth  on  potato  has  a  more  or  less  wrinkled  appearance; 
when  one  of  the  fawn-colored  colonies  is  touched  with  the  platinum  needle 
the  point  touched,  at  the  end  of  two  to  five  minutes,  acquires  an  intense 
dark  leaf-green  color,  which  reaches  its  maximum  intensity  in  about  ten 
minutes,  and  has  faded  out  again  at  the  end  of  half  an  hour.  Ernst  con- 
siders this  "  chameleon  phenomenon"  the  most  characteristic  distinction 
between  the  bacillus  under  consideration,  and  Bacillus  pyocyanus.  In  milk 
a  green  color  is  developed  at  the  surface,  the  casein  is  precipitated  and  sub- 
sequently peptonized. 

287.    BACILLUS   MYCOIDES   ROSEUS    (S(^holl). 

Found  in  the  soil. 

Morphology . — Resembles  the  anthrax  bacillus. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  bacillus. 
Produces  a  red  pigment  when  cultivated  in  the  absence  of  light.  Spore 
formation  not  reported.  Grows  rapidly  at  the  room  temperature.  Upon 
gelatin  plates  forms  colonies  of  interlaced  filaments  which  cause  liquefaction 
of  the  surrounding  gelatin.  In  gelatin  stick  cultures  liquefaction  rapidly 
occurs;  a  red  layer  is  formed  upon  the  surface,  and  a  sediment  of  the  same 
color  is  seen  at  the  bottom  of  the  liquefied  medium,  but  the  gelatin  itself  is 
not  colored.  Upon  the  surface  of  agar,  in  the  dark,  a  pink  layer  is  de- 
veloped, while  in  the  light  it  is  white. 

288.    BACILLUS   ROSACEUM  METALLOIDES    (Dowdeswell). 

Morphology. — Bacilli  from  0.6  to  0.8  n  broad  and  about  twice  as  long. 

Biological  Characters. — An  aerobic,  liquefying,  motile  (usually  not  mo- 
tile), chromogenic  bacillus.  Forms  a  magenta-red  pigment  which  has  a 
metallic  lustre.  Spore  formation  not  observed.  Grows  best  at  15°  C. ;  no 
development  at  35C  C. ;  is  destroyed  in  five  minutes  by  a  temperature  of  55° 
C.  Upon  gelatin  plates,  at  15  C  ,  superficial  colonies  are  developed,  which 
in  the  course  of  a  few  days  are  elevated,  colorless  discs  about  two  milli- 
metres in  diameter ;  under  a  low  power  the  centre  appears  dark,  the  mar- 
gin transparent  and  granular;  later  the  colony  acquires  a  red  color  and 
liquefaction  of  the  surrounding  gelatin  occurs.  In  gelatin  stick  cultures  a 
red  layer  is  developed  upon  the  surface,  and  later  a  broad  funnel  of  lique- 
fied gelatin  is  slowly  developed.  Upon  the  surface  of  agar  a  pale-red 
layer  is  formed.  Upon  potato,  at  15°  C.,  a  thick  layer  quickly  covers  the 
entire  surface ;  this  has  a  beautiful  red  color,  especially  near  the  margins. 

289.  BACILLUS  viscosus  (Frankland). 

Resembles  very  closely,  and  is  perhaps  identical  with,  Bacillus  fluores- 
cens  liquefaciens. 


NON-PATHOGENIC   BACILLI.  641 

Found  in  uu filtered  river  water. 

Morphology. — Bacilli  with  round  ends,  1.5  to  2  /<  long1  and  about  three  or 
four  times  as  long-  as  broad ;  usually  united  in  pairs. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic  ba- 
cillus. Produces  a  fluorescent  green  pigment.  Spore  formation  not  ob- 
served. Grows  rapidly  at  the  room  temperature  in  the  usual  culture  media. 
Upon  gelatin  plates  the  deep  colonies  appear  under  a  low  power  as  finely 
granular  discs  with  a  smooth  contour ;  when  they  come  to  the  surface  the 
margin  is  fringed  and  hair-like  offshoots  extend  into  the  gelatin ;  at  the 
same  time  liquefaction  occurs  around  the  colonies  and  rapidly  extends ;  each 
liquefying1  colony  is  surrounded  by  a  fluorescent  green  zone,  and  the  lique- 
fied gelatin  has  the  same  color.  In  gelatin  stick  cultures  liquefaction  in 
funnel  shape  is  already  seen  on  the  second  day,  and  the  liquefied  gelatin  is 
filled  with  whitish  flocculi,  while  a  slight  green,  fluorescence  is  seen  near 
the  surface ;  liquefaction  progresses  rapidly,  and  a  viscid  layer  of  a  greenish- 
white  color  forms  upon  the  surface,  while  the  liquefied  gelatin  below  is  more 
or  less  clouded  and  has  a  fluorescent  green  color ;  an  abundant  flocculent 
deposit  is  seen  at  the  bottom  of  the  tube.  Upon  the  surface  of  agar  a 
smooth,  glistening,  greenish- white  layer  is  formed  along  the  line  of  inocula- 
tion and  the  agar  quickly  acquires  a  green  color.  In  bouillon,  at  the  end  of 
two  days,  the  liquid  is  clouded,  and  later  a  thin,  greenish-white  layer  forms 
upon  the  surface,  while  the  bouillon  acquires  a  green  color.  Upon  potato 
a  chocolate-colored,  moist-shining  layer  quickly  extends  over  the  entire 
surface. 

290.    BACILLUS  VIOLACEUS. 

First  found  in  the  water  of  the  Spree  at  Berlin,  and  since  by  Frankland  in 
the  water  of  the  Thames  and  of  the  Lea. 

Morphology. — Bacilli  with  round  ends,  about  1.7  /t  longand  0.8  /*  broad; 
usually  in  pairs;  may  grow  out  into  long  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liqiiefy- 
ing,  motile,  chromogenic  bacillus.  Produces  a  dark  -violet  pigment.  Forms 
oval  spores,  which  are  located  in  the  centre  of  the  rods.  Upon  gelatin 
plates,  at  the  end  of  two  days,  the  colonies  are  seen  to  be  irregular  in  out- 
line and  granular;  on  the  fourth  day  a  funnel  of  liquefied  gelatin  is  formed 
by  each  colony,  and  under  a  low  power  an  opaque  mass  surrounded  by  con- 
voluted, filamentous  offshoots  is  seen  at  the  bottom  of  this ;  later  the  funnel 
of  liquefied  gelatin  increases  in  dimensions  and  the  colony  acquires  a  deep- 
violet  color.  In  gelatin  stick  cultures  liquefaction  occurs  rapidly  along  the 
line  of  inoculation  as  a  funnel-shaped  sac ;  the  liquefied  gelatin  is  clouded, 
and  a  violet-colored  deposit  is  seen  at  the  bottom  of  the  tube.  Upon  the  sur- 
face of  agar  a  smooth,  shining  layer  of  a  deep-violet  color  is  quickly  de- 
veloped. Upon  potato  growth  is  limited  to  the  line  of  inoculation  and  a 
dark- violet  stripe  is  slowly  developed.  Blood  serum  is  liquefied  by  this1 
bacillus. 

291.  BACILLUS  SULFUREUM  (Holschewnikoff). 

Morphology.—  Bacilli  with  round  ends,  from  1.6  to  2  A  p  long  and  0.5  n 
broad. 

Biological  Characters.— An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile,  chromogenic'bacillus.  Forms,  in  the  absence  of  oxygen,  a  red- 
dish-brown or  red  pigment.  Produces  sulphuretted  hydrogen  in  sterilized  urine 
and  certain  other  media  when  cultivated  in  the  absence  of  oxygen.  Spore 
formation  not  observed.  Grows  in  the  usual  culture  media  at  the  room  tem- 
perature— also- in  the  incubating  oven.  Upon  gelatin  plates  small,  puncti- 
form  colonies  are  developed  within  forty -eight  hours,  which,  when  they 
reach  the  surface,  cause  a  funnel-shaped  liquefaction ;  as  the  liquefaction 
progresses  very  slowly  the  liquefied  gelatin  is  dried  and  the  funnel- shaped 
cavities  are  filled  with  air.  lu  gelatin  stick  cultures  small  colonies  are  de- 
veloped along  the  line  of  puncture,  and  liquefaction  in  funnel  shape  occurs 


042  NON-PATHOGENIC  BACILLI. 

very  siowiy  ;  in  contact  with  the  air  the  colonies  are  white  :  in  the  absence 
of  oxygen  liquefaction  does  not  occur  and  the  colonies  have  a  reddish- 
brown  or  red  color.  Upon  the  surface  of  agar,  in  the  incubating  oven,  a 
slimy,  gray  layer  is  quickly  developed.  L  pon  potato  no  growth  occurs  in 
the  presence  of  oxygen  ;  when  it  is  excluded  a  reddish-brown  layer  is  de- 
veloped. In  milk,  at  the  end  of  ten  days,  solution  of  the  casein  commences 
without  previous  coagulation. 

292.  BACILLUS  RUBIOUS  (Eisenberg). 

Found  in  water. 

Morphology.  —  Bacilli  of  medium  size,  with  blunt  ends,  often  united  in 
long  filaments. 

Biological  Characters.  —  An  aerobic,  liquefying,  motile,  chromogenic. 
bacillus.  Forms  a  shining,  brownish-red  pigment.  Spore  formation  not 
observed.  Grows  very  slowly  in  the  usual  culture  media  at  the  room  tem- 
perature —  not  in  the  incubator  at  37°  C.  Upon  gelatin  plates  form  spheri- 
cal, finely  granular  colonies,  which  are  of  a  reddish  color  at  the  centre  and 
around  which  the  gelatin  is  slowly  liquefied.  In  gelatin  stick  cultures 
liquefaction  occurs  slowly  and  a  brownish-red  pigment  is  formed.  Upon 
the  surface  of  agar  a  brownish-red  layer  is  developed,  which  quickly  ex- 
tends over  the  surface.  A  similar  development  occurs  iipon  potato  —  not 
limited  to  line  of  inoculation.  Blood  serum  is  liquefied  by  this  bacillus. 


' 


9 
* 


FIG.  213.  FIG.  214. 

FIG.  213.—  Bacterium  terrno  of  Vlgnal,  from  a  bouillon  culture.     X  1,300.    (Vignal.) 
FIG.  214.—  The  same  from  a  culture  fifteen  days  old.     X  1500.    (Vignal.) 


293.    BACTERIUM   TERMO   OF   VIGNAL. 

Found  in  the  salivary  secretions  of  healthy  persons  by  Vignal,  and  de- 
scribed under  the  name  of  Bacterium  termo,  which  was  formerly  given  to 
various  motile  bacilli  encountered  in  putrefying  infusions,  many  of  which 
have  been  differentiated  by  modern  methods  and  are  described  under  differ- 
ent names. 

Morphology. — Bacilli  from  1.5  to  2  n  long,  constricted  in  the  middle,  and 
0.5  to  0.7  /abroad;  never  u*nited  in  chains  or  filaments;  possess  terminal 
flagella. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  in  gelatin  cultures  a  fluorescent  yellowish-gray  pigment. 
Spore  formation  not  determined.  Grows  at  the  room  temperature  in  the 
usual  culture  media — better  at  a  higher  temperature.  Gelatin  cultures  give 
off  a  putrefactive  odor.  Upon  gelatin  plates,  at  the  end  of  twenty -four 
hours,  small,  white  colonies  are  seen ;  at  the  end  of  forty-eight  hours  these 
have  a  diameter  of  two  to  five  millimetres;  the  centre  of  the  colony  is  white 
and  opaque,  and  it  is  surrounded  by  a  zone  of  liquefied  gelatin  which  is. 


NON-PATHOGEXIC   BACILLI.  643 

clouded  and  more  or  less  granular  in  appearance ;  the  area  of  liquefaction 
increases  and  the  opaque  central  colony  disappears,  while  the  margins  of 
the  liquefied  gelatin  are  clouded  and  whitish.  In  gelatin  stick  cultures,  at 
the  end  of  two  days,  liquefaction  has  occurred  all  along  the  line  of  puncture 
and  a  broad  funnel  is  formed  above,  while  below  a  mass  of  white  flocculi 
fills  the  narrow  tube;  at  the  end  of  three  days  the  gelatin  is  completely 
liquefied,  it  is  opalescent,  fluorescent,  and  greenish;  on  the  fifth  or  sixth 
day  it  has  a  yellowish-green  color  and  a  strong  odor  of  putrefaction.  Upon 
the  surface  of  agar,  at  a  temperature  of  36°  C.,  it  forms  circular,  grayish- 
white,  almost  transparent  colonies ;  these  rapidly  coalesce  to  form  a  layer  of 
uniform  thickness,  which  is  easily  broken  up.  In  bouillon  the  liquid  is  at 
first  clouded  throughout,  and  at  the  end  of  a  week  has  a  green  color,  while 
the  bacilli  are  seen  at  the  bottom  as  a  pulverulent  white  deposit.  Blood 
serum  is  slowly  liquefied  and  gives  off  a  strong  putrefactive  odor.  Upon 
potato,  at  the  end  of  forty-eight  hours  in  the  incubating  oven,  a  glairy,, 
grayish  layer  is  formed  the  size  of  a  five-franc  piece ;  later  this  acquires  a 
pale-yellow  color. 

294.    BACILLUS   BUCCALIS   MINUTUS. 

Synonym. — Bacillus  g,  Vignal. 

Found  by  Vignal  in  the  salivary  secretions  of  healthy  persons. 

Morphology. — A  very  short  bacillus,  with  round  ends,  almost  as  broad 
as  long;  in  cultures  upon  agar  the  length  is  from  0.5  to  1  /< — usually  about 
0.7  n ;  in  neutral  bouillon  it  is  from  1  to  1.7  /«  long;  in  old  cultures  involu- 
tion forms  are  common ;  in  stained  preparations  the  two  ends  are  more  deeply 
stained  than  the  central  portion. 

Biological  Characters. — An  aerobic,  liquefying,  chromogenic  bacillus. 
Produces  a  yellow  pigment.  Spore  formation  not  observed.  Motility  not 
mentioned.  Grows  slowly  at  the  room  temperature.  Upon  gelatin  plates, 
at  the  end  of  forty-eight  hours,  the  colonies  are  round,  with  refractive  con- 
tour and  of  a  mastic-yellow  color;  they  are  but  slightly  elevated  and  the 
gelatin  commences  to  liquefy  around  them.  In  gelatin  stick  cultures,  at  the 
end  of  forty-eight  hours,  a  yellowish-white  growth  is  seen  along  the  line  of 
puncture,  and  upon  the  surface  a  layer  having  the  same  color  and  sev- 
eral millimetres  in  diameter  has  developed ;  by  the  fourth  day  the  surface 
growth  has  increased  to  twice  the  size  and  is  yellow  at  the  centre,  while  the 
periphery  is  white;  the  growth  along  the  line  of  puncture  is  abundant  and 
consists  of  small,  closely  crowded  colonies;  below  the  surface  growth  a  cup- 
shaped  cavity  filled  with  clouded  liquefied  gelatin  is  seen ;  by  the  sixth  day 
a  small  funnel  of  liquefaction  has  formed,  the  liquefied  gelatin  is  clear  and 
contains  some  white  flocculi  in  suspension ;  by  the  twelfth  day  the  gelatin 
in  the  tube  is  completely  liquefied,  an  abundant  yellow  deposit  is  seen  at  the 
bottom  and  the  liquefied  gelatin  has  the  same  color.  Upon  the  surface  of 
agar  golden-yellow  plaques  are  developed,  which  are  easily  removed  with 
the  platinum  needle.  In  bouillon  a  thin,  iridescent  pellicle  is  formed  upon 
the  surface  and  the  fluid  below  is  clouded,  while  an  abundant  yellow  deposit 
accumulates  at  the  bottom.  Does  not  grow  well  in  acid  bouillon.  Upon 
potato,  at  the  end  of  forty-eight  hours,  a  thin  and  extended  layer  is  formed 
of  a  yellow  color,  which  later  has  a  brownish  tint. 

295.    BACILLUS   OF   CANESTRINI. 

Found  in  larvae  and  bees  from  infected  hives  in  Italy  (1891). 

Morphology. — Bacilli  with  rounded  ends,  from  4  to  6  ^  long  and  about 
2  n  broad;  the  isolated  elements  ai*e  somewhat  longer  than  those  in  chains; 
solitary,  in  pairs,  or  in  chains  whicli  may  contain  numerous  segments. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
bacillus.  Forms  a  pink  pigment.  The  movements  are  slow  and  oscillating. 
Forms  oval  spores  3  /<  long  and  1.5  /i  broad.  Grows  at  the  room  tempera- 


044:  XOX-PATHOGENIC  BACILLI. 

ture— better  at  37°  C.  Stains  with  the  aniline  colors  and  by  Gram's  method. 
In  gelatin  stick  cultures  causes  liquefaction  of  the  gelatin;  after  some  days 
the  upper  portion  of  the  liquefied  gelatin  has  a  pink  color,  while  at  the  bot- 
tom an  abundant  white  sediment  collects.  Upon  the  surface  of  agar  forms 
a  white  layer  which  contains  numerous  spores.  Liquefies  blood  serum  ;  in 
this  medium  the  bacilli  are  surrounded  by  a  capsule,  and  are  frequently  seen 
in  long  chains  containing  fifteen  to  twenty  elements,  all  enclosed  in  a  sin- 
gle capsular  envelope.  Upon  potato  development  is  rapid  at  37°  C. ;  at  the 
end  of  twenty -four  hours  a  wine-colored  layer  is  formed.  Not  pathogenic 
for  mice  or  guinea-pigs.  Experiments  made  with  pure  cultures  show  that 
it  is  pathogenic  for  bees  and  their  Iarva3,  and  that  it  is  the  cause  of  an  infec- 
tious malady  which  is  destructive  to  these  insects  in  certain  localities  (in. 
Italy). 

C.  Nou-chromogenic,  Non-liquefying  Bacilli. 
296.  BACILLUS  UBIQUITUS  (Jordan). 

Found  in  sewage  at  Lawrence,  Mass. ;  also  in  water  and  in  the  air — "ap- 
parentlv  abundant  everywhere  "  (  ordan). 

Morphology. — Bacilli  from  1.1  to  2  /*  long  and  about  1  ft  broad— reseinble 
micrococci ;  quite  variable  in  f orm ;  in  bouillon  short  filaments  are  some- 
times formed. 

Biological  Characters. — Aja.aSrobio andfacultativeanaerobic,  non-lique- 
fying, non-motile  bacillus.  Spore  formation  not  observed.  Grows  at  the  room 

temperature  in  the  usual  culture  media— also  at 
37°  C.  Upon  gelatin  plates  forms  small,  sphe- 
rical or  oval  colonies,  which  have  a  yellowish 
tins-e;  at  the  end  of  two  days  the  superficial 
colonies  are  prominent,  white,  and  glistening, 
resembling  a  drop  of  milk ;  they  gradually  in- 
crease in  diameter,  become  somewhat  irregular 
in  outline,  and  acquire  a  dull  brownish  tint. 
Under  a  low  power  the  young  colonies  are  seen 
to  be  finely  granular  and  to  have  a  smooth  con- 
tour. In  gelatin  stick  cultures  development 
occurs  upon  the  surface  and  along  the  line  of 
puncture,  producing  a  '' nail-shaped  "  growth 
at  the  end  of  a  week;  the  color  is  at  first  a 
lustrous  porcelain- white,  which  later  changes 
FIG.  215.  -  Bacillus  ubiquitus.  to  a  j^}  brownish-gray ;  grows  well  in  slightly 
x  1,000.  From  a  photomicrograph.  acid  gelatin  _  Upon  the  surface  of  agar  a  whit- 
ish-gray layer  is  developed  which  has  a  slightly 
metallic  lustre.  Upon  potato  a  shining,  white 

growth  of  limited  extent.  In  milk  coagulation  occur-s  quickly  at  37°  C.,  and 
the  milk  acquires  a  strongly  acid  reaction.  Reduces  nitrates  vigorously. 
"  This  species  apparently  resembles  quite  closely  the  Bacillus  candicans  de- 
scribed by  the  Franklands"  (Zeit.fiir  Hyg.,  Bd.  vi.,  page  397).  "  It  differs 
from  that,  however,  among  other  respects,  in  its  capacity  for  reducing  ni- 
trates and  in  its  mode  of  growth  upon  agar  and  potato  "  (Jordan). 

297.  BACILLUS  CAXDICANS  (Fraiiklaiid). 

Found  in  the  soil. 

Morphology. — Short,  thick  bacilli,  resembling  micrococci  ;  often  form 
short  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Does  not  form  spores.  Grows  slowly  at  the  room  temperature  in  the  usual 
culture  media.  Upon  gelatin  plates  the  superficial  colonies  resemble  drops 
of  milk ;  the  deep  colonies  under  a  low  power  are  seen  to  be  spherical,  slightly 


NON-PATHOGENIC  BACILLI.  '  645 

granular  at  the  margins,  and  have  a  smooth  contour.  In  gelatin  stick 
cultures  the  superficial  growth  is  like  a  drop  of  milk  in  appearance;  very 
scanty  growth  along  the  line  of  puncture  at  first,  later  a  row  of  spherical 
colonies  is  seen ;  the  surface  growth  in  old  cultures  has  a  slightly  reddish 
tint.  Upon  the  surface  of  agar  a  thin,  transparent,  grayish- white  layer 
with  smooth  margins.  Upon  potato  an  abundant  layer  is  developed. 

298.  BACILLUS  ALBUS  (Eisenberg). 

Found  in  water. 

Morphology. — Short  bacilli  with  blunt  ends,  often  united  in  short  chains. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  slowly  at  the  room  temperature — 
not  in  the  incubator  at  37°  C.  Upon  gelatin  plates  forms  round,  white 
colonies  the  size  of  a  pin's  head.  In  gelatin  stick  cultures  grows  slowly, 
forming  a  white  line  along  the  puncture  and  a  small,  button-like,  white 
mass  at  the  point  of  entrance.  Upon  the  surface  of  agar  forms  a  milk- 
white  layer.  Upon  potato  a  dirty  yellowish-white  growth,  limited  to  the 
line  of  inoculation. 

299.  BACILLUS  ACIDI  LACTICI  (Hueppe). 

Found  in  sour  milk. 

Morphology. — Bacilli  from  1  to  1.7  V  long  and  from  0.3  to  0.4/*  broad; 
usually  in  pairs,  sometimes  in  chains  of  four. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Forms  spherical  spores,  which  are  located 
at  the  ends  of  the  rods.  Grows  slowly  at  the  room  temperature  in  the  usual 
culture  media.  Upon  gelatin  plates  forms  small,  white,  punctiform  colonies, 
which  later  develop  into  shining,  porcelain-colored  discs  with  a  transparent 
margin;  under  a  low  power  they  have  a  yellowish  tint  in  the  centre  and 
thin,  irregular  margins.  In  gelatin  stick  cultures  small  colonies  are  de- 
veloped along  the  line  of  puncture,  and  later  a  dry,  glistening,  soft,  grayish- 
white,  and  tolerably  thick  layer  is  developed  upon  the  surface.  Upon  potato 
an  extended,  yellowish-brown  layer  is  formed.  In.  milk  lactic  acid  is  pro- 
duced, the  casein  is  precipitated,  and  carbon  dioxide  is  given  off. 

300.  BACILLUS  LIMBATUS  ACIDI  LACTICI  (Marpmann). 

Found  in  fresh  cow's  milk. 

Morphology. — Short,  thick  bacilli,  usually  in  pairs;  every  rod  is  sur- 
rounded by  a  capsule  which  is  not  stained  by  the  aniline  colors. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Does  riot  form  spores.  Grows  slowly  in  the  usual  culture  media  at 
the  room  temperature — also  in  the  incubator.  Upon  gelatin  plates,  at  the 
end  of  twenty-four  hours,  forms  milk-white,  punctiform  colonies.  In  gela- 
tin stick  cultures  scanty  development  occurs  along  the  line  of  puncture, 
and  upon  the  surface  a  flat,  irregular  layer  of  a  white,  pus-like  color  is 
formed.  In  milk,  at  the  end  of  twelve  hours,  a  slightly  reddish  color  is 
seen;  at  the  end  of  twenty -four  hours  coagulation  of  the  casein  and  a 
strongly  acid  reaction — lactic  acid ;  does  not  produce  gas. 

301.   BACILLUS  LACTIS  PITUITOSI. 

Synonym. — Bacillus  der  schleimigen  Milch  (Loffler). 
Found  in  milk. 

Morphology. — Tolerably  thick,  slightly  curved  bacilli,  which  very  quick- 
ly break  up  into  small  segments  resembling  micrococci. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.     Grows 

55 


646  NON-PATHOGENIC   BACILLI. 

rather  rapidly  at  the  room  temperature.  Spore  formation  not  determined. 
Upon  gelatin  plates  forms  white  colonies  with  well-defined  contour,  from 
one-quarter  to  one-half  millimetre  in  diameter;  by  transmitted  light  these 
are  grayish-brown  in  color  and  present  a  slightly  radial  striped  appearance. 
Upon  the  surface  of  agar  a  dirty- white  layer  is  developed.  \Jponpotato  a 

grayish-white,  tolerably  dry  layer.     In  milk  a  slightly  acid  reaction  is  pro- 
uced,  and  a  very  viscid  substance  having  a  peculiar  odor  is  formed,  espe- 
cially in  the  lower  portion  of  the  liquid ;  this  can  be  drawn  out  into  long 
threads. 

302.    BACILLUS  AEROGEXES   (Miller). 

Found  in  the  alimentary  tract  of  healthy  persons. 

Morphology. — Small  bacilli  of  various  lengths. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  at  the  room  temperature.  Upon 
gelatin  plates  forms  spherical,  homogeneous,  transparent,  white  or  slightly 
yellowish  colonies ;  older  colonies  sometimes  appear  to  be  formed  of  con- 
centric rings.  In  gelatin  stick  cultures  development  occurs  along  the  line 
of  puncture  and  the  growth  has  a  yellowish  color;  upon  the  surface  a 
thin,  pearl-gray  layer  with  dentate  margins  is  formed ;  in  old  cultures  the 
line  of  inoculation  acquires  a  dark-brown  color  and  is  surrounded  by  a 
pale-brown  halo.  Upon  potato  a  dry  layer  of  a  dirty  bluish-yellow  color, 
and  with  irregular  outlines,  is  slowly  developed. 

303.   BACTERIUM    AEROGEXES   (Miller). 

Found  in  the  alimentary  tract  of  healthy  individuals. 

Morphology. — Short  rods,  solitary  or  in  pairs. 

Biological  Characters.^ An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Grows  at  the 
room  temperature  in  the  usual  culture  media.  Upon  gelatin  plates  forms 
sharply  denned,  yellowish  colonies,  which  are  marked  by  dark  lines  radi- 
ating from  the  centre  toward  the  margin.  In  gelatin  stick  cultures  devel- 
opment occurs  along  the  entire  line  of  puncture  and  the  growth  has  a  brown- 
ish-yellow color ;  upon  the  sui'face  a  soft,  flat,  grayish- white  mass  is  formed 
about  the  point  of  puncture.  Upon  the  surface  of  agar  a  soft,  grayish- 
white  layer.  Upon  potato  a  soft  layer  with  irregular  margins  and  of  a 
slightly  yellowish-white  color. 

304.    HELICOBACTERIUM  AEROGEXES   (Miller). 

Found  in  the  alimentary  tract  of  healthy  persons. 

Morphology. — Slender  bacilli,  solitary  or  in  chains ;  grow  out  into  long, 
undulating  or  spiral  threads. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at  the 
room  temperature.  Upon  gelatin  plates  forms  transparent,  white  or  slightly 
yellowish  colonies  of  various  forms — spherical,  oval,  snail-shaped,  spindle- 
shaped,  spiral,  etc.  In  gelatin  stick  cultures  grows  upon  the  surface  as  a 
thin,  bluish,  scarcely  visible,  dry  layer,  which  covers  the  entire  surface  at 
the  end  of  forty-eight  hours;  along  the  line  of  puncture  a  uniform,  light- 
yellowish  growth.  Upon  agar  the  growth  is  not  characteristic.  Upon  po- 
tato a  layer  is  formed  which  has  a  dry  surface,  indented  margins,  and  a 
yellowish-brown  color. 

305.  BACILLUS  AQUATILIS  SULCATUS  xo.  I.   ( Weichselbaum). 

Found  in  the  Vienna  water  supply. 

Morphology. — Bacilli  resembling"  the  bacillus  of  typhoid  fe\erinform 
and  dimensions. 


NON-PATHOGENIC   BACILLI.  647 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Gi*ows  rapidly 
at  the  room  temperature — not  so  well  in  the  incubating  oven.  Growth 
occurs  at  a  temperature  as  low  as  5°  to  7°  C.  Upon  gelatin  plates,  at  the 
end  of  two  days,  the  superficial  colonies  are  seen  as  flat  discs  with  a  thicker 
and  whitish  centre  and  very  thin,  bluish,  notched  margins ;  under  a  low 
power  the  surface  is  seen  to  becovered  with  fine  lines  or  furrows  which  cross 
each  other  at  various  angles;  the  color  is  white,  with  a  yellowish  tint  at  the 
centre ;  later  very  numerous  lines  are  seen  crossing  each  other  in  all  direc- 
tions at  the  centre,  while  the  periphery  is  still  white  and  is  marked  by  more 
delicate  lines.  The  deep  colonies  are  round  and  yellowish.  In  gelatin  stick 
cultures  a  flat,  white  layer  with  notched  edges  is  seen  at  the  end  of  twenty- 
four  hours ;  this  becomes  thicker  and  is  of  less  diameter  than  the  surface 
growth  of  the  typhoid  bacillus  under  similar  conditions.  Upon  the  surface 
of  agar,  at  37. 5°  C.,  a  tolerably  thick,  white  layer  is  developed;  this  has  an 
odor  like  that  of  milk.  Upon  potato,  at 37.5°  C.,  the  growth  is  invisible, 
the  line  of  inoculation  having  only  a  moist  appearance ;  at  the  room  tem- 
perature this  is  also  the  case  at  first,  but  later  a  very  thin,  moist-shining, 
of  ten  cream-colored  layer  with  raised  edges  is  seen,  and  the  potato  around 
this  acquires  a  bluish-gray  color,  which  again  fades  out. 

306.  BACILLUS  AQUATILIS  SULCATUS  NO.  ii.  (Weichselbaum). 

Found  in  the  Vienna  water  supply. 

Morphology.  — Short  bacilli  with  round  ends,  of  the  form  and  dimensions 
of  the  shorter  typhoid  bacilli. 

Biological  Characters. — An  aerobic  an d  facultative  anaerobic,  non-lique- 
fying, motile  bacillus.  Spore  formation  not  observed.  Grows  in  the  usual 
culture  media  at  the  room  temperature — not  so  well  in  the  incubating  oven. 
Grows  at  a  lower  temperature  than  the  typhoid  bacillus — 5°  to  7°  C.  Upon 
gelatin  plates,  at  the  end  of  two  days,  the  superficial  colonies  are  similar  to 
those  of  the  typhoid  bacillus  and  of  the  preceding  species,  but  somewhat 
thicker  and  not  visibly  notched ;  under  the  microscope  they  are  seen  to  be  in- 
distinctly notched  and  marked  by  lines,  although  not  so  distinctly  as  are  the 
colonies  of  Bacillus  aquatilis  sulcatus  No.  I. ;  the  centre  of  the  disc-shaped 
colonies  is  yellowish,  the  periphery  white;  after  three  days  they  become 
thicker  and*  the  notching  of  the  margins  and  lines  upon  the  surface  are  no 
longer  seen,  while  the  entire  colony,  with  the  exception  of  the  outer  margin, 
has  a  yellowish  color.  In  gelatin  stick  cultures  a  whitish,  rather  thick 
layer  of  limited  dimensions  is  formed  upon  the  surface.  Upon  the  surface 
of  agar,  in  the  incubator,  a  grayish- white  layer  is  developed  in  twenty -four 
hours.  Upon  potato,  at  the  room  temperatui'e,  a  bluish-gray  color  is  first 
seen  along  the  line  of  inoculation,  and  a  yellowish- gray  or  yellowish-brown 
layer  is  subsequently  developed ;  this  may  become  tolerably  abundant,  while 
the  original  color  disappears ;  potato  cultures  give  off  a  slight  uriiious  odor. 

307.  BACILLUS  AQUATILIS  SULCATUS  NO.  in.  (Weichselbaum). 

Found  in  the  Vienna  water  supply. 

Morphology. — Very  short  bacilli,  frequently  resembling  micrococci. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Grows  at  the 
room  temperature  and  at  5°  to  73  C. — not  so  well  in  the  incubating  oven.  Old 
cultures  give  off  a  disagreeable  odor.  Upon  gelatin  plates,  at  the  end  of 
two  or  three  days,  the  superficial  colonies  are  disc-shaped,  with  a  thicker, 
white  centre  and  a  very  thin,  bluish  periphery;  the  margin  is  notched; 
under  the  microscope  the  surface  is  seen  to  be  marked  with  lines;  later  the 
colonies  increase  in  thickness  and  diameter  and  lose  the  bluish  color ;  the 
system  of  fine  lines  also  disappears,  and  the  surface  is  covered  with  numerous 
short  lines  and  furrows;  the  yellow  color  extends  from  the  centre  nearer  to 


648  NON-PATHOGENIC  BACILLI. 

the  periphery.  In  gelatin  stick  cultures,  at  the  end  of  twenty-four  hours,  a 
very  thin,  white  layer  with  notched  edges  is  developed ;  this  extends  rapidly 
to  the  margins  of  the  tube.  Upon  the  surface  of  agar  an  abundant  grayish- 
white  layer  is  quickly  developed  in  the  culture  oven ;  this  has  an  odor  re- 
sembling that  of  milk.  Upon  potato,  at  the  room  temperature,  a  discolora- 
tion of  the  line  of  inoculation  is  seen  at  the  end  of  twenty -four  hours ;  later 
an  abundant  pale-yellow  layer  with  raised  margins  is  developed  which  has 
an  odor  of  herring  brine;  at  the  end  of  nine  days  the  potato  around  the 
growth  has  a  bluish-green  color. 

308.  BACILLUS  AQUATILIS  SULCATUS  NO.  iv.  (Weichselbaum). 

Found  in  the  Vienna  water  supply. 

Morphology. — Bacilli  of  various  lengths;  often  grow  out  into  filaments. 

Biological  Characters.  —  An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  tnotile  (the  short  rods  only)  bacillus.  Spore  formation  not 
demonstrated.  Grows  slowly  at  the  room  temperature — still  more  so  in  the 
incubating  oven.  Upon  gelatin  plates  the  colonies  are  first  visible  on  the 
fourth  day;  the  superficial  colonies  are  thin,  bluish  discs  with  notched  mar- 
gins and  a  somewhat  thicker,  whitish  centre;  under  a  low  power  the  surface 
is  seen  to  be  covered  with  fine  lines,  and  the  larger  colonies  have  a  yellowish 
color  in  the  centre ;  later  they  increase  in  thickness  and  diameter  and  acquire 
a  yellow  color  throughout,  while  the  system  of  lines  is  replaced  by  more 
numerous  and  shorter  lines  and  furrows.  In  gelatin  stick  cultures  develop- 
ment is  very  slow,  but  at  the  end  of  several  days  a  grayish- white  layer  with 
notched  margins  is  developed,  which  gradually  extends  to  the  walls  of  the 
test  tube.  Upon  the  surface  of  agar,  at  37°  C.,  the  growth  is  very  scanty  at 
the  end  of  six  days ;  at  the  room  temperature  a  grayish- white  layer  of  mode- 
rate thickness  is  formed  within  two  days.  Upon  potato  no  growth  occurs 
either  in  the  incubator  or  at  the  room  temperature. 

309.  BACILLUS  AQUATILIS  SULCATUS  NO.  V.  (Weichselbaum). 

Found  in  the  Vienna  water  supply. 

Morphology. — Bacilli  with  round  or  pointed  ends,  of  various  lengths; 
somewhat  thicker  than  the  typhoid  bacillus. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Grows  at  the 
room  temperature  in  the  usual  culture  media — not  in  the  incubating  oven. 
Upon  gelatin  plates  forms  colonies  resembling  those  of  Bacillus  aquatilis 
sulcatus  No.  I. ,  which  become  visible  in  two  or  three  days.  In  gelatin  stick 
cultures  a  layer  of  moderate  thickness  is  formed,  which  gradually  extends 
over  the  surface ;  this  is  grayish- white  at  first  and  later  has  a  yellow  color 
like  that  of  the  yolk  of  an  egg.  Upon  the  surface  of  agar  no  growth  occurs 
in  the  incubator,  but  at  the  room  temperature  an  abundant,  viscid,  yellow- 
ish layer  is  developed.  Upon  potato,  at  the  room  temperature,  a  bluish-yel- 
low layer  is  formed  and  the  potato  around  it  acquires  a  dark-gray  color, 
which  disappears  later,  while  the  vegetation  after  a  time  has  a  honey -yellow 
color. 

310.   BACILLUS  MULTIPEDICULUS   (Flugge). 

Found  in  the  air  and  in  water. 

Morphology. — Long:  slender  bacilli. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Spore  formation  not  observed.  Grows  at  the  room  temperature  in  the 
usual  culture  media.  Upon  gelatin  plates  forms  spherical  or  oval  opaque 
colonies,  which  under  a  low  power  are  seen  to  give  off  at  certain  points  of 
the  periphery  broad,  segmented  outgrowths  consisting  of  round  zoogloea 


NON-PATHOGENIC   BACILLI.  649 

masses;  at  the  end  of  two  or  three  days  the  oval,  white,  superficial  colonies 
are  seen  with  the  naked  eve  to  be  surrounded  with  these  outgrowths,  whicli 
resemble  the  feet  and  antennae  of  certain  insects.  In  gelatin  stick  cultures 
a  white  layer  is  developed  upon  the  surface  which  gives  off  short,  isolated 
outgrowths.  Upon  potato  a  smooth,  dirty-yellow  layer  of  limited  extent  is 
developed. 

311.    BACILLUS   CYSTIFORMIS    (Clado). 

Found  in  the  urine  of  a  patient  with  cystitis. 

Morphology. — Very  short  and  slender  bacilli. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Grows  slowly  at  the  room  temperature.  Upon  gelatin  plates  forms  trans- 
parent, yellowish  colonies,  first  round  and  later  oval  in  form;  from  the 
fourth  to  the  seventh  day  a  granular  elevation  appears  at  the  centre, 
around  which  a  finely  granular,  yellowish  zone  is  seen,  and  outside  of  this 
a  broad,  transparent  zone  with  double  contour.  In  gelatin  stick  cultures  a 
scanty  development  occurs  along  the  line  of  puncture,  and  on  the  surface  a 
whitish  layer  is  developed.  Upon  agar  a  yellowish- white  layer. 

312.  BACILLUS  HEPATICUS  FORTUITUS  (Sternberg). 

Obtained,  by  inoculation  in  a  guinea-pig,  from  the  liver  of  a  yellow-fever 
cadaver. 

Morphology. — Resembles  Bacillus  coli  communis  in  its  morphology,  but 
differs  from  this  bacillus  in  being  strictly  aerobic. 

Biological  Characters. — An  aerobic, non-liquefying,  non-motile  bacillus. 
Does  not  form  spores.  Grows  at  the  room  temperature  in  the  usual  culture 
media.  Upon  gelatin  plates  the  deep  colonies  are  spherical,  homogeneous 
or  finely  granular,  and  light-brown  in  color;  at  the  end  of  four  days  they 
are  more  or  less  lobate.  The  superficial  colonies  are  sbaped  like  a  mamma, 
with  striatious  radiating  from  the  centre,  and  are  of  a  dark -brown  color 
under  the  microscope.  In  gelatin  stick  cultures  no  growth  occurs  along  the 
line  of  puncture,  except  to  a  slight  extent  near  tbe  surface;  on  the  surface 
a  white,  button-like  mass  is  formed  about  the  point  of  puncture.  Upon  the 
surface  of  glycerin-agar  the  development  is  quite  rapid  at  35°  C.,  the  entire 
surface  being  nearly  covered  with  a  soft,  milk-white  growth  within  twenty- 
four  hours.  Upon  potato,  at  the  end  of  forty-eight  hours,  a  rather  dry  and 
thick,  cream-white  growth  forms  along  the  line  of  inoculation ;  the  potato 
has  a  bluish  discoloration,  which  subsequently  disappears ;  at  the  end  of  two 
weeks  a  rather  thin,  semi-fluid,  light-brown  layer  covers  the  entire  surface. 
Not  pathogenic  for  rabbits — single  experiment. 

313.  BACILLUS  INTESTIXUS  MOTILIS  (Sternberg). 

Obtained  from  the  contents  of  the  intestine  of  yellow-fever  cadavers. 
^Morphology. — Resembles  Bacillus  coli  communis  in  its  morphology,  but 
differs  from  this  bacillus  in  being  very  actively  motile,  in  its  colonies  upon 
gelatin  plates,  etc. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Spore  formation  not  observed.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates, 
at  the  end  of  twenty-four  hours,  the  deep  colonies  are  spherical,  homogene- 
ous, and  of  a  pale-straw  color;  the  superficial  colonies  resemble  little  drops 
of  water  and  are  of  a  pale-brown  color  by  transmitted  light.  In  gelatin 
stick  cultures  pale  straw-colored  colonies  are  developed  all  along  the  line 
of  puncture,  and  a  rather  thin,  translucent,  whitish  layer  forms  upon  the 
surface;  sometimes  a  nebulous  outgrowth  occurs  from  the  line  of  puncture, 
and  tufted  outlying  colonies  are  formed  throughout  the  gelatin;  at  other 
times,  in  old  cultures,  a  few  feathery  tufts  sprout  out  from  the  line  of  punc- 


650        .  NON-PATHOGENIC  BACILLI. 

ture.  Upon  potato  the  growth  is  rather  thin  and  of  a  pale-yellow  color, 
not  extending  far  from  the  line  of  inoculation.  Does  not  form  gas  in  a  sac- 
charine solution — agua  coco. 

314.  BACILLUS  CAVI^E  FORTUITUS  (Sternberg). 

Obtained,  by  inoculation  in  a  guinea-pig,  from  the  liver  of  a  yellow- 
fever  cadaver,  preserved  for  forty-eight  hours  in  an  antiseptic  wrapping. 

Morphology. — Bacilli  with  round  ends,  from  1  to  4/«  long  and  0.5  to  0.8 
//  broad;  often  in  pairs. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Spore  formation  not  observed.  Grows 
in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates, 
at  the  end  of  three  days,  the  colonies  are  small,  spherical,  and  under  the 
microscope  light-brown  in  color ;  later  opaque,  or  sometimes  with  an  opaque 
centre  surrounded  by  a  transparent  zone.  In  gelatin  stick  cultures  there  is. 
a  scanty  growth  about  the  point  of  puncture;  growth  occurs  all  along  the 
line  of  puncture  in  the  form  of  spherical,  translucent,  straw  colored  colo- 
nies, which  have  a  pearly  lustre  by  reflected  light.  Upon  potato,  at  the  end 
of  a  week,  development  has  occurred  in  the  form  of  small,  dirty-yellow 
masses.  Does  not  form  gas  in  a  saccharine  liquid — agua  coco. 

315.  BACILLUS  COLI  siMiLis  (Sternberg). 

Obtained  from  a  piece  of  liver — of  man — kept  in  an  antiseptic  wrapping 
for  forty-eight  hours. 

Morphology. — A  bacillus  with  round  ends,  from  1  to  3  >"  long  and  from. 
0.4  to  0.5  p  thick;  solitary  or  in  pairs. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Spore  formation  not  observed.  Grows  at 
the  room  temperature  in  the  usual  culture  media — better  at  37°  C.  Upon 
gelatin  plates,  at  the  end  of  two  days,  the  deep  colonies  are  spherical  and 
pale-brown  in  color;  later  they  become  opaque.  The  superficial  colonies  are 
at  first  translucent,  homogeneous,  drop-like  elevations ;  later  .they  are  quite 
thin  and  have  a  pale-brown  color.  In  gelatin  stick  cultures  a  translucent 
growth  with  irregular  margins  is  developed  upon  the  surface,  and  a  rather 
scanty  line  of  growth  is  seen  along  the  track  of  the  inoculating  needle.  On 
potato,  at  22°  C.,  a  thick,  dirty -white  or  pale-brown  layer  is  developed  along 
the  impfstrich.  Not  pathogenic  for  rabbits  or  guinea-pigs. 

316.  BACILLUS  FILIFORMIS  HAVANIENSIS  (Sternberg). 

Obtained  in  anaerobic  cultures  from  the  liver  of  a  yellow-fever  cadaver. 

Morphology. — Long  and  slender  bacilli,  about  0.3>"  in  diameter,  and 
forming  long,  homogeneous  filaments  in  aerobic  cultures,  while  the  bacilli 
are  shorter  and  thicker  in  anaerobic  cultures  in  glycerin-agar. 

Biological  Characters. — An  anaerobic  and  facultative  aerobic,  non- 
liquefying,  non-motile  bacillus.  Does  not  form  spores.  In  gelatin  stick 
cultures  a  scanty  growth  occurs  along  the  line  of  puncture ;  no  growth  on  the 
surface.  In  anaerobic,  glycerin-agar  roll  tubes  colonies  are  developed  which 
are  spherical  or  irregular  in  outline,  of  a  pale-brown  or  straw  color  by  trans- 
mitted light,  white  and  opaque  by  reflected  light ;  the  superficial  colonies 
are  thin  and  translucent,  and  have  a  bluish  lustre  by  reflected  light ;  later 
they  appear  as  opaque,  cream-like  masses  with  irregular  contour.  In  nutrient 
agar  a  scanty,  milk-white  growth  occurs  upon  the  surface  and  an  opaque, 
branching  growth  along  the  line  of  puncture.  No  growth  upon  potato. 
Grows  in  neutral  bouillon,  causing  a  slight  opalescence,  and  later  a  scanty 
white  deposit  at  the  bottom  of  the  tuoe.  Not  pathogenic  for  rabbits  or 
guinea-pigs. 


NON-PATHOGENIC   BACILLI.  651 

317.  BACILLUS  MARTINEZ  (Sternberg). 

Obtained  from  the  liver  of  a  yellow-fever  cadaver,  kept  for  forty-eight 
hours  in  an  antiseptic  wrapping. 

Morphology. — A  short,  oval  bacillus  from  1  to  1.2/f  long  and  from  0.5 
to  0.8  n  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Does  not  form  spores.  Grows  in  the  usual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates  the  deep  colo- 
nies are  spherical  and  translucent ;  superficial  colonies  shaped  like  a  mam- 
ma, with  a  central  nipple-like  projection,  the  surface  covered  with  mosaic 
markings.  In  gelatin  stick  cultures  a  thin,  translucent,  scanty  growth  upon 
the  surface,  and  large,  spherical,  translucent  colonies  along  the  line  of 
puncture.  In  glycerin-agar  stick  cultures  growth  to  the  bottom  of  the  line 
of  puncture,  and  scanty  development  on  the  surface. 

318.  BACILLUS  EPIDERMIDIS  (Bizzozero). 

Synonym. — Leptothrix  epidermidis. 

Found  attached  to  scales  of  epidermis  from  between  the  toes. 

Morphology. — Bacilli  from  2.8  to  3  //  long  and  0.3  /*  broad. 

Biological  Characters. — An  aerobic,  non  liquefying  bacillus.  Forms 
long,  oval  spores— at  25°  C.  in  three  days.  Grows  best  at  a  temperature  of  15° 
to  20°  C.  Very  scanty  growth  in  gelatin.  Grows  upon  the  surface  of  agar. 
Upon  potato,  at  15°  to  20°  C.,  the  development  at  first  is  in  the  form  of  vis- 
cid, transparent,  drop-like  colonies,  which  gradually  coalesce  and  form  a 
rather  thick  layer. 

319.  BACILLUS  NODOSUS  PARVus  (Lustgarten). 

Found  in  the  healthy  urethra  of  man. 

Morphology. — Bacilli  from  1.2  to  2.4  n  long  and  0.4  /*  broad;  one  ex- 
tremity often  presents  an  irregular  club  shape ;  usually  united  in  pairs,  in 
which  the  elements  lie  parallel  or  are  united  at  an  acute  angle. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Grows  best  in  the  incubating  oven.  Spore 
formation  not  observed.  Very  slow  and  scanty  growth  in  nutrient  gelatin. 
Upon  the  surface  of  agar,  at  37°  C.,  at  the  end  of  twenty-four  hours  a  white 
line  of  growth  is  seen  along  the  line  of  inoculation;  at  the  end  of  two  to 
three  days  this  has  a  breadth  of  five  to  six  millimetres,  and  the  central  por- 
tion of  the  layer  is  white,  chalky  in  appearance,  porous,  and  lustreless; 
around  this  is  a  smooth,  flat,  glistening,  grayish- white  marginal  zone  one  to 
two  millimetres  broad.  In  agar  stick  cultures,  at  the  end  of  five  to  eight 
days,  growth  is  seen  along  the  line  of  puncture  as  a  white  stripe  made  up  of 
confluent  spherical  colonies,  while  at  the  point  of  puncture  a  small,  stearin- 
like  drop  is  seen. 

320.    BACILLUS   HYACINTHI   SEPTICUS   (Heinz). 

Found  in  diseased  hyacinths. 

Morphology.  —Bacilli  with  round  ends,  4  to  6  n  long  and  about  1  n  broad ; 
always  solitary. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  observed.  Grows  at  the 
room  temperature.  Old  cultures  have  a  sti'Oiig  putrefactive  odor.  Upon 
gelatin  plates  the  superficial  colonies  are  flat,  shining,  bluish-white  in  color 
with  a  somewhat  darker  centre,  transparent,  and  about  two  millimetres  in 
diameter;  the  deep  colonies  are  oval  with  rather  sharp  poles,  yellowish- 
white,  and  lustreless.  In  gelatin  stick  cultures  growth  occurs  all  along  the 


G52  NON-PATHOGENIC   BACILLI. 

Hue  of  puncture,  and  on  the  surface  as  a  shining  layer  of  moderate  extent. 
Upon  agar  the  growth  is  similar  to  that  upon  gelatin.  Upon  potato,  at  the 
end  of  thirty-six  hours,  a  dirty-yellow,  slimy,  granular  layer. 

321.  BACTERIUM  GLISCROGENUM  (Malerba). 

Found  in  urine  which  was  viscid  and  acid  in  reaction. 

Morphology.— Oval  bacilli,  from  0.57  to  1.14  u  long  and  0.41  jit  broad. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  at  the  room  temperature  in  the  usual 
culture  media — better  at  30°  to  37°  C.  Upon  gelatin  plates,  at  the  end  of  two 
days,  puuctiform  colonies  are  seen,  which  gradually  increase  in  size,  are  per- 
fectly round,  granular,  and  lenticular  in  form ;  later  there  is  a  wavy  depres- 
sion of  the  surface  of  the  gelatin  and  gas  bubbles  are  formed  in  the  interior. 
In  gelatin  stick  cultures  growth  occurs  along  the  line  of  puncture  and  upon 
the  surface  in  nail  shape ;  the  growth  along  the  line  of  inoculation  consists 
of  disc-shaped,  isolated  colonies  closely  piled  one  upon  another.  Upon  the 
surface  of  agar,  at  the  room  temperature,  a  granular,  opalescent  stripe  is 
developed  in  from  three  to  five  days ;  at  37°  C.  an  abundant  development 
occurs  in  twenty-four  hours;  a  white,  viscid  film  forms  upon  the  surface  of 
the  condensation  water.  Upon  potato  a  yellowish  or  yellowish-brown  layer 
is  developed,  and  in  the  course  of  a  few  days  numerous  gas  bubbles  are 
formed,  which  become  confluent ;  later  the  growth  becomes  viscid  and  ex- 
tends over  the  entire  surface.  In  bouillon  diffuse  cloudiness  is  seen  at  the 
end  of  twenty-four  hours,  and  the  fluid  becomes  viscid ;  at  the  end  of  four 
to  five  days  a  whitish  layer  forms  upon  the  surface. 

322.    BACILLUS  OVATUS  MINUTISSIMUS   (Unna). 

Found  upon  the  skin  in  cases  of  eczema  seborrhoeicum. 

Morphology. — Short  oval  bacilli  with  pointed  ends,  0.6  to  0.8/*  long  and 
0.4  //  broad;  associated  in  irregular  groups. 

Biological  Characters. — An.  aerobic-  and  facultative  anaerobic,  non- 
liquefying  bacillus.  Spore  formation  not  observed.  Grows  at  the  room 
temperature  in  the  usual  culture  media.  Gelatin  and  potato  cultures  give 
off  a  strong  and  disagreeable  odor.  Updn  gelatin  plates,  at  the  end  of 
eight  days,  the  superficial  colonies  are  the  size  of  a  mustard  seed,  prominent, 
spherical,  grayish-white,  shining,  and  resemble  a  drop  of  a  solution  of  gum 
tragacanth;  the  deep  colonies  are  punctiform  and  grayish- white  in  color; 
later  the  superficial  colonies  become  flat,  or  occasionally  preserve  the  form 
of  a  small  pearl ;  these  are  almost  one  centimetre  in  diameter,  round,  finely 
granular,  yellowish-gray,  with  a  darker  centre  and  a  more  transparent  peri- 
pheral zone;  the  margins  are  notched.  The  deep  colonies,  under  a  low 
power,  are  seen  to  be  spherical  or  oval,  opaque,  finely  granular,  dark-yel- 
lowish in  the  centre  and  paler  at  the  periphery;  they  may  attain  the  size  of 
a  pea.  In  gelatin  stick  cultures  growth  is  rather  rapid  upon  the  surface  in 
form  of  an  abundant,  slimy,  grayish-white  layer  with  irregular  outlines; 
this  later  becomes  dry  and  opaque,  and  presents  small,  spherical  protu- 
berances which  are  more  transparent;  along  the  line  of  puncture  numerous 
grayish- white,  closely  crowded,  punctiform  colonies.  Upon  a^ar  the  growth 
is  similar  to  that  upon  gelatin.  Upon  potato  an  abundant,  grayish-white, 
dull-glistening  layer. 

323.    CAPSULE   BACILLI   OP   SMITH. 

Theobald  Smith  has  described  three  species  or  vai-ieties  ( 0  of  capsule  ba- 
cilli, resembling  Friedlander's  bacillus,  obtained  by  him  from  the  intestine  of 
swine.  These  he  designates  by  the  letters  a,  b,  and  c. 

Morphology. — Slight  morphological  differences  were  detected  by  culti- 
vating all  under  the  same  circumstances  in  peptone-bouillon . 


XOX-PATHOGEXIC  BACILLI.  653 

a.  1.2  /*  long  and  0.8  to  0.9  H  broad ;  capsule  not  visible  in  hanging1  drop. 

b.  1.6  to  1.8  Jt  long  and  0.8  to  0.9  ju  thick;  capsule  clearly  visible  in 
hanging  drop ;  usually  in  pairs ;  both  ends  somewhat  thickened  as  in  a. 

c.  Bacilli  somewhat  thicker  than  b  ;  capsule  not  visible. 

Friedlander's  bacillus,  1  to  2  n  long  and  1  M  thick.  A  second  examina- 
tion of  all  four,  made  at  the  end  of  forty-eight  hours,  showed  no  apparent 
difference  in  a,  b,  and  Friedlander's  bacillus,  while  c  remained  shorter  than 
the  others.  None  of  the  species  retained  their  color  when  treated  by  Gram's 
method. 

Biological  Characters. — Aerobic  and  facultative  anaerobic,  non-liquefy- 
ing, non-motile  bacilli. 

Upon  gelatin  plates — 

a  forms  colonies  resembling  those  of  Bacillus  coli  communis;  they  spread 
out  in  a  thin  layer,  tbe  margins  of  which  are  very  thin  and  bluish  by  trans- 
mitted light ;  the  contour  is  irregular ;  later  the  colonies  become  thicker, 
white,  and  opaque,  and  flap-like  processes  may  be  given  off  from  the  mar- 
gins which  double  the  original  diameter  of  the  colony — of  four  to  five  mil- 
limetres; in  the  centre  a  small,  button-like  elevation  is  seen. 

b.  The  colonies  are  at  first  thicker  and  more  opaque  than  those  of  a ; 
they  reach  a  diameter  of  four  millimeti'es,  and  are  thinner  toward  the  mar- 
gin, which  is  irregular  in  outlhie;  a  small  central  prominence  is  usually 
observed. 

c.  The  colonies  are  thicker,  circular  in  outline,  with  smooth  margins,  and 
attain  a  diameter  of  five  millimetres ;  the  central  projection  is  strikingly 
large. 

In  peptone-bouillon,  at  36°  C.,  at  the  end  of  five  hours  a,  b,  and  c  all 
cause  the  culture  medium  to  be  decidedly  clouded,  while  Friedlander's  ba- 
cillus only  causes  a  slight  cloudiness  at  the  end  of  twenty-four  hours.  At 
the  end  of  a  week  the  cultures  of  a  show  a  dense  clouding  and  an  abun- 
dant deposit  at  the  bottom  of  the  tube,  but  110  layer  on  the  surface ;  the  cul- 
tures of  b  a  similar  cloudiness  and  deposit,  and  also  a  thick,  gelatinous 
layer  on  the  surface ;  the  cultures  of  c  a  densely  clouded  medium  with  a 
thin  film  upon  the  surface.  Friedlander's  bacillus,  cultivated  in  the  same 
medium,  showed  a  slight  cloudiness  and  a  few  fragments  of  a  mycoderma 
floating  upon  the  surface.  In  the  cultures  of  b  the  whole  fluid  becomes 
very  viscid  and  can  be  drawn  out  into  long  threads ;  the  same  character  is 
developed  later  and  to  a  less  extent  in  cultures  of  a  ;  and  in  c  the  superficial 
film  is  somewhat  viscid — cultures  of  Friedlander's  bacillus  do  not  exhibit 
this  character.  All  of  the  cultures  have  an  alkaline  reaction,  and  those  of 
a,  b,  and  c  after  a  time  have  a  disagreeable  odor. 

In  milk,  at  37°  C.,  at  the  end  of  a  week  coagulation  is  not  complete, 
although  the  fluid  is  very  thick;  b  causes  milk  to  be  quite  thick  in  two  days, 
and  to  be  completely  coagulated  in  four  days;  c,  at  the  end  of  a  few  days, 
causes  the  lower  half  of  the  milk  to  coagulate,  and  at  the  end  of  a  week  the 
whole  is  firmly  coagulated ;  Friedlander's  bacillus  in  milk  did  not  produce 
any  apparent  change.  The  milk  cultures  of  a,  b,  and  c  had  an  acid  reac- 
tion ;  at  the  end  of  two  weeks  some  viscid  serum  was  seen  above  the  coagu- 
lum  in  a,  and  the  culture  smelled  like  sour  dough ;  at  the  same  time  the 
whole  coagulum  was  viscid  in  the  culture  of  b  and  a  similar  odor  was  per- 
ceived ;  the  culture  of  c  showed  a  superficial  layer  of  serum  which  was  not 
viscid,  and  the  odor  was  that  of  cheese. 

Upon  potato  a  and  b  developed  a  thin,  shining,  grayish,  transparent 
layer ;  the  growth  of  c  upon  potato  was  thick  and  cream- white,  resembling 
that  of  Friedlander's  bacillus.  In  cultures  containing  glucose,  and  in 
mashed  potato,  c  produced  considerable  quantities  of  gas— equal  parts  of 
COa  and  of  H.  Upon  agar  the  growth  of  all  is  similar  in  appearance,  but 
that  of  a  and  b  is  very  viscid,  that  of  c  less  so,  while  Friedlander's  bacillus 
was  destitute  of  this  character. 

Smith  concludes  his  description  of  these  bacilli  by  the  remark  that  they 
may  be  identical  with  Bacillus  lactis  aerogeiies  of  Escherich. 


054  NON-PATHOGENIC   BACILLI. 

324.  BACILLUS  PUTRIFICUS  COLI   (Bienstock). 

Found  in  human  faeces. 

Morphology. — Slender  bacilli,  about  3  ju  long,  often  shorter,  frequently- 
united  in  long  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Forms  large  spherical  end  spores, 
which  give  the  bacilli  the  form  of  a  drumstick;  the  motile,  spore  bearing 
rods  always  advance  with  the  spore  in  front.  Grows  at  the  room  tempera- 
ture. Upon  nutrient  gelatin  a  layer  having  a  pearly  lustre  is  developed ; 
later  this  has  a  yellowish  color  and  is  homogeneous  in  appearance.  This 
bacillus  was  supposed  by  Bienstock  to  be  constantly  present  in  faeces,  and  to 
be  especially  concerned  in  the  decomposition  of  albuminous  substances.  Its 
characters  of  growth  have  not  been  determined  with  precision. 

325.    BACILLUS  SUBTILIS  SIMULANS    NO  I.    (Bienstock). 

Found  in  human  fasces. 

Morphology. — Bacilli  with  round  ends,  resembling  Bacillus  subtilis  ; 
grows  out  into  long  filaments,  which  become  segmented  and  form  short 
chains  of  two  to  five  elements;  or,  more  commonly,  separate  into  single 
rods. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Grows  best  at  37°  to  39°  C.  Forms  oval  spores,  in  which  germination  oc- 
curs at  the  two  poles  simultaneously,  leaving  the  central  portion  of  the  new- 
formed  bacillus  bulging  from  the  presence  of  the  spore  membrane.  Upon 
nutrient  agar  this  bacillus  grows  out  in  the  form  of  a  mesentery,  yellowish- 
white  ' '  veins  "  running  in  all  directions,  which  are  united  with  each  other 
smaller  anastomosing  branches. 

326.    BACILLUS  SUBTILIS  SIMULANS  NO.    II.    (Bienstock). 

Found  in  human  faeces. 

Morphology. — The  same  as  the  preceding  species. 

Biological  Character s. — An  aerobic,  non-liquefying  bacillus.  Grows  very 
rapidly — best  at  37°  to  39°  C.  Upon  the  surface  of  agar  forms  a  glistening, 
white  layer,  which  is  at  first  smooth  and  later  has  a  somewhat  uneven  sur- 
face, while  the  margins  are  surrounded  by  grape-like  outgrowths.  Imper- 
fectly described. 

327.  BACILLUS  STRIATUS  ALBUS  (Von  Besser). 

Found  in  nasal  mucus  from  healthy  individuals. 

Morphology. — Small,  thick  bacilli,  of  about  the  size  of  the  diphtheria  bacil- 
lus ;  often  more  or  less  curved ;  in  preparations  stained  with  methylene  blue 
the  bacilli  have  a  striped  appearance;  club-shaped  involution  forms  may  be 
seen. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  Spore 
formation  not  observed.  Grows  at  the  room  temperature  in  the  usual  cul- 
ture media.  Upon  gelatin  plates  forms  small,  dry,  superficial  colonies. 
Upon  agar  plates  forms  prominent,  milk-white  colonies,  one-half  centime- 
tre in  diameter,  which  under  the  microscope  have  a  brown  nucleus  sur- 
rounded by  a  paler  brown  marginal  zone.  Upon  the  surface  of  agar  forms 
a  flat,  shining,  grayish-white  layer.  Upon  potato  a  scanty,  transparent,, 
jelly-like  layer. 

328.  BACILLUS  STOLON ATUS  (Adametz). 

Found  in  water. 

Morphology. — Bacilli  two  and  one  half  times  as  long  as  thick. 


NON-PATHOGENIC  BACILLI. 


Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile 
bacillus.  Spore  formation  not  observed.  Grows  rather  quickly  in  the  usual 
culture  media  at  the  room  temperature.  Upon  gelatin  plates  the  deep  colo- 
nies are  small,  spherical  or  oval,  finely  granular,  whitish  or  yellowish- 
brown;  the  superficial  colonies  are  whitish  or  brownish,  elevated,  hemi- 
spherical, with  sharply  defined  outlines,  and  about  one  /*  in  diameter.  In 
gelatin  stick  cultures  a  granular  growth  is  slowly  developed  along  the  line 
of  puncture  and  a  white  layer  about  the  point  of  inoculation ;  at  the  end  of 
two  to  three  weeks  the  upper  part  of  the  line  of  puncture  forms  a  saucer  or 
flask-shaped  cavity  and  the  walls  are  covered  with  a  white  layer;  there  is, 
however,  no  liquefaction  of  the  gelatin.  Upon  agar  plates  the  growth  is 
very  characteristic :  branches  are  given  off  from  a  central  point ;  these  are 
variously  bent  and  give  off  numerous  smaller,  wavy  branches ;  these  colo- 
nies extend  only  upon  the  surface  and  may  have  a  diameter  of  two  to  three 
centimetres ;  under  a  low  power  they  are  seen  as  very  thin,  finely  granular, 
yellowish  layers  with  club-shaped  branches.  Upon  potato  forms  a  dirty- 
white  layer. 


FIG.  216.— Bacterium  Zopfli ;  a,  long  filament  with  commencement  of  "ball  formation";  b 
shows  the  breaking  up  into  short  rods;  c,  further  breaking  up  into  spherical  elements  ;  e,f,  spirilla- 
like  filaments,  x  740.  (Kurth.) 

329.  BACILLUS  VENTRICULI  (Raczynssky). 

Found  in  the  stomach  of  dogs  fed  exclusively  on  meat. 

Morphology  — Bacilli  from  1.5  to  3  /*  long  and  1  n  thick;  united  in  pairs 
or  in  chains  of  four. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Does  not  form  spores.  Grows  slowly  at  the 
room  temperature.  Upon  gelatin  plates  forms  round  colonies,  which  are 
opaque  at  the  centre  and  become  more  transparent  toward  the  margin,  which 
is  surrounded  by  a  dark  contour.  In  gelatin  stick  cultures  small,  white, 
punctiform  colonies  are  developed  along  the  line  of  puncture.  Upon  agar 
a  whitish  layer  is  formed.  This  bacillus  is  said  to  cause  the  peptonization  of 
albuminous  substances  when  the  reaction  is  acid  or  neutral. 


656  NON-PATHOGENIC   BACILLI. 

330.  BACTERIUM  ZOPFH  (Kurth). 

Found  in  the  intestine  of  chickens. 

Morphology. — Bacilli  from  2  to  5  fj.  long  and  0.75  to  1  ju  broad;  form  long 
filaments,  which  in  gelatin  cultures  are  folded  and  coiled  in  a  peculiar  man- 
ner. In  liquid  media  straight  filaments  only  are  seen.  The  coiled  filaments 
in  gelatin  cultures  form  tangled  balls,  in  which  they  subsequently  break  up 
into  short  rods  and  finally  into  spherical  bodies  which  appear  to  be  repro- 
ductive elements. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile 
bacillus.  Forms  spherical  spores  (?),  which  are  not  highly  refractive  and 
stain  deeply  with  the  aniline  colors.  Grows  best  at  the  room  temperature ; 
at  30°  to  37°  C.  the  bacillus  is  no  longer  motile ;  at  37°  to  40°  C.  involution 
forms  are  developed.  Upon  gelatin  plates,  at  the  end  of  twenty-eight 
hours,  white,  punctiform  colonies  are  developed,  from  which  as  a  centre  a 
mass  of  fine,  radiating  filaments  is  given  off;  among  these  numerous  small, 
white  points  aue  distributed,  which  under  the  microscope  are  seen  to  be 
spherical  zoogloea  masses  of  a  brownish-yellow  color ;  the  centre  of  the  colo- 
nies consists  of  bundles  of  interlaced  or  parallel  filaments.  In  gelatin  stick 
cultures,  at  the  end  of  twenty-four  hours,  a  thick,  white  layer  is  developed 
along  the  upper  portion  of  the  line  of  puncture,  and  later  radiating  lines  of 
growth  are  given  off  from  this;  these  cross  each  other  in  various  directions 
and  resemble  the  mycelium  of  a  fungus.  No  development  occurs  on  blood 
serum. 

331.   BACTERIUM  ZURNIANUM   (List). 

Found  in  water. 

Morphology.  —Short  rods  with  slightly  pointed  ends,  from  1.2  to  1.5  n 
long  and  0.6  to  0.8  /*  broad;  in  stained  preparations  the  ends  are  most  deeply 
stained,  giving  the  rods  the  appearance  of  diplococci. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Does  not  form  spores.  Grows  in  the  usual  culture  media  at  the  room 
temperature — better  at  25°  to  30°  C.  Upon  gelatin  plates  forms  spherical, 
dirty-white  or  gray,  extremely  viscid  colonies,  which  develop  into  slimy, 
grape-like  masses.  In  gelatin  stick  cultures  a  grape-like  mass  upon  the 
surface  and  scanty  growth  along  the  line  of  puncture.  Upon  potato,  at  25 J 
to  30°  C.,  a  slimy,  translucent,  gray  or  yellowish-white  layer  extends  over 
the  surface  within  forty-eight  hours. 

332.   BACILLUS  OF  COLOMIATTI. 

Obtained  from  xerotic  masses  from  the  eye  of  a  child  and  in  certain  forms 
of  conjunctivitis. 

Morphology. — Bacilli  which  correspond  with  the  bacillus  of  mouse  septi- 
caemia in  length,  associated  in  irregular  masses. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacillus. 
Does  not  grow  at  the  room  tempei^ature.  Forms  spherical  spores,  which  lie 
at  the  ends  of  the  rods.  Does  not  grow  in  nutrient  gelatin  or  on  potato. 
Upon  the  surface  of  agar  a  thin  film  is  developed  at  34°  to  39°  C. ,  which 
gives  to  the  surface  a  fatty  lustre.  Upon  blood  serum,  at  35°  to  39°  C.,  de- 
velopment occurs  along  the  line  of  inoculation  as  a  dull-gray  layer  with  a 
fatty  lustre,  which  has  a  breadth  of  two  to  three  millimetres  and  a  rosette- 
like  form. 

333.  BACILLUS  SCISSUS  (Frankland). 

Found  in  the  soil. 

Morphology. — A  short,  thick  bacillus  of  variable  dimensions;  usually 
about  1  /LI  broad  and  1  to  2  it  long ;  resembles  Bacillus  prodigiosus,  and,  like 


NON-PATHOGENIC  BACILLI.  657 

this,  may  easily  be  mistaken  for  a  micrococcus ;  sometimes  in  pairs  or  in  short 
chains. 

Biological  Characters.— An  aerobic,  non-liquefying,  non-motile  bacillus. 
Spore  formation  not  observed.  Grows  slowly  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin  plates  the  deep  colonies  are  yellowish 
and  punctiform ;  under  a  low  power  they  are  seen  to  be  opaque  in  the  mid- 
dle and  have  dentate  margins;  when  they  break  through  to  the  surface  they 
form  small,  prominent  masses,  and  from  these  superficial  colonies  are  de- 
veloped which  have  a  pale-greenish  tint,  a  deeply  dentate  margin,  and  are 
seen  under  the  microscope  to  be  finely  granular  In  gelatin  stick  cultures 
a  very  thin,  smooth,  shining  layer  is  developed  upon  the  surface;  this  has 
an  irregular  and  deeply  dentate  margin;  the  gelatin  acquires  a  greenish 
tint;  no  development  occurs  along  the  line  of  puncture.  Upon  the  surface 
of  agar  a  smooth,  shining  layer  with  wrinkled  margins  is  formed ;  the  agar 
acquires  a  green  tint.  Upon  potato  a  shining,  flesh-colored  layer  extends 
over  a  considerable  portion  of  the  surface. 


jrf?Sv,®  ,    ^ 

%%  j^i 


FIG.  217.  FIG.  218. 

FIG.  217.— Bacillus  scissus.    X  1,000.    (Frankland.) 
FIG.  218.— Bacillus  scissus;  superficial  colony  on  gelatin  plate,    x  100.    (Frankland.) 

334.  BACILLUS  NO.    I.    OF  FULLES. 

Found  in  the  soil. 

Morphology. — Bacilli  from  1  to  1.2  u  long  and  0.6  ja  broad. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Upon  gelatin  plates  forms  spherical,  finely 
granular  colonies ;  under  the  microscope  these  have  a  yellowish-brown  cen- 
tre surrounded  by  a  yellowish  marginal  zone ;  later  these  differences  in  color 
are  not  seen,  and  to  the  naked  eye  the  colonies  are  bluish-white.  In  gelatin 
stick  cultures  a  thin  layer  forms  upon  the  surface  which  is  not  characteris- 
tic. In  bouillon,  at  the  room  temperature,  the  liquid  becomes  densely 
clouded  and  white  flocculi  are  deposited  at  the  bottom  of  the  tube.  Upon 
potato  a  moist,  dirty -yellow  layer  is  developed.  Not  pathogenic  for  mice  or 
for  guinea-pigs. 

335.  BACILLUS  NO.   II.   OF  FULLES. 

Found  in  the  soil. 

Morphology. — Small  bacilli  with  round  ends;  resemble  cocci. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  Spore  for- 
mation not  observed.  Presents  oscillatory  movements  only.  Upon  gelatin 
plates  somewhat  elevated,  round,  grayish-white  colonies  are  developed  upon 
the  surface ;  the  deep  colonies  are  small,  yellowish  in  color,  and  under  a  low 
power  are  seen  to  be  finely  granular,  brownish-yellow,  and  with  sharp  con- 
tours. The  superficial  colonies  attain  a  diameter  of  two  millimetres  and 
have  a  brownish-yellow  color.  In  gelatin  stick  cultures  the  growth  is  at 


658  NON-PATHOGENIC   BACILLI. 

first  nail-shaped ;  later  it  spreads  out  upon  the  surface.  Upon  agar  a  thin, 
white  layer  with  irregular  outlines  is  developed.  In  bouillon,  at  the  room 
temperature,  a  dense  cloudiness  is  developed  and  a  thick,  slimy  deposit  ac- 
•cumulates  at  the  bottom  of  the  tube.  Upon  potato  a  moist,  granular,  yel- 
lowish-white layer  is  developed.  In  milk  an  acid  reaction  is  not  produced. 

336.    BACILLUS   PHOSPHORESCENS   GELIDUS    (Forster). 

Found  in  phosphorescent  sea  fish. 

Morphology. — In  recent  cultures  the  bacilli  appear  as  small  rods  with 
slightly  rounded  ends  and  about  three  times  as  long  as  broad ;  in  cultures 
more  than  twenty-four  hours  old  they  are  thicker  and  nearly  oval  in  form. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  Spore 
formation  not  positively  determined.  Grows  slowly  at  the  room  tempera- 
ture, and  even  as  low  as  0'  C. ;  is  killed  in  a  few  hours  by  exposure  to  a 
temperature  of  35°  to  37°  C.  Cultures  freely  exposed  to  the  air  are  phos- 
phorescent in  the  dark  when  kept  at  a  temperature  between  0°  and  20°  C. — 
phosphorescence  ceases  at  32°  C.  Upon  gelatin  plates,  at  the  end  of  forty- 
eight  hours,  small,  punctiform  colonies  are  developed ;  under  the  microscope 
these  are  seen  to  be  spherical,  grayish-white  in  color  with  a  greenish  shim- 
mer ;  later  granular,  yellowish,  and  with  somewhat  irregular  outlines.  In 
gelatin  stick  cultures  a  white  layer  is  developed  upon  the  surface;  very 
scanty  growth  along  the  line  of  puncture.  Upon  agar  the  growth  is  simi- 
lar to  that  011  gelatin.  Upon  potato  a  broad,  white  layer  is  developed. 

337.    BACILLUS   SMARAGDINO-PHOSPHORESCENS    (Katz). 

Obtained  from  a  herring  from  the  fish  market  at  Sydney,  New  South 
Wales. 

Resembles  Photobacterium  phosphorescens  (Cohn)  described  by  Beyer- 
inck,  and  Photobacterium  Pfliigeri  (Ludw.). 

Morphology. — Bacilli  with  somewhat  pointed  ends,  about  2  n  long  and 
1  n  broad ;  solitary  or  in  pairs ;  in  recent  cultures  closely  resemble  cocci. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at 
the  room  temperature.  Upon  gelatin  plates,  at  the  end  of  eighteen  hours, 
the  deep  colonies  are  seen  as  grayish  points,  and  the  superficial  as  thin, 
grayish- white  drops ;  under  a  low  power  these  are  pale-gray  with  a  yellow- 
ish tint,  finely  granular,  and  transparent  near  the  margins,  which  are  finely 
dentate ;  diameter  from  0.3  to  0.45  millimetre.  -The  deep  colonies,  under  the 
microscope,  are  seen  to  be  oval  or  lemon-shaped,  with  a  smooth,  well-defined 
contour,  and  about  0.15  millimetre  in  diameter;  they  consist  of  a  broad  cen- 
tral portion  surrounded  by  a  narrow  central  and  still  narrower  marginal 
zone ;  zone  formation  not  observed  in  colonies  in  eight-per-cent  gelatin.  At 
the  end  of  twenty  days  the  superficial  colonies  attain  a  diameter  of  two  milli- 
metres ;  they  are  flat,  have  irregular  outlines,  and  are  composed  of  a  rela- 
tively small  central  portion  of  a  yellowish  color,  surrounded  by  a  slate-col- 
ored marginal  zone ;  the  deep  colonies  at  this  time  (twenty  days)  are  about 
0.6  millimetre  in  diameter  and  yellowish- white  in  color — under  the  micro- 
scope straw-yellow.  In  gelatin  stick  cultures  (six  per-cent  gelatin)  a  thin, 
white  line  of  growth  is  seen  along  the  line  of  puncture,  and  a  flat,  round, 
grayish-white  layer,  with  a  stearin  lustre,  is  developed  upon  the  surface;  this 
acquires  a  diameter  of  about  five  millimetres.  Cultures  made  by  Katz  for  a 
year  in  six-per-cent  gelatin  gave  no  evidence  of  liquefaction,  but  subse- 
quently the  same  bacillus,  cultivated  in  six-per-cent  gelatin  containing  2.7 
per  cent  of  sodium  chloride,  caused  liquefaction  of  the  gelatin  beneath  the 
surface  growth,  which  gradually  extended  downward.  Growth  occurs  upon 
the  surface  of  agar,  but  this  is  not  a  very  favorable  medium.  In  neutral 
bouillon  development  occurs,  and  a  diffuse  cloudiness  is  seen,  but  no  growth 
occurs  in  simple  flesh  infusion;  when,  however,  2.5  per  cent  of  sodium 


NON-PATHOGENIC   BACILLI.  659 

chloride  is  added  to  this  it  constitutes  a  favorable  medium.  Upon  the  sur- 
face of  sterilized  milk  a  tolerably  abundant,  sticky,  glistening-  layer  of  a 
cream-white  color  is  developed.  Upon  cooked  egg  a  thin,  grayish-white, 
phosphorescent  layer  is  formed.  No  growth  on  potato  which  has  an  acid 
reaction,  but  when  the  acidity  is  neutralized  with  a  solution  of  sodium  phos- 
phate a  thin,  brownish-yellow  layer  is  developed.  Small  quantities  of  a 
pure  culture  added  to  sea  water  cause  it  to  exhibit  a  very  decided  phospho- 
rescence, and  the  addition  of  sodium  chloride  to  culture  media  favors  the 
growth  of  the  bacillus  and  its  phosphorescent  power.  Free  access  of  oxygen 
is  essential  for  the  growth  and  phosphorescence  of  this  species.  The  color 
of  the  light  given  off  by  fresh  cultures  is  emerald-green ;  it  is  less  intense  in 
ao-ar  cultures  than  in  cultures  in  nutrient  gelatin,  bouillon,  or  upon  cooked 
fish. 

338.  BACILLUS  ARGENTEO-PHOSPHORESCENS  NO.    I.    (Katz). 

Obtained  from  sea  water  at  Elisabeth  Bay,  Sydney,  New  South  Wales. 

Morphology. — Slender,  slightly  curved  bacilli  with  pointed  ends,  about 
2.5  jit  long  and  one-third  as  thick  as  they  are  long;  solitary  or  in  pairs;  oc- 
casionally in  long,  wavy  filaments. 

Biological  CJiaracters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at  the 
room  temperature — not  in  the  incubator  at  35°  C.  Upon  gelatin  plates 
(six-per-ceiit  gelatin),  at  the  end  of  twenty  hours,  the  superficial  colonies  ap- 
pear as  flat,  shining,  transparent  drops  from  0.4  to  0.6  millimetre  in  dia- 
meter; under  the  microscope  they  are  seen  to  be  homogeneous  and  usually 
circular  in  outline,  with  a  dentate  margin.  The  deep  colonies  are  spherical 
or  short  oval;  they  have  a  smooth,  well-defined  contour  and  pale-yellow 
color.  At  the  end  of  forty- eight  hours  the  superficial  colonies  are  granular, 
pale-yellow,  with  an  undulating  contour,  and  about  1.25  millimetres  in  dia- 
meter; at  the  same  time  the  deep  colonies  are  pea-yellow  and  uniformly 
granular ;  later  the  deep  colonies  present  three  well-defined  zones ;  the  super- 
ficial colonies  also,  at  the  end  of  twenty  days,  present  two  or  three  distinct 
zones;  they  attain  a  diameter  of  about  three  millimetres.  In  eight-percent 
gelatin  the  deep  colonies,  at  the  end  of  two  days,  are  oval,  and  under  the 
microscope  show  three  well-defined  zones;  the  superficial  colonies  present 
the  same  appearance  in  from  four  to  seven  days,  at  which  time  they  have  a 
diameter  of  three  millimetres — later  as  much  as  seven  millimetres.  In  gela- 
tin stick  cultures  (six  per  cent)  development  occurs  upon  the  surface  as  a 
flat,  shining,  usually  circular  layer,  about  one  cubic  centimetre  in  diameter, 
and  of  a  greenish-yellow  or  wax-like  color.  No  growth  occurs  in  acid  gela- 
tin. In  old  gelatin  cultures  containing  2.7  per  cent  of  sodium  chloride 
liquefaction  sometimes  occurs  at  a  temperature  approaching  that  at  which 
the  gelatin  would  become  liquid.  In  bouillon  a  diffuse  cloudiness  is  pro- 
duced and  a  film  is  formed  upon  the  surface ;  no  growth  occurs  in  flesh  in- 
fusion without  the  addition  of  peptone  and  salt,  but  the  addition  of  2.5  per 
cent  of  sodium  chloride  to  neutral  flesh  infusion  makes  it  a  favorable  me- 
dium. Upon  the  surface  of  sterilized  fish  a  pale-yellow,  glistening,  sticky 
layer  is  developed.  Upon  cooked  egg  a  thin,  grayish- white  layer.  No  growth 
on  potato.  Phosphorescence  depends  upon  the  presence  of  certain  salts — 
especially  sodium  chloride— in  the  culture  medium,  and  upon  the  free  access 
of  oxygen.  In  bouillon  cultures,  when  a  mycoderma  has  formed  upon  the 
surface  this  shows  phosphorescence,  while  the  liquid  below  does  not.  The 
light  given  off  is  of  a  silver-white  color,  and  a  recent  culture  upon  the  sur- 
face of  gelatin  gives  sufficient  light  to  enable  one  to  determine  the  time  from 
a  watch  in  a  dark  room. 

339.  BACILLUS  ARGENTEO-PHOSPHORESCENS  NO.    II.    (Katz). 

Obtained  from  phosphorescent  pieces  of  fish  found  in  the  market  at  Syd- 
ney, New  South  Wales. 


000  NON-PATHOGENIC  BACILLI. 

Morphology. — Bacilli  with  round  ends,  about  2. 7  n  long  and  0. 67 n  broad; 
occasionally  form  short  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile  bacil- 
lus. Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at 
the  room  temperature — not  so  well  at  32°  to  34°  C.  Upon  gelatin  plates  (six 
percent),  at  the  end  of  twenty-four  hours  at  18°  to  20°  C.,  the  superficial 
colonies  have  a  diameter  of  0.5  millimetre  and  resemble  little  drops  of  stea- 
rin; they  have  a  circular  and  sharply  defined  contour,  are  homogeneous, 
and  of  a  pale  yellowish-gray  color ;  at  the  end  of  forty-eight  hours  they  are 
grayish-yellow,  finely  granular,  with  irregular  contour,  and  about  one  milli- 
metre in  diameter.  The  deep  colonies  are  much  smaller,  have  a  greenish- 
yellow  color,  granular  contents,  and  a  smooth,  well-defined  contour.  The 
deep  colonies  which  come  to  the  surface  spread  out  to  form  a  bluish-gray, 
shining  disc,  which  may  attain  a  diameter  of  six  millimetres.  In  gelatin 
stick  cultures  scanty  development  along  the  line  of  puncture,  and  a  grayish- 
white,  glistening  layer  of  limited  extent  upon  the  surface.  Upon  the  sur- 
face of  ten-per-cent  gelatin  a  bluish-gray  band  with  cloudy  margins  along 
the  impfstrich.  In.  bouillon  cultures  the  liquid  is  diffusely  clouded,  but  no 
mycodermais  formed  upon  the  surface.  Upon  sterilized  fish  a  shining,  sticky 
layer  of  a  yellowish  color — here  and  there  lemon-yellow;  the  cultures 
have  a  silver-white  phosphorescence  in  the  dark,  and  a  small  quantity  added 
to  a  considerable  quantity  of  sea  water  causes  this  to  be  phosphorescent. 
The  presence  of  certain  salts,  and  especially  of  sodium  chloride,  and  free 
contact  with  oxygen,  is  favorable  to  the  growth  of  this  bacillus  and  to  the 
development  of  phosphorescence. 

340.   BACILLUS  ARGENTEO-PHOSPHORESCENS  NO.    III.    (Katz). 

Obtained  from  a  fragment  of  cuttlefish  which  was  phosphorescent,  at 
Sydney,  New  South  Wales. 

Morphology. — Resemble  Bacillus  argenteo-phosphorescens  No.  II.,  but 
the  rods  are  a  little  thinner  and  are  motile;  frequently  united  in  pairs  and 
occasionally  form  short  filaments. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  at  the  room  temperature  in  the  usual 
culture  media— not  so  well  at  32°  to  34°  C.  Upon  gelatin  plates,  at  the  end 
of  twenty-four  hours  at  18°  to  20°  C.,  the  superficial  colonies  appear  as  white 
scales  with  irregular  outlines,  sometimes  wrinkled,  and  marked  with  fine 
lines  or  furrows,  about  0.45  millimetre  in  diameter.  The  deep  colonies  are 
spherical,  oval,  or  lemon-shaped,  homogeneous,  and  greenish-yellow  in  color; 
at  the  end  of  forty-eight  hours  th^y  appear  finely  granular  and  divided  into 
two  zones.  At  the  end  of  a  week  the  superficial  colonies  attain  a  diameter 
of  about  three  millimetres ;  they  are  bluish-gray  and  cloudy  in  appearance, 
quite  thin,  and  have  a  notched  or  dentate  margin.  Upon  the  surface  of  gelatin 
stick  cultures  a  layer  is  developed  which  extends  nearly  to  the  walls  of  the 
tube,  and  which  becomes  very  thin  at  the  margins.  Development  occurs 
upon  the  surf  ace  of  agar,  but  this  is  not  a  very  favorable  medium.  In  bouil- 
lon a  diffuse  cloudiness  is  produced  and  a  mycoderma  forms  upon  the  surface. 
The  addition  of  2.5  per  cent  of  sodium  chloride  to  bouillon  or  other  media  is 
favorable  to  the  growth  and  phosphorescence  of  this  bacillus,  as  of  those 
previously  described.  Upon  sterilized  fish  a  viscid,  glistening,  yellowish 
layer  is  developed.  No  growth  upon  acid  potato.  The  cultures  give  off  a 
silver- white,  phosphorescent  light.  Bouillon  cultures  commence  to  give  off 
light  from  the  surface  at  the  end  of  four  or  five  days,  and  at  the  end  of  eight 
days  the  floating  mycoderma  may  give  a  light  by  which  the  time  can  be  dis- 
cerned,^in  a  dark  room,  from  a  watch ;  the  light  is  a  "  bluish-greenish  white.'* 


NON-PATHOGENIC   BACILLI.  661 

D.  Non-chromogenic,  Liquefying  Bacilli. 

341.   BACILLUS  CYANEO-PHOSPHORESCENS   (Katz). 

Obtained  from  sea  water  at  Little  Bay,  near  Sydney,  New  South  Wales. 
Very  nearly  related  to  Bacillus  phosphoresceiis  of  Fischer  (Katz). 

Morphology. — Bacilli  with  round  ends,  about  2.6  ju  long  and  1  ft  thick ; 
solitary  oriii  pairs;  occasionally  grow  out  into  long  filaments. 

Stains  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  not  observed.  The  cultures  give  off 
a  bluish  phosphorescence  which  has  a  faint  greenish  tint.  Grows  in  the 
usual  culture  media  at  the  room  temperature — best  at  26°  C. ;  very  scanty 
growth  upon  nutrient  agar  at  32°  to  34°  C.  Upon  gelatin  plates,  at  the  end 
of  eighteen  hours,  colonies  are  already  visible ;  those  upon  the  surface  and 
those  in  the  interior  of  the  gelatin  are  of  about  the  same  dimensions — 0.25  to 
0.4  millimetre;  under  the  microscope  they  are  seen  to  be  finely  granular, 
have  a  sharply  defined,  smooth  contour  and  a  dark-gray  color;  the  superfi- 
cial colonies  are  finely  granular  and  pale  yellowish-gray  in  color.  At  the 
end  of  forty-eight  hours  the  superficial  colonies  are  surrounded  by  a  broad 
girdle  of  liquefied  gelatin,  at  the  bottom  of  which  they  lie  in  contact  with 
the  glass  plate ;  they  are  of  a  dirty  brownish-yellow  color  and  irregular  in 
outline;  the  liquefied  gelatin  is  pale-gray  or  yellowish-gray  by  transmitted 
light,  and  contains  here  and  there  granular  masses  scattered  through  the 
more  finely  granular  structure.  At  this  time  the  deep  colonies  are  yet  well 
defined,  have  irregular  outlines,  and  are  of  a  dirty  yellowish-brown  color ; 
they  have  a  diameter  of  about  0.3  to  0.5  millimetre,  and  are  surrounded  by  a 
zone  of  liquefied  gelatin  about  0.05  to  0.1  millimetre  in  diameter ;  this  is  finely 
granular,  light-brown  or  light-gray  in  color,  and  marked  by  delicate  radial 
striations.  When  the  colonies  are  crowded  upon  a  plate  liquefaction  may 
be  complete  at  the  end  of  eighteen  hours ;  the  liquefied  gelatin  gives  off  a 
peculiar  odor.  In  gelatin  stick  cultures  (six-per-cent  gelatin)  liquefaction 
commences  beneath  the  surface  growth,  and  at  the  end  of  forty-eight  hours 
a  shallow  cavity  of  Avatch-glass  form  is  seen  which  has  a  diameter  of  about 
five  millimetres — temperature  of  20°  to  22°  C. ;  at  the  bottom  of  this  a  gray- 
ish-white layer  is  seen,  and  below  this  a  line  of  development  along  the  track 
of  the  inoculating  needle;  this  is  surrounded  by  a  narrow  zone  of  liquefac- 
tion. At  the  end  of  three  or  four  days  liquefaction  at  the  surface  reaches 
the  walls  of  the  test  tube ;  when  liquefaction  is  complete  a  yellowish,  viscid 
mass  is  seen  at  the  bottom  of  the  tube  and  a  mycoderma  upon  the  surface; 
the  gelatin  is  at  first  diffusely  clouded  and  later  becomes  transparent;  it  has 
a  yellowish  color,  which  gradually  changes  to  reddish-brown.  In  six-per- 
cent gelatin  containing  2.7  per  cent  of  sodium  chloride  development  is  espe- 
cially abundant  and  rapid,  and  short,  radiating  processes  are  given  off  into 
the  gelatin  in  advance  of  liquefaction.  In  bouillon  diffuse  cloudiness  occurs 
and  a  mycoderma  forms  upon  the  surface.  No  development  occurs  in 
simple  flesh  infusion,  but  the  addition  of  0.5  per  cent  of  sodium  chloride  to 
this  constitutes  a  medium  in  which  growth  occurs — still  better  2.5  per  cent. 
Upon  sterilized  fish  a  glistening,  sticky  layer  of  a  yellowish  or  yellowish- 
brown  color,  in  the  thicker  places,  is  developed.  Phosphorescence  depends 
upon  the  free  access  of  oxygen  and  the  presence  of  certain  salts,  especially 
sodium  chloride.  A  very  minute  quantity  of  a  culture  added  to  sea  water 
causes  it  to  exhibit  phosphorescence.  Cultures  upon  the  surface  of  agar 
give  sufficient  light  to  enable  one  to  distinguish  printed  letters  in  a  dark 
room.  No  growth  upon  potato. 

342.    BACILLUS   ARGENTEO-PHOSPHORESCENS  LIQUEFACIENS  (Katz). 

Obtained  from  sea  water  at  Bondi  Bay,  near  Sydney,  New  South  Wales. 
Resembles  Photobacterium  luminosum  of  Beyerinck. 

56 


662  NON-PATHOGENIC  BACILLI. 

Morphology. — Straight  or  slightly  curved  bacilli  with  round  ends;  about 
two  /*  long  and  one-third  as  broad;  grow  out  into  filaments  of  various 
lengths. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  not  observed.  Cultures  give  off  a 
silvery  phosphorescence,  which  is  less  intense  than  with  the  previously  de- 
scribed species.  Grows  at  the  room  temperature  in  the  usual  culture  media 
— best  at  25°  C. ;  does  not  grow  in  the  incubating  oven  at  34°  C.  Upon 
gelatin  plates,  at  the  end  of  twenty-four  hours  at  the  room  temperature, 
small,  hyaline  discs  are  developed,  which  under  the  microscope  are  seen  to 
be  finely  granular  and  light-brown  in  color;  they  are  irregularly  circular  in 
outline  and  about  0.7  millimetre  in  diameter;  the  deep  colonies  are  con- 
siderably smaller,  mulberry-like  in  structure,  and  straw-yellow  in  color. 
At  the  end  of  forty-eight  hours  shallow  liquefaction  has  occurred  beneath 
the  superficial  colonies,  in  watch-glass  form,  and  about  two  millimetres  in 
diameter ;  under  the  microscope  a  central  mass  of  a  straw- yellow  color  is  seen, 
around  this  a  narrow,  light-brown  zone  with  granular  contents,  and  outside 
of  this  a  broader  peripheral  zone,  from  which  fine,  radiating  outgrowths  are 
given  off  into  the  non-liquefied  gelatin.  At  the  same  time  (forty-eight  hours) 
the  deep  colonies  have  a  diameter  of  0.3  to  0.45  millimetre  and  a  more  or  less 
polygonal  contour;  they  are  straw-yellow  in  color  and  consist  of  a  finely 
granular  central  mass,  surrounded  by  a  slender,  marginal  zone  which  is 
marked  by  radial  striations.  After  complete  liquefaction  of  the  gelatin  the 
colonies,  which  remain  attached  to  the  glass  plate,  have  a  lemon-yellow  color. 
In  gelatin  stick  cultures  (six  per  cent)  liquefaction  occurs  beneath  the  super- 
ficial layer  which  is  developed,  in  form  of  a  shallow  watch  glass,  and 
gradually  extends  in  diameter  and  depth;  growth  also  occurs  along  the  line 
of  puncture,  and  the  cultures  resemble  those  of  Bacillus  cyaneo-phosphores- 
cens,  but  with  less  rapid  development  and  liquefaction  of  the  gelatin ;  also 
without  the  formation  of  hair-like  outgrowths  into  the  non-liquefied 
gelatin.  The  addition  of  2.7  per  cent  of  sodium  chloride  is  favorable  for  the 
development  of  this  as  for  the  previously  described  species  of  phosphorescent 
bacilli;  on  the  other  hand,  the  addition  of  two  per  cent  of  glucose  exercises 
a  restraining  influence  upon  the  growth  of  all  the  species  studied  by  Katz. 
In  bouillon  a  diffuse  cloudiness  is  produced  by  the  growth  of  this  bacillus, 
and  a  mycoderma  is  formed  upon  the  surface.  No  growth  occurs  in  simple 
meat  infusion,  but  an  abundant  development  when  2.5  per  cent  of  sodium 
chloride  is  added  to  this.  Upon  sterilized  fish  a  shining,  sticky,  yellowish- 
gray  layer  is  developed.  No  growth  upon  potato. 

343.   BACILLUS  PHOSPHORESCENS  INDICUS  (Fischer). 

Found  in  sea  water  from  the  Gulf  of  Mexico. 

Morphology. — Bacilli  with  rounded  and  pointed  ends,  from  two  to  three 
times  as  long  as  broad;  length  from  one-sixth  to  one-quarter  the  diameter 
of  a  red  blood  corpuscle ;  solitary  or  in  pairs ;  also  in  short  filaments. 

Stains  readily  with  the  aniline  colors,  but  unstained  places  are  often  seen 
in  the  interior  of  the  rods. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Cultures,  especially  upon  animal  substances  and 
in  presence  of  certain  soda  salts,  exhibit  a  decided  phosphorescence  in  the 
dark  ;  this  depends  upon  free  access  of  air,  and  is  most  marked  at  a  tem- 
perature of  25°  to  30°  C.  It  is  no  longer  manifested  at  a  temperature  of 
0°  C.,  and  is  neutralized  by  putrefaction.  Grows  in  the  usual  culture  media 
at  the  room  temperature — not  so  well  in  the  incubating  oven.  Upon  gelatin 
plates,  at  the  end  of  thirty-six  hours,  small,  round,  grayish- white,  punctiform 
colonies  are  developed ;  under  a  low  power  these  are  seen  to  be  spherical, 
with  well-defined  outlines,  and  have  a  sea-green  color  with  a  pink  shimmer; 
later  they  become  granular,  have  a  wavy  outline  and  a  dirty-yellow  color. 
In  gelatin  stick  cultures,  at  the  end  of  four  days,  a  grayish-white  line  of 


NON-PATHOGENIC  BACILLI.  063 

growth  is  seen  along1  the  track  of  the  inoculating  needle,  and  at  the  surface 
a  cup-shaped  depression,  the  size  of  a  hempseed,  which  contains  air;  in  older 
cultures  the  gelatin  is  liquefied  near  the  surface  and  a  thin,  dirty-yellow  film 
swims  upon  it.  Upon  the  surface  of  agar  a  grayish-white  layer  is  devel- 
oped. Upon  potato,  at  15°  to  20°  C.,  a  thin  and  broad  white  layer.  Upon 
blood  serum  a  narrow,  grayish-white  stripe,  which  extends  to  a  tolerably 
deep  channel,  with  irregular  margins,  from  0.5  to  1  centimetre  wide;  this  is 
lined  with  a  slimy,  grayish-white  growth.  Cooked  fish  or  flesh  constitutes 
a  favorable  medium  for  the  growth  of  this  bacillus.  By  means  of  the  phos- 
phorescent light  given  off  by  cultures  of  this  bacillus,  Fischer  has  succeeded 
in  making  photographs  not  only  of  the  cultures,  but  of  a  watch  dial  placed 
between  two  cultures — an  exposure  of  twenty-four  hours'  duration  and  a 
very  sensitive  dry  plate  were  required  to  accomplish  this. 

344.   BACILLUS  PHOSPHORESCENS  INDIGENUS   (Fischer). 

Found  in  sea  water  from  the  harbor  at  Kiel  and  upon  phosphorescent 
herring. 

Morphology. — Bacilli  with  round  and  slightly  pointed  ends;  somewhat 
shorter  than  Bacillus  phosphorescent  Indicus,  but  of  the  same  thickness — 
from  1.3  to  2.1  u  long  and  0.4  to  0.7  /*  broad;  solitary  or  in  pairs;  may  grow 
out  into  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Cul- 
tures give  off  a  bluish- white,  phosphorescent  light — not  so  intense  as  that 
from  Bacillus  phosphorescens  Indicus ;  phosphorescence  depends  upon  free 
access  of  oxygen.  Sea  water  to  which  a  small  amount  of  a  culture  is  added 
is  phosphorescent  in  the  dark  Spore  formation  not  observed.  Grows  at  the 
room  temperature  in  the  usual  culture  media— more  slowly  than  Bacillus 
phosphorescens  Indicus.  Grows  at  5°  to  10°  C.,  and  even  below;  at  a  tem- 
perature of  32°  C.  development  still  occurs,  but  the  cultures  do  not  exhibit 
phosphorescence.  Upon  gelatin  plates  the  gelatin  is  depressed  about  the 
small  spherical  colonies,  and  at  the  end  of  a  week  cylindrical  cavities  filled 
with  air,  and  not  more  than  one  millimetre  in  diameter,  are  formed  in  the 
gelatin ;  at  the  bottom  of  these,  on  the  surface  of  the  plate,  the  colonies  are 
seen ;  these  are  the  size  of  a  pin's  head,  thin,  disc-formed,  and  dirty  yellow  in 
color ;  under  a  low  power  very  young  colonies  are  seen  to  be  circular,  with 
well-defined  margins,  and  of  a  pale  sea-green  color;  here  and  there  reddish- 
shimmering  granules  are  seen  in  the  otherwise  homogeneous  contents ;  the 
older  colonies  are  made  up  of  irregular,  dirty  yellowish-gray  masses.  In 
gelatin  stick  cultures,  at  the  end  of  a  week,  a  conical  cavity  forms  near  the 
surface,  which  is  filled  with  air  and  is  lined  with  a  thin,  friable  growth;  at 
the  surface  the  mouth  of  the  cone  measures  about  two  millimetres  in  diame- 
ter; this  cavity  increases  in  dimensions  without  containing  any  liquefied 
gelatin;  in  old  cultures  it  may  be  three  to  five  millimetres  in  diameter  and 
two  to  three  centimetres  deep,  the  walls  being  covered  with  a  thin  layer  of 
bacilli,  and  a  mass  of  the  same  accumulating  at  the  bottom.  No  growth 
occurs  upon  potato  or  upon  blood  serum. 

345.  BACILLUS  CIRCULANS  (Jordan). 

Found  occasionally  in.  water  from  the  Merrimac  Eiver. 

Morphology. — Bacilli  with  round  ends,  from  2  to  5  n  long  and  about  1 
H  broad ;  usually  solitary,  but  sometimes  in  loosely  connected  chains  of 
three  or  four  elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Forms  oval  spores,  which  are  located  at  the  ends  of 
the  rods  and  are  of  about  the  same  diameter  as  these.  Grows  in  the  usual 
culture  media  at  the  room  temperature — better  at  37°  C.  Upon  gelatin 
plates,  at  the  end  of  two  days,  round,  brownish  colonies  become  visible ; 
under  a  low  power  the  liquid  contents  of  these  colonies  are  seen  to  be  in  mo- 


664  NON-PATHOGENIC  BACILLI. 

tioii,  owing  to  the  active  movements  of  the  individual  bacteria;  the  motion 
may  be  compared  to  the  circulation  of  protoplasm  in  a  cell ;  this  is  seen  after 
forty-eight  hours  of  growth,  but  ceases,  as  a  rule,  on  the  third  day,  at  which 
time  the  contents  are  seen  to  be  coarsely  granular ;  a  round,  deep,  even  de- 
pression is  formed  in  the  gelatin,  which  at  the  end  of  several  weeks  may 
have  a  diameter  of  a  centimetre;  the  contour  of  the  colonies  is  usually 
smooth,  but  may  be  somewhat  lobate  and  irregular.  In  gelatin  stick  cul- 
tures development  is  slow  along  the  upper  part  of  the  line  of  puncture,  and 

a  conical-shaped  cavity  is  formed,  at  the  bot- 
tom of  which  a  precipitate  accumulates,  while 
above  the  conical  cavity  is  empty  owing  to  the 
slowness  of  growth  and  drying-up  of  the  liq- 
uefied gelatin.  The  upper  part  of  the  cone 
often  has  a  somewhat  ringed  appearance.  This 
bacillus  grows  well  in  a  slightly  acid  medium. 
Upon  the  surface  of  agar  development  occurs 
along  the  line  of  puncture,  and  a  very  thin, 
translucent  layer  is  formed  upon  the  surface. 
Upon  potato  a  slow  and  scanty  growth  having 
about  the  same  color  as  the  cut  surface  of  the 
potato.  In  milk  a  slightly  acid  reaction  oc- 
curs and  the  casein  is  slowly  precipitated; 
FIG.  219.  —  Bacillus  circulans,  after  cultivation  for  several  months  the  bacil- 
from  an  agar  culture  five  days  old.  lus  no  longer  caused  coagulation  of  milk.  In 
x  1,000.  (Jordan.)  bouillon  a  cloudiness  is  seen  at  the  end  of  three 

or  four  days,  and  a  considerable  slimy  preci- 
pitate is  formed ;  no  film  forms  upon  the  surface.  Nitrates  are  slowly  re- 
duced to  nitrites  by  this  bacillus. 

346.  BACILLUS  SUPERFICIALIS  (Jordan). 

Found  frequently  in  sewage  at  Lawrence,  Mass. 

Morphology. — Bacilli  with  round  ends,  about  2.2  ft  long  and  1  n  broad ; 
solitary  or  in  pairs. 

Biological  Characters. — Anaerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  at  the  room  temperature  in  the  usual  cul- 
ture media— better  at  37°  C.  Upon  gelatin  plates  colonies  become  visible  at 
the  end  of  forty-eight  hours;  under  a  low  power  they  are  seen  to  be  divided 
by  irregular  lines  into  angular  lumps,  giving  a  cracked  appearance  to  the 
whole  colony,  which  is  irregularly  spherical  in  form.  Upon  coming  to  the 
surface  the  colonies  spread  out  to  form  a  round,  finely  granular  disc,  which 
to  the  naked  eye  looks  like  a  projecting,  translucent  drop;  this  slowly  in- 
creases in  dimensions,  and  the  surrounding  gelatin  is  slowly  liquefied ;  after 
some  days  the  colony  has  an  opaque,  yellowish-brown  centre  and  a  translu- 
cent edge.  In  gelatin  stick  cultures  there  is  a  very  scanty  growth  along  the 
line  of  puncture  and  more  abundant  development  upon  the  surface;  lique- 
faction proceeds  slowly,  and  by  the  end  of  ten  days  may  reach  the  walls  of 
the  test  tube.  This  bacillus  grows  well  in  acid  gelatin.  Upon  the  surface 
of  agar  a  moist,  lustrous,  gray,  translucent  layer  is  developed;  at  the  end  of 
several  weeks  this  growth  is  still  smooth  and  glistening,  and  has  a  light- 
brown  tint.  Does  not  grow  upon  potato.  Does  not  cause  coagulation  of 
milk,  which,  however,  acquires  a  slightly  acid  reaction.  In  bouillon  a  dif- 
fuse cloudiness  is  slowly  developed,  and  after  some  time  a  scanty  white 
sediment  is  seen ;  no  film  forms  upon  the  surface. 

347.  BACILLUS  RETICULARIS  (Jordan). 

Found  in  water  at  Lawrence,  Mass. 

Morphology.—  Bacilli  with  slightly  rounded  ends,  about  5  n  long  and  1 
/u  broad ;  often  united  in  chains  of  eight  to  ten  elements. 


NON-PATHOGENIC   BACILLI.  665 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Motion  slow  and  sinuous.  Grows  at  the  room 
temperature  in  the  usual  culture  media — much  better  at  37°  C.  Upon  gela- 
tin plates  the  deep  colonies  send  out  long,  spiral  filaments,  which  give  a  hazy 
appearance  to  the  colony ;  under  a  low  power  the  colony,  surrounded  by  ra- 
diating filaments,  resembles  a  jelly-fish  with  streaming  tentacles;  the  sur- 
rounding gelatin  is  slowly  liquefied.  Oncoming  to  the  surface  the  colony 
spreads  out  as  an  irregular  expansion,  under  which  the  gelatin  is  slowly 
liquefied,  and  at  the  same  time  dried  out  so  as  to  form  shallow,  cup-shaped 
depressions.;  the  surface  of  these  cavities  is  mottled  in  appearance,  as  if  cov- 
ered with  a  fine,  irregular  reticulation.  In  gelatin  stick  cultures,  at  the  end 
of  two  days,  the  growth  at  the  surface  resembles  a  cup  with  flaring  edges  ; 
liquefaction  occurs  slowly,  and  the  liquefied  gelatin  is  dried  by  evaporation, 
so  that  the  cup-shaped  cavity  gradually  increases  in  dimensions ;  it  is  lined 
with  a  reticulated  growth  similar  to  that  seen  in  the  colonies  upon  gelatin 
plates ;  at  the  end  of  three  days  fine  filaments  begin  to  grow  out  from  the  line 
of  puncture,  but  these  do  not  reach  any  considerable  length.  This  bacillus 
exhibits  a  scanty  development  under  a  mica  plate.  Upon  the  surface  of  agar 
,a  prominent,  dull,  dry  layer  is  slowly  developed.  Upon  potato  a  white, 
•dull,  dry  layer  is  developed  at  the  end  of  two  days,  and  at  the  end  of  five 
days  this  has  a  characteristic  woolly  appearance.  Milk  acquires  an  acid  re- 
.action  and  is  slowly -coagulated — fifteen  to  twenty  days  at  the  room  tempe- 
rature. Bouillon  slowly  becomes  turbid  and  a  slight  viscid  sediment  is 
formed.  Nitrates  are  rapidly  reduced  to  nitrites  by  this  bacillus. 

348.  BACILLUS  HYALINUS  (Jordan). 

Found  in  large  numbers  in  the  sand  of  Tank  13  at  Lawrence,  Mass.,  "at 
;a  time  when  the  tank  was  nitrifying  well.'' 

Morphology. — Bacilli  with  round  ends,  from  3. 6  to  4  /*  long  and  1.5  JJ. 
broad ;  usually  united  in  short  chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Spore  formation  not  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature — better  at  37°  C.  Upon  gelatin 
plates  the  colonies  are  visible  at  the  end  of  twenty-four  hours;  they  are  seen 
to  consist  of  a  dark  central  nucleus  surrounded  by  a  broad,  translucent  zone, 
which  gives  the  colonies  a  hazy  appearance ;  under  a  low  power  the  interior 
is  seen  to  present  a  coarsely  fibrillar  appearance,  with  short  fibrils  radiating 
from  the  edge.  In  two  days  the  colonies  attain  a  diameter  of  about  one  and 
one-half  centimetres;  they  are  round  in  contour,  with  a  distinct,  opaque, 
yellowish  margin,  from  which  radiating  fibrils  are  given  off ;  the  interior  is 
slightly  translucent.  In  gelatin  stick  cultures,  at  the  end  of  two  days,  a 
long  and  narrow,  funnel-shaped  growth  is  seen;  the  gelatin  is  rapidly  lique- 
fied and  is  at  first -clouded,  with  a  white  deposit  at  the  bottom  of  the  funnel; 
later  a  lustrous  and  tenacious  white  layer  is  seen  upon  the  surface  and  a 
slight  flocculent  deposit  at  the  bottom,  while  the  liquefied  gelatin  between 
is  entirely  transparent.  This  bacillus  grows  well  in  acid  gelatin.  Upon  the 
surface  of  agar  a  dry.,  grayish,  spreading  growth  is  rapidly  developed  ; 
when  four  or  five  days  old  small,  warty  projections  are  seen ;  growth  also 
occurs  along  the  line  of  puncture  in  agar  stick  cultures.  Upon  potato,  at 
the  end  of  two  days,  the  growth  is  just  visible;  at  the  end  of  four  days  a 
dry,  whitish-gray,  spreading  layer  is  developed;  later  small  protuberances 
.are  seen  upon  the  surface  of  this.  In  milk  a  strongly  acid  reaction  with  co- 
agulation of  the  casein  is  produced  in  seven  days.  In  bouillon  a  diffuse 
cloudiness  is  quickly  produced ;  a  viscid  sediment  is  formed  and  a  myco- 
derma  forms  upon  the  surface.  This  bacillus  reduces  nitrates  vigorously  and 
rapidly. 

349.  BACILLUS  CLOAC.E  (Jordan). 

Isolated  from  sewage  at  Lawrence,  Mass. — "one  of  the  most  common 
ibacteria  in  sewage." 


666  NON-PATHOGENIC   BACILLI. 

Morphology. — Short  oval  bacilli  with  round  ends,  from  0.8  to  1.9  /* 
long1  and  from  0.7  to  1  /*  broad;  frequently  united  in  pairs. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, actively  motile  bacillus.  Spore  formation  not  observed.  Grows  in- 
the  usual  culture  media  at  the  room  temperature — better  at  37°  C.  Upon 
gelatin  plates,  at  the  end  of  one  or  two  days,  spherical,  yellowish  colonies 
are  seen ;  upon  coming  to  the  surface  these  form  a  slight  bluish  expansion 
with  irregularly  notched  edges,  and  liquefaction  of  the  gelatin  quickly  oc- 
curs; under  the  microscope  the  colonies  are  seen  to  have  an  opaque  centre 
surrounded  by  a  translucent  zone  and  a  darker  margin ;  the  interior  is  finely 
granular ;  liquefaction  of  the  entire  plate  occurs  within  three  or  four  days. 
In  gelatin  stick  cultures  development  occurs  along  the  line  of  puncture,  and 
liquefaction  rapidly  occurs;  later  an  iridescent  film  is  seen  upon  the  surface 
of  the  gelatin  and  an  abundant  flocculent,  whitish  sediment  at  the  bottom  of 
the  tube.  This  bacillus  grows  well  in  slightly  acid  gelatin.  Upon  the  sur- 
face of  agar  a  moist,  slimy,  porcelain-white  layer  is  developed ;  an  abun- 
dant growth  also  occurs  along  the  line  of  puncture  in  agar  stick  cultures. 
Upon  potato  a  prominent,  yellowish-white  layer  is  quickly  formed.  In 
milk  coagulation  occurs  in  about  four  days,  with  a  strongly  acid  reaction . 
In  bouillon  a  diffuse  cloudiness  is  seen  at  the  end  of  two  days,  and  at  the  end 
of  ten  to  fourteen  days  an  abundant  whitish  sediment  is  seen ;  a  slight  film 
forms  upon  the  surface;  this  falls  to  the  bottom  when  the  tube  is  disturbed; 
the  bouillon  is  still  clouded  at  the  end  of  two  or  three  weeks.  This  bacillus 
reduces  nitrates,  in  bouillon,  vigorously. 

350.  BACILLUS  DELICATULUS  (Jordan). 

Found  in  the  water  supply  at  Lawrence,  Mass. 

Morphology.—  Bacilli  about  2  jo.  long  and  1  ju.  broad;  often  united  in 
pairs  or  in  short  chains. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacil- 
lus. Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at 
the  room  temperature — somewhat  better  at  37°  C.  Upon  gelatin  plates  the 
young  colonies  are  seen  as  whitish,  homogeneous  spheres  with  a  regular,  ra- 
diating margin ;  at  the  end  of  two  days  liquefaction  of  the  surrounding 
gelatin  occurs  In  gelatin  stick  cultures  liquefaction  progresses  rapidly 
along  the  line  of  puncture  and  is  complete  in  about  seven  days ;  a  thick, 
whitish  layer  is  then  seen  upon  the  surface,  and  an  abundant  flocculent, 
brownish  deposit  at  the  bottom  of  the  tube ;  the  liquefied  gelatin  remains 
clouded.  Grows  well  in  slightly  acid  gelatin.  Upon  the  surface  of  agar  a 
wrinkled,  grayish  layer  is  developed,  which  later  becomes  porcelain-white 
and  glistening ;  development  also  occurs  along  the  line  of  puncture  in  agar 
stick  cultures.  Upon  potato  a  thin,  spreading,  gray  layer  is  developed. 
Milk  acquires  a  strongly  acid  reaction  and  is  coagulated.  Bouillon  quickly 
becomes  clouded ;  a  white  film  forms  upon  the  surface  and  a  white  deposit 
is  seen  at  the  bottom  of  the  tube.  Nitrates  are  quickly  and  completely  re- 
duced to  nitrites  by  this  bacillus.  Does  not  grow  at  a  temperature  below 
15°  C. ,  and  quickly  dies  out  in  artificial  culture  media— in  a  few  weeks. 

351.  BACILLUS  AQUATILIS  (Frankland). 

Found  in  water — often  almost  the  only  microorganism  in  water  from  a 
deep  well  in  the  chalk  formation  at  Kent. 

Morphology. — Bacilli  about  2. 5  y«  in  length;  grow  out  into  filaments  of 
17  /*  or  more  in  length — resembles  Bacillus  arborescens  (Frankland). 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Ex- 
hibits oscillatory  movements  only.  Spore  formation  not  observed.  Grows 
very  slowly  in  the  usual  culture  media  at  the  room  temperature.  Upon 
gelatin  plates  the  deep  colonies  are  at  first  smooth  in  outline,  later  the  mar- 


NON-PATHOGENIC  BACILLI. 


667 


gin  is  irregular;  when  the  colony  reaches  the  surface  a  very  slow  liquefac- 
tion of  the  gelatin  commences  and  the  appearance  of  the  colonies  becomes 
very  characteristic.  From  the  yellowish- brown  centre  twisted  bundles  of 
filaments  are  given  off  which  are  at  first  also  of  a  yellowish-brown  color, 
but  gradually  become  colorless  toward  the  periphery.  In  gelatin  stick  cul- 
tures development  is  extremely  slow ;  upon  the  surface  a  small,  yellowish 
mass  is  formed  at  the  point  of  puncture,  while  the  line  of  inoculation  is 
scarcely  visible ;  liquefaction  occurs  later  and  the  liquefied  gelatin  is  clouded ; 
when  liquefaction  has  once  commenced  it  progresses  more  rapidly.  Upon 
the  surface  of  agar  a  glistening,  yellowish  layer  is  developed  which  extends 
but  little  beyond  the  impfstrich.  In  bouillon  a  diffuse  cloudiness  is  pro- 
duced and  a  whitish  sediment  is  seen  at  the  bottom  of  the  tube;  no  film  is 
formed  upon  the  surface.  Upon  potato  scarcely  any  development  occurs — 
a  faint  yellowish  stripe  along  the  impfstrich  only.  Reduces  nitrates  with 
formation  of  ammonia. 


352.  BACILLUS  DIPFUSUS  (Frankland). 


broad;  solitary  or  in 


Found  in  the  soil. 

Morphology. — Bacilli  about  1.7  j^  long  and  0.5 
pairs;  also  grow  out  into  long,  flexible  filaments. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Exhibits  ro- 
tatory and  oscillatory  movements  only.  Spore  formation  not  observed. 
Grows  in  the  usual  culture  media  at  the  room  temperature.  Upon  gelatin 
plates  the  superficial  colonies  after  a  time  have  a  very  characteristic  ap- 
pearance; they  extend  from  the  original 
centre  as  a  broad, thin, bluish-green  layer. 
Under  a  low  power  the  deep  colonies  re- 
semble colonies  of  the  cholera  spirillum; 
they  are  nearly  sphei'ical,  coarsely  gran- 
ular, and  have  somewhat  jagged  mar- 
gins ;  later  the  margins  are  still  more  ir- 
regular and  finely  dentate,  while  the 
surface  near  the  margin  appears  coarsely 
granular;  when  the  colonies  come  to  the 
surface  the  centre  is  no  longer  well  de- 
fined, but  remains  granular,  while  about 
it  a  very  characteristic  surface  growth 
occurs.  In  gelatin  stick  cultures  the 
development  is  almost  limited  to  the  sur- 
face, upon  which  a  smooth,  thin,  shin- 
ing, somewhat  greenish-yellow  layer  is 
formed;  liquefaction  of  the  gelatin  be- 
neath this  progresses  very  slowly.  Upon 
the  surface  of  agar  a  very  thin,  shining,  smooth  layer  of  a  feebly  yellow 
or  cream  color  is  developed.  In  bouillon  a  diffuse  cloudiness  is  developed 
and  a  greenish-yellow  sediment  is  formed,  while  some  flocculi  may  float 
upon  the  surface,  which,  however,  do  not  constitute  a  film.  Upon  potato  a 
thin,  smooth,  shining,  faintly  greenish-yellow  layer  is  formed. 


FIG.  220.  FIG.  221. 

FIG.  220.— Bacillus  diffusus,  from  a  gela- 
tin culture.  X  1,000.  (Frankland.) 

FIG.  221.— Bacillm  diffusus;  superficial 
colonies  in  nutrient  gelatin.  X  100. 
(Frankland.) 


353.  BACILLUS  LIQUIDUS  (Frankland). 

Found  in  river  water  from  the  Thames ;  very  common. 

Morphology.— Short  and  thick  bacilli  with  round  ends;  usually  in  pairs, 
of  which  the  length  varies  from  1.5  to  3.5  M ;  differ  greatly  in  dimensions. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  at  the  room  temperature  in  the  usual  cul- 
ture media.  Upon  gelatin  plates  the  deep  colonies,  under  a  low  power,  are 
seen  to  be  spherical,  with  smooth  outlines ;  when  liquefaction  commences 


668  NON-PATHOGENIC  BACILLI. 

the  margin  becomes  somewhat  granular  and  jagged,  while  the  centre  re- 
mains opaque;  development  and  liquefaction  of  the  surrounding  gelatin 
progress  rapidly,  so  that  the  colonies  soon  coalesce.  In  gelatin  stick  cul- 
tures development  occurs  along  the  entire  line  of  puncture,  and  a  broad 
funnel  of  liquefied  gelatin  is  formed  in  the  course  of  a  few  days;  this  is 
clouded  and  contains  numerous  flocculi ;  later  the  surface  is  covered  with  a 
a  thin  film,  which  sinks  to  the  bottom  when  the  test  tube  is  shaken.  Upon 
the  surface  of  agar  development  also  occurs  rapidly,  forming  a  smooth, 
shining  layer  on  both  sides  of  the  impfstrich.  In  bouillon  a  diffuse  cloudi- 
ness is  developed ;  an  abundant  deposit  collects  at  the  bottom  of  the  tube, 
and  a  film  is  formed  upon  the  surface.  Upon  potato  a  thick,  flesh-colored 
layer  covered  with  protuberances  and  having  a  dull,  moist  surface.  This 
bacillus  reduces  nitrates  with  the  production  of  nitric  acid 

354.  BACILLUS  VERMICULARIS  (Frankland). 

Found  in  water  from  the  river  Lea. 

Morphology. — Bacilli  with  round  ends,  from  2  to  3  jn  long  and  1  u  broad; 
may  grow  out  into  ' '  worm-shaped  "  filaments.  Upon  potato  oval  spores  are 
formed;  these  are  about  1.5  u  long  and  1  ju  broad;  they  are  formed  in  the 
centre  of  the  rods,  and  remain  attached  to  each  other  in  chains  of  consider- 
able length. 

Biological   Characters. — An  aerobic,  liquefying  bacillus.     Exhibits  os- 
cillatory movements  only.     Forms  oval  spores.     Grows  slowly  in  the  usual 
culture  media  at  the  room  temperature.     Upon  gelatin  plates  the  deep  col- 
onies  have    a   somewhat   irregular 
contour ;  upon  the  surface  flat  colo- 

|^|       £r  nies  are  developed,  which  have  ir- 

J  Q.  ^K  regular  margins  composed  of  wavy 

^  bundles  of  bacilli  closely  crowded 

together;  the  centre  of   the  super- 
ficial  colonies  is  rough  and  wrinkled ; 
later  liquefaction  slowly  occurs  and 
Fio.  222.— Bacillus  vermicuiaris;  a,  from  a  ge-     the  colonies  sink  beneath  the  surface 

latin  culture;  b,  spore-bearing  filaments  from      of  the  gelatin.      In  gelatin  stick  cul- 

a  potato  culture,   x  i,ooo.   (Frankland..)  tares  a  moist,  shining,  gray  layer 

with  dentate   margins  is  developed 

upon  the  surface ;  this  does  not  extend  far  from  the  point  of  puncture ;  a 
scanty  growth  is  seen  along  the  line  of  puncture;  after  some  time  the  gela- 
tin commences  to  liquefy  beneath  the  surface  growth.  Upon  the  surface 
of  agar  a  smooth,  shining  layer  of  a  gray  color  is  slowly  developed.  In 
bouillon  the  liquid  remains  clear,  and  a  white,  flocculent  growth  is  seen 
at  the  bottom  of  the  tub.  Upon  potato  a  thick,  flesh-colored  layer  with 
irregular  outlines.  Eeduces  nitrates  to  nitrites. 

355.  BACILLUS  NUBILUS  (Frankland). 

Found  in  filtered  London  water. 

Morphology. — Bacilli  about  3  JLI  long  and  0.3  /n  broad;  solitary  or  in  short 
chains;  grow  out  into  long  filaments  in  bouillon  cultures — these  maybe 
twisted  in  spiral  form;  upon  potato  the  short  bacilli  are  often  curved,  and 
the  long  filaments  may  have  a  spiral  form. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing bacillus.  Exhibits  rotatory  movement's  without  change  of  location. 
Spore  formation  not  observed.  Grows  slowly  at  the  room  temperature  in 
the  usual  culture  media.  Upon  gelatin  plates  the  colonies  are  very  charac- 
teristic; at  the  end  of  forty -eight  hours  small  clouded  spots  are  seen,  which 
are  not  sharply  defined ;  under  the  microscope  these  are  seen  with  difficulty 
by  transmitted  light ;  on  the  third  day,  when  the-gelatin,  commences  to  be 


NON-PATHOGENIC  BACILLI.  GG9 

softened,  these  colonies  are  seen  to  consist  of  a  network  of  interlaced  fila- 
ments ;  at  the  centre  a  thicker  portion  is  often  seen  in  the  cloud-like  colonies 
of  interlaced  threads;  liquefaction  progresses  rapidly,  the  colonies  become 
confluent,  and  soon  the  plate  is  destroyed.  In  gelatin  stick  cultures  the 
gelatin  is  liquefied  upon  the  surface,  but  liquefaction  does  not  progress  rap- 
idly ;  the  liquefied  gelatin  is  clouded,  and  a  yellowish  deposit  accumulates 
at  the  bottom  of  the  liquefied  gelatin ;  along  the  line  of  puncture,  almost  to 
the  surface,  no  growth  is  seen,  but  around  it  a  row  of  flat,  horizontal  rings 
are  developed,  the  diameter  of  which  increases  from  above  downward;  the 
lower  end  of  the  line  of  puncture  is  uniformly  clouded ;  the  rings  described 
are  made  up  of  delicate,  cloud-like  masses ;  the  culture  somewhat  resembles 
that  of  the  bacillus  of  mouse  septicaemia;  liquefaction  progresses  slowly,  but 
finally  the  entire  amount  of  gelatin  is  liquefied.  Upon  the  surface  of  agar  a 
thin,  opalescent,  bluish-white  layer  is  formed,  the  fringed  margins  of  which 
show  a  violet  fluorescence.  In  bouillon  a  diffuse  cloudiness  is  developed, 
and  a  dirty- white  deposit  collects  at  the  bottom  of  the  tube,  while  a  very 
thin  film  collects  upon  the  surface ;  this  falls  to  the  bottom,  when  the  tube  is 
shaken.  Upon  potato  the  growth  is  almost  invisible  and  of  a  very  faint  yel- 
low color;  it  extends,  however,  over  a  great  portion  of  the  surface. 

356.  BACILLUS  PESTIPER  (Frankland). 

Found  in  the  air. 

Morphology. — Bacilli  with  round  ends,  2.3//  long  and  1  /*  broad;  often 
grow  out  into  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  slowly  at  the  room  temperature.  Upon 
gelatin  plates  forms  colonies  resembling  those  of  Bacillus  vermicularis,  but 
the  deep  colonies  are  more  regular  and  the  superficial  colonies  have  a  smooth 
centre.  Upon  the  surface  of  agar  a  shining,  transparent  layer  with  dentate 
margins.  Upon  potato  a  thick,  irregular,  flesh-colored  layer. 

357.    BACILLUS   FILIFORMIS    (Tils). 

Found  in  water. 

Morphology. — Bacilli  with  round  ends,  4  jn  long  and  1  u  broad ;  usually 
united  in  chains,  which  may  consist  of  as  many  as  ten  segments  which  are 
indistinctly  separated  from  each  other. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Exhibits  os- 
cillatory movements  only.  Forms,  in  potato  cultures,  large  oval  spores. 
Upon  gelatin  plates  grayish-white  colonies  are  developed  which  have  a 
marbled  structure;  under  a  low  power  the  deep  colonies  are  seen  to  be  finely 
granular  and  irregular  in  outline ;  the  superficial  colonies  have  a  dentate 
margin,  which  is  composed  of  many  bundles  of  bacilli  closely  crowded  to- 
gether; the  centre  is  somewhat  rough,  elevated,  and  granular;  the  colonies 
are  colorless  at  the  margin,  but  have  a  yellowish  color  at  the  (^nti-e;  at  the 
end  of  eight  to  ten  days  liquefaction  commences  and  the  colonies  sink  slowly 
beneath  the  surface.  In  gelatin  stick  cultures  a  moist  layer  with  deeply 
dentate  margins  forms  around  the  point  of  puncture;  the  gelatin  is  slowly 
liquefied  and  thick,  flocculent  masses  of  bacilli  accumulate  at  the  bottom. 
In  bouillon  growth  occurs  chiefly  upon  the  surface  in  the  form  of  a  firm  my- 
coderma.  Upon  the  surface  of  agar  a  white  layer  is  developed  like  that 
upon  gelatin.  Upon  potato  a  thick,  slimy,  dirty- white  layer,  which  later 
becomes  dry  and  acquires  a  gray  or  brownish  color.  In  milk  coagulation 
occurs  at  the  end  of  tliirty-six  hours,  and  an  odor  of  putrefaction  is  perceived. 

358.  BACILLUS  DEVORANS  (Zimmermann). 

Found  in  well  water. 

Morphology. — Bacilli  with  round  ends,  from  0.09  to  1.2  /*  long  and  about 
0.74 //  thick;  solitarv,  in  pairs,  or  occasionally  in  short  chains. 
57 


670  NON-PATHOGENIC   BACILLI. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Spore  formation  not  observed.  Grows  at  the 
room  temperature  in  the  usual  culture  media.  Upon  gelatin  plates  the  dee}) 
colonies  appear  as  small,  white  spheres ;  the  superficial  colonies  are  seen  as 
round,  white,  not  homogeneous  masses  at  the  bottom  of  a  funnel  of  lique- 
fied gelatin;  under  a  low  power  they  have  a  granular-thready  structure 
and  yellowish-gray  color,  and  the  margins  are  surrounded  by  thread-like 
processes  of  various  lengths.  In  gelatin  stick  cultures  growth  is  visible 
along  the  line  of  puncture  at  the  end  of  twenty-four  hours;  on  the  second 
or  third  day  an  air  bubble  is  seen  at  the  upper  portion  and  a  whitish  growth 
below;  the  funnel-shaped  cavity  gradually  extends  in  dimensions  without  a 
trace  of  liquid  being  seen,  and  the  growth  is  distributed  upon  the  walls  and 
at  the  bottom  of  this  cavity ;  often  liquefaction  occurs.  Upon  the  surface  of 
agar  a  thin,  uniform,  gray  layer  is  developed,  which  covers  the  entire  sur- 
face at  the  end  of  two  or  three  days.  No  growth  upon  potato. 

359.  BACILLUS  GRACILIS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology.— Long  bacilli  with  round  ends,  usually  more  or  less  curved, 
from  2.4 to  3.6  fj,  long  and  about  0.77  ju  broad;  grow  out  into  long  filaments, 
which  are  bent  at  an  angle  or  present  several  wave-like  curves. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing bacillus.  Forms  oval  spores  1.83  //  long  and  1.3  fi  broad.  Exhibits  ro- 
tatory and  oscillatory  movements  only.  Grows  slowly  at  the  room  tempe- 
rature— not  in  the  incubating  oven.  Upon  gelatin  plates  the  deep  colonies 
appear  as  small,  grayish-white  spheres,  which  at  first  are  well  defined,  but 
later  have  very  indistinct  outlines;  under  a  low  power  they  are  first  seen  as 
sharply  defined,  pale-yellow  discs,  which  are  gradually  surrounded  by  nu- 
merous thread-like  outgrowths,  which  after  a  time  form  a  thick  network. 
Upon  the  surface  there  is  no  development  or  small,  yellowish-gray,  drop-like 
colonies  are  seen ;  at  the  end  of  five  days  these  attain  a  diameter  of  four  to 
six  millimetres  and  are  circular  in  outline ;  the  centre  is  round,  nebulous, 
and  bluish-gray,  and  outside  of  this  one  or  two  concentric,  nebulous  rings 
are  seen.  In  gelatin  stick  cultures  there  is  a  scanty  growth  upon  the  sur- 
face, often  appearing  as  an  opalescent  film,  or  the  superficial  layer  of  the 
gelatin  is  penetrated  by  radiating  lines  given  off  from  centres  of  growth 
which  do  not  extend  above  the  surface.  Along  the  line  of  puncture  a  row 
of  whitish  discs  is  developed  which  are  largest  above ;  at  the  end  of  three 
to  five  weeks  the  upper  portion  of  the  gelatin  is  liquefied  to  some  extent. 
Upon  the  surface  of  agar  a  thin,  irregular  layer  of  a  bluish- white  color  is 
developed ;  an  abundant  growth  occurs  along  the  line  of  puncture  in  agar 
stick  cultures.  Upon  potato  the  development  is  very  scanty. 

*360.  BACILLUS  GUTTATUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  with  round  ends,  from  1  to  1.13  n  long  and  0.93  n 
broad ;  at  first  solitary  or  in  pairs,  later  united  in  chains  containing  several 
elements. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  mottle  bacillus.  Appears  to  form  spherical  spores  (?).  Grows 
best  at  the  room  temperature.  Upon  gelatin  plates  the  deep  colonies  are 
small,  grayish- white  spheres;  under  a  low  power  these  are  seen  to  be  finely 
granular  and  have  a  gray  or  bluish-brown  color.  The  superficial  colonies 
appear  as  bluish-gray  drops ;  under  the  microscope  a  brownish  shimmer  is 
observed  at  the  centre,  while  the  sharply  defined  margins  are  colorless  and 
are  distinguished  from  the  surrounding  gelatin  only  by  being  less  transpa- 
rent; later  the  outline  sometimes  becomes  irregular.  In  gelatin  stick  cul- 
tures an  irregular,  bluish-white,  shining  layer  is  developed,  the  surface  of 


NON-PATHOGENIC  BACILLI.  071 

which  is  frequently  opalescent ;  an  abundant  development  occurs  along  the 
line  of  puncture,  consisting1  of  a  series  of  spherical  colonies :  liquefaction  oc- 
curs after  a  considerable  time — four  weeks.  Upon  the  surface  of  agar  a 
thin,  grayish-white  layer  is  developed  along  the  iinpfstrich.  Upon  potato  a 
tolerably  abundant  slimy,  yellowish-green  layer. 

361.  BACILLUS  IMPLEXUS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  with  blunt  ends,  about  2.5  ju.  long  and  1.15  //  broad; 
form  long,  jointed  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile  bacillus. 
Forms  oval  spores  about  1.6  n  long  and  0.95  /u  thick.  Grows  at  the  room 
temperature — more  quickly  at  30°  C.  Upon  gelatin  stick  cultures,  at  the 
end  of  twenty-four  to  thirty-six  hours,  whitish,  punctiform  colonies  become 
visible;  under  a  low  power  these  are  seen  to  be  granular,  opaque,  and  ir- 
regular in  outline — more  transparent  toward  the  margin ;  under  a  higher 
power  (1  : 175)  filaments  are  seen  which  are  interwoven ;  these  grow  out 
from  the  margins  and  again  become  contorted  and  interlaced ;  at  the  end  of 
three  days  the  round  colony  sinks  into  the  liquefied  gelatin  and  appears  then 
as  an  interlaced  mass  of  fine  white  filaments.  In  gelatin  stick  cultures 
growth  is  visible  along  the  line  of  puncture  at  the  end  of  twenty -four  hours, 
and  at  the  end  of  seventy-two  hours  bundles  of  short  threads  radiate  into 
the  gelatin  in  all  directions;  liquefaction  soon  occurs,  which  quickly  reaches 
the  walls  of  the  test  tube  at  the  surface;  a  thick,  white  layer  forms  upon  the 
surface  of  the  liquefied  gelatin,  and  it  is  filled  below  with  white  flocculi. 
Upon  the  surface  of  agar  a  tolerably  thick,  white  layer  is  formed  which  has 
a  dull,  shagreen-like  surface  and  soon  becomes  wrinkled.  Upon  potato  a 
yellowish  or  greenish- white,  felt-like  layer  is  formed. 

362.  BACILLUS  PUNCTATUS  (Zimmermann). 

Common  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  from  1  to  1.60 /i  long — when  in  rapid  multiplica- 
tion— and  0.77  f*  broad;  solitary,  in  pairs,  or  in  chains  containing  several 
elements.  Do  not  stain  readily  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacillus. 
Spore  formation  not  observed.  Grows  rapidly  at  the  room  temperature  — 
still  better  at  30°  C.  Upon  gelatin  plates  the  colonies,  on  the  third  day,  al- 
ready have  a  diameter  of  twelve  millimetres  and  have  caused  a  saucer- 
shaped  liquefaction  of  the  gelatin ;  in  the  grayish-blue  liquid  whitish,  punc- 
tiform collections  of  bacteria  are  seen,  which  are  often  united  with  each 
other  by  whitish  strings.  In  gelatin  stick  cultures  liquefaction  occurs  in . 
stocking  shape;  the  liquefied  gelatin  is  uniformly  clouded,  and  an  abundant 
white  deposit  accumulates  at  the  bottom  of  the  tube.  Upon  the '  surface  of 
agar  a  delicate,  gray,  glistening  layer  with  a  perfectly  smooth  surface  is 
developed.  Upon  potato  an  abundant  brownish  or  flesh-colored  layer  soon 
extends  over  the  entire  surface;  gradually  this  acquires  a  darker  hue. 

363.  BACILLUS  RADIATUS  AQUATILIS  (Zimmermann). 

Found  in  the  Chemnitz  water  supply. 

Morphology. — Bacilli  about  0.65  n  broad  and  from  1  to  0.5  fj.  long. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  The  shortest 
rods  only  exhibit  slight  movements.  Spore  formation  not  observed.  Grows 
best  at  the  room  temperature  Upon  gelatin  plates,  at  the  end  of  two  days, 
irregular,  bluish-white  colonies  are  seen,  which  often  have  a  white  point  in 
the  middle;  under  the  microscope  the  colonies  have  a  root-like  appearance, 
being  surrounded  by  simple  and  branching  mycelial-like  offshoots;  at  the 


G73  NON-PATHOGENIC  BACILLI. 

end  of  three  days  these  colonies  are  nearly  spherical,  and  under  the  microscope 
resemble  1  ittle  balls  of  wool,  from  the  margins  of  which  fine  filaments  are  given 
otf ;  finally  they  break  through  the  gelatin  and  appear  upon  the  surface  as 
one  or  more  small,  transparent  droplets.  At  the  end  of  four  days  the  gelatin 
is  liquefied  in  saucer  shape;  in  the  middle  is  seen  a  yellowish- white  or  cream- 
colored  mass ;  around  this  a  ring  of  a  still  deeper  color,  and  from  this  deli- 
cate offshoots  radiate  toward  the  periphery  of  the  saucer-shaped  cavity.  In 
gelatin  stick  cultures  a  thin,  round  layer  appears  upon  the  surface,  which 
is  often  delicately  wrinkled  in  a  radial  direction  ;  below  development  occurs 
along  the  line  of  puncture  in  the  form  of  a  slender  funnel,  and  011  the  third 
day  liquefaction  commences ;  a  yellowish  deposit  collects  at  the  bottom  of 
the  liquefied  gelatin,  which  is  clouded  throughout  and  contains  numerous 
flocculi  of  various  dimensions.  Upon  the  surface  of  agar  a  smooth,  glis- 
tening layer  is  developed,  which  is  yellowish-brown  by  transmitted  light 
and  pale  bluish-green  by  reflected  light.  Upon  potato  an  ochrous-yellow 
layer  is  formed,  which  may  have  a  reddish-brown  tint. 

364.  BACILLUS  VERMICULOSUS  (Zimmermann). 

Found  in  water. 

Morphology. — Bacilli  with   round  ends,    1.5  ju   long  and  about  0  85  /j. 
broad ;  united  in  pairs  or  chains  of  three,  or  in  long,  worm-like  filament 
in  which  segmentation  is  very  indistinct;  the  bacilli  are  surrounded  by  a 
slimy  envelope. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  The  smaller 
rods  exhibit  a  rotatory  or  oscillating  motion.  Spore  formation  not  observed. 
Grows  slowly  at  the  room  temperature— better  at  25°  to  30°  C.  Upon  gela- 
tin plates  the  deep  colonies  appear  as  small,  white  spheres ;  under  a  low 
power  they  are  seen  to  be  nearly  round,  well  defined,  gray,  and  granular. 
The  superficial  colonies  are  flat,  gray,  drop-like  discs;  under  a  low  power 
they  are  seen  to  be  irregular  in  outline,  with  a  wavy  or  bulging  contour; 
the  interior  is  marked  with  paler  lines,  which  cross  each  other  in  various  di- 
rections, dividing  the  colony  into  mesh-like  fields;  later  this  appearance  is 
only  seen  at  the  margin.  In  gelatin  stick  cultures  a  pale-gray,  viscid  layer 
with  finely  notched  margins  is  developed  upon  the  surface ;  after  the  fourth 
day,  when  this  has  attained  a  diameter  of  about  seven  millimetres,  liquefac- 
tion commences  and  the  superficial  growth  becomes  depressed ;  liquefaction 
extends  slowly  toward  the  walls  of  the  tube,  and  very  slowly  in  a  down- 
ward direction,  until  about  one-third  of  the  gelatin  is  liquefied ;  at  the  bot- 
tom of  this  clouded  liquid  an  abundant  reddish-gray  sediment  is  formed. 
Upon  the  surface  of  agar  a  flat,  smooth,  glistening  layer  is  developed ;  later 
the  surface  of  this  is  opalescent.  Upon  potato  an  abundant  yellowish-gray, 
shining  layer  is  formed. 

365.   BACILLUS  AEROPHILUS  (Liborius). 

Found  as  an  accidental  contamination,  probably  from  the  air. 

Morphology. — Slender  rods  of  various  lengths,  about  two-thirds  as  thick 
as  Bacillus  subtilis;  frequently  united  in  jointed  filaments. 

Biological  Characters. — A  strictly  aerobic,  liquefying,  non-motile  ba- 
cillus. Forms  oval  spores.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Upon  gelatin  plates  small,  punctiform  colonies  are  developed 
at  the  end  of  forty  hours;  under  alow  power  these  are  seen  to  be  oval  or 
pear-shaped,  well  defined,  and  of  a  yellowish-gray  color;  liquefaction  quick- 
ly occurs  and  the  colonies  do  not  increase  materially  in  size.  In  gelatin  stick 
cultures  a  broad,  sac-like  channel  of  liquefaction  is  formed,  the  upper  part 
of  the  liquefied  gelatin  is  opaque  and  yellowish-gray,  while  the  lower  portion 
is  clearer  simply  contains  suspended  flocculi.  Upon  potato  a  yellowish 
layer  is  formed;  this  has  a  dull,  smooth  surface  and  a  paraffin-like  lustre; 


NON-PATHOGENIC   BACILLI.  (j^o 

later  it  becomes  drier  at  the  periphery,  slightly  granular,  and  has  a  striped 
appearance. 

36G.    BACILLUS   MYCOIDES    (Fltigge). 

Found  in  the  soil  and  in  water — common. 

Morphology. — Bacilli  from  1.6  to  2.4  /*  in  length  and  about  0. 9  /*  thick; 
usually  in  long  filaments,  which  when  stained  are  seen  to  be  made  up  of 
separate  elements ;  as  a  rule,  the  long  filaments  are  united  in  tangled  bun- 
dles. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
elliptical  spores  from  1.3  to  1.48  n  long  and  from  0.74  to  0  9  u  broad.  Grows 
very  rapidly — best  at  the  room  temperature.  Upon  gelatin  plates  the  colo- 
nies first  appear  as  cloudy,  white  spots,  in  which  fine,  white,  interlaced 
threads  are  soon  developed;  very  soon  a  mycelial-like  branching  occurs, 
giving  the  colony  the  appearance  of  the  commencing  growth  of  a  microsco- 
pic fungus ;  as  long  as  the  bundles  of  filaments  remain  beneath  the  surface 
of  the  gelatin  they  are  delicate  and  slender,  but  when  they  reach  the  surface 
they  spread  out,  lose  their  sharply  defined  outlines,  and  liquefy  the  gelatin. 
In  gelatin  stick  cultures,  at  the  end  of  eighteen  hours,  a  superficial  layer  of 
about  four  millimetres  in  diameter  has  formed  and  already  commences  to 
sink  in  the  gelatin;  on  the  third  day  liquefaction  has  reached  the  walls  of 


FIG.  233.  FIG.  224. 

FIG.  223. — Bacillus  mesentericus  vulgatus,  from  a  culture  in  bouillon,    x  1,000.    (VignalO 
FIG.  224.— Bacillus  mesentericus  vulgatus,  from  an  agar  culture.    X  1,400.    (Vignal  ) 

the  test  tube,  and  from  the  line  of  puncture  a  branching,  filamentous  growth 
is  given  off;  liquefaction  extends  downward  from  the  surface,  and  after  the 
tenth  day  the  bacterial  growth  is  seen  suspended  in  the  liquefied  gelatin. 
Upon  the  surface  of  agar  a  mycelial-like,  branching  growth  develops  along 
the  line  of  inoculation.  Upon  potato,  at  the  end  of  twenty-four  hours,  a 
whitish-gray,  shining  layer,  about  three  millimetres  broad,  is  developed;  at 
the  end  of  forty-eight  hours  this  has  extended  over  the  entire  surface. 

367.    BACILLUS   MESENTERICUS   VULGATUS. 

Synonym. — Potato  bacillus. 

First  found  upon  potatoes — a  common  and  widely  distributed  species  ; 
found  in  milk  by  Loftier,  in  the  Freiburg  water  supply  by  Tils,  in  the  ali- 
mentary tract  of  man  by  Vignal.  etc. 

Morphology. — Thick  bacilli  with  round  ends,  from  1.2  to  3.5  ju.  long;  often 
united  in  pairs,  or  in  chains  containing  several  elements. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Forms  spheri- 
cal spores.  Grows  rapidly  at  the  room  temperature— also  in  the  incubating 
oven.  Upon  gelatin  plates  the  colonies  are  at  first  almost  transparent,  blu- 
ish white,  later  with  an  opaque,  white  centre;  the  superficial  colonies  may 
attain  a  diameter  of  nearly  one  centimetre;  they  are  somewhat  sunken  in 
the  liquefied  gelatin ;  under  a  low  power  they  are  seen  to  be  granular  and 
have  rough  margins  ;  liquefaction  of  the  gelatin  is  rapidly  induced.  In 


674 


NON-PATHOGENIC  BACILLI. 


gelatin  stick  cultures  liquefaction  occurs  at  first  in  funnel  form  along  the 
line  of  inoculation,  and  rapidly  progresses  until  the  gelatin  is  entirely  lique- 
fied; numerous  grayish  flocculi  are  seen  in  the  liquefied  gelatin,  and  a  deli- 
cate, grayish-white,  wrinkled  layer  forms  upon  the  surface;  an  abundant 
flocculent  deposit  collects  at  the  bottom  of  the  tube.  Upon  the  surface  of 
agar  a  dirty-white  layer  is  developed.  Upon  potato  a  thick,  wrinkled, 
white  layer,  extending  over  the  entire  surface,  is  quickly  developed ;  this 
penetrates  the  substance  of  the  potato  and  is  extremely  viscid,  stringing  out 
into  long  threads  when  touched  with  the  platinum  needle.  Spores  are 
formed  in  the  bacilli  cultivated  upon  potato.  Upon  blood  serum  a  white 
layer  is  developed  and  liquefaction  of  the  medium  occurs.  Grows  in  bouil- 
lon containing  one  part  in  two  hundred  of  hydrochloric  acid  (Vignal).  In 
milk  causes  coagulation  of  the  casein,  which  is  subsequently  dissolved  and 
floats  upon  the  surface  as  a  slimy  layer  (Fliigge). 

368.   BACILLUS  MESENTERICUS  FUSCUS   (Flugge). 

Found  in  the  air,  in  hay  dust,  upon  potato,  and  in  water — a  common  and 
widely  distributed  species. 

Morphology. — Slender  and  short  bacilli,  often  in  pairs  or  in  chains  of  four. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacillus. 
Forms  small,  shining  spores  which  are  irregularly  distributed  in  the  rods. 
Grows  at  the  room  temperature.  Upon  gelatin  plates  forms  spherical, 
whitish  colonies,  which  under  a  low  power  are  seen  to  have  a  well-defined 
contour;  later  these  are  surrounded  by  delicate  offshoots,  have  a  yellowish- 
brown  color  and  a  finely  granular  surface  ;  liquefaction  of  the  gelatin 
quickly  occurs.  In  gelatin  stick  cultures  a  whitish  cloudiness  is  first  seen 
along  the  line  of  puncture,  and  at  the  same  time  liquefaction  commences 
near  the  surface  in  funnel  form;  this  extends  to  the  walls  of  the  tube  in 
from  four  to  six  days,  and  the  liquefied  gelatin  contains  numerous  grayish- 
white  flocculi.  Upon  potato,  at  the  end  of  twenty-four  hours,  a  smooth, 
yellowish  layer  is  developed ;  the  surface  of  this  soon  becomes  wrinkled  and 
brown  in  color ;  the  growth  is  comparatively  thin  and  does  not  penetrate 
deeply  into  the  potato,  as  is  the  case  with  Bacillus  mesentericus  vulgatus ; 
it  extends  rapidly  over  the  entire  surface. 

369.   BACILLUS  MEGATHERIUM   (De  Bary). 

First  found  upon  the  leaves  of  boiled 
cabbage. 

Morphology.  —  Bacilli  with  round 
ends,  about  2.5  ft,  thick  and  three  to  four 
times  as  long  as  broad ;  often  somewhat 
curved ;  forms  chains  containing  as  many 
as  ten  elements;  the  protoplasm  of  the 
cells  is  granular;  involution  forms  are 
common. 

Biological  Characters. — An  aerobic, 
liquefying,  motile  bacillus.  The  move- 
ments are  peculiar,  being  slow  and 
amoeboid  in  character.  Forms  long- 
oval  spores  which  are  nearly  as  long  as 
the  cells  containing  them,  but  not  so 
broad.  Grows  best  at  the  room  tempe- 
rature— also  in  the  incubating  oven. 
Upon  gelatinplates  forms  whitish,  puiic- 
tiform  colonies,  which  under  the  micro- 
scope are  yellowish  and  irregular  in 
form.  The  superficial  colonies  are  some- 
times kidney-shaped  or  crescentic ;  they 
cause  the  gelatin  to  be  slowly  liquefied.  In  gelatin  stick  cultures  lique- 


FIG.  225.— Bacillus  megatherium;  a, chain 
of  bacilli  (x  250);  6,  bacilli  (x  COO);  c-f 
shows  the  development  of  (spores ;  h-m 
shows  the  germination  of  spores;  p,  bacilli 
stained  with  solution  of  iodine.  (De  Bary.) 


NON-PATHOGENIC   BACILLI.  675 

faction  occurs  in  funnelform  along  the  upper  portion  of  the  line  of  inocu- 
lation and  gradually  extends  downward;  an  abundant  deposit  is  seen  at  the 
bottom  of  the  tube,  and  the  liquefied  gelatin  above  is  but  slightly  clouded ; 
no  mycoderma  forms  upon  the  surface.  Upon  the  surface  of  agar  a  whitish 
layer  is  developed  which  is  easily  separated  from  the  culture  medium.  Upon 
potato  a  thick,  cheesy,  yellowish-white  layer  is  quickly  developed  along  the 
line  of  inoculation ;  in  potato  cultures  an  abundant  development  of  spores 
occurs  and  involution  forms  are  common. 

370.  BACILLUS  ALBUS  PUTIDUS  (De  Bary). 

Found  in  water. 

Morphology. — Small  bacilli,  which  grow  out  into  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  rapidly  at  the  room  temperature.  Upon 
gelatin  plates  forms  thin,  round  colonies  upon  the  surface,  which  under  a 
low  power  are  light-brown  in  color  and  are  surrounded  by  a  transparent 
aureole  which  at  the  end  of  four  days  has  a  diameter  of  five  millimetres.  In 
gelatin  stick  cultures  development  occurs  both  on  the  surface  and  along  the 
line  of  puncture,  producing  rapid  liquefaction  of  the  gelatin;  gelatin  cul- 
tures give  off  an  intense  and  disagreeable  odor,  like  that  of  liquid  manure. 
Upon  the  surface  of  agar  a  smeary  layer  is  developed.  Upon  potato  a 
slimy  growth. 

371.  BACILLUS  BRASSic^E  (Pommer). 

Obtained  from  an  infusion  of  cabbage  leaves. 

Morphology. — Bacilli  from  1.9  to  5.4/t  Iongand0.91  tol  2 p  thick;  differ 
greatly  in  different  culture  media,  forming  sometimes  twisted  and  tangled 
filaments,  often  spiral  in  form,  and  producing  at  times  a  network  similar  to 
that  of  Bacterium  Zopfii ;  the  filaments  are  often  segmented  and  slightly 
notched  and  bent  at  the  points  where  the  segments  join. 

Biological  Characters. — Anaerobic  and  facultative  anaerobic,  liquefy- 
ing, non-motile  bacillus.  Forms  spores.  Grows  in  the  usual  culture  media 
at  the  room  temperature.  Upon  gelatin  plates  forms  colonies  which  resem- 
ble the  mycelium  of  a  mucor  and  cause  liquefaction  of  the  gelatin.  In  gela- 
tin stick  cultures  a  branching,  mycelial-like  growth  is  seen  along  the  line 
of  puncture,  in  funnel  form,  and  liquefaction  of  the  gelatin  quickly  occurs. 
Upon  the  surface  of  agar  a  layer  is  formed  consisting  of  spots  surrounded 
by  a  dull  cloudy  appearance ;  later  these  have  a  whitish  or  yellowish  color ; 
under  the  microscope  they  are  seen  to  consist  of  closely  lying  parallel  fila- 
ments, which  may  run  in  a  straight  or  serpentine  direction,  or  may  form 
circular  and  ellipsoidal  figures.  Along  the  line  of  puncture  in  agar  cultures 
small,  white  colonies  are  developed,  which  are  seen  under  the  microscope  to 
be  made  up  of  a  confused  mass  of  straight  or  curved,  short  filaments,  and  a 
network  of  filaments  is  given  off  from  these. 

372.    BACILLUS  BUTYRICUS   OF  HUEPPE. 

Found  in  imperfectly  sterilized  milk. 

Morphology. — Bacilli,  often  slightly  curved,  about  2.1  ft  long  and  0.38  M 
thick ;  may  grow  out  into  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Forms,  at  30°  C.,  oval  spores  which  are  lo- 
cated in  the  centre  of  the  rods.  Grows  at  the  room  temperature — more  rap- 
idly at  35°  to  40°  C.  Upon  gelatin  plates  deep-lying  colonies  of  yellow 
color  are  developed,  which  cause  rapid  liquefaction  of  the  gelatin  and  unite 
into  coarsely  granular,  brown  masses.  In  gelatin  stick  cultures  liquefaction 
rapidly  occurs  along  the  entire  line  of  puncture ;  upon  the  surface  of  the 


G76  NON-PATHOGENIC  BACILLI. 

liquefied  gelatin  a  thin,  whitish-gray,  slightly  wrinkled  film  is  formed,  and 
below  this  it  is  densely  clouded  and  of  a  yellowish  color.  Upon  the  surface 
of  agar  a  thin,  smeary,  yellowish  layer  is  formed.  Upon  potato  a  fawn- 
colored,  transparent  layer,  which  is  sometimes  slightly  wrinkled ;  later  the 
surface  loses  its  transparency  and  becomes  clouded.  In  milk  coagulation 
occurs  and  the  precipitated  casein  is  subsequently  dissolved;  the  milk  ac- 
quires a  bitter  taste;  produces  butyric  acid  in  milk.  Bouillon  cultures  to 
which  sulphuric  acid  has  been  added  give  off  an  acid  distillate  which  has  the 
odor  of  butyric  acid. 

373.  BACILLUS  GASOFORMANS  (Eisenbergj. 

Found  in  water. 

Morphology. — Small  bacilli. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Spore  formation  not  observed.  Grows  rap- 
idly at  the  room  temperature — not  in  the  incubating  oven  at  37°  C.  Upon 
gelatin  plates  forms  tolerably  large,  saucer-shaped  cavities  of  liquefied  gela- 
tin, the  contents  of  which  are  finely  granular  and  may  contain  gas  bubbles. 
In  gelatin  stick  cultures  liquefaction  rapidly  occurs  all  along  the  line  of 
puncture  and  gas  bubbles  form  in  the  non  liquefied  gelatin. 

374.  BACILLUS  CARABIFORMIS  (Kaczynsky). 

Found  in  the  stomach  of  dogs  which  had  been  fed  exclusively  on  meat 
for  three  days. 

Morphology. — Short  and  slender  bacilli. 

Biological  Characters. — An  aerobic,  liquefying  actively  motile  bacillus. 
Spore  formation  not  observed.  Grows  rapidly  at  the  room  temperature. 
Upon  gelatin  plates  foi-ms  small  colonies,  from  the  centre  of  which  are  given 
off  long  processes  with  jagged  outlines.  In  gelatin  stick  cultures  liquefac- 
tion occurs  along  the  line  of  puncture,  and  the  liquefied  gelatin  has  a  green- 
ish-yellow color,  while  a  whitish  deposit  accumulates  at  the  bottom.  Upon 
the  surface  of  agar  a  yellowish-white  layer. 

375.  BACILLUS  GRAVEOLENS  (Bordoni-Uffreduzzi). 

Found  attached  to  scales  of  epidermis  from  between  the  toes  of  man. 

Morphology. — Bacilli  0.8  «  long  and  of  about  the  same  breadth  (micro- 
cocci  ?) 

Biological  Characters. — An  aerobic,  liquefying  bacillus  (?).  Grows  at 
the  room  temperature.  Cultures  have  a  disagreeable  odor.  Upon  gelatin 
plates  forms  irregular,  grayish-white  spots  which  cause  rapid  liquefaction 
of  the  gelatin  and  give  off  a  disagreeable  odor  like  that  from  the  feet;  later 
the  gelatin  has  a  greenish-yellow  color.  Upon  potato  forms  a  grayish,  stink- 
ing layer.  Liquefies  blood  serum. 

376.    BACILLUS  CAROTARUM   (A.  Koch). 

Obtained  upon  cooked  carrots  and  sugar  beets. 

Morphology. — Bacilli  from  0.97  to  1.05  /u  long;  grows  out  into  long,  flexi- 
ble filaments — resembles  Bacillus  brassicae. 

Biological  Characters. — An  aerobic,  liquefying,  non-motile  bacillus. 
Forms  large  oval  spores.  Grows  best  at  40°  C.  Upon  gelatin  plates  forms 
round,  white  colonies  upon  the  surface,  which  under  a  low  power  appear  to 
be  perforated  with  holes  at  the  centre  and  are  marked  by  fine  lines.  The 
deep  colonies  in  the  liquefied  gelatin  are  spherical,  with  a  sharply  defined, 
smooth  outline.  In  gelatin  stick  cultures  a  considerable  growth  occurs 
upon  the  surface  ;  very  scanty  development  along  the  line  of  puncture. 


NON-PATHOGENIC  BACILLI.  077 

Upon  the  surface  of  cigar  a  white  layer  is  formed.  Upon  potato  a  light- 
brown,  circular  layer  is  quickly  developed;  this  at  first  has  a  dull  and  later 
a  shining  surface. 

377.    BACILLUS  INFLATUS   (A.  Koch). 

Found  as  an  accidental  impurity — from  the  air  ? 

Morphology. — Bacilli  from  4.6  to  5,5  /*  long  and  0.6  to  0.8  //  broad;  often 
grow  out  into  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacillus. 
Forms  two  large  spores  in  each  rod.  Grows  at  the  room  temperature.  Upon 
gelatin  plates  forms  spherical  white  colonies  with  folded  margins,  from 
which  an  outgrowth  of  delicate  filaments  is  seen,  similar  to  Bacillus  alvei. 
In  gelatin  stick  cultures  development  occurs  all  along  the  line  of  puncture, 
and  short,  hair-like  filaments  radiate  into  the  gelatin,  which  is  very  slowly 
liquefied.  Upon  the  surface  of  agar  forms  a  thin,  slimy,  light-brown 
layer.  In  bouillon  a  thin,  slimy,  whitish  film  forms  upon  the  surface, 
which  sinks  to  the  bottom  when  the  tube  is  shaken. 

378.   BACILLUS  RAMOSUS. 

Synonym.— "Wurtzel  bacillus. 

Found  in  the  soil  and  in  water — common. 

Morphology. — Bacilli  with  round  ends,  about  three  times  as  long  as 
broad — "about  as  long  as  Bacillus  subtilis,  but  thicker "  (Frankel) ;  fre- 
quently united  in  long  chains,  or  may  grow  out  into  filaments. 

Biological  Characters. — Anaerobic,  liquefy  ing  bacillus.  Exhibits  slight 
movements.  Forms  large  oval  spores  which  are  located  at  the  centre  of 
the  rods.  Grows  rapidly  at  the  room  temperature — also  in  the  incubating 
oven.  Upon  gelatin  plates,  at  the  end  of  two  days,  veil-like,  rapidly  ex- 
tending, whitish  colonies  with  ill-defined  margins  are  developed;  these  re- 
semble the  mycelium  of  a  fungus ;  under  a  low  power  the  colonies  are  seen 
to  consist  of  a  network  of  twisted  and  interwoven  filaments ;  liquefaction  oc- 
curs in  the  course  of  a  few  days.  In  gelatin  stick  cultures  an  outgrowth  of 
branching  filaments  occurs  along  the  line  of  puncture,  looking  ' '  like  a 
sma1!  fir  tree  turned  upside  down  ";  upon  the  surface  a  moist  and  shining, 
white  layer  is  developed ;  liquefaction  soon  occurs  at  the  surface,  and  pro- 
gresses until  the  gelatin  is  entirely  liquefied ;  in  old  cultures  a  mycoderma 
is  seen  upon  the  surface,  the  gelatin  below  this  is  transparent,  and  at  the 
bottom  there  is  a  deposit  of  crumbling,  whitish  flocculi.  Upon  the  surface 
of  agar  a  development  of  branching  filaments  occurs  along  the  line  of  in- 
oculation; these  form  a  moist- looking,  grayish- white  layer,  which  later  be- 
comes thicker  at  the  centre,  and  the  root-like  growth  is  only  seen  at  the 
edges.  Upon  potato  a  whitish,  smeary  streak  is  developed  along  the  line  of 
inoculation ;  the  bacilli  form  numerous  large  oval  spores  when  cultivated 
on  potato. 

379.  BACILLUS  SUBTILIS  (Ehrenberg). 

Synonym. — Hay  bacillus. 

A  widely  distributed  species;  found  in  hay  infusion,  in  water,  in  the 
soil,  etc. 

Morphology. — Bacilli  with  slightly  rounded  corners,  from  4. 5  to  6  n  long, 
and  about  three  times  as  long  as  broad ;  usually  in  chains  consisting  of 
several  elements ;  often  grows  out  into  very  long  filaments;  possesses  a  ter- 
minal flagellum  at  each  end  of  a  single  rod  or  at  the  two  extremities  of  a 
chain. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
large  oval  spores,  which  are  located  at  the  centre  of  the  rods;  these  are 
about  1.2  long  and  0.6  n  broad.  The  movements  are  of  a  waddling  charac- 
58 


678 


NON-PATHOGENIC  BACILLI. 


ter  and  not  very  rapid.  Grows  rapidly  at  the  room  temperature — better  at 
30'  C.  Development  may  occur  at  any  temperature  between  10°  and  45°  C. 
Spore  formation  is  favored  by  a  temperature  of  30°  C.  The  spores  ger- 
minate most  readily  at  30°  to  40°  C.  The  exosporium  is  ruptured  at  one 
side  of  the  long-oval  spore,  and  the  newly  formed  bacillus  takes  its  exit  from 
this  opening  in  a  direction  perpendicular  to  the  long  axis  of  the  reproductive 
element.  The  spores  have  great  resistance  to  heat  and  to  chemical  agents. 
By  boiling  a  hay  infusion  for  a  short  time  a  pure  culture  may  often  be  ob- 
tained, as  other  microorganisms  present  are  killed,  while  the  spores  of  Ba- 
cillus subtilis  survive  and  subsequently  germinate.  Upon  gelatin  plates 
small,  white  colonies  are  first  developed,  which  under  the  microscope  are 
seen  to  be  slightly  granular,  somewhat  irregular  in  outline,  and  of  a  green- 
ish tint;  development  progresses  very  rapidly,  and  liquefaction  of  the  sur- 
rounding gelatin  is  quickly  induced,  forming  saucer-like  cavities  with  gray- 
ish, translucent  contents ;  the  central  portion  is  white  and  opaque ;  frequently 


8 


FIG.  226. — Bacillus  subtilis;  A,  bacilli;  B  shows  formation  of  spores;  C  shows  the  germina- 
tion of  a  spore,  a,  and  development  of  a  short  rod,  /,  and  subsequently  of  a  longer  filament,  h. 
X  1,020.  (Trazmowski.) 


a  radiate  appearance  of  the  bacterial  growth  is  observed ;  under  the  micro- 
scope a  dense,  grayish-yellow  central  mass  is  seen,  arid  around  this  a  tangled 
network  of  filaments  and  of  rods  undergoing  the  characteristic  waddling 
movements ;  at  the  -margins  the  filaments  are  seen  to  radiate  into  the  non- 
liquefied  gelatin,  forming  a  crown-like  aureole.  In  gelatin  stick  cultures 
liquefaction  quickly  occurs  along  the  entire  line  of  puncture ;  later  a  dense, 
dry.  and  friable  mycoderma  forms  upon  the  surface,  and  the  gelatin  below, 
which  was  at  first  filled  with  whitish  flocculi,  becomes  clear  as  a  result  of 
their  deposition  at  the  bottom  of  the  tube.  Upon  the  surface  of  agar  a 
wrinkled,  white  layer  is  developed  which  is  easily  lifted  entire  from  the  cul- 
ture medium.  Blood  serum  is  liquefied  by  this  bacillus,  and  a  wrinkled  myco- 
derma forms  upon  the  surface.  Upon  potato  the  entire  surface  is  soon  cov- 
ered with  a  cream-like,  white  layer,  which  in  a  short  time  contains  an  abun- 
dance of  spores. 


NON-PATHOGENIC   BACILLI.  079 

380.  BACILLUS  SUBTILIS  siMiLis  (Sternberg). 

Obtained  in  cultures  from  the  liver  of  a  yellow-fever  cadaver  in  Ha- 
vana, 1889. 

Morphology. — Bacilli  with  slightly  rounded  ends,  from  2  to  4  ^  long 
and  about  1  M  thick ;  grow  out  into  jointed  filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Forms  long-oval  spores,  which  are  centrally  located 
and  nearly  as  long  as  the  cells  in  which  they  are  developed.  The  motion  is 
like  that  of  Bacillus  subtilis,  viz. :  a  slow,  to-and-fro,  progressive  movement. 
Upon  gelatin  plates  the  deep  colonies,  at  the  end  of  thirty-six  hours  at  the 
room  temperature,  are  spherical,  finely  granular,  and  pearl-like  by  reflected 
light;  the  superficial  colonies  have  commenced  to  liquefy  the  gelatin  at  this 
time,  and  have  a  granular,  white  mass  at  the  centre  surrounded  by  a  saucer- 
shaped  cavity  containing  liquefied  gelatin.  In  gelatin  stick  cultures  lique- 
faction does  not  occur  as  rapidly  as  with  Bacillus  subtilis ;  at  the  end  of  ten 
days  at  the  room  temperature  the  upper  half  of  the  gelatin  is  liquefied  and 
small,  pearl-like  colonies  are  scattered  along  the  line  of  puncture  below;  on 
the  floor  of  the  liquefied  gelatin  is  a  flocculent,  white  deposit  and  a  thin  my- 
coderma  is  seen  upon  the  surface.  On  potato  a  dry,  yellowish- white  layer 
the  size  of  a  dime  is  formed  at  the  end  of  forty -eight  hours  at  30°  (J.,  and 
the  bacilli,  which  grow  out  into  long,  jointed  filaments,  contain  spores. 
Upon  the  surface  of  agar  a  thick,  cream-white  layer  is  formed  in  four  or 
five  days  at  the  room  temperature.  In  agar  stick  cultures  there  is  a  branch- 
ing growth  along  the  upper  portion  of  the  line  of  puncture;  in  old  agar  cul- 
tures variously  contorted  involution  forms  are  seen  in  the  surface  growth 
and  but  few  spores  are  present. 

381.   BACILLUS  LEPTOSPORUS    (L.  Klein). 

Obtained  as  an  accidental  contamination  of  a  pure  culture— from  the  air  ? 

Morphology. — Resembles  Bacillus  subtilis;  when  cultivated  at  35°  C. 
forms  short  chains ;  at  18°  to  20°  C.  grows  out  into  long,  twisted  and  inter- 
laced filaments.  Forms  spores  which  are  0.6  u  thick  and  1.5/tlong;  in 
vegetating,  these  first  increase  in  thickness  to  1  to  1.2  # — the  thickness  of  the 
vegetative  cells;  the  spores  have  a  membranous  envelope  consisting  of  two 
layers,  and  are  Fsurrounded  by  a  jelly-like  substance  having  a  dull  silvery 
lustre ;  vegetation  occurs  at  the  same  time  fi'om  both  poles,  and  the  mem- 
branous envelope  is  not  ruptured  and  left  intact  after  the  emergence  of  the 
vegetative  cell,  as  is  the  case  with  Bacillus  subtilis,  but  is  gradually  dis- 
solved, or  serves  as  the  cell  wall  of  the  newly  formed  bacillus  (?). 

Biological  Characters. — Characters  of  growth  in  solid  culture  media  not 
given.  The  motions  are  said  to  be  peculiar,  especially  in  filaments  made  up 
of  four,  eight,  or  sixteen  elements ;  one  end  of  the  chain  is  jerked  hither 
and  thither  with  a  whip-like,  convulsive  motion,  by  which  the  elements  are 
thrown  into  various  and  constantly  changing  angular  figures. 

382.  BACILLUS  SESSILIS  (L.  Klein). 

Found  in  the  blood  of  a  cow  supposed  to  have  died  of  anthrax. 

Morphology. — Resembles  Bacillus  subtilis,  but  is  distinguished  from  this 
species  by  the  germination  of  the  spores. 

Biological  Characters. — An  aerobic,  non-motile  bacillus.  In  alkaline 
bouillon  at  28°  C.  a  diffuse  cloudiness  is  seen  on  the  second  day,  and  on  the 
fourth  day  a  mycoderma  is  developed  upon  the  surface,  which  contains  spore- 
bearing  bacilli.  The  spores  resemble  those  of  Bacillus  subtilis,  but  the  ger- 
mination of  these  reproductive  elements  is  quite  different  and  resembles 
more  that  of  Bacillus  butyricus.  The  vegetative  cell  emerges  from  a  rup- 
ture at  one  of  the  poles  of  the  exosporium,  and  a  second  rod  appears  to  fol- 


080  NON-PATHOGENIC  BACILLI. 

low  the  first,  pushing  it  before  it;  this  appearance  is,  however,  due  to 
binary  division  of  the  vegetative  cell  before  it  has  completely  emerged  from 
the  spore  membrane.  Characters  of  growth  in  solid  media  not  given.  Not 
pathogenic  for  guinea-pigs. 

383.    BACILLUS  ALLANTOIDES    (L.  Klein). 

Obtained  as  an  accidental  contamination  from  a  culture  of  Bacillus  me- 
gatherium— from  the  air  ? 

Morphology. — Bacilli  about  0.5  /<  thick  and  three  to  four  times  as  long  as 
thick;  form  chains  of  four  to  eight  elements,  the  members  of  which  are 
rather  widely  separated  from  each  other,  but  are  firmly  bound  together  by  a 
jelly-like  membrane  which  is  somewhat  narrower  than  the  rods.  The  rods 
exhibit  an  intermittent  to-aiid-fro  movement ;  subsequently  they  undergo 
segmentation  into  spherical  elements  which  are  surrounded  by  a  jelly-like 
material  and  form  sausage-shaped  zoogloea  masses.  Characters  of  growth  in 
solid  media  not  determined. 

384.    BACILLUS   OF   SCHEUELEN. 

Found  in  cancerous  tissues  by  Scheurleii ;  upon  the  skin  of  healthy  per- 
sons by  Bordoni-Uff reduzzi  (Bacillus  epidermidis) ;  in  scales  of  epidermis 
from  the  nipple  and  in  the  mammae  of  healthy  women  by  Rosenthal. 

Morphology.  —Bacilli  from  1.5  to  2.5  ju  long  and  0.5  u-  broad. 

Biological  Characters.— Anaerobic,  liquefying,  motile  bacillus.  Forms 
long-oval  spores.  Grows  very  slowly  at  the  room  temperature — best  at  29° 
C.  In  gelatin  stick  cultures,  at  the  end  of  eight  to  fourteen  days,  a  funnel- 
sliaped  cavity  is  formed  near  the  surface,  which  is  covered  by  a  wrinkled, 
membranous  layer,  while  but  little  liquid  gelatin  is  contained  in  it.  Upon 
the  surface  of  agar,  at  39°  C.,  at  the  end  of  twelve  hours  a  dull,  fissured, 
colorless  layer  is  developed.  Upon  potato,  at  the  end  of  twelve  to  twenty- 
four  hours  in  the  incubating  oven,  the  whole  surface  is  covered  with  a  yel- 
low, wrinkled  layer ;  the  potato  beneath  this  has  a  dirty-pink  color. 

385.    BACILLUS  LACT1S  ALBUS    (Loffler). 

Found  in  milk. 

Morphology. — Bacilli  which  average  3.4  «  in  length  and  0.96  /*  in  thick- 
ness ;  in  milk  grow  out  into  long  filaments ;  resembles  the  bacillus  of  an- 
thrax. 

Biological  Characters. — Anaerobic,  liquefying,  motile  bacillus.  Forms 
large  spores.  Grows  slowly  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  liquefaction  occurs  slowly,  and  upon  the 
surface  of  the  liquefied  medium  a  whitish  layer,  made  up  of  interlaced  fila- 
ments, is  seen.  Upon  the  surface  of  agar  forms  a  tolerably  thick  layer 
with  thinner  margins.  Upon  potato  a  thin,  dry,  white  layer.  In  milk 
causes  coagulation  and  subsequent  solution  of  the  casein,  and  produces  leu- 
cin  and  ty rosin. 

38G.  BACILLUS  LIODERMOS  (Loffler). 

Synonym.  — Gummibacillus. 

Found  in  milk 

Morphology.— Resembles  Bacillus  mesentericus  vulgatus— small,  thick 
rods  with  round  ends,  in  pairs  or  in  jointed  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
spores.  Grows  rapidly  at  the  room  temperature.  In  gelatin  stick  cultures 
causes  rapid  liquefaction  in  funnel  form ;  the  liquefied  gelatin  is  slightly 
clouded  and  is  soon  covered  with  a  whitish  mycoderma.  Upon  the  surface 


NON-PATHOGENIC   BACILLI.  681 

of  agar  a  whitish,  rosette-like  layer  is  developed.  Upon  potato  forms  a 
transparent,  gum-like  layer,  which  later  is  thrown  into  thick,  soft  folds, 
similar  to  the  growth  of  Bacillus  mesentericus  vulgatus.  In  milk  causes  co- 
agulation of  the  casein,  winch  at  30°  C.  is  precipitated  as  a  whitish,  cloudy 
sediment,  above  which  a  clear  serum  is  seen ;  the  casein  is  subsequently 
peptonized. 

387.    BACILLUS    ULNA    (Cohn). 

First  described  by  Cohn,  and  subsequently  found  by  Prazmowski  in  a 
solution  of  egg  albumin. 

Morphology. — Bacilli  of  1.5  to  2.2  ju  in  breadth  and  of  various  lengths — at 
least  3  M  ;  forms  long,  jointed  filaments;  forms  spores  which  are  2.5  to  2.8  n 
long  and  1  /*  broad. 

Biological  Characters. — An  aerobic,  motile  bacillus  which  is  said  to 
grow  only  in  albuminous  solutions  (?),  in  which  it  develops  as  cloudy  masses 
wrhich  collect  at  the  surface  and  form  a  thick,  dry  mycoderma  consisting 
of  long,  interlaced  filaments  in  bundles  and  irregular  aggregations ;  does  not 
give  on  a  putrefactive  odor.  Imperfectly  described. 


388.    BACILLUS   ULNA   OF   VIGNAL. 

Found  by  Vignal  in  the  salivary  secretions  of  healthy  persons,  and  sup- 
posed to  correspond  with  Bacillus  ulna  of  Cohn. 

Morphology. — Straight  bacilli  with  round  ends,  about  2  u  long ;  often 
united  in  pairs,  in  which  the  elements  are  strongly  adherent;  rarely  in 
chains  containing  more  than  two  segments. 

Biological  Characters . — An  aerobic,  liquefying  bacillus.  Spore  forma- 
tion not  observed.  Motility  not  mentioned.  Upon  gela- 
tin plates,  at  the  end  of  twenty-four  hours,  small,  gray- 
ish superficial  colonies  are  formed ;  the  centre  of  these 
is  thicker  than  the  periphery;  under  the  microscope  the 
peripheral  zone  is  seen  to  be  made  up  of  fine  interlaced 
filaments ;  by  the  second  or  third  day  the  colonies  have 
increased  considerably  in  size,  and  a  small,  grayish- 
white,  opaque  mass  is  seen,  which  is  surrounded  oy  an 
extended  zone  of  liquefied  gelatin ;  this  is  seen  to  con- 
sist of  four  secondary  zones :  next  the  central  mass  the 
gelatin  is  almost  transparent,  outside  of  this  is  a  granular  FIG.  227.  —  Bacillus 
zone,  outside  of  this  a  grayish,  less  granular  zone,  and  ulna  of  Vignal,  from  a 
finally  an  outer  zone  which  is  almost  transparent.  In  culture  in  nutrient 
gelatin  stick  cultures,  at  the  end  of  forty-eight  hours,  agar.  x  i.soo.  (Tig- 
liquefaction  in  funnel  form  has  occurred  along  the  line  nai.) 
of  puncture ;  the  liquefied  gelatin  is  transparent  and  con- 
tains suspended  opaque,  white  flocculi,  which  accumulate  at  the  bottom ;  by 
the  fourth  day  the  gelatin  is  completely  liquefied  as  far  as  the  inoculating 
needle  penetrated,  and  a  whitish  film  is  seen  upon  the  surface.  Upon  the 
surface  of  agar  a  very  adherent,  white  layer  is  developed  which  presents 
punctiform  and  linear  depressions ;  the  agar  below  acquires  a  slightly  brown- 
ish color.  In  bouillon  the  liquid  remains  transparent  and  acquires  a  yel- 
lowish tint,  while  a  tolerably  thick,  fragile,  smooth,  white  mycoderma  is 
formed  upon  the  surface ;  rather  a  scanty  white  deposit  accumulates  at  the 
bottom.  Grows  in  acid  bouillon— 1  :2,000  of  hydrochloric  acid.  Upon  po- 
tato a  thin,  grayish-white  layer  is  formed  at  the  end  of  forty-eight  hours, 
upon  the  surface  of  which  fine,  slightly  elevated  lines  cross  each  other  in  all 
directions  ;  sometimes  this  forms  quite  regular  hexagonal  figures  Blood 
serum  is  liquefied  by  this  bacillus.  All  the  cultures  have  a  disagreeable 
odor,  similar  to  that  given  off  by  Bacillus  pyogenes  fcetidus. 


682  NON-PATHOGENIC   BACILLI. 

389.  BACILLUS  LIQUEFACIENS  (Eisenberg). 

Found  ill  water. 

Morphology. — Short,  rather  thick  rods  with  round  ends. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacil- 
lus. Spore  formation  not  observed.  Grows  rapidly  at  the  room  tempera- 
ture— not  at  37°  C.  Upon  gelatin  plates  forms  round  colonies  with  a 
smooth  margin,  which  in  the  middle  are  white  and  slimy ;  liquefaction  com- 
mences in  saucer  shape  and  progresses  rapidly;  after  a  time  a  putrefactive 
odor  is  given  off.  In  gelatin  stick  cultures  development  is  rapid  and  lique- 
faction occurs  in  the  form  of  a  funnel,  often  like  an  air  bubble;  the  line  of 
puncture  is  filled  with  a  whitish,  granular  mass.  Upon  the  surface  of  agar 
forms  a  dirty-white  layer.  Upon  potato  a  pale-yellow  growth. 

390.  BACILLUS  MAIDIS  (Cuboni). 

Obtained  from  corn  which  had  been  soaked  in  water  for  eight  hours  at 
30°  C.,  and  in  the  faeces  of  individuals  suffering  from  pellagra. 

Morphology. — Bacilli  with  square  ends,  from  2  to  3  n  long;  solitary,  in 
pairs,  or  in  chains  of  three  elements — seldom  more ;  resembles  Bacillus  me- 
sentericus  f  uscus  in  morphological  and  biological  characters. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacil- 
lus. Forms  large  oval  spores  located  at  the  centre  of  the  rods.  Grows  in 
the  usual  culture  media  at  the  room  temperature — best  at  26°  to  30°  C.  Pro- 
duces in  saccharine  solutions  acetic  and  butyric  acids.  Upon  gelatin  plates, 
at  the  end  of  twenty-four  to  thirty-six  hours,  grayish-white,  puiictiform  col- 
onies are  developed  below  the  surface,  which  have  a  yellowish  color.  The 
superficial  colonies  are  thin  and  veil-like ;  under  a  low  power  they  are  seen 
to  be  finely  granular  and  have  an  irregularly  folded  margin ;  later  liquefac- 
tion commences  and  they  have  a  radiate,  finely  striped  margin ;  the  lique- 
faction progresses  rapidly,  forming  shallow,  saucer-like  cavities.  In  gelatin 
stick  cultures  liquefaction  occurs  along  the  line  of  puncture  within  twenty- 
four  hours  in  the  form  of  a  funnel  or  cylindrical  tube,  and  rapidly  extends 
to  the  walls  of  the  test  tube  at  the  surface.  Upon  the  surface  of  agar,  at  34° 
to  36°  C.,  a  thin,  dry,  wrinkled  layer  covers  the  entire  surface  within  twen- 
ty-four hours ;  this  is  white  or  yellowish-white  and  easily  detached.  Upon 
potato  a  white,  somewhat  granular,  and  later  finely  wrinkled  layer,  which 
acquires  a  yellowish-brown  color.  Blood  serum  is  liquefied  by  this  bacillus. 

391.  PROTEUS  SULFUREUS  (Lindenborn). 

Found  in  water. 

Morphology. — Bacilli  of  various  lengths,  the  average  length  being  about 
1.6  fJ-  and  the  breadth  0.8  /*;  often  in  long  chains  or  filaments.  Resembles 
Proteus  vulgaris,  and  is  perhaps  identical  with  this  species  (Eisenberg). 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  rapidly  at  the  room  temperature.  Forms 
sulphuretted  hydrogen.  Upon  gelatin  plates  forms  white  colonies,  from 
which  filamentous  outgrowths  upon  the  surface  of  the  gelatin  are  given  off ; 
these  form  "swimming  islands";  later  liquefaction  occurs  in  the  form  of 
broad  funnels  with  grayish -white  contents.  In  gelatin  stick  cultures  devel- 
opment occurs  along  the  line  of  puncture,  and  liquefaction  in  funnel  shape 
near  the  surface.  Upon  the  surface  of  agar  a  thick,  grayish-white  layer  is 
developed.  Upon  potato  a  slimy,  grayish- white  layer,  which  later  acquires 
a  brownish  color.  In  milk  an  alkaline  reaction  is  produced  in  the  course  of 
several  weeks,  and  the  casein  is  peptonized  without  previous  precipitation ; 
the  milk  acquires  a  bitter  taste  and  a  yellowish  color. 

392.  BACILLUS   THERMOPHILUS    (Miquel). 

Found  in  the  contents  of  sewers,  in  the  alimentary  tract  of  man  and  ani- 
mals, and  in  the  soil. 


NON-PATHOGENIC  BACILLI.  683 

Morphology.—  Bacilli  about  1  u  thick,  which  form  filaments  of  various 
lengths. 

^Biological  Characters. — Anaerobic,  non-motile  bacillus.  Forms  spores, 
which  are  located  at  the  extremities  of  the  rods.  No  growth  in  gelatin  at 
the  room  temperature.  Grows  at  temperatures  between  42°  and  72°  C. .  but 
not  below  42°  or  above  72° ;  grows  best  at  65°  to  70°  C.  Upon  the  surface 
of  agar,  at  42°  to  45°  C.,  a  white,  disc  shaped,  prominent  layer  is  formed — 
more  abundant  growth  at  50°  to  65°  C.  In  bouillon,  at  50°  C.,  development 
occurs  upon  the  surface  in  the  form  of  a  mycoderma  which  is  easily  broken 
up,  and  the  liquid  below  is  diffusely  clouded. 

393.    BACILLUS   TUMESCENS    (Zopf). 

Found  upon  beets. 

Morphology. — Short  bacilli,  about  1.17  Abroad;  grow  out  into  irregu- 
larly bent  and  twisted  filaments;  resembles  Bacillus  megatherium. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Move- 
ments slow.  Forms  oval  spores.  Grows  rapidly  at  temperatures  above 
20°  C.  Upon  gelatin  plates  forms  round,  superficial  colonies  which  have  a 


FIG.  228.— Bacillus  buccalis  maximus,  after  treatment  with  iodine  solution.     X  1,800.    (Miller.) 

brownish-yellow  color ;  after  several  days  the  margins  are  no  longer  well 
defined,  but  have  a  fringed  appearance,  and  liquefaction  commences.  Upon 
potato  a  thick,  white,  viscid  layer,  with  somewhat  folded  margins,  is  de- 
veloped ;  later  this  extends  over  the  entire  surface. 

394.    BACILLUS  BUCCALIS  MAXIMUS   (Miller). 

Found  in  the  mouth  of  man — common. 

Morphology. — "Isolated  bacilli  or  threads,  but  much  oftener  tufts  of 
threads,  parallel  to  or  crossing  each  other,  from  30  to  150  /*  long,  and  dis- 
tinctly articulated.  The  rods  are  from  2  to  10  /*  long,  sometimes  even 
longer,  and  from  1  to  1.3  /*  broad.  This  bacterium  is  therefore  the  largest 
occurring  in  the  mouth;  it  has  a  very  1'egular  contour  and  usually  the  same 
thickness  throughout.  Not  all  of  the  cells  of  this  bacterium  show  the  iodine 
reaction — a  statement  which  applies  equally  well  to  most  bacteria  that  turn 
blue  on  the  addition  of  iodine.  The  majority  of  them,  however,  respond 
very  distinctly  to  the  test,  becoming  stained  brown-violet,  either  through- 
out or  only  in  isolated  places." 

Biological  Characters  not  determined. 


084  NON-PATHOGENIC   BACILLI. 

395.    LEPTOTHRIX   BUCCALIS    OF   VIGNAL. 

Found  by  Vignal  in  the  healthy  human  mouth — rare.  Supposed  by 
Vignal  to  be  identical  with  Leptothrix  buccalis  of  Robin ;  but  as  the  charac- 
ters of  the  microorganism  receiving  this  name  were  not  definitely  deter- 
mined by  Robin,  such  identification  is  impossible.  It  seems  more  probable 
that  the  large  bacillus  described  by  Miller  (Bacillus  buccalis  maximus), 
which  is  found  very  commonly  in  the  human  mouth,  but  has  not  been  cul- 
tivated, is  the  leptothrix  of  Robin. 

Morphology. — Bacilli  from  1  to  1.5  IJL  in  breadth  and  varying  greatly  in 
length — from  1.6  to  BO  M;  often  united  in  long  chains,  or  in  filaments  which 
are  seen  to  be  segmented  when  treated  with  staining,  agents.  This  lepto- 
thrix is  characterized  by  the  presence  of  transverse  partitions  in  the  interior 
of  the  rods,  seen  only  in  stained  preparations ;  these  are  best  seen  in  old 
rods,  which  are  less  deeply  stained  than  those  of  more  recent  development; 
the  partitions  in  these  are  more  deeply  stained  than  the  remaining  portion 
of  the  filament. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Spore  forma- 
tion not  observed.  Grows  very  slowly  in  the  usual  culture  media  at  tempe- 
ratures above  20°  C.  Upon  gelatin  plates,  by  the  third  or  fourth  day,  small, 
round,  grayish-white,  projecting  colonies  are  formed ;  by  the  fifth  or  sixth 
day  an  irregular  border  of  rounded  festoons  is  developed;  this  is  semi-trans- 
parent and  presents  depressions  and  ridges  which  are  radial  or  parallel 
with  the  margin;  the  prominent  centre  remains  opaque  and  of  a  grayish- 
white  color;  later  this  border  extends  considerably  and  the  gelatin  below  it 
becomes  liquefied.  In  gelatin  stick  cultures,  at  the  end  of  forty-eight 
hours,  a  small  mass  is  developed  at  the  point  of  puncture,  about  two  milli- 
metres in  diameter,  and  a  slender  line  of  growth  is  visible  along  the  track  of 
the  needle  below ;  by  the  fourth  day  the  surface  growth  has  a  diameter  of  five 
to  six  millimetres,  and  below  it  a  little  transparent,  liquefied  gelatin  is  seen  in 
a  cup-shaped  cavity ;  this  increases  slowly  in  dimensions  and  the  liquefied  gela- 
tin remains  clear,  while  a  bluish  mycoderma  is  seen  upon  the  surface;  the 
growth  along  the  line  of  puncture  remains  scanty,  but  is  a  little  more  abun- 
dant above  in  contact  with  the  cup  shaped  cavity;  by  the  eighth  day  this  ex- 
tends to  the  walls  of  the  tube;  by  the  twelfth  day  the  cup  form  has  disap- 
peared and  the  gelatin  is  liquefied  to  a  depth  of  about  one  centimetre ;  it  is 
still  covered  with  a  bluish  membranous  layer,  and  a  scanty  whitish  deposit 
of  leptothrix  filaments  is  seen  at  the  bottom  of  the  liquefied  gelatin  Upon 
the  surface  of  agar,  at  the  end  of  twenty-four  hours  at  36°  to  38°  C.,  a 
slightly  wrinkled,  transparent,  white  layer  is  developed;  later  this  is  still 
more  wrinkled,  dry,  and  of  a  transparent  yellow  color;  it  is  easily  broken 
up.  In  neutral  bouillon  a  slight  cloudiness  is  produced  and  a  scanty  white 
precipitate  is  formed  at  the  bottom  of  the  tube;  no  mycoderma  develops  upon 
the  surface.  Upon  potato  a  layer  is  developed  which  is  of  a  dirty-white 
color  at  the  centre  and  of  a  purer  white  near  the  margins. 

396.    BACILLUS   b   OF   VIGNAL. 

Obtained  quite  frequently  by  Vignal  in  cultures  from  healthy  buccal  se- 
cretions. 

Morphology. — Bacilli  with  square  ends,  straight  or  slightly  curved,  about 
0.5  n  in  diameter  and  varying  greatly  in  length — from  1.5  to6.5//;  often 
united  in  chains. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Spore  forma- 
tion not  observed.  Motility  not  mentioned.  Grows  rather  slowly  at  the 
room  temperature— more  abundantly  at  37°  C.  Upon  gelatin  plates,  at  the 
end  of  twenty-four  hours  at  a  temperature  of  18'  to  20°  C.,  prominent, 
small,  grayish-white  colonies  are  developed  upon  the  surface;  at  the  end  of 
forty-eight  hours  a  collarette  with  irregularly  festooned  margins  is  devel- 
oped around  this  central  mass ;  this  is  thinner  and  much  more  transparent 


XOX-PATHOGENIC  BACILLI.  685 

than  the  central  portion  of  the  colony ;  under  a  low  power  it  is  seen  to  be 
formed  of  an  innumerable  series  of  skein-like  bundles,  arranged  side  by 
side  and  more  or  less  twisted,  which  proceed  from  the  central  mass.  In 
gelatin  stick  cultures,  at  the  end  of  forty-eight  hours,  a  small,  flat  mass  is 
developed  at  the  point  of  puncture,  and  a  scanty  growth  is  seen  along  the 
line  of  inoculation.  On  the  fourth  day  the  superficial  growth  covers  the 
entire  surface,  it  is  translucent  by  transmitted  light  and  white  by  reflected 
light;  by  the  sixth  day  the  gelatin  is  liquefied  to  a  depth  of  one  centimetre 
below  the  superficial  growth  ;  the  liquefied  gelatin  remains  transparent  ; 
upon  the  surface  is  seen  a  white,  membranous  layer,  and  at  the  bottom  a 
rather  scanty  white  deposit ;  liquefaction  slowly  extends  downward,  and  by 
the  twelfth  day  has  reached  a  level  corresponding  with  the  bottom  of  the 
line  of  puncture.  Upon  the  surface  of  agar,  at  the  end  of  twenty-four  hours 
at  36°  to  38°  C.,  a  dull- white  layer,  having  a  thickness  of  about  one  milli- 
metre, is  developed ;  this  is  easily  broken  up  with  the  platinum  needle.  In 
neutral  bouillon  a  slight  cloudiness  is  quickly  produced,  a  thin  film  forms 
upon  the  surface,  and  a  scanty  white  precipitate  at  the  bottom  of  the  tube. 
Upon  potato,  at  the  end  of  forty-eight  hours,  a  layer  the  size  of  a  five-franc 
piece  is  developed,  which  has  a  pale-pink  color  and  a  rough  surface — resem- 
bling a  lichen.  Blood  serum  is  liquefied  rather  rapidly,  and  acquires  a 
brownish  color,  while  an  abundant  white  precipitate  accumulates  at  the 
bottom  of  the  tube. 

397.    BACILLUS  /  OP  VIGNAL. 

Found  by  Yignal  in  the  salivary  secretions  of  healthy  persons. 

Morphology. — Bacilli  with  slightly  rounded  ends,  from  0.8  to  1.2  u  in 
length  when  cultivated  upon  agar,  and  from  1.4  to  2.4  u  when  cultivated  in 
neutral  bouillon ;  usually  solitary,  occasionally  united  in  short  chains. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Spore  forma- 
tion not  observed.  Motility  not  mentioned.  Grows  rather  slowly  at  the  room 
temperature — more  rapidly  at  37°  C.  Upon  gelatin  plates,  at  the  end  of  forty- 
eight  hours,  small,  projecting,  opaque,  white  colonies  are  developed ;  at'  the 
end  of  four  days  the  colonies  are  seen  as  conical,  opaque,  white  masses,  di- 
vided into  about  twenty  segments  by  grooves  which  start  from  the  summit. 
In  gelatin  stick  cultures  a  small  but  prominent  white  mass  is  seen  at  the 
point  of  puncture,  and  a  scanty  line  of  development  along  the  track  of  the 
inoculating  needle;  on  the  fourth  day  the  surface  growth  has  extended 
nearly  to  the  walls  of  the  tube,  and  just  below  this  some  fine  branches  are 
given  off  from  the  line  of  growth ;  the  sixth  day  the  entire  surface  is  covei'ed 
and  the  gelatin  below  is  liquefied  for  a  short  distance;  the  eighth  day  the 
liquefaction  has  extended  downward,  and  the  solid  gelatin  below  has  a 
clouded  appearance  owing  to  the  development  of  a  quantity  of  small,  white 
colonies ;  by  the  twelfth  day  the  liquefied  gelatin  has  a  depth  of  about  two 
centimetres,  a  shining,  white  mycoderma  is  seen  upon  the  surface,  a  white 
deposit  at  the  bottom,  and  below  this  numerous  small  colonies  in  the  solid 
gelatin.  Upon  the  surface  of  agar  very  adherent,  white  colonies  are 
formed,  which  later  extend  to  form  a  transparent,  white  membrane.  In 
neutral  bouillon  a  slight  cloudiness  is  produced,  and  a  very  scanty,  whitish 
deposit  is  seen  at  the  bottom  of  the  tube.  Does  not  develop  well  in  acid 
bouillon.  Upon  blood  serum  a  whitish  layer  is  formed,  which  later  becomes 
semi-transparent  and  causes  a  slow  liquefaction  of  the  medium.  Uponpo- 
tato,  at  the  end  of  forty-eight  hours,  a  layer  is  developed  which  has  a  vel- 
vety appearance  in  the  centre,  and  a  yellowish  or  brownish-white  color ; 
by  the  end  of  forty -eight  hours  this  layer  is  as  large  as  a  five-franc  piece. 

398.  BACILLUS  BUCCALIS  FORTUITUS. 

Synonym. — Bacillus./,  Vignal. 

Found  by  Vignal  in  the  salivary  secretions  of  healthy  persons. 

59 


686  NON-PATHOGENIC   BACILLI. 

Morphology. — Bacilli  with  square  ends,  from  1.4  to  3/<  long;  often  united 
in  pairs,  the  elements  of  which  may  be  joined  at  an  angle  of  greater  or  less 
degree. 

Biological  Characters. — An  aerobic,  liquefying  bacillus.  Spore  for^ 
mation  not  observed:  Motility  not  mentioned.  Grows  at  the  room  tempera- 
ture in  the  usual  culture  media.  Upon  gelatin  plates,  at  the  end  of  forty- 
eight  hours,  small,  round  colonies  are  developed,  which  increase  considerably 
in  thickness  and  diameter,  and  by  the  fourth  or  fifth  day  have  caused  lique- 
faction of  the  sm*roundiiig  gelatin.  In  gelatin  stick  cultures,  at  the  end  of 
forty-eight  hours,  a  small  mass  has  formed  at  the  point  of  inoculation,  and  a 
scanty  line  of  development  is  seen  along  the  track  of  the  inoculating  needle ; 
by  the  fourth  day  the  growth  has  extended  over  the  entire  surface  and  pre- 
sents a  decided  prominence  at  the  centre ;  the  gelatin  below  is  liquefied  and 
remains  transparent,  with  some  opaque,  white  flocculi  in  suspension ;  by  the 
twelfth  day  the  liquefaction  extends  to  a  depth  of  two  centimetres,  and  a 
yellowish- white,  abundant  deposit  is  seen  at  the  bottom.  Upon  the  surface 
of  agar  at  36°  to  38°  C.,  small,  white,  opaque  colonies  are  developed,  which 
present  a  small,  nipple-like  projection  at  the  centre.  In  neutral  bouillon  a 
diffuse  cloudiness  is  produced ;  a  thick,  dull- white  layer  forms  upon  the  sur- 
face, and  an  abundant  dull-white  deposit  is  seen  at  the  bottom  of  the  tube. 
Does  not  grow  well  in  acid  bouillon.  Upon  potato  a  rather  thick  growth  is 
developed,  which  extends  slowly  and  acquires  a  slightly  pinkish  tint.  . 

399.   BACILLUS  HAVANIENSIS  LIQUEFACIENS   (Sternberg). 

Obtained  in  cultures  from  the  sui'face  of  the  body  of  patients  in  the  char- 
ity hospital  at  Havana. 

Morphology. — Bacilli  with  round  ends,  about  0.8  /*  thick  and  varying 
greatly  in  length — from  1.2  to  5  /< ;  solitary,  in  pairs,  or  may  grow  out  into 
long  filaments. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  Grows  at  the  room  temperature — better  at  37°  C. 
Upon  gelatin  plates,  at  the  end  of  twenty-four  hours  at  22°  C.,  round  colo- 
nies are  developed  which  have  a  milky  opacity  and  are  surrounded  by  a 
transparent  marginal  zone  with  irregular  margins;  under  the  microscope 
these  colonies  are  seen  to  be  finely  granular  ;  at  the  end  of  twenty-four 
hours  liquefaction  commences.  In  gelatin  stick  cultures  liquefaction  occurs 
along  the  entire  line  of  puncture;  at  the  end  of  four  days  the  liquefied  gela- 
tin is  clouded  throughout ;  in  old  cultures  it  is  quite  transparent,  and  a  slight 
flocculent  deposit  is  seen  at  the  bottom  of  the  tube.  Upon  the  surface  of 
agar,  at  the  end  of  two  weeks,  a  thin,  pale-brown  layer  is  developed.  No 
growth  upon  potato.  Not  pathogenic  for  rabbits.  . 

400.  BACILLUS  LIQUEFACIENS  COMMUNIS  (Sternberg). 

Obtained  in  cultures  from  the  faeces  of  yellow-fever  patients  at  Decatur, 
Ala.  (1888). 

Morphology. — Bacilli  with  round  ends,  from  1  to  2  {t  long  and  about  0.7  /< 
thick ;  solitary  or  in  pairs. 

Biological  Characters. — Anaerobic  and  facultative  anaerobic,  liquefy- 
ing, actively  motile  bacillus.  Grows  in  the  usual  culture  media  at  the  room 
temperature,  also  at  comparatively  low  temperatures,  and  in  th  i  incubating- 
oven  at  37°  C.  Spore  formation  not  observed.  Grows  in  an  acid  medium — 
1  :  500  of  hydrochloric  acid.  In  gelatin  stick  cultures  liquefaction  occurs 
rapidly  in  the  form  of  a  purse.  On  potato,  at  the  end  of  t\vo  weeks,  an  ir- 
regular, corrugated  layer  is  developed  which  has  a  pinkish  color.  Not 
pathogenic  for  rabbits. 


NOX-PATHOGENIC  BACILLI.  G87 

E.  Strictly  Anaerobic  Bacilli. 

•401.  BACILLUS  MUSCOIDES  (Liborius). 

Found  in  the  soil  by  inoculations  in  mice,  also  in  old  cheese,  and  in  the 
excrement  of  cattle. 

Morphology.—  Bacilli  about  1  ju  thick,  with  slight  inclination  to  form  fila- 
ments. 

Biological  Characters. — An  anaerobic,  non-liquefying,  motile  bacillus. 
Forms  short-oval  spores,  which  are  located  at  the  ends  of  the  rods.  In  gela- 
tin and  in  agar  forms  colonies  which  give  off  delicate,  branching,  moss-like 
offshoots.  In  gelatin  stick  cultures  a  delicate,  branching  growth  is  given 
off  from  the  lower  two-thirds  of  the  line  of  puncture. 


FIG.  229.— Bacillus  muscoides;  colony  in  nutrient  gelatin,    x  80.    (Liborius.) 


402.  BACILLUS  SOLIDUS  (Luderitz). 

Obtained  from  garden  earth  by  inoculation  into  mice  and  guinea-pigs. 

Morphology. — Bacilli  of  from  1  to  10  n  in  length — average  4  5  ju— and 
0. 5  n  thick ;  the  longer  bacilli  consist  of  two  segments,  but  regular  filaments 
are  not  formed. 

Biological  Characters. — An  anaerobic,  non-liquefying,  motile  bacillus. 
Movements  tolerably  active,  pendulous  and  progressive.  In  old  gelatin 
cultures  some  of  the  bacilli  contain,  at  one  or  both  ends,  small  refractive 
bodies  which  are  probably  spores.  Grows  at  the  room  temperature.  In 
nutrient  gelatin  containing  grape  sugar,  at  the  end  of  two  days,  punctiform 
colonies  are  developed  which  later  attain  the  size  of  a  poppy  seed ;  they  are 
spherical  and  have  smooth  outlines;  the  gelatin  is  not  liquefied,  but  gas  bub- 
bles are  formed,  and  a  disagreeable  odor  is  given  off  by  the  cultures,  resem- 
bling decomposing  perspiration  from  the  feet.  In  the  absence  of  grape 
sugar  the  development  is  scanty  and  there  is  no  development  of  gas.  In 
nutrient  agar  the  colonies  are  but  little  larger,  they  are  transparent,  and 
under  a  low  power  resemble  little  flocculi  of  cotton.  In  blood  serum  devel- 
opment occurs  only  in  the  middle  and  lower  part  of  the  line  of  puncture. 


G88  NON-PATHOGENIC   BACILLI. 

In  bouillon,  when  oxygen  is  excluded,  an  abundant  development  occurs  at 
37°  C.  at  the  end  of  twenty-four  hours;  the  bouillon  becomes  clouded  and 
gives  off  stinking  gases. 

403.  BACILLUS  POLYPIFORMIS  (Liborius). 

Found  in  the  soil  by  inoculations  in  mice,  in  the  excrement,  of  cows,  etc 
Morphology. — Slender  bacilli  of  various  lengths,  a  little  more  than  1  n 
thick ;  do  not  form  filaments. 

Biological  Characters. — An  anaerobic,  non-liquefying  bacillus  ;  ex- 
hibits very  slight  independent  motion.  Forms  long-oval  spores,  which  oc- 
cupy one-half  to  two-thirds  of  the  length  o£  the  rods,  and  the  diameter  of 
which  is  a  little  more  than  that  of  the  bacilli.  The  colonies  in  gelatin  con- 
sist of  small,  yellowish  masses  with  irregular,  broad,  flap-like  projections ; 
under  the  microscope  these  are  seen  to  consist  of  variously  twisted  and  bent 
outgrowths,  varying  in  thickness,  which  are  given  off  in  all  directions  like 
the  tentacles  of  a  polyp;  later  these  outgrowths  increase  in  thickness.  In 
agar  white  colonies  of  irregular  form,  the  size  of  a  pin's  head,  are  developed ; 
under  a  low  power  these  appear  as  finely  granular,  brownish,  mulberry -like 


FIG.  230.— Bacillus  polypiformis;  colony  in  nutrient  gelatin,    x  80.    (Liborius.) 

masses.  In  blood  serum  a  diffuse  cloudiness  is  developed  at  the  bottom  of 
the  line  of  puncture.  The  addition  of  two  per  cent  of  sugar  to  culture 
media  favors  the  growth  of  this  bacillus ;  no  gas  is  developed  as  a  result  of 
its  growth  in  such  a  medium. 

404.  BACILLUS  BUTYRICUS  (Prazmowski). 

Synonyms. — Bacillus  amylobacter;  Clostridium  butyricum. 

Found  in  putrefying  vegetable  infusions,  in  old  cheese  and  milk,  in  the 
soil,  etc. 

Morphology.  —Bacilli  with  round  ends,  from  3  to  10  n  long  and  about  1  u 
thick;  frequently  associated  in  chains ;  also  in  filaments  not  apparently  seg- 
mented. The  rods  assume  a  spindle  or  tadpole  form  when  spore  formation 
is  about  to  occur,  and  may  then  be  from  1.8  to  2.6 /Uhick;  the  spores  are 
oval,  about  2  to  2.5  //  long  and  1  /u  broad,  and  are  located  centrally  or  at  one 
extremity.  When  the  spore  vegetates  a  rupture  of  the  exosporium  occurs  at 
one  of  the  poles,  and  the  bacillus  grows  out  in  the  direction  of  the  long  axis 
of  the  reproductive  element ;  the  empty  spore  case  retains  its  form  after  the 
vegetative  cell  is  extruded. 

Biological  Characters. — An  anaerobic,  motile  bacillus.  Forms  large  oval 
spores.  Grows  at  the  room  temperature,  in  the  absence  of  oxygen.  The 


NON-PATHOGENIC  BACILLI. 


689 


spores  are  destroyed  by  a  temperature  of  100°  C.  maintained  for  five  minutes. 
In  solutions  containing-  starch,  sugar,  dextrin,  or  salts  of  lactic  acid  this  ba- 
cillus produces  a  considerable  quantity  of  butyric  acid,  and  at  the  same  time 
carbon  dioxide  and  hydrogen  are  given  off.  The  most  favorable  tempera- 
ture for  its  development  is  from  35 J  to  40°  C.  According  to  Fitz,  it  does  not 
cause  the  coagulation  of  sterilized  milk,  but  the  casein  is  slowly  peptonized. 
This  bacillus  also  causes  the  decomposition  of  cellulose,  producing  hydrogen 
and  carbon  dioxide,  or  methane,  carbon  dioxide,  and  sulphuretted  hydrogen, 
according  to  the  composition  of  the  culture  medium  (Tappeiner).  It  appears 
to  be  the  bacillus  which  usually  gives  rise  to  butyric  acid  fermentation  in 
milk  which  has  been  kept  for  some  time,  and  also  in  cheese ;  this  occurs  in 
milk  after  the  lactic  acid  fermentation,  which  is  due  to  aerobic  bacilli,  and 
especially  to  Bacillus  acidi  lactici.  The  characters  of  growth  in  solid  media 
have  not  been  determined.  A  peculiar  staining  reaction  occurs  when  this 


D 


FIG.  231.— Bacillus  butyricus;  A,  single  bacilli;  B,  chains  and  filament;  C,  spore  formation, 
showing  "  clostridium  form  " ;  D,  germination  of  a  spore — a  to  i.    X  1,020.    (Prazmowski.) 


bacillus  from  cultures  containing  starch  or  cellulose  is  treated  with  iodine 
solution ;  the  protoplasm  of  the  cells  acquires  a  blue  or  dark-violet  color,  the 
younger  cells  being  of  a  pure  blue ;  in  some  cases  an  oblique  zone  of  blue 
only  is  seen,  in  others  the  entire  cell  is  stained. 

405.    CLOSTRIDIUM  FCETIDUM    (Liborius). 

Obtained  from  garden  earth  by  inoculations  in  mice,  etc. 

Morphology. — Bacilli  of  various  lengths  and  about  1  u  thick ;  sometimes 
grow  out  into  filaments.  Forms  large  oval  spores,  located  centrally  or  at 
one  end  of  the  rod ;  these  are  of  greater  diameter  than  the  bacilli  before  spore 
formation,  and  cause  the  rods  to  have  a  spindle  (clostridium)  form,  or  oc- 
casionally an  expanded  extremity ;  resembles  Bacillus  butyricus. 

Biological  Characters. — An  anaerobic,  liquefying,  actively  motile  ba- 
cillus. Forms  spores.  Grows  in  the  usual  culture  media,  in  the  absence  of 


690 


NON-PATHOGENIC  BACILLI. 


oxygen,  at  the  room  temperature.  Upon  cigar  plates,  in  the  absence  of  air, 
small,  yellowish-white  colonies  are  developed  which  are  irregular  in  form 
and  vary  considerably  in  size;  these  are  surrounded  by  outgrowths  which 
are  more  compact  and  less  branched  than  similar  colonies  of  the  bacillus  of 
malignant  oedema.  In  nutrient  gelatin  irregular,  spherical  colonies  are  de- 
veloped, which  rapidly  cause  liquefaction  of  the  surrounding  gelatin,  and 
spherical  cavities  filled  with  a  deeply  clouded  liquid  are  formed.  In  blood 
serum  a  homogeneous  cloudiness  is  seen  in  the  vicinity  of  the  line  of  punc- 
ture, and  at  the  lower  part  of  this  a  few  isolated,  irregularly  branching  col- 
onies are  developed.  A  considerable  amount  of  gas  is  formed  in  the  cultures 
in  various  media ;  this  appears  as  scattered  bubbles,  and  also  causes  a  split- 
ting-up  of  the  culture  medium ;  in  gelatin  cultures  liquefaction  gradually 
extends  upward  until  it  reaches  the  surface.  The  gases  evolved  have  an  ex- 
tremely disagreeable  odor;  they  are  produced  more  abundantly  in  culture 
media  containing  sugar. 

406.  BACILLUS  LIQUEFACIENS  MAGNUS    (Luderitz). 

Found  in  garden  earth  by  inoculations  in  mice  and  guinea-pigs. 
Morphology. — Bacilli  with  slightly  rounded  ends,  straight  or   slightly 
curved,  from  3  to  6  u  long  and  from  0.8  to  1.1  /z  thick;  may  grow  out  into 
long,  flexible  filaments. 

Biological  Characters. — A  a  anaerobic,  lique- 
fying, motile  bacillus.  Grows  rapidly  at  the 
room  temperature,  in  the  absence  of  oxygen,  in 
the  usual  culture  media.  Forms  long-oval 
spores,  from  1  to  2  /*  long  and  0.8  n  broad; 
these  are  located  at  or  near  the  middle  of  bacilli 
from  4  to  6  /*  long — not  in  the  long  fila- 
ments unless  these  are  segmented.  When  culti- 
vated in  a  medium  containing  grape  sugar,  the 
spore-bearing  bacilli  are  stained  violet  with 
iodine  solution — sometimes  pale  and  in  places 
only,  at  others  throughout.  In  gelatin  cultures 
development  is  already  evident,  at  the  end  of 
twenty -four  hours,  one  or  two  centimetres  below 
the  surface,  as  scattered  punctiform  colonies ;  at 
the  end  of  two  days  these  are  one  to  two  milli- 
metres in  diameter  and  have  smooth  margins, 
with  transparent,  dull-white  contents;  at  the 
end  of  three  or  four  days  the  gelatin  is  usually 
entirely  liquefied ;  the  liquefaction  extends  upward,  and  the  liquefied  gela- 
tin, which  at  first  is  clouded,  becomes  clear,  while  a  slimy,  whitish  deposit 
is  seen  at  the  bottom  of  the  tube.  In  cultures  containing  grape  sugar  some 
gas  is  developed ;  this  has  a  disagreeable  odor  like  that  of  old  cheese.  In 
gelatin  stick  cultures  liquefaction  begins  along  the  line  of  puncture,  from 
1  to  1.5  centimetres  below  the  surface,  within  forty-eight  hours;  and  a  sau- 
sage-shaped  collection  of  liquefied  gelatin,  of  a  dull-white,  or  silver-gray  color, 
is  seen.  In  long  agar  cultures  development  is  rapid,  and  colonies  are  seen 
nearer  the  surface  than  in  similar  gelatin  cultures — often  within  five  milli- 
metres; the  young  colonies  have  a  delicately  branched,  moss-like  appear- 
ance; in  older  colonies  the  branching  is  coarser.  In  stick  cultures  in  blood 
serum,  in  the  incubating  oven,  at  the  end  of  twenty  four  hours  a  simple 
line  of  growth  is  seen  along  the  lower  portion  of  the  track  of  the  inoculat- 
ing needle ;  later  numerous  lateral  offshoots  give  the  growth  a  brush-like 
appearance;  the  blood  serum  is  soon  liquefied  and  foul-smelling  gases  are 
given  off.  Not  pathogenic  for  mice  or  for  guinea-pigs. 

407.  BACILLUS  LIQUEFACIENS   PARVUS    (Luderitz). 
Obtained  from  garden  earth  by  inoculations  in  mice  and  guinea-pigs. 


FIG.  232.  —  Bacillus  liquefa- 
ciens  magnus  ;  young  colonies  in 
nutrient  gelatin,  x  60.  (Lude- 
ritz.) 


NON-PATHOGENIC   BACILLI. 


GUI 


Morphology. — Bacilli  from  2  to  5  jn  long  and  0.5  to  0.7  /*  thick;  often 
grow  out  into  long,  flexible  filaments. 

Biological  Characters. — An  anaerobic,  liquefying,  non-motile  bacilhis. 
Grows  rapidly  at  the  room  temperature,  in  the  absence  of  oxygen,  in  the 
usual  culture  media.  In  bouillon  cultures  the  thickness  of  many  of  the 
rods  is  increased  to  1  or  1.2  /*,  and  in  these  small,  round,  refractive  bodies 
are  seen  at  the  ends,  or  in  a  linear  series,  which  are  probably  spores.  The 
addition  of  two  per  cent  of  grape  sugar  to  culture  media 
is  favorable  to  the  growth  of  this  bacillus.  In  gelatin 
cultures  development  occurs  at  a  distance  of  one  to 
two  centimetres  below  the  surface ;  at  the  end  of  two 
days,  at  20°  C.,  punctiform  colonies  are  developed; 
these,  when  not  too  close  together,  attain  a  diameter  of 
2  to  2.5  millimetres;  they  are  filled  above  with  trans- 
parent liquid  gelatin  and  below  with  a  whitish  mass  of 
bacteria.  In  gelatin  stick  cultures  a  row  of  spherical 
colonies  is  developed  along  the  line  of  puncture ;  these 
increase  in  diameter  from  above  downward.  In  nu- 
trient agar  opaque  colonies  are  developed  within  0.5  to 
1  millimetre  of  the  surface ;  these  are  tabular,  almond- 
shaped,  or  whetstone-shaped,  and  have  a  tolerably 
smooth  contour  at  first ;  later  they  are  irregular  in  out- 
line. Blood  serum  is  slowly  liquefied  by  this  bacillus. 
In  agar  cultures  a  few  gas  bubbles  are  developed,  and 
also  in  blood  serum.  In  bouillon  a  decided  putrefac- 
tive odor  is  developed..  Not  pathogenic  for  mice. 


FIG.  233.— Bacillus  li- 
quefaciens  parvus;  col- 
ony in  nutrient  agar. 
X  60.  (Luderitz.) 


408.  BACILLUS  RADIATUS  (Liideritz). 

Obtained  from  garden  earth  by  inoculations  in  mice  and  guinea-pigs. 
Morphology. — Bacilli  with  round  ends,  from  4  to  7  /*  long  and  about  0.8 
H  thick ;  often  grow  out  into  long  filaments,  which  are  seen  to  be  composed 
of  separate  segments. 

Biological  Characters. — An  anaerobic,  liquefying,  motile  bacillus.  Move- 
ments are  less  active  than  in  Bacillus  liquefaciens  magnus,  and  only  ob- 
served in  specimens  from  a  recent  culture.  Spores  are  developed  in  the  sin- 
gle rods  only— not  in  the  filaments;  they  are  from  1.2  to  2  n  long  and  0.8  to 

0.9  n  thick,  and  are  centrally  located  in  the 
rods;  the  spore-bearing  bacilli  are  somewhat 
thicker  than  others,  but  do  not  acquire  a  spin- 
dle shape.  Grows  in  the  usual  culture  media 
at  the  room  temperature  when  oxygen  is  ex- 
cluded. The  addition  of  two  per  cent  of 
grape  sugar  is  favorable  to  the  development 
of  this  bacillus.  In  test-tube  cultures  in  nu- 
trient gelatin,  at  22°  C.,  colonies  are  developed 
to  within  one  or  two  centimetres  of  the  sur- 
face ;  when  these  are  numerous  the  gelatin  is 
penetrated  throughout,  below  the  limit  men- 
tioned, with  numerous  glistening  threads,  and 
within  two  or  three  days  is  liquefied;  some 
gas  accumulates  beneath  the  layer  of  solid 
gelatin  above ;  later  liquefaction  extends  to  the 
surface,  and  the  liquefied  gelatin,  which  at  first 
is  clouded,  gradually  becomes  transparent  from 
a  deposition  of  the  suspended  bacilli.  When  only  a  few  colonies  are  developed 
the  growth  resembles  that  of  the  mycelium  of  a  fungus,  the  margin  consist- 
ing of  interlaced  filaments,  while  the  centre  shows  commencing  liquefac- 
tion; new  centres  of  development  are  formed  by  the  filaments  wnich  pene- 
trate the  gelatin,  and  this  is  soon  completely  permeated  and  at  the  same 


FIG.  234.  —  Bacillus  radiatius; 
young  colony  in  nutrient  gelatin. 
X  60.  (Luderitz.) 


002  ^OX-PATHOGENIC  BACILLI. 

time  liquefied ;  a  similar  appearance  is  observed  when  gelatin  plates  are  pre- 
pared arid  kept  in  an  atmosphere  of  hydrogen.  When  successive  cultures 
are  made  in  gelatin  tubes  the  bacillus  gradually  loses  its  vigor  of  growth 
and  the  colonies  have  a  different  appearance ;  the  thread-like  outgrowths  are 
no  longer  seen,  or  are  developed  to  a  slighter  extent,  and  the  spherical  or 
balloon-shaped  colonies  are  filled  with  a  clouded  liquid,  while  a  thick  sedi- 
ment is  formed.  In  gelatin  stick  cultures  development  occurs  along  the 
line  of  puncture  to  within  one  or  two  centimetres  of  the  surface;  at  the  end 
of  two  days  numerous  branching  filaments  are  given  off,  which  give  the 
growth  the  appearance  of  a  hairy  caterpillar.  In  nutrient  agar  stick  cul- 


FIG.  285.  FIG.  236.  FIG.  287.  FIG.  238.  FIG.  239. 

FIG.  235.— Bacillus  liquefaciens  magnus;  stick  culture  in  nutrient  gelatin.    (Luderitz.) 
FIG.  236.— Bacillus  radiatus ;  stick  culture  in  nutrient  gelatin.    (Luderitz.) 
FIG.  237.— Bacillus  spinosus ;  stick  culture  in  nutrient  gelatin.    (Luderitz  ) 
FIG.  238.— Bacillus  liquefaciens  parvus;  stick  culture  in  jiutrient  gelatin.    (Luderitz.) 
FIG  .  239.— Clostridium  f oetidum ;  culture  in  nutrient  agar,  under  oil.    (Liborius.) 

tures  growth  occurs  to  within  one  centimetre  of  the  surface;  it  is  branching 
in  character  and  resembles  that  of  Bacillus  liquefaciens  magnus,  but  the 
filaments  are  more  delicate;  later  the  principal  branches  are  thicker,  and 
they  are  surrounded  by  a  denser  mass  of  fine  filaments,  among  which  some 
thick  outgrowths  are  also  seen.  Blood  serum  is  rapidly  liquefied  by  this 


NON-PATHOGENIC  BACILLI.  693 

bacillus.  The  gases  which  are  developed  in  cultures  containing  sugar  have 
a  disagreeable  odor  like  that  of  cheese  and  onions ;  cultures  in  blood  serum 
give  off  a  putrefactive  odor.  Not  pathogenic  for  mice. 

409.  BACILLUS  SPINOSUS  (Liideritz). 

Obtained  from  garden  earth  by  inoculations  into  mice  and  guinea-pigs. 

Morphology. — Bacilli  with  round  ends,  straight  or  curved,  about  0.6  n 
thick  and  of  various  lengths — usually  from  3  to  8  // ;  may  grow  out  into  long, 
segmented,  flexible  filaments.  Spores  are  formed  in  the  single  rods  only 
and  are  long- oval  in  form ;  they  are  located  toward  one  or  the  other  ex- 
tremity of  the  rod,  which  is  from  1  to  1.2  fi  broad  at  the  point  where  they  are 
developed,  and  has  more  strongly  rounded  or  pointed  ends  than  those  not 
containing  spores. 

Biological   Characters. — An    anaerobic,    liquefying,    motile   bacillus. 
Grows  in  the  usual  culture  media,  with  the  addition  of  two  per  cent  of  grape 
sugar,  at  the  room  temperature,  in  the  absence  of  oxygen.     In  gelatin  tube 
cultures,  at  the  end  of  twodays  at  20°  C.,  colonies 
are  formed  in  the  deepest  portion  of  the  gelatin 
to  within  3  or  3.5  centimetres  of  the  surface;  these 
are  irregular  in  form  and  the  size  of  a  poppy-  or 
hemp-seed ;  they  contain  liquefied  gelatin,  and  as 
they  increase  in  size  the  gray,  shining  contents 
are  seen  to  contain  a  radiating,  whitish  growth ; 
this  is  most  marked  in  the  deep-lying  colonies,  in 
which  the  radiating  growth  extends  to  the  non- 
liquefied  gelatin   around  the  colony;    later  the 
colonies  become  confluent  and  the   liquefaction 
slowly  extends  upward.     In  agar  tubes  opaque 
colonies  are  developed  which  may  attain  a  dia- 
meter of  four  millimetres ;  under  the  microscope 
they  are  seen  to  be  made  up  of  numerous  inter-         FIG.  240.-Bacillus  spinosus; 
laced  filaments  which  in  old  colonies  are  only      colony  in  nutrient  agar,  one 
seen  in  the  marginal  zone ;  or  they  may  be  com-      day  old.   x  60.   (Luderitz.) 
posed  of  thick,  knotty  masses.     Blood  serum  is 

liquefied  by  this  bacillus.  Gas  is  formed  in  all  of  the  cultures,  and  in  those 
containing  sugar  it  has  an  odor  which  is  compared  to  a  mixture  of  Swiss 
cheese  and  fermented  raspberry  juice.  Not  pathogenic  for  mice  or  guinea- 
pigs. 

410.    BACILLUS   ANAEROBICUS   LIQUEFACIENS    (Sternberg). 

Obtained  in  anaerobic  cultures  from  the  contents  of  the  intestine  of  a 
yellow-fever  cadaver. 

Morphology. — Slender  bacilli,  about  0.6  /*  in  diameter  and  three  to  five 
times  as  long  as  broad;  often  in  pairs:  grows  out  into  long  filaments. 

Biological  Characters. — An  anaerobic,  liquefying,  non-motile  bacillus. 
Forms  spores.  Grows  in  the  usual  culture  media  at  the  room  temperature, 
when  oxygen  is  excluded.  In  gelatin  roll  tubes  (Esmarch's)  filled  with 
hydrogen,  granular,  white  colonies  are  developed,  around  which  the  gelatin 
is  liquefied.  In  a  long  stick  culture  in  nutrient  agar  it  grows  along  the 
line  of  puncture  nearly  to  the  surface.  Pathogenic  power  not  tested. 

60 


X. 
NOX-PATHOGENIC    SPIRILLA. 

411.    SPIRILLUM  SPUTIGENUM  (Miller). 

Found  in  the  mouths  of  healthy  individuals,  especially  along  the  margin 
of  inflamed  gums  in  neglected  mouths— common. 

Moi'phology. — Curved  rods  which  resemble  the  "commas"  of  Spirillum 
choleras  Asiaticae ;  these  are  frequently  united  in  S-form  or  in  short,  spiral 
filaments — actively  motile. 

This  spirillum  was  supposed  by  Lewis  to  be  identical  with  Koch's  "  comma 
bacillus,"  but  Miller  has  shown  that  it  differs  essentially  from  this,  inasmuch 
as  it  fails  to  grow  in  the  usual  culture  media.  He  says :  '  'Although  I  obtained 
nearly  pure  culture  material  in  several  cases  and  used  all  possible  kinds  of 
nutrient  media,  I  did  not  succeed  in  producing  the  slightest  growth  of  this 
fungus." 

412.    SPIRILLUM   DENTIUM. 

Synonyms. — Spirochaete  denticola;  Spirochaete  dentium. 

Found  in  the  mouths  of  healthy  individuals,  ' '  under  the  margins  of  the 


Fl°-  841-  FIG.  242.  FIG.  243. 

FIG.  241.—  "Spirochsete  dentium."    x  1,100.    (Miller.) 

FIG.  242.—"  Spirochsete  plicatilis  (6),  Vibrio  rugula  (a),  and  other  bacteria."    X  500.    (Fluggej 

FIG.  243.—  "Spirillum  dentium."    x  500.    (Flugge.) 


ms,  when  they  are  covered  with  a  dirty  deposit  and  slightly  inflamed  " 

Morphology.—  Long,  flexible,  spiral  filaments  of  unequal  thickness  and 
irregular  spiral  windings;  from  eight  to  twenty-five  V  long. 

Biological  Characters.—  Not  known,  as  all  attempts  to  cultivate  this 
spirillum  have  been  unsuccessful. 

413.    SPIRILLUM   PLICATILE. 

%no?i2/?n.—  Spirochaete  plicatilis. 

Found  in  swamp  water  containing  decomposing  algae. 


NON-PATHOGENIC  SPIRILLA. 


695 


Morphology. — Long,  flexible,  spiral  filaments.  The  spiral  curves  are 
close  and  regular,  but  the  extremely  long  filaments  present  secondary,  wave- 
like  curves  which  are  not  uniform.  The  ends  of  the  filaments  are  blunt. 
They  may  attain  a  length  of  one  hundred  to  two  hundred  jn ;  the  movements 
are  extremely  active. 

Biological  Characters  not  determined. 

414.   VIBRIO  RUGULA  (Mliller). 

Found  in  swamp  water,  in  faeces,  and  in  tartar  from  the  teeth. 

Morphology. — Kod-shaped  cells  from  6  to  8  /*  long  and  from  0.5  to  2.5  /* 
thick,  slightly  bent  or  with  a  flat  spiral  curve;  sometimes  united  in  long 
chains.  Spores  are  developed  at  one  extremity  of  the  slightly  curved  rods ; 
they  are  spherical,  and  the  end  of  the  rods  containing  them  presents  a  sphe- 
rical enlargement,  giving  them  a  comma-like  appearance ;  terminal  flagella 
have  been  demonstrated  by  Koch. 


a  b  c 

FIG.  244.— Vibrio  rugula;  a,  young  rods;  6,  thicker  rods;  c,  spore-bearing  rods. 
(Prazmowski.) 


X  1,020. 


Biological  Characters. — The  earlier  investigators  did  not  determine  the 
characters  of  growth  of  Vibrio  rugula,  but  Vignal  (1886)  has  succeeded  in 
cultivating  a  strictly  anaerobic  microoganism,  obtained  by  him  from  the 
human  mouth,  which  he  has  described  under  the  same  name,  although  he  is 
not  entirely  satisfied  that  it  is  identical  with  Vibrio  rugula  of  Prazmowski 
and  previous  observers.  The  biological  characters,  as  determined  by  the  au- 
thor named,  are  as  follows:  An  anaerobic,  liquefying,  motile  "vibrio." 
Movements  rotary  and  progressive.  Forms  terminal  spores,  which  are  rather 
pear-shaped  than  round.  Upon  gelatin  plates,  in  the  absence  of  oxygen,  it 
forms  spherical,  opaque,  yellowish  colonies;  about  the  third  day  the  ori- 
ginal colony  is  surrounded  by  a  zone  of  transparent,  liquefied  gelatin.  In 
gelatin  stick  cultures,  in  an  atmosphere  of  hydrogen,  development  occurs 
along  the  line  of  puncture  within  twenty-four  hours,  and  a  small  mass  is 
formed  at  the  point  of  puncture;  at  the  end  of  forty-eight  hours  liquefaction 
occurs  in  funnel  form ;  the  liquefied  gelatin  is  clouded,  white,  and  opaque ; 
later  it  becomes  transparent.  In  long  stick  cultures  in  nutrient  gelatin, 
without  exclusion  of  the  air,  development  occurs  only  at  the  bottom  of  the 
line  of  puncture.  Upon  the  surface  of  agar  a  white,  slightly  wrinkled  pel- 
licle, covering  the  entire  surface,  is  formed  in  an  atmosphere  of  hydrogen. 
Development  occurs  in  neutral  or  in  acid  bouillon,  which  becomes  diffusely 
clouded,  and  from  which  an  abundant  white  sediment  is  deposited.  Upon, 
the  surface  of  blood  serum  a  white  layer  is  developed  and  liquefaction  of  the 
medium  occurs.  Upon  potato  a  wrinkled,  white  layer  is  rapidly  developed; 


696 


NON-  PATHOGENIC   SPIRILLA. 


later  tli  is  acquires  a  yellowish  tiut;  the  growth  penetrates  the  potato  to  a 
considerable  depth.  Much  gas  is  formed  in  all  of  the  cultures,  and  they 
give  off  a  strong  faecal  odor.  According  to  Prazmowski,  Vibrio  rugula 
causes  an  energetic  decomposition  of  cellulose. 

415.  SPIRILLUM  VOLUTANS  (Ehrenberg). 

Found  in  swamp  water,  etc. 

Morphology.  —  Spiral  filaments  with  round  and  somewhat  pointed  ends, 
from  1.5  to  2  /u  thick  and  25  to  30  //long;  each  filament  consists  of  two 
and  one-half  to  three  and  one-half  —  rarely  six  or  seven  —  spiral  turns  which 
are  from  9  to  13  p  long;  a  single  long,  whip-like  flagellum  at  each  extremity  ; 
the  protoplasm  contains  numerous  opaque  granules.  Exhibits  active  rotary 
and  progressive  movements  —  sometimes  motionless. 

Biological  Characters  not  determined. 


FIG.  245.  FIG.  246. 

FIG.  245.—  Spirillum  volutans.    X  600.    (Cohn.) 
FIG.  246.—  Spirillum  sanguineum.     X  600.    (Cohn.) 

416.    SPIRILLUM   SANGUINEUM. 

Synonym.  —  Ophidomonas  sanguinea. 

Found  in  brackish  water  containing  putrefying  marine  algae. 

Morphology.  —  Rigid  spiral  filaments  with  round  ends,  3  n  or  more  thick, 
and  having  two  to  two  and  one-half  spiral  turns,  each  9  to  12  /*  long  ;  the 
protoplasm,  contains  numerous  refractive  red  granules. 


FIG.  247.  Fio.  848. 

FIG.  247.—  Spirillum  serpens.     X  650.    (Flugge.) 
FIG.  248.—  Spirillum  tenue.     X  650.    (Flugge.) 
FIG.  249.—  Spirillum  uudula.     X  650.    (Flugge.) 


FIG.  849. 


417.  SPIRILLUM  SERPENS  (Muller). 

Synonym.  —  Vibrio  serpens. 

Found  in  stagnant  water,  vegetable  infusions,  etc. 

Morphology.  —  Rigid  filaments  having  two  or  three  wave-like  undulations, 
from  11  to  28  n  long  and  0.8  to  1.1  u  thick;  sometimes  united  in  chains. 
Actively  motile  and  often  associated  in  closely  crowded  swarms. 

Biological  Characters  not  determined. 


NON-PATHOGENIC    SPIRILLA.  697 

418.  SPIRILLUM  UNDULA  (Ehrenberg). 

Found  in  putrefying  animal  and  vegetable  infusions. 

Morphology. — Rigid,  spiral  filaments,  from  8  to  12  /*  long  and  from  1.1 
to  1.4  H  thick.  Each  spiral  turn  has  a  length  of  4  to  5  jn  and  each  filament 
from  one-half  to  three  turns.  A  long,  whip-like  flagellum  may  be  demon- 
strated at  each  extremity.  The  movements  are  rotary  and  rapidly  progres- 
sive— darting. 

Biological  Characters  riot  determined. 

419.   SPIRILLUM  TENUE  (Ehrenberg). 

Found  in  putrefying  vegetable  infusions,  etc. 

Morphology. — Slender  spiral  filaments,  from  4  to  15  ft  long.  The  height 
and  length  of  a  single  turn  are  from  2  to  3  u,  and  each  filament  has  from 
one  and  a  half  to  five  turns.  Often  associated  in  closely  crowded  swarms. 
Motions  rotary  and  progressive — extremely  rapid. 

Biological  Characters  not  determined. 

420.    SPIRILLUM   LINGU/E. 

Synonyms. — Vibrio  lingualis;  Zungenbelag  vibrio  (Weibel). 

Obtained  from  deposit  upon  the  tongue,  by  inoculation  in  a  mouse. 

Morphology. — Curved  rods  of  the  size  of  the  cholera  spirillum ;  sometimes 
in  S- shape.  Grow  out  into  longer  or  shorter  wavy  filaments,  the  'extremi- 
ties of  which  are  sometimes  enlarged— button-like.  Involution  forms  are 
common. 

Stains  by  Gram's  method,  and  is  differentiated  by  this  from  other 
' '  vibrios  "  described  by  Weibel. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non. 
liquefying,  non-motile  spirillum  ("vibrio"). 
Spore  formation  not  determined.  Grows 
at  the  room  temperature  in  the  usual  cul- 
ture  media.  Upon  gelatin  plates  forms 
dirty -white  colonies,  which  at  the  end  of  a 
week  may  attain  a  diameter  of  one  milli- 
metre. Under  a  low  power  the  margin  of 
the  deep  colonies  is  seen  to  consist  of  fine, 
white,  interlaced  filaments,  with  irregular 
offshoots.  The  margin  of  the  superficial 
colonies  has  a  greenish-yellow  shimmer, 
and  thread-like  offshoots  are  given  off  in 
a  tangential  direction ;  the  contour  is  round. 

In  gelatin  stick  cultures  a  delicate,  white,  Fm.  250.— Spirillum  linguae.  (Weibel.) 
veil-like  stripe  is  developed  along  the  line 

of  puncture,  and  no  growth  occurs  upon  the  surface.  Upon  the  surface  of 
agar  a  dirty-white,  finely  granular — not  slimy — layer  is  developed.  In 
bouillon  a  flocculent  deposit  collects  at  the  bottom  of  the  tube,  and  the  liquid 
above  is  slightly  clouded.  The  flocculi  in  bouillon  cultures  consist  of  closely 
interlaced  filaments,  and  frequently  shorter  rods  or  fragments  are  so  placed 
as  to  give  the  impression  that  they  are  bud-like  offshoots  from  the  longer 
filaments. 

Not  pathogenic  for  Avhite  mice. 

421.    SPIRILLUM   NASALE. 

Synonyms. — Vibrio  nasalis;  Naseiischleimvibrio  (Weibel). 

Found  in  nasal  mucus. 

Morphology. — Curved  rods  with  rounded  ends,  about  as  thick  as  the  an- 


098  NON-PATHOGENIC   SPIRILLA. 

thrax  bacillus,  and  two  to  five  times  as  long  as  thick ;  the  amount  of  curva- 
ture varies  considerably,  from  nearly  straight  to  semicircular,  and  short  rods 
may  be  quite  straight.  In  preparations  from  agar  or  gelatin  cultures  long, 
closely  wound  spiral  filaments  are  sometimes  seen,  or  the  filaments  may  be 
wavy  or  made  up  of  curved  segments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  spirillum.  Grows  slowly  at  the  room  temperature — 
better  at  37°  C.  Spore  formation  not  determined.  Upon  gelatin  plates,  at 
the  room  temperature,  grows  very  slowly ;  by  the  fifth  day  the  colonies  may 
have  a  diameter  of  0.3  millimetre,  and  finally  of  0.6  millimetre  at  the  out- 
side; under  a  low  power  they  are  seen  to  be  finely  granular,  and  yellowish- 
brown  by  transmitted  light ;  they  are  spherical  in  form,  with  sharply  defined 
margins.  In  gelatin  stick  cultures  a  delicate,  veil-like  growth  is  seen  along 
the  track  of  the  needle ;  no  growth  upon  the  surface.  Upon  the  surface  of 
agar  a  dirty- white,  slimy  layer  is  developed  at  37°  C.  No  growth  upon  po- 
tato. 

422.   SPIRILLUM  a  OF  WEIBEL. 

Synonym. — Vibrio  saprophiles  a  (Weibel). 
Found  in  putrefying  hay  infusion  and  in   slime  from  sewers. 
Morphology. — Curved  rods,  with  pointed  ends,  about  0.6  n  thick  at  the 
centre,  and  averaging  3  /*  in  length ;  often  two  are  united  in  S-form — longer 


%$iimf 

~'-  t'&i?je~' 


FIG.  251.  FIG.  252. 

FIG.  251.— Spirillum  «  of  Weibel.    (Weibel.) 
FIG.  252.— Spirillum  ft  of  Weibel.    (Weibel.) 

chains  are  not  common;  grow  out  into  spiral  filaments;    involution  forms 
common. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile 
spirillum.  Grows  rather  slowly  at  the  room  temperature.  Spore  formation 
not  determined.  Potato  cultures  give  off  a  strong  odor  of  ammonia.  Upon 
gelatin  plates  the  deep  colonies,  by  the  third  day,  are  from  0.2  to  0.3  milli- 
metre in  diameter;  later  they  may  attain  a  diameter  of  0.6  millimetre; 
under  a  low  power  they  are  seen  to  be  spherical  and  yellowish-brown  in 
color ;  the  opaque  centre  is  surrounded  by  concentric  rings.  The  superficial 
colonies  are  flat  white  or  yellowish  discs,  irregular  in  outline,  with  a  finely 
granular  structure ;  the  centre  is  greenish-yellow  and  opaque,  and  the  color 
fades  out  toward  the  periphery;  at  the  end  of  a  week  they  may  attain  a  dia- 
meter of  two  millimetres.  In  gelatin  stick  cultures  a  veil-like,  white  growth 
is  seen  along  the  line  of  puncture;  later  this  has  a  dirty  yellowish-red  color ; 
upon  the  surface  a  whitish  layer  gradually  extends  from  the  point  of  punc- 
ture, and  beyond  this  a  transparent,  whitish  film  covers  the  surface.  Upon 
the  surface  of  agar  a  cream-like,  yellowish-white  layer  is  developed,  and 
the  agar  beneath  is  clouded  to  a  depth  of  one  to  two  millimetres.  Upon  po- 
tato, at  the  end  of  twodays,  an  abundant  slimy  layer  is  developed;  this  lias 
a  yellowish-red  to  chocolate-brown  color,  and  resembles  the  growth  of  the 
bacillus  of  glanders. 


NON-PATHOGENIC    SPIRILLA.  699 

423.    SPIRILLUM  ft   OF    WEIBEL. 

Synonym.—  Vibrio  saprophiles  ft  (Weibel). 

Found  in  putrefying  hay  infusion. 

Morphology.— Slender,  curved  rods,  of  about  the  thickness  of  the  tubercle 
bacillus,  and  averaging 2u  in  length;  the  ends  are  blunt;  frequently  two 
elements  are  united  in  S-form,  but  long  filaments  do  not  occur;  involution 
forms  common. 

Biological  Characters.— An  aerobic,  non-liquefying,  actively  motile 
spirillum  ("vibrio").  Spore  formation  not  determined.  Grows  rather 
slowly  at  the  room  temperature.  Upon  gelatin  plates  the  colonies  never  ex- 
ceed 0.3  millimetre  in  diameter;  they  are  spherical,  and  by  transmitted 
light  have  a  yellowish-brown  color.  In  gelatin  stick  cultures  the  growth  is 
similar  to  that  of  the  preceding  species—Spirillum  a.  In  agar  stick  cul- 
tures  no  growth  occurs  along  the  line  of  puncture;  on  the  surface  a  cream - 
like,  yellowish-white,  viscid  layer  is  formed,  which  cannot  be  raised  with- 
out bringing  away  some  of  the  culture  medium.  Upon  potato  a  thin 


a 


FIG.  253.  FIG.  254. 

FIG.  253.— Spirillum  y  of  Weibel.    (Weibel.) 
Fio.  254.— Spirillum  aureum.     (Weibel.) 

shining,  varnish-like  layer  of  a  dirty   brownish-green   color  and  a  viscid, 
•dry  consistence,  which  is  with  difficulty  removed  by  the  platinum  needle. 

424.    SPIRILLUM   Y  OP  WEIBEL. 

Synonym. — Vibrio  saprophiles  y  (Weibel). 

Found  in  the  slime  deposited  in  sewers. 

Morphology. — Curved  rods  with  round  ends,  one-half  larger  than  "Vib- 
rio saprophiles  a.  "  of  Weibel ;  S-shaped  forms  are  seen,  but  spiral  filaments 
are  rare;  involution  forms  very  common  in  old  cultures. 

Biological  Characters.— -An  aerobic,  non-liquefying,  actively  motile  spi- 
rillum ("vibrio").  Spore  formation  not  determined.  Grows  rather  quickly 
at  the  room  temperature.  Upon  gelatin  plates  the  deep  colonies  are  white, 
and  at  the  end  of  a  week  about  0.5  millimetre  in  diameter;  under  a  low 
power  they  are  seen  to  be  spherical,  granular,  and  orange- colored  at  the  cen- 
tre, with  a  sharply  defined,  pale-yellow  marginal  zone.  The  superficial  colo- 
nies are  flat,  dirty-white,  slightly  opalescent,  with  a  more  prominent  white 
centre ;  under  a  low  power  the  "margin  is  irregular  and  notched,  the  mar- 
ginal zone  white  and  marked  by  numerous  fine,  anastomosing  furrows, 
next  to  this  a  light  ochre-yellow  zone  marked  by  darker  lines,  and  at  the 
centre  a  golden-brown  nucleus  marked  by  delicate,  dark,  interlacing  lines ; 
at  the  end  of  a  week  the  superficial  colonies  may  attain  a  diameter  of  five 
millimetre*.  In  gelatin  stick  cultures  development  occurs  along  the  line  of 


700  NOX-PATHOGENIC  SPIRILLA. 

puncture  and  to  a  moderate  extent  upon  the  surface.  In  agar  stick  cultures 
no  growth  occurs  along  the  track  of  the  inoculating  needle ;  on  the  surface 
a  dirty-white,  pap-like  layer  is  developed.  Upon  potato  the  growth  is 
sometimes  dry,  viscid,  and  dark-brown  in  color,  or  it  may  be  of  a  mahogany- 
brown  with  a  moist  lustre. 

425.    SPIRILLUM  AUREUM. 

Synonym. — Vibrio  aureus  (Weibel). 

Found  in  the  air  and  in  the  slimy  deposit  in  sewers. 

Morphology. — Curved  rods  with  blunt  ends,  about  one-half  thicker  than 
the  Spirillum  cholerae  Asiaticae,  and  varying  greatly  in  length;  typical 
"commas"  and  S-forms  are  seen;  also  filaments  of  various  lengths  and 
sometimes  regular  spiral  filaments  which  are  extremely  slender ;  also  invo- 
lution forms. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic  spirillum.  Produces  a  golden  or  orange-yellow  pigment.  Spore 
formation  not  determined.  Grows  rather  rapidly  at  the  room  temperature 
— also  in  the  incubating  oven.  Upon  gelatin  plates  the  deep  colonies,  at 
the  end  of  three  days,  have  a  diameter  of  0.3  millimetre  (in  ten  days  of  one 
millimetre);  under  a  low  power  they  are  seen  to  be  coarsely  granular, 
spherical  or  whetstone-shaped,  golden-yellow  in  the  centre  and  later  brown 
or  black,  with  more  transparent,  golden-yellow  margins.  The  superficial 
colonies  are  round,  "with  well-defined  margins,  granular,  and  of  a  pure 
golden-yellow  color;  at  the  end  of  three  days  they  have  a  diameter  of  one 
millimetre  and  in  ten  days  of  three  to  four  millimetres.  In  gelatin  stick  cul- 
tures a  tolerably  abundant,  finely  granular  growth  is  seen  along  the  line  of 
puncture;  upon  the  surface  a  rounded  mass  of  a  yellow-ochre  color  is  de- 
veloped about  the  point  of  puncture.  Upon  the  surface  of  agar  a  dirty- 
white  layer  extends  over  the  entire  surface ;  later  round,  elevated,  golden- 
yellow  islands  are  seen,  and  finally  a  uniform  pap-like  layer  two  millimetres 
thick.  Upon  potato  an  abundant,  thick,  pap-like  growth  of  a  golden- 
yellow  or  orange-yellow  color. 

426.    SPIRILLUM  FLAVESCENS. 

Synonym. — Vibrio  flavescens  (Weibel). 

Found  in  the  slimy  deposit  of  sewers. 

Morphology. — The  same  as  Spirillum  aureum. 

Biological  Characters. — An  aerobic,  non-liquefying,  non-motile,  chro- 
mogenic  spirillum.  Produces  a  dirty  yellowish-green  pigment.  Grows 
rather  rapidly  at  the  room  temperature.  Upon  gelatin  plates  the  colonies 
resemble  those  of  Spirillum  aureum,  except  that  the  yellow  color  is  developed 
later  and  the  shade  is  paler,  duller,  and  less  pure — upon  a  transparent  back- 
ground a  dirty  yellowish-green.  In  gelatin  stick  cultures  a  finely  granu- 
lar line  of  growth  is  seen  along  the  track  of  the  needle,  and  along  the  mar- 
gin of  this  in  old  cultures  are  coarser  granular  masses;  upon  the  surface  a 
pale-yellow,  flat  layer  with  flap-like  margins  slowly  extends  from  the  point 
of  puncture.  Upon  agar  a  dirty-white  color  is  developed,  which  gradually 
extends  to  the  walls  of  the  test  tube;  elevated,  round,  yellow  masses  are  de- 
veloped in  this,  which  increase  in  diameter,  become  confluent,  and  finally 
form  a  thick  and  uniform  pap-like  layer.  Upon  potato  an  abundant  dull- 
yellow,  pap-like  layer. 

427.    SPIRILLUM  PLAVUM. 

Synonym. — Vibrio  flavus  (Weibel). 
Found  in  the  slimy  deposit  in  sewers. 
Morphology. — The  same  as  Spirillum  aureum. 


NON-PATHOGENIC  SPIRILLA.  701 

Biological  Characters. — The  same  as  Spirillum  aureum,  but  the  pigment 
produced  is  ochre-yellow.  Upon  a  dark  background  the  colonies  appear 
grayish-yellow,  on  a  white  ground  straw-yellow ;  under  a  low  power  the 
deep  colonies  are  first  pale-yellow  then  golden-yellow,  and  of  the  same  tint 
throughout,  without  being  darker  in  the  centre ;  they  are  finely  granular, 
with  a  net-like  marking.  The  superficial  colonies  under  the  microscope  are 
pale-yellow  with  dull-gray  spots;  on  the  margin  the  color  usually  remains 
white ;  upon  the  surface  of  agar  an  ochre-yellow  layer;  the  same  on  potato. 

428.  SPIRILLUM  CONCENTRICUM  (Kitasato). 

Found  in  putrefying  blood. 

Morphology. — Short  spirilla  with  pointed  ends,  with  two  to  three  spiral 
turns  which  are  3.5  to  4  ju  in  length  and  2  to  2.5/<  in  diameter — i.e.,  each 
complete  spiral ;  the  filaments  are  a  little  thicker  than  the  cholera  spirillum ; 
in  bouillon  they  grow  out  into  long  spirals  having  from  five  to  twenty  turns. 

Biological  Characters. — An  aerobic,  non-liquefying,  actively  motile 
spirillum.  Grows  best  at  a  temperature  of  20°  to  23°  C.  Spore  formation 
not  observed.  Upon  gelatin  plates  the  colonies,  by  transmitted  light,  are 
seen, to  be  made  up  of  concentric  rings,  which  from  the  centre  to  the  peri- 
phery are  alternately  opaque  and  transparent ;  the  contour  is  round,  and 
from  the  margin  numerous  small,  spiral  outgrowths  are  given  off.  In  gela- 
tin stick  cultures  development  occurs  principally  upon  the  surface  as  £ 
cloudy  layer  penetrating  the  medium  to  a  depth  of  one  millimetre.  Upon 
the  surface  of  agar  a  diffuse  growth  which  adheres  firmly  to  the  culture 
medium.  Upon  potato  no  growth  occurs.  In  bouillon  a  diffuse  cloudiness 
is  slowly  developed;  later  the  medium  becomes  clear  and  an  abundant, 
slimy  deposit  is  seen  at  the  bottom  of  the  tube. 

429.  SPIRILLUM  RUBRUM  (Von  Esmarch). 

Obtained  from  the  putrefying  cadaver  of  a  mouse. 

'Morphology.—  Spirilla  about  twice  as  thick  as  the  cholera  spirillum  and 
having  from  one  to  three  spiral  turns ;  in  bouillon  grows  out  into  very  long, 
spiral  filaments. 

Biological  Characters. — An  aerobic  and  .facultative  anaerobic,  non- 
liquefying,  actively  motile,  chromogenic  spirillum.  Produces  a  wine-red 
pigment  in  the  absence  of  oxygen  only;  on  the  surface  of  culture  media  the 

trowth  is  colorless.  According  to  Lofner,  this  spirillum  has  numerous  short 
agella.  In  old  cultures  unstained,  slightly  refractive  bodies  are  seen  in 
the  filaments,  which  appear  to  be  spores.  Grows  very  slowly — best  at  37°  C. 
Upon  gelatin  plates  small,  slightly  granular  colonies  with  a  tolerably 
smooth  contour  are  developed  at  the  room  temperature;  these  are  at  first 
gray  and  bluish-red,  later  wine-red  in  color.  In  gelatin  stick  cultures  closely 
crowded,  isolated,  spherical  colonies  are  developed  along  the  line  of  punc- 
ture ;  the  growth,  except  upon  and  near  the  surface,  has  from  the  outset  a 
beautiful  wine-red  color.  Upon  the  surface  of  agar  a  grayish- white  layer 
of  limited  extent  is  developed ;  later  this  has  a  pink  color.  Upon  potato 
deep-red  colonies  the  size  of  a  hempseed  are  developed. 

130.    SPIRILLUM  OF  SMITH. 

Found  in  the  intestine  of  swine. 

Morphology. — Comma-shaped  rods  and  spiral  filaments  of  one  and  a  half 
to  two  or  even  as  many  as  ten  spiral  turns ;  have  terminal  flagella. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  spirillum. 
Grows  at  the  room  temperature.  Upon  gelatin  plates,  at  the  end  of  thirty- 
six  to  forty-eight  hours,  small,  spherical,  finely  granular  colonies  are  de- 
veloped, which  have  a  brownish  color;  and  upon  the  surface  small,  round 
colonies  with  a  somewhat  irregular  contour.  In  roll  tubes,  when  the  colo- 

61 


702  NON-PATHOGENIC   SPIRILLA. 

nies  are  not  crowded,  they  may  have  a  diameter  of  0.3  to  0.5  millimetre, 
and  at  the  end  of  several  days  appear  to  be  made  up  of  concentric  zones ;  at 
the  end  of  several  weeks  they  have  the  appearance  of  the  end  of  a  tree  trunk 
which  has  been  sawed  off  and  shows  many  concentric  rings  of  growth, 
which  are  not  very  clearly  defined.  Under  certain  circumstances  outgrowths 
occur  around  some  of  the  deep  colonies,  which  give  them  the  appearance  of 
a  raspberry.  The  superficial  colonies  may  attain  a  diameter  of  three  to  five 
millimetres ;  they  remain  flat  and  circular  in  outline  and  acquire  a  slight 
yellowish  color.  Upon  agar  plates  the  deep  colonies  have  a  diameter  of  0.5 
to  0.7  millimetre ;  those  upon  the  surface  are  flat,  round  discs  of  a  gray  color 
and  smooth  appearance ;  they  may  attain  a  diameter  of  five  millimetres. 
In  neutral  bouillon  containing  one-fourth  to  one  per  cent  of  peptone,  at 
36°  C.,  development  is  abundant,  and  the  culture  liquid  in  a  few  days  is 
densely  clouded ;  examined  in  a  hanging-drop  culture,  they  appear  a  little 
larger  than  the  spirillum  of  cholera  and  exhibit  very  active  movements. 
They  grow  in  milk  without  producing  any  perceptible  change  in  this  fluid. 
The  cultures  acquire  a  slightly  alkaline  reaction.  Upon  potato,  at  37°  C.,  a 
thin,  yellow  layer  is  developed  in  the  course  of  a  few  days. 
Not  pathogenic  for  guinea-pigs  or  pigeons. 

431.    SPIRILLUM   OP  MILLER. 

Synonym. — Miller's  bacillus. 

Obtained  by  Miller  (1884)  from  carious  teeth. 

Morphology. — Straight  or  slightly  curved  rods,  frequently  in  pairs  in 
form  of  a  letter  S  or  of  an  O  ;  also  in  homogeneous  or  segmental  spiral 
filaments. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  spirillum.  Spore  formation  not  observed.  Grows  at  the  room 
temperature  in  the  usual  culture  media.  No  growth  upon  the  surface  of 
gelatin  cultures,  which  are  liquefied.  Upon  agar  the  growth  is  similar  to 
that  of  the  SDirillum  of  Finkler  and  Prior.  Growth  upon  potato  not  charac- 
teristic. 


XI. 

LEPTOTRICHE^E  AND   CLADOTRICHE^E. 

ZOPF  and  other  systematic  botanists  place  among  the  bacteria  cer- 
tain microorganisms  which  are  more  interesting  to  the  student  of 
general  biology  than  to  the  pathologist,  but  which  require  description 
in  a  manual  of  bacteriology.  In  our  descriptions  of  the  species  in- 
cluded by  Zopf  in  the  Leptotrichese  and  Cladotrichese  we  shall  follow 
the  author  named.  Four  genera  are  included  in  the  LEPTOTRICHE^E, 
viz.:  Crenothrix,  Beggiatoa,  Phragmidiothrix,  and  Leptothrix. 
The  CLADOTRICHE^E  are  included  in  a  single  genus  :  Cladothrix. 

432.  CRENOTHRIX  KUHNIANA  (Rabenhorst). 

Synonym. — Brunnenfaden. 

Very  common  in  running  or  in  stagnant  water.  It  sometimes  develops 
so  abundantly  in  reservoirs  and  conduits  of  water  that  the  water  supply  is 
unfit  for  drinking  or  for  certain  industrial  purposes. 

Morphology, — In  different  stages  of  development  appears  as  cocci,  short 
rods,  and  long  filaments.  The  cocci  are  small  spheres  of  from  1  to  6  p  in 
diameter ;  the  cell  wall  of  these  becomes  gelatinous  and  they  multiply  by 
binarv  division,  the  gelatinous  capsule  of  the  daughter  cell  remaining  en- 
closed in  that  of  the  mother  cell ;  later  they  are  set  free  by  the  solution  of 
this  gelatinous  envelope ;  the  zooglcea  formed  by  these  cocci  are  irregular  in 
form  and  may  attain  a  diameter  of  one  centimetre  or  more.  These  zooglcea 
sometimes  accumulate  in  enormous  masses  in  reservoirs  of  water;  at  first 
they  are  colorless,  but  later  they  are  colored  by  hydrated  oxide  of  iron  and 
appear  brick-red,  olive  green,  dark-brown,  or  brownish-black.  When  culti- 
vated in  swamp  water  these  cocci  grow  out  into  rods,  which  by  binary  divi- 
sion produce  filaments ;  these  are  seen  projecting  in  all  directions  from  the 
zoogloea  masses.  When  these  reach  a  certain  age  they  become  segmented, 
and  the  segments,  enclosed  in  a  common  sheath,  acquire  a  rusty-red  or 
dark-brown  color  from  being  impregnated  with  oxide  of  iron ;  the  rod-shaped 
segments  break  up  into  spherical  bodies  which  are  comparatively  large 
("  macrococci ")  ;  some  broad  filaments,  however,  contain  disc-like  seg- 
ments, which  break  up  into  smaller  cocci.  The  rod-shaped  and  spherical 
segments  escape  from  the  ruptured  extremity  of  the  common  sheath.  Some- 
times the  sheath  becomes  prematurely  gelatinous,  and  the  cocci  and  rods 
remain  in  situ  and  germinate ;  in  this  case  they  break  through  the  gelati- 
nous walls,  and  the  original  filament  is  seen  to  be  surrounded  by  a  brush- 
like  outgrowth  of  filaments.  In  these  secondary  filaments,  as  well  as  in  the 
primary,  there  is  a  distinct  differentiation  of  the  two  extremities,  growth 
occurring  at  the  free  extremity  and  not  at  the  base.  The  filaments  are  some- 
times wavy  or  even  spiral  in  form. 

Biological  Characters  not  well  determined,  owing  to  the  difficulty  of  cul- 


704 


LEPTOTRICHE^J  AND   CLADOTRICHE^E. 


tivating  this  microorganism  in  artificial  media.     It  is  aerobic.     Genuine 
spore  formation  has  not  been  demonstrated. 

The  BEGGIA.TOA  are  distinguished  by  the  presence  of  grains  of  sulphur  in 
the  vegetative  cells;  these  are  seen  as  highly  refractive  granules  with  a 
dark  contour.  They  are  widely  distributed,  and  are  found  both  in  salt  and 
fresh  water  containing  decomposing  animal  or  vegetable  material ;  in  sul- 
phurous waters  they  are  especially  abundant,  and  accumulate  upon  the 
muddy  bottom,  or  upon  organic  substances  undergoing  decomposition,  as  a 
milk-white,  gray,  pink,  or  purple  layer;  the  bottom  of  ponds  or  of  small 
bays  is  often  colored  red  by  an  extended  and  abundant  growth  of  these  wa- 
ter bacteria.  Meyer  has  shown  that  they  are  able  to  decompose  sulphate  of 


FIG.  255.  Fjo>  256. 

FIG.  255.— CrenothrixKuhniana;  a-e,  cocci  in  various  stages  of  division;  /,  zooglcea  of  cocci 
(X  400);  g,  zoogloea  of  various  forms  (natural  size);  h,  colony  of  short  filaments,  composed  of 
rod-shaped  cells,  and  developed  from  a  group  of  cocci;  i-r,  filamentous  forms,  partly  spirally  bent 
and  of  different  thicknesses.  (Zopf .) 

FIG.  256.-Beggiatoa  alba  (x  400);  a  and  6,  filaments  having  an  evident  difference  between 
base  and  extremity,  being  segmented  and  free  from  sulphur  grains  below;  2-5,  fragments  of 
filaments  of  various  thicknesses  and  containing  a  greater  or  less  number  of  sulphur  grains;  6-8, 
filaments  stained  with  methyl  violet,  showing  segmentation  into  rods  and  cocci-like  elements;  9, 
cocci;  10,  development  of  a  rod,  c,  from  a  coccus,  a  (X  600).  (Zopf.) 

soda  in  organic  solutions  suitable  for  their  growth.  Like  the  previously  de- 
scribed genus  (Crenothrix),  spherical,  rod-shaped,  filamentous,  and  spiral 
forms  are  included  in  the  life  history  of  the  species.  The  filaments  show  a 
differentiation  as  to  base  and  free,  growing  extremity,  but,  unlike  the  Creno- 
thrix, the  segments  into  which  the  filaments  divide  are  not  included  in  an 
external  sheath.  The  filaments  are  flexible  and  exhibit  a  gliding  movement; 


LEPTOTRICHE.^E  AND  CLADOTRICHEJE.  705 

they  are  able  to  multiply  abundantly  in.  thermal  sulphur  waters  having  a 
temperature  of  55°  C.  and  above. 

433.    BEGGIATOA  ALBA   (Vauch.). 

This  is  an  extremely  common  and  widely  distributed  species ;  found  es- 
pecially in  thermal  waters  and  in  the  refuse  waters  from  sugar  refineries 
and  factories  of  different  kinds. 

Morphology, — The  filaments  differ  greatly  in  diameter  as  well  as  in  length 
— from  1  to  5  M  in  diameter;  the  young  and  slender  filaments  often  contain 
hut  few  grains  of  sulphur  or  none  at  all;  the  older  filaments  usually  con- 
tain a  considerable  number  of  fine  or  coarser  granules  of  sulphur.  The 
filaments,  which  are  attached  to  some  substance,  are  usually  seen  to  be  seg- 
mented, even  without  the  use  of  reagents,  at  least  near  the  base  where  the 
grains  of  sulphur  are  less  numerous  or  absent ;  the  free  ends,  containing 
numerous  grains  of  sulphur,  may  not  appear  to  be  segmented,  but  when, 
they  are  stained  with  one  of  the  aniline  colors,  or  treated  with  hot  glycerin, 
segmentation  becomes  apparent.  In  the  thicker  threads  the  segments  divide 
into  thin  discs,  and  these  again,  under  certain  circumstances,  divide,  in  a  di- 
rection parallel  with  the  long  axis  of  the  filament,  into  quadrants,  each  of 
which  later  becomes  a  spherical  or  ellipsoidal  coccus;  these  usually  contain 
one  or  several  large  grains  of  sulphur.  These  cocci  remain  attached  for  a 
time,  then  under  favorable  conditions  become  separated  and  enter  upon  the 
"  swarm  stage  "  of  their  existence,  during  which  they  are  endowed  with  ac- 
tive movements.  They  come  to  rest  upon  some  filament  of  an  alga  or  other 
substance,  which  may  be  completely  covered,  and  has  a  dark  color  as  a  re- 
sult of  their  presence.  They  multiply  by  binary  division  and  form  zooglcea 
masses  of  irregular  form.  Under  certain  circumstances  they  form  straight 
or  curved  rods,  which  may  also  exhibit  active  movements.  When  these 
come  to  rest  they  grow  out  into  long  filaments,  which  may  be  straight  or 
spirally  curved.  Fragments  of  the  spiral  filaments  may,  under  certain  cir- 
cumstances, become  actively  motile  and  resemble  genuine  spirilla;  their 
movements  are  due  to  the  presence  of  terminal  flagella.  The  diameter, 
length,  and  the  height  of  the  spiral  turns  vary  greatly.  The  straight  fila- 
ments also  show  a  decided  tendency  to  break  up  into  longer  or  shorter  frag- 
ments, but  these  do  not  exhibit  active  motions;  they,  in  common  with  the 
fragments  of  spiral  filaments,  are,  however,  flexible  and  exhibit  "  crawling  " 
motions. 

434.    BEGGIATOA  ROSEO-PERSICINA   (Zopf). 

Synonyms. — Clathrocystis  roseo-persicina  (Cohn) ;  Ophidomonas  san- 
guinea  (Ehrenberg) ;  Bacterium  rubescens  (Lankester). 

Found  upon  the  surface  of  putrefying  animal  or  vegetable  material  in 
fresh  or  salt  water. 

Morphology. — Presents  the  same  developmental  forms  as  Beggiatoa  alba, 
viz.,  cocci,  rods,  filaments,  and  spiral  threads.  The  filaments  correspond 
with  those  of  Beggiatoa  alba,  but  are  distinguished  by  their  red  or  violet 
color.  The  cocci,  formed  in  the  filaments,  when  set  free  undergo  binary 
division  and  form  characteristic  zoogloea  of  very  various  forms ;  these  were 
formerly  described  by  Cohn  under  the  name  of  Clathrocystis  roseo-persi- 
cina. These  zoogloea  may  be  spherical,  oval,  irregularly  branched,  etc. ;  at 
one  time  they  may  contain  but  a  little,  and  at  another  considerable  gela- 
tinous intercellular  material.  Rods  are  developed  from  the  cocci  under  cer- 
tain circumstances,  which  may  be  straight  or  curved.  In  suitable  media 
both  the  cocci  and  the  rods,  after  the  intercellular  substance  is  dissolved, 
may  become  actively  motile — "  swarm  stage."  The  short  rods  grow  out  into 
filaments,  and  these  may,  under  certain  circumstances,  become  spiral  in 
form,  either  partially  or  entirely;  the  spiral  filaments  may  break  up  into 
onotile  fragments  which  correspond  with  Ophidomonas  sanguinea  of  Ehren- 


706  LEPTOTRICHE.E  AND   CLADOTRICHEJE. 

berg  (Spirillum  sanguineum,  No.  416).  The  red  pigment  produced  by  this 
species  is  known  as  bacterio-purpurin.  It  is  insoluble  in  water,  alcohol, 
chloroform,  ammonia,  or  acetic  acid,  and  is  changed  by  hot  alcohol  into  a 
brown,  and  by  chloroform  into  an  orange-brown,  substance. 

435.    BEGGIATOA   MIRABILIS   (Colin). 

Found  in  sea  water,  upon  the  surface  of  putrefying  animal  and  vegetable 
substances,  as  a  white  layer;  common  upon  the  coasts  of  Denmark  and  Nor- 
way (Warming). 

^Morphology. — This  species  is  distinguished  by  the  considerable  thickness 
of  the  filaments,  which  may  be  as  much  as  30  n ;  these  undergo  segmenta- 
tion into  cylindrical  masses,  which  again  break  up  into  thin  discs,  and  these 
are  supposed  to  divide  into  cocci-like  elements  such  as  Zopf  has  described  in 
the  other  species  of  this  genus.  The  complete  life  history  of  this  species  has 
not  been  determined.  Like  the  other  species  described,  the  cells  contain 
granules  of  sulphur. 

436.    PHRAGMIDIOTHRIX  MULTISEPTATA   (Engler). 

Found  in  sea  water,  attached  to  crabs 

Morphology. — Filaments  from  3  to  6  jit  in  diameter,  made  up  of  thin  disc- 
like  segments,  the  diameter  of  which  is  four  to  six  times  less  than  the  thick- 
ness; these  cylindrical  segments  undergo  segmentation  into  halves  and 
quadrants,  and  finally  into  still  smaller  fragments  which  become  rounded 
and  resemble  cocci ;  these  probably  are  set  free,  but  this  has  not  been  ob- 
served; apparently  they  grow  out  first  into  very  thin  filaments  which  subse- 
quently increase  in  diameter.  The  genus  to  which  this  species  belongs  is 
distinguished  from  Beggiatoa  by  the  absence  of  sulphur  grains,  and  from 
Crenothrix  by  the  fact  that  the  segments  are  not  enveloped  in  an  exterior 
sheath,  as  well  as  by  the  comparative  thinness  of  the  cylindrical  segments. 

LEPTOTHRIX  BUCCALIS. — According  to  Zopf,  the  leptothrix  so  common  in 
the  human  mouth  presents  the  same  variety  of  forms  as  has  been  ascribed 
to  the  Beggiatoa  and  Crenothrix.  We  cannot  accept  this  as  established,  and 
have  described  Leptothrix  buccalis  among  the  bacilli  (No.  395).  "Vignal 
claims  to  have  cultivated  this  species,  but,  in  view  of  the  failure  of  Miller  and 
others  to  obtain  it  in  cultures,  it  appears  doubtful  whether  the  microorganism 
described  by  him  under  this  name  corresponds  with  the  Leptothrix  buccalis 
of  Robin  (see  page  683). 

437.    CLADOTHRIX   DICHOTOMA   (Cohn). 

Found  in  stagnant  and  running  water — very  common.  It  is  frequently 
associated  with  Beggiatoa  and  is  common  in  the  refuse  water  of  factories, 
especially  of  sugar  factories.  In  Russia  it  is  often  found  in  abundance  in  the 
water  supply  of  towns.  It  may  readily  be  obtained  from  the  surface  of  pu- 
trefying algae  or  animal  substances  immersed  in  river  or  swamp  water. 

Morphology. — According  to  Zopf,  the   cocci-like  reproductive  elements 

grow  out  into  rods,  and  these  into  fine  filaments,  from  which  later  pseudo- 
ranches  are  given  off.  This  apparent  branching  of  the  filaments  is  the  dis- 
tinguishing generic  character  of  Cladothrix.  Under  a  sufficiently  high 
power  the  branched  appearance  is  seen  not  to  be  a  true  dichotomous  ramifica- 
tion, but  to  result  from  the  growing  out  in  a  lateral  direction  of  a  detached 
segment.  These  long  filaments  break  up  again  into  long  rods,  these  into 
shorter  rods,  and  finally  into  cocci.  The  sheath  of  the  filaments  is  often  col- 
ored yellow,  rusty-red,  olive-green,  or  dark-brown  by  oxide  of  iron.  The 
segments  are  forced  from  the  free  extremity  of  the  common  sheath  by  the 


LEPTOTKICHE^E  AND   CLADOTRICHEJE. 


707 


growth  and  binary  division  of  those  lying  deeper,  or  by  their  own  motility 
— "swarm  stage";  they  may  emerge  from  the  sheath  either  solitary  or  in 
chains  of  several  elements.  Sometimes  the  cocci-like  forms  germinate 
within  the  common  sheath  and  grow  out  through  its  walls  into  filaments. 
Fragments  of  the  filaments  are  sometimes  seen  to  exhibit  peculiar  gliding 
movements;  again  they  may  exhibit  very  active  movements  as  a  result  of 
the  development  of  terminal  flagella.  The  filaments  are  sometimes  straight 
and  sometimes  twisted  in  spiral  form,  the  spiral  turns  being  sometimes  quite 
flat  and  at  others  well-developed  corkscrew-like  convolutions.  When  the 
spiral  filaments  break  up  into  motile  fragments  provided  with  flagella  they 


FIG.  857. — Cladothrix  dichotoma;  A,  branching  plant  with  wavy  (a)  or  spiral  (6)  filaments;  B, 
spiral  filament  more  highly  magnified;  C,  long  spirochsete-like  filament;  D,  fragment  with  one 
extremity  spiral;  E,  spiral  filaments  segmenting  into  rods  (7>)  and  cocci  (c);  F,  spirocheete  form, 
a  undivided,  6  dividing  into  long  rods,  c  into  short  rods,  d  into  cocci-like  elements.  (Zopf..) 

resemble  genuine  spirilla.     According  to  Zopf,  the  so-called  zoogloea  rami- 
gera  is  one  form  of  development  of  Cladothrix  dichotoma. 
Biological  Characters  not  determined. 


438.    CLADOTHRIX   FOERSTERI. 

Synonym. — Streptothrix  Foersteri  (Cohn). 

Found  by  Grafe  in  the  lachrymal  ducts  of  the  human  eye. 

Morphology. — Forms  cocci-like  masses,  rods,  and  leptotiirix  filaments, 
which  may  be  spirally  curved.  According  to  Zopf,  this  species  closely  re- 
sembles Cladothrix  dichotoma. 

Biological  Characters  not  determined. 


708  LEPTOTRICHE^E   AND   CLADOTRICHE^E. 

439.    CLADOTHRIX   INTRICATA  (Russell). 

Obtained  by  Russell  (1891)  from  mud  at  the  bottom  of  the  Gulf  of  Na- 
ples. 

Morphology. — Differs  considerably,  according  to  the  age  of  the  culture 
and  the  culture  medium.  In  gelatin  it  forms  long  filaments  made  up  of  long 
and  slender  cells  having  homogeneous  contents.  In  potato  cultures  the  cells 
are  shorter  and  with  rounded  ends;  these  elements  divide  into  several  short 
and  thick  separate  cells,  and  many  of  these  finally  contain  a  slender,  oblong 
spore.  The  filaments  in  agar  and  potato  cultures  may  present  the  appear- 
ance characteristic  of  the  genus  Cladothrix,  viz. ,  a  false  branching. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  liquefying,  slightly  motile  clado- 
thrix.  Forms  long-oval  spores.  Grows  in  the  usual  culture  media  at  the  room 
temperature.  Upon  gelatin  plates  colonies  are  developed  in  from  twenty- 
four  to  thirty-six  hours ;  these  resemble,  to  the  naked  eye,  colonies  of  mould 
fungi ;  under  a  low  power  the  interior  of  the  colony  is  seen  to  be  made  up 
of  a  thick  network  of  filaments,  from  which  a  quantity  of  curled  and  inter- 
twined filaments  extend  in  all  directions.  The  outside  filaments  are  often 
tolerably  straight,  but  they  soon  become  more  or  less  spiral  and  intertwined, 
or  are  united  into  interwoven,  braid-like  masses  which  extend  in  various 
directions  from  the  principal  colony.  Liquefaction  of  the  gelatin  quickly 
occurs,  and  the  filaments  form  in  the  liquefied  gelatin  a  felt-like  mass. 
When  a  cover  glass  is  placed  over  a  young  colony  and  a  microscopical  ex- 
amination is  made  with  a  tolerably  high  power,  the  straight  filaments  at  the 
margin  of  the  colony  are  seen  to  present  pseudo-branches.  In  gelatin  stick 
cultures  development  is  rapid ;  at  the  end  of  twenty-four  hours  the  line  of 
inoculation  is  marked  by  finely  curled  filaments,  which  extend  horizontally 
into  the  gelatin  in  all  directions,  the  growth  being  most  abundant  near  the 
surface.  The  gelatin  near  the  surface  is  soon  liquefied,  and  the  liquefaction 
gradually  extends  downward.  Upon  potato  an  irregular,  dull-white  mass  is 
quickly  developed  which  is  not  especially  characteristic ;  this  ceases  to  ex- 
tend after  three  days.  Upon  agar  a  tolerably  abundant  but  thin,  dull  white 
layer  is  developed,  and  fine  filaments  extend  from  this  into  the  culture  me- 
dium, giving  the  culture  a  characteristic  appearance.  An  abundant  devel- 
opment occurs  in  bouillon  and  a  jelly-like  mass  accumulates  at  the  bottom 
of  the  tube ;  this  is  readily  broken  up  by  shaking  the  tube. 


XII. 

ADDITIONAL  SPECIES  OF  BACTERIA,   NOT 
CLASSIFIED. 

440.  NITROMONAS  OF  WINOGRADSKY. 

Obtained  from  the  soil  at  Zurich  by  Winogradsky  (1890),  who  says:  "  In 
speaking  of  a  nitrifying  ferment  I  do  not  wish  to  affirm  that  there  is  but  a 
single  species  capable  of  exercising  this  function  over  the  whole  surface  of 
the  globe.  That  appeal's  to  me  not  at  all  probable.  .  .  .  But  it  is  probable 
that  there  are  but  few.  At  Zurich,  for  example,  up  to  the  present  time  I 
have  found  but  a  single  one." 

Morphology. — Ellipsoidal  cells,  more  or  less  elongated,  the  youngest 
cells  often  nearly  spherical;  0.9  to  1  n  broad  and  from  1.1  to  1.8  M  long;  the 
longer  cells  already  show  the  central  constriction  which  precedes  binary  di- 
vision; sometimes  among  the  oval  cells  spindle-shaped  cells  are  seen,  and  oc- 
casionally this  is  the  prevailing  form.  As  a  rule,  the  cells  do  not  remain  as- 
sociated after  binary  division  has  occurred,  but  occasionally  a  chain  of  three 
or  four  elements  is  seen.  Irregular  masses  are  formed  in  cultures,  which  are 
held  together  loosely  by  a  gelatinous  material. 

Biological  Characters, — Does  not  grow  in  the  usual  culture  media,  but 
was  cultivated  by  Winogradsky  in  a  solution  containing  one  gramme  of 
potassium  phosphate  and  one  gramme  of  ammonium  sulphate  in  one  thousand 
grammes  of  pure  water.  To  this  solution  he  adds  half  a  gramme  to  a  gramme 
of  basic  magnesium  carbonate. 

In  testing  the  nitrifying  power  of  the  ferment  the  ammonium  sulphate  is 
added  in  separate  portions,  a  standard  solution  of  ten  grammes  in  five  hun- 
dred cubic  centimetres  of  water  being  used.  From  two  to  five  cubic  centi- 
metres of  this  solution  are  added  at  intervals  of  twenty-four  to  forty-eight 
hours,  according  to  the  rapidity  of  the  ferment  action,  and  the  absence  of 
ammonia  as  a  result  of  this  action  is  determined  by  the  use  of  Nessler's  solu- 
tion. The  cultures  are  kept  at  the  room  temperature. 

The  nitromonas  of  Winogradsky  does  not  form  spores.  It  is  sometimes 
seen  to  exhibit  active  movements,  but  is  usually  at  rest.  The  researches  of 
the  author  named  show  that  it  is  capable  of  growing  and  of  exercising  its 
ferment  action  in  solutions  from  which  all  organic  matter  has  been  excluded, 
and  the  conclusion  is  reached  that  it  is  able  to  assimilate  the  carbon  required 
for  its  development  from  the  carbonic  acid  set  free  in  the  culture  liquid  as  a 
result  of  the  action  of  the  nitric  acid  formed  by  the  nitrifying  ferment  upon 
the  magnesium  carbonate  in  suspension. 

Recently  (1891)  Winogradsky  has  succeeded  in  cultivating  this  nitrifying 
ferment  in  a  solid  medium  containing  soluble  silicates,  which  form  a  gela- 
tinous mass  (see  page  47).  The  bacillo-cocci  of  G.  and  P.  F.  Frankland 
appear  to  be  identical  with  the  nitromonas  of  Winogradsky.  The  authors 
named,  finding  that  the  nitrifying  ferment  did  not  grow  in  nutrient  gelatin, 
succeeded  in  isolating  it  in  liquid  cultures  by  the  method  of  dilution.  They 
describe  the  nitrifying  organism  obtained  by  this  method  as  a  bacillus  which 
is  but  little  longer  than  it  is  broad,  and  which  they  designate  a  "  bacillo- 
coccus."  In  this  country  E.  O.  Jordan  and  Ellen  H.  Richards  have  also 


710 


ADDITIONAL  SPECIES  OF 


succeeded  in  isolating  a  nitrifying  ferment  by  the  method  of  dilution  and  by 
cultivation  in  a  liquid  containing  certain  salts  dissolved  in  distilled  water. 
Their  culture  medium  was  constituted  as  follows : 


Ammonium  chloride  (resublimed) , 
Sodium  carbonate, 
Sodium  phosphate,     .  .  . 

Potassium  sulphate, 


1.9070  grammes. 
3.7842 

0.2000          " 
0.2000          " 


"  These  salts  were  dissolved  in  such  a  quantity  of  redistilled  water  that  the 
solution  contained  one  hundred  parts  of  nitrogen  per  one  hundred  thousand, 
and  two  equivalents  of  alkali.  Ten  cubic  centimetres  of  this  solution  were 
mixed  with  one  litre  of  redistilled  water  and  then  inoculated  as  desired . " 

The  nitrifying  ferment  obtained  by  Jordan  and  Eichards  is  described  as  a 
short  bacillus  of  a  slightly  oval  shape,  about  8  to  9  M  broad  and  from  1.1  to 
1.7  u  long.  These  bacilli  are  associated  in  irregular  zooglcea  by  a  jelly-like 
material.  The  masses  are  found  chiefly  at  the  bottom  of  the  flasks,  as  was 
the  case  with  the  nitrifying  ferment  isolated  by  Winogradsky.  No  inde- 
pendent movements  were  observed  by  Jordan  and  Richards,  who  state  that 
they  have  not  been  able  to  determine  in  a  definite  manner  whether  the  nitri- 
fying organism  isolated  by  them  is  identical  with  that  of  Winogradsky  and 
of  the  Franklands.  They  remark  that  their  bacillus  stains  with  some  diffi- 
culty with  the  usual  aniline  dyes. 

441.    NITRIFYING  BACILLUS  OF  WINOGRADSKY. 

Obtained  by  Winogradsky  (1891)  from  the  soil  by  cultivation  in  a  gela- 
tinous medium  containing  soluble  silicates. 

Morphology. — Small  bacilli  of  somewhat  irregular  form,  often  pyriform ; 

the  average  length  does  not  usually  exceed 
0.5  /u,  and  the  breadth  is  quite  variable, 
even  in  the  same  cell.  The  bacilli  are 
grouped  in  irregular  masses  and  united 
into  a  membranous  pellicle  by  a  gelatin- 
ous material.  This  pellicle  in  old  cultures 
is  seen  attached  to  the  bottom  of  the  tube 
as  a  transparent  membrane,  which  may  be 
detached  by  agitation ;  in  more  recent 
cultures  it  is  firmly  adherent  and  sa 
transparent  as  to  be  seen  with  difficulty ; 
it  gives  to  the  glass  a  feeble  bluish-gray 
tint,  and  is  not  detached  by  repeatedly 
rinsing  the  tube  with  distilled  water.  The 
bacilli  are  somewhat  difficult  to  recognize 
in  stained  preparations,  owing  to  the  stain- 
ing of  the  gelatinous  intercellular  sub- 
stance. Winogradsky  recommends  wash- 
ing the  stained  preparation  with  water  at 
50°  to  60°  C.  to  remove  the  color  from  the 
gelatinous  material. 
The  Biological  Charactersof  this  bacillus  have  not  been  fully  determined. 
In  a  gelatinous  medium  made  by  the  addition  of  silicic  acid  to  a  culture  liquid 
containing  certain  salts,  yellowish-gray,  lenticular  colonies  were  developed, 
from  which  liquid  cultures  were  subsequently  made  by  Winogradsky.  In 
these  the  liquid  remained  transparent,  and  no  pellicle  formed  upon  the  sur- 
face, but  a  very  transparent,  gelatinous  film  was  found  attached  to  the  bot- 
tom of  the  flask ;  the  bacillus  above  described  was  found  to  be  present  in  this 
and  to  be  the  cause  of  the  active  oxidation  of  nitrites  present  in  the  culture 
medium.  With  reference  to  its  ferment  action  Winogradsky  says:  "The 
oxidizing  power  of  this  imponderable  quantity  of  a  living  ferment  is  aston- 
ishing. "  When  this  bacillus  is  associated  with  the  microorganism  previously 


Fin.  258.— Nitrifying  bacillus  of  Wino- 
gradsky. x  1,000.  From  a  photomicro- 
graph. (VVinogradsky.) 


BACTERIA,    NOT  CLASSIFIED.  711 

described  (No.  440)  in  a  solution  containing  salts  of  ammonia,  the  ' '  nitro- 
monas"  takes  theprecedence ;  and,  according  to  Winogradsky,  when  the  oxi- 
dation of  the  ammonia  is  completed  this  ferment  ceases  to  absorb  oxygen 
and  enters  into  a  state  of  repose,  while  the  nitrifying  bacillus  commences  to 
multiply  and  to  exercise  its  special  ferment  action. 

442.    STREPTOCOCCUS  CONGLOMERATE   (Kurth). 

Obtained  by  Kurth  (1890)  from  cases  of  scarlet  fever. 

Morphology. — As  obtained  from  bouillon  cultures  it  consists  of  masses 
made  up  of  chains  of  cocci ;  free  chains  are  only  occasionally  seen. 

Biological  Characters. — This  streptococcus  is  said  to  differ  from  Strepto- 
coccus pyogenes  and  various  other  previously  described  streptococci  by  the 
fact  that  in  bouillon  cultures,  at  a  temperature  of  37°  C. ,  it  forms  at  the  bot- 
tom of  the  tube  smooth,  round,  and  very  firm  white  scales,  or  a  single  flat 
layer  which  is  not  disintegrated  when  the  tube  is  slightly  agitated ;  other 
streptococci  are  said  to  form  a  loose  deposit  which  is  either  entirely  broken, 
up  or  forms  viscid  threads  when  the  tube  is  gently  rotated. 

Pathogenesis. — Very  pathogenic  for  mice. 

443.    BACILLUS   THALASSOPHILUS    (Russell). 

Obtained  by  Russell  (1891)  from  mud  at  the  bottom  of  the  Gulf  of  Na- 
ples. 

Morphology. — A  slender  bacillus,  varying  greatly  in  length,  which  grows 
out  into  filaments  which  are  not  visibly  segmented. 

Stains  with  ZiehFs  solution  when  obtained  from  a  recent  culture,  but 
not  by  Loffler's  solution  or  fuchsin. 

Biological  Characters. — An  anaerobic,  liquefying,  motile  bacillus.. 
Forms  spores,  which  are  very  small  and  are  located  at  the  middle  or  the 
ends  of  the  rods.  Grows  at  the  room  temperature  in  the  absence  of  oxygen. 
In  nutrient  gelatin,  prepared  with  sea  water,  at  the  end  of  two  or  three 
days  colonies  appear  at  the  bottom  of  the  line  of  puncture  in  the  form  of 
small,  clouded  bubbles;  later  other  colonies  develop  above  these,  forming- 
finally  a  long,  irregular,  grayish,  semi-transparent,  liquid,  sac-like  mass. 
At  the  upper  portion  of  this  sac  gas  accumulates.  The  gelatin  is  now  rap- 
idly liquefied,  except  above,  the  liquefaction  extending  to  the  walls  of  the  tube. 
Finally  the  entire  amount  of  gelatin  is  liquefied,  and  becomes  clear  above 
from  the  deposition  of  the  bacilli  at  the  bottom  of  the  tube,  wrhere  they 
form  a  thick,  sticky  mass.  The  cultures  give  off  a  penetrating,  disagree- 
able odor.  In  gelatin  between  double  plates  colonies  first  appear  at  the- 
end  of  two  or  three  days ;  under  a  low  power  these  show  a  very  thin  net- 
work of  filaments,  which  penetrate  the  gelatin  in  all  directions.  Much 
gas  is  developed  in  the  colonies,  and  when  the  upper  plate  is  lifted  an  odor 
of  skatol  is  given  off.  The  colonies  soon  become  confluent  and  the  gelatin 
is  entirely  liquefied.  In  agar  a  scanty  development  occurs  along  the  line  of 
puncture  to  within  two  centimetres  of  the  surface. 

444.    BACILLUS   GRANULOSUS    (Russell). 

Obtained  by  Russell  (1891)  from  the  mud  at  the  bottom  of  the  Gulf  of 
Naples;  common,  even  at  a  depth  of  1,100  metres. 

Morphology. — In  hanging-drop  cultures  this  bacillus  grows  out  into  long, 
slender  filaments,  made  up  of  tolerably  large  bacilli  having  a  thick  cell  wall 
and  finely  granular  protoplasmic  contents.  In  older  cultures  the  long  fila- 
ments are  broken  up  into  shorter,  irregular  fragments,  and  the  separate  seg- 
ments are  seen  as  short,  thick  rods  with  coarsely  granular  contents.  Upon 
agar  and  potato  the  development  of  filaments  is  irregular  and  they  break  up 
into  a  grape-like  mass.  These  masses,  which  might  be  taken  for  involution 


712 


ADDITIONAL   SPECIES   OF 


forms  or  degenerative  products,  are  capable  of  forming  spores.  In  potato 
cultures  these  masses  are  seen  to  consist  of  short,  plump  cells,  each  one  of 
which  contains  a  highly  refractive  spore.  The  segments  of  a  filament  divide 
as  in  Bacillus  megatherium,  without  any  external  appearance  of  division,  the 
new  cells  growing  in  breadth  rather  than  in  length ;  as  a  result  of  unequal 
growth  irregular  masses  are  formed,  in  which  later  spores  are  developed.  In 
anaerobic  cultures  the  cells  are  usually  solitary,  or,  at  most,  united  in  pairs. 
The  protoplasm  of  young  cells  is  fine  and  granular;  in  older  cells,  and  espe- 
cially in  unfavorable  media,  the  contents  consist  of  large,  shining  granules. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method ;  the  granules 
are  deeply  stained  by  Kiihne's  car bol-methyl- blue  solution. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, usually  non-motile  bacillus;  in  bouillon  cultures  kept  at  37°  C.  a 
slight  to-and-fro  movement  may  be  observed.  Forms  spores.  Grows  in  the 


^ 


FIG.  259.  FIG.  260. 

FIG.  25D.— Bacillus  thalassophilus;  culture  in  nutrient  gelatin  at  end  of  fourth  day;  a,  drum- 
rstick  forms  from  gelatin  culture;  e,  bacilli  containing  spores.  (Russell.) 

FIG.  2CO.— Bacillus  granulosus;  young  surface  colony  upon  gelatin  plate;  a,  b,  c,  normal 
forms  from  recent  gelatin  culture;  /, /',  from  an  old  gelatin  culture;  g-h,  abnormal  forms  from 
potato  culture— at  A,  spores.  (Russell.) 


usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  the  col- 
onies differ  considerably  in  appearance,  especially  those  upon  the  surface. 
At  first  they  are  usually  thin,  almost  transparent,  and  leaf -like;  under  a  low 
power  these  colonies  are  seen  to  be  covered  with  irregular,  concentric  lines, 
which  are  formed  by  the  parallel  arrangement  of  the  filaments,  and  under 
the  microscope  resemble  the  anastomosing  "nerves  "  upon  a  leaf.  Liquefac- 
tion of  the  gelatin  quickly  occurs.  The  deep  colonies  are  not  characteristic, 
and  remain  as  small,  round,  shining,  opaque  masses.  The  colonies  are  vis- 
cid, drawing  out  into  threads,  or,  when  touched  with  the  platinum  needle, 
the  entire  colony  may  be  picked  up.  In  gelatin  stick  cultures  liquefaction 
ioccurs  near  the  surface,  forming  a  shallow  cavity,  at  the  bottom  of  which 


BACTERIA,   NOT   CLASSIFIED. 


713 


the  bacilli  accumulate  in  zooglcea  masses ;  later  the  liquefaction  extends  to 
the  deeper  layers  of  the  gelatin  medium.  Upon  agar,  in  the  course  of  two  or 
three  days  at  the  room  temperature,  or  in  twenty-four  hours  in  the  incubat- 
ing1 oven,  rather  scanty  and  thin,  whitish  or  yellowish  colonies  are  developed, 
which  remain  separated  where  the  culture  medium  is  scanty,  as  at  the  upper 
part  of  oblique  cultures,  while  below,  where  the  culture  medium  is  moist, 
development  is  more  abundant.  In  bouillon  an  abundant  development 
occurs,  which  causes  a  diffused  cloudiness  of  the  liquid  and  a  considerable 
deposit  at  the  bottom  of  the  tube.  The  growth  upon  potato  is  quite  charac- 
teristic. At  the  end  of  twenty- four  hours  at  the  room  temperature  a  moist, 
white,  shining  patch  is  seen ;  instead  of  extending  over  the  surface,  this  in- 
creases in  thickness,  forming  a  thick,  viscid,  shining-white  mass;  later  this 
loses  its  lustre,  becomes  dull  and  waxy  in  appearance,  and  acquires  a 
brownish  color. 

445.    BACILLUS  LIMOSUS  (Russell). 

Obtained  by  Russell  (1891)  from  mud  from  the  bottom  of  the  Gulf  of 
Naples ;  very  abundant  in  all  of  the  specimens  examined. 


FIG.  261.  FIG.  262. 

FIG.  261.— Bacillus  limosus;  culture  in  nutrient  gelatin  made  with  sea  water,  at  end  of  two 
days,  and  bacilli  from  a  gelatin  culture.  (Russell.) 

FIG.  262.— Spirillum  marinum;  culture  in  nutrient  gelatin  made  with  sea  water,  at  end  of  two 
days,  and  spirilla.  (Russell.) 

Morphology. — Long  and  slender  bacilli,  1.25  u  broad  and  3  to  4  n  long; 
usually  united  in  pairs,  or  in  chains  containing  several  elements.  In  hang- 
ing-drop preparations  from  potato  cultures  the  cells  are  shorter  and  thicker 
than  in  gelatin  cultures ;  the  ends  are  rounded,  and  the  cell  contents  often 
appear  finely  granular. 

Biological  Characters. — Anaerobic,  liquefying,  motile  bacillus  ;  exhibits 
slow  to-and-fro  movements.  Forms  spores,  which  are  located  at  one  ex- 
tremity of  the  rods.  Grows  in  the  usual  media  at  the  room  temperature — 


714  ADDITIONAL  SPECIES   OF 

more  luxuriantly  in  nutrient  gelatin  made  with  sea  water.  Upon  gelatin  plates 
colonies  are  developed  in  from  twenty-four  to  thirty  hours,  which  at  first 
are  almost  transparent;  under  a  low  power  these  are  seen  to  be  surrounded 
by  long,  slender  filaments  which  extend  far  out  into  the  gelatin ;  in  its 
further  development  the  central  portion  of  the  colony  extends  and  includes 
the  slender  filaments,  forming  a  round  mass  surrounded  by  little,  thorn-like 
projections ;  liquefaction  commences  at  the  centre,  causing  a  depression  of 
•the  colony ;  in  old  colonies  the  liquefied  gelatin  has  a  grayish  color  and  a 
thin  pellicle  forms  upon  the  surface ;  below  this  swim  flocculent  masses, 
and  around  the  margins  the  thorny  appearance  is  preserved.  In  gelatin 
stick  cultures  containing  sea  water  development  is  very  rapid,  and  at  the 
end  of  twenty-four  hours  a  funnel-shaped  cavity,  containing  liquefied  gelatin 
which  is  clouded  throughout,  has  been  formed ;  in  the  course  of  seventy 
hours  the  gelatin  is  entirely  liquefied  and  light,  flocculent  masses  collect 
in  the  lower  portion  of  the  tube,  while  upon  the  surface  a  thin  pellicle  is 
formed  which  is  easily  broken  up.  Upon  agar  the  development  is  abun- 
dant, forming  a  moist,  shining-white  layer.  In  bouillon  a  dense  cloudiness 
is  developed,  and  a  thick  and  very  resistant  layer  is  formed  upon  the  surface, 
while  a  considerable  deposit  accumulates  at  the  bottom  of  the  tube.  Upon 
potato  a  thin,  grayish-white  layer  is  formed,  which  covers  the  greater  part 
of  the  surface. 

446.    SPIRILLUM   MARINUM  (Russell). 

Obtained  by  Russell  from  mud  at  the  bottom  of  the  Gulf  of  Naples,  and 
from  water  from  the  same  source ;  not  very  abundant. 

Morphology. — Bods  which  are  usually  more  or  less  curved,  like  the 
cholera  spirillum ;  usually  in  pairs,  but  several  elements  are  sometimes 
united  to  form  a  spiral  filament ;  the  rods  are  sometimes  straight. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  spiril- 
lum. Spore  formation  not  observed.  The  movements  are  sometimes  rotary, 
and  sometimes  progressive  without  rotation.  Grows  in  the  usual  culture 
media  at  the  room  temperature,  but  not  in  the  incubating  oven;  grows 
•better  in  media  made  without  the  addition  of  sea  water.  Upon  gelatin  plates 
the  colonies  are  first  seen  as  round,  granular  masses,  often  presenting  radial 
striations.  When  liquefaction  of  the  gelatin  commences  the  colonies  have 
.a  rougher  appearance,  and  flocculent  masses  float  in  the  shallow  cavities 
containing  liquefied  gelatin.  In  gelatin  stick  cultures  development  is  very 
rapid  at  first;  the  gelatin  is  liquefied  and  clouded,  and  a  thin,  semi-trans- 
parent membrane  forms  upon  the  surface;  later  a  stratum  of  liquefied  gelatin 
is  seen  above,  while  below  the  culture  medium  remains  unaltered.  Upon 
agar  the  growth  is  luxuriant  and  forms  a  moist,  white,  pus-like  layer.  Upon 
potato  the  growth  is  very  characteristic ;  at  the  end  of  twenty-four  hours 
a  reddish-brown,  sharply  defined  layer  is  developed,  and  the  potato  changes 
its  color  in  the  vicinity  of  the  line  of  inoculation ;  the  growth  increases  .in 
dimensions  and  forms  a  thick,  wax-like  mass,  which  after  a  time  covers  the 
greater  portion  of  the  surface ;  it  remains  soft  and  does  not  penetrate  the 
potato,  which  gradually  acquires  a  dark  greenish-gray  color.  In  bouillon 
made  with  sea  water  development  is  abundant  and  causes  the  culture  liquid 
to  be  densely  clouded;  a  smooth,  white  layer  forms  upon  the  surface. 

__447.    BACILLUS  LITORALIS   (RuSSell). 

Obtained  by  Russell  (1891)  from  mud  at  the  bottom  of  the  Gulf  of  Na- 
ples, near  the  shore. 

Morphology. — Bacilli  two  to  four  times  as  long  as  broad. 

Stains  with  Loffler's  solution,  but  not  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, motile  bacillus.  Spore  formation  not  observed.  Movements  very 


BACTERIA,    NOT   CLASSIFIED. 


715 


irregular.  Grows  slowly  in  the  usual  culture  media  at  the  room  temperature. 
Upon  gelatin  plates  deep  colonies  are  seen  at  the  end  of  three  days  as  well- 
defined,  small,  brown  points.  The  superficial  colonies  are  at  first  shining  and 
opalescent ;  under  the  microscope  they  are  seen  to  be  finely  granular  and 
have  smooth  margins;  at  the  end  of  five  to  eight  days  the  colonies  in  con- 
tact with  the  air  commence  to  cause  liquefaction  of  the  gelatin ;  liquefac- 
tion progresses  so  slowly  that  evaporation  keeps  pace  with  it,  and  the  colo- 
nies slowly  sink  into  the  gelatin ;  when  the  layer  of  gelatin  is  quite  thin  a 
ring  of  liquefied  gelatin  may  surround  the  colony.  In  gelatin  stick  cultures 
a  scanty  gi-owth  is  seen  along  the  line  of  puncture  at  the  end  of  twenty-four 
hours.  Upon  the  surface  a  thin,  irregular,  whitish  layer  commences  to 
form  around  the  point  of  inoculation  at  the  end  of  three  or  four  days;  the 
gelatin  is  slowly  liquefied  below  this,  and  as  a  result  of  evaporation  a  small 
•cavity  is  formed  which  is  lined  with  a  thin  layer  of  bacilli.  But  little  de- 


«  0 

c 


Fia.  263.  FIG.  264. 

FIG.  263.— Bacillus  litoralis;  A,  colony  upon  gelatin  plate,  ten  days  old;  B,  gelatin  stick  culture 
ten  days  old;  C,  bacilli  from  hanging-drop  culture.  (Russell.) 

FIG.  264.— Bacillus  halophilus;  A,  culture  in  nutrient  gelatin  at  end  of  twenty -four  hours;  B 
culture  in  sea-water  gelatin  at  end  of  twenty- four  hours.  (Russell.) 

velopment  occurs  along  the  line  of  inoculation  below,  but  the  growth  often 
acquires  a  reddish-brown  color,  and  the  gelatin  around  it  is  stained  brown — 
this  color  is  only  developed  in  the  absence  of  oxygen.  In  streak  cultures 
white,  semi-transparent  colonies  are  formed  along  the  line  of  inoculation ; 
these  become  visible  after  the  second  day,  extend  slowly,  and  finally  coal- 
esce; in  the  course  of  five  to  seven  days  the  thicker  white  colonies  com- 
mence to  sink  below  the  surface  as  a  result  of  liquefaction  and  evaporation ; 
liquefaction  now  progresses  more  rapidly,  and  after  a  time  the  deposit  at  the 
bottom  of  the  liquefied  gelatin  acquires  a  reddish-brown  tint.  No  growth 
occurs  upon  potato.  Upon  agar  a  scanty,  thin,  moist-looking,  grayish-white 
layer  is  formed.  In  bouillon  a  uniform  cloudiness  is  developed  and  no  pel- 
licle forms  upon  the  surface. 


716  ADDITIONAL   SPECIES   OF 

448.    BACILLUS   HALOPHILUS   (Russell). 

Obtained  by  Russell  (1891)  from  water  of  the  Gulf  of  Naples  and  from 
mud  from  the  bottom. 

Morphology, — Recent  cultures  in  nutrient  gelatin  made  with  sea  water 
contain  bacilli  of  from  1.5  to  3.5  ju.  in  length  and  0.7//  broad;  these  are  often 
united  in  pairs.  In  older  cultures  the  form  quickly  changes,  and  at  the  end 
of  two  days  cells  resembling  those  of  a  torula — "yeast-like" — are  seen; 
these  abnormal  forms  increase  in  number  and  variety  as  the  culture  becomes 
older ;  some  contain  a  granular  protoplasm,  and  some  are  so  transparent  as 
to  be  easily  overlooked.  These  cells,  however,  are  motile  and  resemble 
the  so-called  monads.  The  variability  of  form  is  still  greater  in  ordinary 
nutrient  gelatin,  which  is  a  less  favorable  medium  than  gelatin  made  with 
sea  water. 

Stains  with  difficulty,  and  not  at  all  with  Loffler's  solution;  does  not 
stain  by  Gram's  method;  the  protoplasm  is  irregularly  stained  by  Ziehl's 
solution,  while  fuchsin  solution  stains  it  feebly  but  homogeneously. 

Biological  Characters. — An  aerobic,  liquefying,  actively  motile  bacil- 
lus. Spore  formation  not  observed.  Grows  slowly  in  the  usual  culture 
media  at  the  room  temperature.  In  stick  cultures  in  nutrient  gelatin  made 
with  sea  water,  at  the  end  of  twenty-four  to  thirty-six  hours,  punctiform 
colonies  are  developed,  which  quickly  coalesce  ;  liquefaction  occurs  along 
the  line  of  growth  and  gas  is  developed ;  sometimes  this  is  so  abundant  that 
the  liquefied  gelatin  is  forced  up  over  the  surface  of  the  culture  as  a  foamy 
mass ;  later  the  liquefied  gelatin  becomes  transparent,  and  a  fine  deposit  is 
seen  at  the  bottom  of  the  tube.  In  nutrient  gelatin  not  made  with  sea  wa- 
ter the  growth  is  considerably  slower;  at  first  a  white  line  is  seen,  extending 
only  along  a  portion  of  the  puncture;  in  the  course  of  seventy  hours  a 
slender  cavity  is  formed  as  a  result  of  slow  liquefaction  and  evaporation  ; 
this  gradually  increases  in  length  and  gives  to  the  cultures  a  characteristic 
appearance.  In  plates  made  with  sea- water  gelatin,  spherical,  grayish- 
white,  semi-transparent  colonies  are  developed;  these  cause  liquefaction, 
and  by  evaporation  sharply  defined,  deep  funnels  are  formed  in  the  gelatin. 
The  cultures  have  a  strongly  alkaline  reaction. 

449.    BACILLUS   CAPSULATUS   MUCOSUS   (Fasching). 

Obtained  from  the  nasal  secretion  in  two  cases  of  influenza. 

Morphology. — Bacilli  from  3  to  4  ft  long  and  0.75  to  1  n  thick,  enveloped 
in  a  capsule  containing  one  to  four  individuals. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
motile,  non-liquefying  bacillus.  Does  not  form  spores.  Grows  in  the  usual 
culture  media  at  18°  to  35°  C.  Upon  gelatin  plates  circular,  milk-white  colo- 
nies are  developed ;  these  have  a  faint  aromatic  odor  and  are  cupped  upon 
the  upper  surface ;  they  resemble  drops  of  mucus  about  the  size  of  a  pin's  head. 
In  stick  cultures  in  gelatin  a  nail-like  growth,  like  that  of  Friedlander's  bacil- 
lus, is  seen,  and  there  is  a  formation  of  gas.  . 

Stains  with  the  usual  aniline  colors,  but  not  by  Gram's  method. 

Pathogenesis. — White  mice  and  field  mice  die  from  general  infection  in 
from  thirty-six  to  forty-eight  hours  after  inoculation ;  they  also  suffer  from 
conjunctivitis.  Not  pathogenic  for  rabbits  or  for  pigeons. 

450.  BACILLUS  OF  POTATO  ROT  (Kramer). 

Obtained  by  Kramer  (1891)  from  potatoes  affected  with  wet  rot — "  Nass- 
faue. 

Morphology.— Bacilli  with  round  ends,  from  2.5  to  4  n  long  and  0.7  to 


BACTERIA,    NOT  CLASSIFIED.  717 

0.8  /it  broad;  often  united  in  chains;  grow  out  into  filaments;  in  old  cultures 
thicker  rods  of  an  ellipsoidal  form  are  seen,  and  spores  are  formed  which  en- 
tirely fill  the  cell  containing  them. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
large  oval  spores.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  liquefaction  occurs  rapidly,  forming  a  fun- 
nel, at  the  bottom  of  which  the  bacilli  accumulate.  In  streak  cultures  upon 
gelatin,  at  the  end  of  twelve  hours,  an  elevated,  dirty-white  line  of  growth 
is  seen  along  the  impfstrich ;  this  extends  latei-ally,  and  the  margins  are  scal- 
loped so  that  the  growth  resembles  a  leaf.  Upon  nutrient  agar  small,  dirty- 
white,  slimy  drops,  with  sharply  defined  margins,  are  developed.  Gelatin 
cultures  containing  litmus  or  carmine  are  decolorized  by  this  bacillus.  In 
solutions  containing  dextrose  it  multiplies  abundantly,  producing  carbon 
dioxide  and  butyric  acid.  In  starch  paste  containing  ammonium  tartrate 
the  starch  is  only  dissolved  to  a  slight  extent,  and  no  butyric  acid  is  de- 
veloped. It  has  but  slight  action  upon  cellulose.  Potatoes  sterilized  by 
steam  and  inoculated  with  a  pure  culture  of  the  bacillus  undergo  changes 
corresponding  with  "  Nassfaule  "  in  these  tubers.  These  consist  of  a  decom- 
position of  soluble  carbohydrates  (sugar),  with  a  formation  of  carbon  dioxide 
and  butyric  acid ;  then  of  the  intercellular  substance  and  the  cell  membranes, 
producing  an  acid  reaction  in  the  contents  of  the  tuber.  The  starch  is  not 
changed.  The  albuminous  substances  undergo  putrefactive  decomposition, 
with  production  of  ammonia,  methylamin,  and  trimethylamin.  These  bases 
first  neutralize  the  butyric  acid,  and  later  cause  an  alkaline  reaction  of  the 
affected  portions  of  the  potato.  In  milk  coagulation  of  the  casein  occurs, 
but  no  putrefactive  change  is  induced,  even  at  the  end  of  several  weeks,  as  is 
the  case  with  Bacillus  butyricus  (Hueppe). 

451.  BACILLUS  VACUOLOSis  (Sternberg). 

Obtained  by  Sternberg  (1888)  in  cultures  from  the  intestine  and  stomach 
of  yellow-fever  cadavers. 

Morphology. — Bacilli  with  round  ends,  which  vary  considerably  in  the  r 
dimensions  and  are  sometimes  slightly  curved;  length  from  1.5  to  5  >u, 
breadth  about  1  /*.  In  stained  preparations  unstained  places — vacuoles  ? — 
are  seen  in  the  rods.  In  surface  cultures  upon  agar  various  involution  forms 
are  seen,  which  also  present  vacuoles  and  which  are  usually  considerably 
larger  than  the  normal  bacilli.  The  bacilli  sometimes  grow  out  into  long, 
jointed  filaments. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
large  oval  spores.  Grows  in  the  usual  culture  media  at  the  room  tempera- 
ture. In  gelatin  stick  cultures  liquefaction  occurs  slowly,  near  the  surface, 
forming  a  cup-shaped  cavity.  The  liquefied  gelatin  is  quite  viscid,  and  a 
cream- white  layer  of  bacilli  forms  upon  the  surface  of  the  liquefied  medium. 
In  nutrient  agar  the  development  along  the  line  of  puncture  is  scanty ;  on 
the  surface  a  cream-white  layer  is  formed  and  the  bacilli  are  united  in  long, 
jointed  filaments.  It  is  not  always  seen  to  be  motile,  but  under  certain  cir- 
cumstances exhibits  slowly  progressive,  to-and-fro  movements,  as  if  propelled 
by  a  flagellum.  Does  not  grow  in  an  acid  medium.  On  potato  a  thin, 
cream-white  layer  is  formed. 

Pathogenesis. — Not  pathogenic  for  rabbits.  Not  tested  upon  other  ani- 
mals. 

452.    BACILLUS   OF   DANTEC. 

Synonym. — Bacille  du  rouge  de  morue. 

Obtained  by  Dantec  (1891),  in  association  with  other  microorganisms, 
from  salted  codfish,  to  which  it  imparts  a  red  color. 

62 


718  ADDITIONAL,  SPECIES  OF 

Morphology.—  Bacilli  with  round  ends,  from  4  to  12  n  long,  and  usually 
containing  a  spore  at  one  extremity.  Resembles  the  bacillus  of  tetanus,  but 
is  considerably  thicker. 

Biological   Characters. — An  aerobic,  liquefying,   motile,  chromogenic 
bacillus.     Foi'ms  spores.     Grows   in   the   usual  culture   media  at  the  room 
temperature.     Produces  a  red  pigment.     In  gelatin  stick  cultures  liquefac- 
tion  in  funnel  form  occurs  along  the  line  of 
puncture.    In  old  gelatin  liquefaction  may  not 
v*  occur.     Upon  the  surface  of  nutrient  gelatin  a 

s    »         » I  red  streak  is  developed  along  the  line  of  in- 

t**         s  |l  oculation,  and  the  gelatin  below  this  is  very 

"*      \  ,N'  \     *  v  ^  slowly  liquefied.    The  colonies  in.  gelatin  plates 

•*    V  *  '3  may  attain    a    diameter  of  two  millimetres; 

i  ^  /     ^     i     \  they  have  a  pale-red  centre  with  a  deeper  red 

N   %\      .      »'  o      periphery,  and  are  disc-shaped.     In  bouillon 

~  A!   *         *     i       \     I          development  is  abundant,  but  without  the  for- 
»          I.     ^         "S.  mation  of  pigment.    Does  not  grow  well  upon 

°        «.*      x*     ./  §  potato.     Pigment  is  formed  more  abundantly 

lx       *       '  *  at  10°  to  15 3  C.  than  at  a  higher  temperature. 

Upon  dried  codfish  it  grows  readily,  forming 
a  red  pigment,  especially  upon  the  side  which 

FIG.  a65.-Bac.llus  of  Dantee.  hag  ^  exposed  {o  the  ^.lt 

Not  pathogenic. 

453.  BACILLUS  (MICROCOCCUS  ?)  HAVANIENSIS  (Sternberg). 

Morphology.— Short-oval  bacilli,  usually  in  pairs,  about  0.4  to  0.5  u  in 
diameter.  The  cells  are  so  nearly  spherical  that  the  writer  has  been  in  doubt 
whether  to  describe  this  microorganism  as  a  bacillus  or  as  a  micrococcus. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic  ba- 
cillus(?).  Grows  slowly  in  the  usual  culture 
media  at  the  room  temperature.  Upon  gelatin 
plates  forms  small,  spherical,  translucent  colo- 
nies of  a  beautiful  blood-red  color.  In  gelatin 
stick  cultures  a  thick,  opaque,  carmine  layer 
develops  about  the  point  of  inoculation  and 
slowly  increases  in  thickness  and  circumference ; 
very  scanty  growth,  without  color,  at  the  upper 
part  of  the  line  of  puncture.  Upon  the  surface 
of  agar  the  growth  is  slow  but  continuous,  and 
forms,  at  the  room  temperature,  a  thick,  carmine 
layer  along  the  line  of  inoculation  ;  this  has 
wavy  outlines  and  a  glistening,  varnished-like 
surface  ;  it  gradually  extends  in  thickness  and 
breadth,  which  at  the  end  of  a  month  may  bo  FlG-  266. -Bacillus  Havanien- 
five  to  six  millimetres.  Frequently  this  micro-  sis-  x  1,000.  (Sternberg.) 
coccus  fails  to  grow  on  potato,  perhaps  because 

of  an  acid  reaction.  But  upon  old  and  rather  dry  potato  it  sometimes  de- 
velops, as  it  does  on  nutrient  agar,  forming  a  thick,  irregular  mass  of  a 
carmine  color.  The  pigment  is  only  formed  in  the  free  pi'esence  of  oxygen. 

454.  BACILLUS  AMYLOZYMA  (Perdrix). 

Obtained  by  Perdrix  (1891)  from  the  hydrant  water  of  Paris — best  from 
the  deposit  left  in  a  Chamberlain  filter  through  which  this  water  has  been 
passed. 

Morphology. — Bacilli  with  round  ends,  from  2  to  3  n  longandO.5// 
broad ;  usually  in  pairs,  or  in  chains  of  several  elements. 

Stains  with  the  usual  aniline  colors. 


BACTERIA,    NOT   CLASSIFIED.  719 

Biological  Characters. — A.  strictly  anaerobic,  non-liquefying,  motile 
bacillus.  Forms  spores.  Grows  in  the  usual  culture  media  in  ail  atmo- 
sphere of  hydrogen  at  the  room  temperature.  In  nutrient  gelatin  colonies 
are  developed  at  the  end  of  five  or  six  days ;  these  are  small,  white  plaques 
surrounded  by  gas  bubbles.  Upon  potato,  in  an  atmosphere  of  hydrogen, 
whitish  colonies  are  developed,  around  which  the  potato  appears  excavated; 
at  the  same  time  it  is  partly  liquefied  by  the  ferment  action  of  the  bacillus,' 
and  the  liquid  collects  at  the  bottom  of  the  tube.  When  these  potato  tubes 
are  opened  there  is  a  little  explosion,  due  to  escaping  gas.  The  development 
of  the  bacillus  is  most  rapid  and  its  ferment  action  most  energetic  at  a  tem- 
perature of  about  35°  C  It  causes  fermentation  of  sugar  and  of  starch,  but 
not  of  cellulose.  It  ceases  to  grow  in  cultures  containing  0.10  to  0.12  per 
cent  of  acid  (estimated  in  sulphuric  acid),  and,  as  it  produces  an  acid  reac- 
tion of  the  culture  medium,  it  is  necessary  to  add  carbonate  of  lime  to  this 
to  insure  its  continuous  development.  The  acids  formed  from  the  fermenta- 
tion of  sugar  are  acetic  (at  the  outset)  and  butyric.  In  culture  media  con- 
taining starch,  ethylic  and  amylic  alcohol  are  produced,  as  well  as  butyric 
acid ;  a  considerable  portion  of  the  starch  is  converted  into  sugar,  and  hydro- 
gen and  carbon  dioxide  are  given  off  freely  as  a  result  of  the  fermentation. 

455.  BACILLUS  RUBELLUS  (Okada). 

Obtained  by  Okada  (1892)  from  dust  by  inoculations  in  guinea-pigs.  Not 
pathogenic,  but  found  in  association  with  pathogenic  bacteria  in  the  bloody 
serum  effused  about  the  point  of  inoculation— with  dust  from  the  streets. 

Morphology. — Resembles  Bacillus  cedematis  maligni  in  its  form  and  di- 
mensions. Bacilli  with  slightly  rounded  ends,  usually  in  pairs  or  chains  of 
three;  in  old  bouillon  cultures  grows  out  into  filaments  10  to  15 // long; 
these  are  often  surrounded  by  a  capsule-like  envelope.  The  rods  show  a 
slight  swelling  when  spore  formation  occurs,  becoming  spindle  shaped  or 
having  an  expanded  extremity,  according  as  the  spore  is  formed  in  the 
middle  or  at  one  extremity.  Flagella  may  be  demonstrated  by  Loffler's 
method  of  staining;  these  are  seen  at  one  or  at  both  extremities. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters.— An  anaerobic,  chromogenic,  liquefying,  motile 
bacillus.  Forms  large  oval  spoi-es,  which  are  located  at  one  extremity  or  in 
the  centre  of  the  rods.  In  gelatin  plates  kept  in  an  atmosphere  of  hydro- 
gen, dull-white,  punctiform  colonies  are  developed  at  the  end  of  ten  days  at 
15°  to  18°  C  ;  under  a  low  power  these  are  seen  to  be  long-oval  in  form  and 
surrounded  by  fine  offshoots  ;  after  a  time  the  gelatin  is  liquefied  and  ac- 
quires a  reddish  color.  In  deep  gelatin  stick  cultures  development  com- 
mences at  the  bottom  of  the  line  of  puncture,  where,  at  the  end  of  ten  days, 
small,  dull-white,  spherical  or  oval  colonies  are  developed ;  these  are  seen  to 
be  surrounded  by  radiating  offshoots ;  the  colonies  increase  in  size,  and  the 
gelatin  is  gradually  liquefied  in  the  lower  two-thirds  of  the  tube,  while 
above  it  remains  solid ;  a  flocculent  deposit  is  now  seen  at  the  bottom  of  the 
tube,  which  has  a  reddish  color;  finally  the  upper  portion  of  the  gelatin  is 
also  liquefied  and  the  whole  of  the  fluid  has  a  red  color.  Upon  agar  plates, 
at  37°  C. ,  development  is  more  abundant  and  rapid ;  colonies  are  developed  in 
twenty-four  hours,  which  subsequently  increase  in  size  and  acquire  a  red 
color.  In  deep  stick  cultures  in  agar,  in  the  incubating  oven,  development 
occurs  below  at  the  end  of  twenty-four  hours  and  gradually  extends  up- 
ward to  near  the  surface.  Gradually  the  upper  portion  of  the  growth  ac- 
quires a  red  color,  which  increases  in  intensity,  and  the  upper  portion  of  the 
culture  medium  is  after  a  time  diffusely  colored.  In  bouillon  in  an  atmo- 
sphere of  hydrogen,  at  37°  C. ,  development  is  abundant  and  rapid,  and  the 
medium  acquires  a  red  color. 

Not  pathogenic. 


720  ADDITIONAL  SPECIES   OF 

456.  BACTERIUM   URE^E   (Jaksch). 

Found  in  ammoniacal  urine. 

Morphology. — Bacilli  with  round  ends,  about  2  M  long  and  1  M  thick. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying  bacillus.  Spore  formation  riot  observed.  Grows  very  slowly  at 
the  room  temperature.  Changes  urea  into  carbonate  of  ammonia.  Upon 
gelatin  plates  forms  small,  almost  transparent  colonies,  which  at  the  end  of 
ten  days  may  have  the  diameter  of  a  "  pfennig."  In  gelatin  stick  cultures 
a  thin,  gray,  branching  growth  is  seen  along  the  line  of  puncture.  Old 
cultures  have  the  odor  of  herring-brine.  Imperfectly  described. 

457.  SARCINA  MOBILIS  (Maurea). 

Obtained  by  Maurea  (1892)  from  ascitic  fluid  which  had  been  preserved 
a  long  time  in  a  test  tube. 

Morphology. — Micrococci  having  a  diameter  of  1.5  /*  and  associated  in 
pairs  or  in  tetrads. 

Stains  with  the  usual  aniline  colors  and  also  by  Gram's  method. 

Biological  Characters. — An  aerobic,  liquefying,  motile,  chromogenic 
sarcina.  Does  not  grow  in  the  incubating  oven  at  37°  C.  Motions  progres- 
sive, serpentine,  or  rotatory  (?).  Upon  gelatin  plates,  at  15°  to  20°  C.,  puncti- 
form,  white  colonies  are  seen  on  the  third  day.  By  the  seventh  day  lique- 
faction of  the  gelatin  commences  around  the  colonies  and  a  brick-red  pig- 
ment is  formed.  In  gelatin  stick  cultures,  at  the  end  of  five  days,  a  scanty 
development  is  seen  along  the  line  of  puncture  and  a  more  abundant  growth 
upon  the  surface ;  later  the  surface  growth  acquires  a  brick-red  color  ;  in 
from  fifteen  to  twenty  days  liquefaction  has  occurred  in  the  form  of  a  small 
funnel,  and  by  the  end  of  thirty  days  one-half  of  the  contents  of  the  tube  is 
liquefied.  In  bouillon  the  fluid  becomes  clouded  in  two  or  three  days,  and 
later  a  yellowish-red  deposit  is  seen  at  the  bottom  of  the  tube.  In  agar 
stick  cultures  a  whitish  layer  is  developed  on  the  surface,  which  later  ac- 
quires a  brick-red  color.  In  milk  growth  occurs  without  producing  coagu- 
lation. No  growth  upon  potato.  In  hay  infusion  sarcina-like  packets  are 
developed  in  abundance,  as  well  as  tetrads  and  diplococci. 

458.   BACILLUS  STOLONIFERUS  (Pohl). 

Obtained  from  swamp  water  (1892). 

Morphology. — Bacilli  1.2  ^  long  and  0.8  fi  broad. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  In  gelatin  stick  cultures  liquefaction,  in  funnel 
form,  commences  at  the  end  of  twenty-four  hours  and  progresses  rap- 
idly. Upon  the  surface  of  agar  a  thick,  white  mass  develops  along  the 
track  of  the  inoculating  needle.  Upon  potato  small  colonies  the  size  of  a 
pin's  head  are  developed  along  the  line  of  inoculation  and  extend  over  the 
entire  surface.  In  milk  a  scanty  development  occurs ;  the  milk  is  not  coagu- 
lated and  no  acid  is  formed. 

459.   BACILLUS  INCANUS   (Pohl). 

Obtained  from  swamp  water. 

Morphology. — Bacilli  1.7  n  long  and  0.4  n  broad. 

Biological  Characters. — An  aerobic,  liquefying,  slightly  motile  bacillus, 
In  gelatin  stick  cultures  growth  occurs  along  the  line  of  puncture  and  upon 
the  surface  as  a  grayish-white,  elevated  mass.  At  the  end  of  forty-eight 
hours  slight  liquefaction  is  observed ;  this  progresses  very  slowly.  Upon  the 
surface  of  agar  a  grayish-white,  granular  mass  is  developed  along  the  track 
of  the  inoculating  needle.  Upon  potato  a  gray,  viscid  layer  is  formed,  which 


BACTERIA,    NOT   CLASSIFIED.  721 

quickly  extends  over  the  entire  surface.     Does  not  produce  an  acid  reaction 
in  milk. 

460.    BACILLUS  INUNCTUS   (Pohl). 

Obtained  from  swamp  water. 

Morphology. — Bacilli  3.5  n  long  and  0.8  to  0.9  ju  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Spore  formation  not  observed.  Upon  gelatin  plates 
forms  oval  or  round  colonies  with  a  smooth  margin  and  oily,  shining  ap- 
pearance. In  gelatin  stick  cultures  grows  along  the  line  of  puncture,  and 
below  the  growth  has  a  radiating  appearance;  upon  the  surface  a  thick, 
white,  shining  layer  is  quickly  formed ;  later  liquefaction  commences  and 
progresses  slowly.  Upon  the  surface  of  agar  white,  cloud-like  masses  are 
formed  along  the  streak.  Upon  potato  a  white,  slimy  mass  is  formed  which 
soon  covers  the  entire  surface.  In  milk  an  acid  reaction  is  produced  by  the 
growth  of  this  bacillus,  but  no  coagulation  occurs.  In  Pasteur's  solution  con- 
taining cane  sugar  or  starch  an  abundant  development  of  alcohol  occurs. 

461.    BACILLUS  FLAVESCENS   (Pohl). 

Obtained  from  swamp  water  (1892). 

Morphology.—  Bacilli  2.1  to  2.2  /*  long  and  0.8  /*  broad. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic, 
slightly  motile  bacillus.  Spore  formation  not  determined.  Forms  a  yellow 
pigment.  Upon  gelatin  plates,  at  the  end  of  four  days,  colonies  are  visible ; 
these  are  yellow,  granular,  and  attain  the  size  of  a  pin's  head.  In  gelatin 
stick  cultures  it  grows  along  the  line  of  puncture,  and  slowly  extends  over 
the  entire  surface.  Upon  the  surface  of  agar  small,  solitary,  yellow  colo- 
nies are  developed  along  the  track  of  the  needle.  Upon  potato  development 
is  somewhat  more  rapid,  and  at  the  end  of  four  days  the  entire  surface  is 
covered  with  a  slimy,  yellow  layer.  Gelatin  colored  blue  with  litmus  is  de- 
colorized without  the  previous  change  of  color  to  red.  In  milk  an  acid  reac- 
tion is  produced  without  coagulation. 

462.    BACILLUS  BUTYRICUS  OF  BOTKIN. 

Obtained  by  Botkin.  in  anaerobic  cultures  from  milk,  from  hydrant  wa- 
ter, well  water,  garden  earth,  and  dust. 

Morphology. — In  agar  and  gelatin  cultures  containing  one  and  one-half 
per  cent  of  grape  sugar  the  bacilli  are  0.5  ju  long  and  1  to  3  n  in  diameter, 
with  round  ends ;  they  are  often  united  in  pairs  or  in  chains  of  three ;  in 
liquid  media  they  are  not  so  thick,  and  often  attain  a  length  of  10  ju.  or  more, 
without  segmentation ;  long  chains  may  also  be  observed.  The  spores  are 
located  in  the  centre  of  the  rods,  or  occasionally  at  one  extremity ;  they  vary 
greatly  in  their  dimensions;  the  diameter  is  usually  about  1  >«  and  the 
length  2  to  3  //.  In  old  cultures  various  involution  forms  are  seen. 

Stains  with  the  usual  aniline  colors. 

Biological  Characters.  —  An  anaerobic,  liquefying,  slightly  motile  ba- 
cillus. Forms  large  oval  spores,  which  have  a  high  resisting  power  for 
heat.  To  obtain  pure  cultures  Botkin  subjects  milk  containing  this  bacillus 
to  the  boiling  temperature  —in  the  steam  'sterilizer— for  half  an  hour.  The 
spores  resist  this  temperature,  and  the  flask  containing  the  milk  is  hermeti- 
cally sealed  and  placed  in  an  incubating  oven  at  37°  C.  At  the  end  of  twelve 
hours,  as  a  rule,  fermentation  commences;  the  casein  is  coagulated  and  col- 
lects, together  with  the  fat,  at  the  upper  part  of  the  flask,  while  a  clear,  yel- 
lowish serum  is  seen  below ;  there  is  an  abundant  development  of  gas.  The 
most  favorable  temperature  for  growth  is  37°  to  38°  C.,  but  development 
may  occur  at  temperatures  ranging  from  18°  to  42°  C. ;  at  18°  development 
is  very  slow  and  usually  no  gas  is  formed.  In  culture  media  containing 


722  ADDITIONAL  SPECIES  OF 

starch  many  of  the  bacilli,  at  the  end  of  two  or  three  days,  contain  granules 
which  acquire  a  deep-blue  color  when  treated  with  iodine  solution.  Upon 
agar  plates  (with  1.5  per  cent  of  grape  sugar),  in  an  atmosphere  of  hydro- 
gen, colonies  are  developed  in  fifteen  to  eighteen  hours,  which  under  the 
microscope  are  seen  to  be  round  or  elliptical  in  form  and  to  consist  of  closely 
interwoven  filaments ;  as  a  rule,  the  margins  are  not  well  defined,  and  radiat- 
ing filaments  are  given  off  from  the  felt-like  colony.  In  deep  stick  cultures 
in  agar,  growth  commences  at  a  depth  of  one  and  one-half  centimetres  below 
the  surface;  later,  when  the  oxygen  is  displaced  by  the  gases  produced,  it 
approaches  the  surface.  The  growth  along  the  line  of  puncture  has  an  ir- 
regular outline  with  wave-like  projections.  In  gelatin  (with  1.5  per  cent  of 
grape  sugar)  growth  begins,  in  deep  stick  cultures,  about  two  centimetres 
below  the  surface ;  much  gas  is  developed  and  the  gelatin  is  quickly  lique- 
fied. In  bouillon  (with  1.5  per  cent  of  grape  sugar)  an  abundant  develop- 
ment occurs  within  twenty-four  hours  in  an  atmosphere  of  hydrogen.  The 
fluid  becomes  clouded  and  much  gas  is  developed;  at  the  end  of  three  days 
the  fermentation  ceases,  the  bouillon  becomes  clear,  and  a  thick,  white  de- 
posit is  seen  at  the  bottom  of  the  tube.  In  milk,  contained  in  flasks  com- 
pletely full,  and  from  which  the  oxygen  has  been  expelled  by  boiling, 
growth  commences  near  the  bottom,  where  at  the  end  of  fifteen  hours  a 
transparent  layer  of  serum  is  seen,  from  which  numerous  gas  bubbles  are 
given  off ;  the  fermentation  progresses  rapidly,  and  at  the  end  of  eighteen 
hours  the  coagulated  casein  and  particles  of  fat  have  accumulated  at  the 
upper  part  of  the  flask;  the  pressure  of  gas  is  so  great  that  many  of  the 
flasks  are  blown  into  fragments;  at  the  end  of  a  week  development  has 
ceased  and  the  casein  is  almost  entirely  dissolved,  the  contents  of  the  flask 
consisting  of  a  transparent,  yellowish  fluid,  with  spongy  masses  of  fatty 
material  upon  the  surface  and  a  flocculeiit,  white  deposit  at  the  bottom. 
Upon  potato,  in  an  atmosphere  of  hydrogen,  development  occurs  in  the  in- 
terior of  the  potato,  but  not  upon  the  surface. 

Not  pathogenic. 

Note. — Botkin  is  not  able  to  identify  the  bacillus  described  by  him  with 
butyric-acid  bacilli  described  by  Pasteur,  Cohn,  Hueppe,  and  other  authors, 
which  for  the  most  part  have  been  cultivated  only  in  liquid  media.  He  re- 
marks that  it  is  differentiated  from  Clostridium  butyricum  of  Prazmowski 
(Vibrion  butyrique  of  Pasteur)  by  the  fact  that  it  does  not  decompose  cellu- 
lose or  salts  of  lactic  acid.  It  closely  resembles  a  butyric-acid  ferment  de- 
scribed by  Perdrix,  but  is  differentiated  from  it  by  the  fact  that  the  bacillus 
of  Perdrix  does  not  liquefy  gelatin. 

463.  UROBACILLUS  PASTEURI  (Miquel). 

Obtained  by  Miquel  from  decomposed  urine. 

Morphology. — Bacilli  differing  greatly  in  dimensions  in  different  media — 
the  diameter  may  be  as  much  as  1.2  ju.  In  urine  to  which  two  per  cent  of 
urea  has  been  added  it  is  usually  seen  in  the  form  of  short  rods  united  in 
chains  of  two  to  six  elements.  In  gelatin  cultures  containing  urea  the  ba- 
cilli are  from  4  to  6  M  long  and  are  usually  in  pairs. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
spherical  spores,  usually  solitary,  and  situated  at  one  extremity  of  the  rod. 
Grows  at  the  room  temperature  in  the  usual  culture  media  when  these  are 
made  alkaline  by  the  addition  of  ammonia,  or  when  urea  is  added.  In  gela- 
tin plates  containing  urea  minute  colonies  are  developed  within  twenty- four 
hours  and  an  ammoniacal  odor  is  given  off ;  under  a  low  power  the  colonies 
are  seen  to  be  spherical  or  oval,  yellowish,  and  surrounded  by  dumbbell- 
shaped  crystals ;  at  the  end  of  eight  days  the  gelatin  commences  to  liquefy, 
and  after  a  time  has  the  consistence  of  castor  oil.  In  ordinary  flesh-peptone- 
gelatin  no  development  occurs,  unless  the  medium  has  a  distinctly  alkaline 
reaction.  No  growth  occurs  in  the  usual  agar-agar  medium,  but  when  urea 


BACTERIA,    NOT   CLASSIFIED.  723 

is  added  an  abundant  development  occurs,  and  numerous  very  minute  crys- 
tals are  scattered  through  the  culture  medium.  In  urine  alkaline  fermenta- 
tion is  quickly  induced,  and  an  abundant  deposit  of  crystals  of  ammonio- 
magnesian.  phosphate  and  of  alkaline  urates,  together  with  the  bacilli, 
accumulates  at  the  bottom  of  the  test  tube ;  this  deposit  acquires  a  blackish 
color.  The  most  favorable  temperature  for  the  growth  of  this  bacillus  is  30° 
to  40°  C. 

464.    UROBACILLUS  DUCLAUXI  (Miquel). 

Obtained  by  Miquel  (1879)  in  the  water  of  sewers,  and  subsequently  in 
river  water — very  common  and  widely  distributed. 

Morphology. — Slender  filaments,  from  0.6  to  0.8  in  diameter  and  from 
2  to  10  u  long.  In  alkaline  bouillon  it  may  attain  a  diameter  of  1  ft ;  the  ba- 
cilli are  frequently  united  in  chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  motile, 
liquefying  bacillus.  The  movements  are  comparatively  slow.  Forms 
spores  located  at  the  centre  of  the  rods,  which  then  are  spindle-shaped.  De- 
velops most  rapidly  at  40°  C.  No  development  occurs  at  5°  C.,  but  at  8°  to 
10°  the  fermentation  of  a  culture  medium  containing  urea  is  accomplished  in 
about  a  month,  and  at  20°  in  two  or  three  days.  Does  not  grow  in  ordinary 
bouillon  or  nutrient  gelatin,  but  grows  in  the  usual  culture  media  when  they 
are  rendered  alkaline  by  the  addition  of  ammonia,  or  when  urea  is  added. 
In  nutrient  gelatin  containing  urea  numerous  small,  white  colonies  are  de- 
veloped along  the  track  of  the  needle,  and  a  quantity  of  minute  crystals  are 
scattered  through  the  culture  medium.  At  the  end  of  three  or  four  months 
the  gelatin  medium  is  transformed  into  a  transparent,  ammoniacal,  syrupy 
liquid.  In  alkaline  gelatin  not  containing  urea  liquefaction  does  not  occur. 
In  bouillon  made  alkaline  by  the  addition  of  ammonia,  growth  occurs,  caus- 
ing the  liquid  to  become  clouded  within  twenty -four  hours ;  later  an  abun- 
dant sediment  accumulates  at  the  bottom  of  the  tube,  the  liquid  becomes  vis- 
cid and  gives  off  a  disagreeable  odor. 

465.    UROBACILLUS  FREUDEXREICHI  (Miquel). 

Obtained  by  Miquel  from  the  air,  from  dust,  from  sewer  water,  etc. 

Morphology. — Closely  resembles  Urobacillus  Pasteuri,  but  forms  longer 
chains  and  has  more  active  movements.  The  rods  are  from  1  to  1.3  n  thick 
and  have  rounded  extremities  ;  the  length  varies  considerably,  but  in  recent 
cultures  is  usually  5  to  6  ju.  Under  favorable  conditions  of  temperature, 
30°  C. ,  actively  motile  filaments,  consisting  of  six  to  ten  elements,  are  de- 
veloped in  alkaline  bouillon  ;  upon  solid  media  long  filaments,  composed 
of  comparatively  short  elements  and  quite  motionless,  are  developed. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
spores.  The  most  favorable  temperature  for  the  development  of  this  bacillus 
is  from  33°  to  35 J  C.  As  a  ferment  of  urea  it  is  ten  times  less  active  than 
Urobacillus  Pasteuri.  In  nutrient  gelatin,  at  20°  C  ,  development  occurs 
upon  the  surface  as  a  milk-white  growth,  which  is  visible  at  the  end  of  two 
days,  and  later  forms  a  layer  with  irregular  outlines  having  a  diameter  of 
three  to  four  millimetres  ;  but  little  development  occurs  along  the  track  of 
the  inoculating  needle  ;  liquefaction  commences  at  the  surface  at  the  end 
of  eight  to  ten  days  and  progresses  slowly  ;  at  the  end  of  thirty  to  forty 
days  the  gelatin  is  completely  liquefied,  it  is  of  a  pale-yellow  color  and  quite 
viscid  ;  an  abundant  white  deposit  accumulates  at  the  bottom  of  the  tube. 
Upon  gelatin  plates  (containing  urea)  small,  spherical,  white  colonies  are 
developed  in  two  or  three  days ;  these  gradually  increase  in  dimensions 
and  are  surrounded  by  an  aureole  of  minute  crystals ;  later  the  development 
ceases  and  the  bacilli  are  killed  by  an  excess  of  carbonate  of  ammonia  re- 
sulting from  the  decomposition  of  the  urea.  In  neutral  bouillon,  at  the  end 
of  two  or  three  days,  a  slight  cloudiness  is  developed,  and  later  a  scanty 
white  deposit  is  seen  at  the  bottom  of  the  tube. 


724:  ADDITIONAL  SPECIES  OF 

466.    UROBACILLUS  MADDOXI  (Miquel). 

Obtained  from  sewer  water  and  from  river  water — relatively  rare. 

Morphology. — Bacilli  with  round  ends,  1  u  thick  and  3  to  6  ft  long  ;  in 
old  cultures  the  bacilli  are  often  seen  as  oval  or  spherical  cells  having  a 
diameter  of  6  to  8  /* ;  in  solid  media  the  length  is  usually  from  2  to  3  /*. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
spores.  Grows  best  at  38°  C.,  but  causes  fermentation  of  urine  at  the  end 
of  several  days  at  a  temperature  as  low  as  10°  C.  In  nutrient  gelatin  it 
usually  fails  to  grow,  but  occasionally  a  scanty  development  occurs  along 
the  track  of  the  needle  in  the  form  of  small,  spherical  colonies.  In  nutrient 
gelatin  containing  urea  the  line  of  inoculation  is  marked  by  numerous  crys- 
tals, which  are  seen  at  the  end  of  twenty  hours,  although  the  growth  of  the 
bacilli  is  scarcely  apparent.  In  gelatin  plates  containing  urea  very  small, 
spherical,  opaque,  whitish  colonies,  surrounded  ^by  crystals,  may  be  seen 
under  a  low  power.  In  nutrient  agar  containing  urea,  at  30°  to  35°  C.,  a 
layer  is  formed  upon  the  surface,  which  is  at  first  white  and  la.ter  of  a  grayish- 
yellow  color.  In  bouillon  which  is  slightly  alkaline  it  grows  rapidly,  and 
produces,  at  the  end  of  two  days,  a  dense  turbidity  of  the  culture  liquid ; 
later  an  abundant  glairy  sediment  accumulates  at  the  bottom  of  the  tube. 
Iri  one  litre  of  bouillon  an  amount  of  soluble  ferment  is  produced  by  this 
bacillus  which  is  capable  of  decomposing  sixty  to  eighty  grammes  of  urea 
in  the  course  of  two  or  three  hours. 

467.    UROBACILLUS  SCHUTZENBERGI    (Miquel). 

Obtained  by  Miquel  from  river  water  and  from  the  water  of  sewers. 

Morphology. — Small  oval  bacilli  about  0. 5  M  thick  and  1  n  long ;  usually 
united  in  pairs. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Spore 
formation  not  observed.  In  nutrient  gelatin,  at20°C.,  liquefaction  in  cup 
shape  occurs  at  the  surface  and  progresses  rapidly,  being  complete  by  the  end 
of  ten  days.  In  gelatin  containing  two  per  cent  of  urea  liquefaction  com- 
mences at  the  surface  and  numerous  crystals  are  formed  in  the  solid  portion 
of  the  culture  medium ;  growth  is  soon  arrested  by  the  antiseptic  action  of 
the  products  developed.  In  gelatin  plates  small,  translucent,  spherical 
colonies  are  developed,  which  increase  rapidly  in  size  and  acquire  a  milky 
appearance;  when  the  colonies  reach  the  surface  liquefaction  rapidly  occurs ; 
when  the  gelatin  contains  urea  the  colonies  cease  growing  after  attaining  a 
diameter  of  one  to  two  millimetres,  and  they  are  surrounded  by  a  zone  of 
crystals.  Upon  nutrient  agar,  at  28°  to  30°  C. ,  development  occurs  in  the 
form  of  a  whitish  layer  with  a  slightly  greenish  tint.  In  bouillon,  at  the 
end  of  twenty-four  hours,  the  medium  becotnes  clouded ;  later  a  thin  pellicle 
forms  upon  the  surface  and  extends  upward  for  a  short  distance  upon  the 
walls  of  the  test  tube;  the  bouillon  remains  clouded  for  several  weeks. 
When  urea  is  added  to  peptonized  bouillon  development  is  still  more  abun- 
dant, but  ceases  at  the  end  of  four  or  five  days  and  the  liquid  becomes  en- 
tirely transparent. 

468.   BACILLUS  OF  BOVET. 

Obtained  by  Bovet  (1891)  from  the  intestine  of  a  woman  who  died  of  an 
acute  enteritis  with  choleraic  symptoms. 

Morphology. — Bacilli  from  1  to  1.5  jit  thick  and  2  to  4  n  long,  isolated  or 
in  pairs. 

Stains  with  carbol-fuchsin  solution. 

Biological  Characters. — An  aerobic,  non-liquefying,  motile  bacillus. 
Spore  formation  not  observed.  Grows  in  the  usual  culture  media  at  the 
room  temperature — more  rapidly  at  37°  C.  In  nutrient  gelatin,  at  15°  to  18° 
C.,  a  grayish- white,  somewhat  translucent  layer  with  irregular  outlines  is 


BACTERIA,    NOT   CLASSIFIED.  T^o 

developed  in  two  or  three  days ;  along1  the  line  of  the  inoculating-  needle  in 
stick  cultures  a  granular  growth  is  seen  which  has  a  brownish-gray  color. 
Upon  agar  the  surface  growth  is  similar  to  that  upon  gelatin  and  quickly 
covers  the  entire  surface.  When  the  culture  medium  contains  sugar  or  gly- 
cerin lenticular  bubbles  of  gas  are  formed  in  it.  Upon  potato  a  thick  layer 
is  developed  resembling  puree  of  peas,  but  not  so  decidedly  yellow  in  color ; 
in  old  cultures  the  color  is  a  dirty-gray.  In  anaerobic  cultures  a  scanty  de- 
velopment occurs. 

Pathogenesis. — Subcutaneous  injections  in  rabbits  or  guinea-pigs  gave  a 
negative  result.  Iritraperitoneal  injections  in  guinea-pigs  produce  peritoni- 
tis and  death. 

469.  BACILLUS  SCHAFFEKI  (Freudenreich). 

Obtained  by  Freudenreich  from  cheese  and  from  fermenting  potato — 
fragments  of  raw  potato  in  water. 

Morphology. — Bacilli  about  1  n  thick  and  from  2  to  3  //  long;  in  old  cul- 
tures long  filaments  are  common — 20  to  25  fi. 

Stains  well  with  the  usual  aniline  colors;  in  gelatin  cultui'es  the  rods 
are  frequently  only  partly  stained ;  generally  the  central  portion  is  stained 
while  the  poles  remain  unstained,  but  occasionally  one-half  is  colored,  or 
two  stained  portions  may  be  separated  by  a  clear  space.  Does  not  stain  by 
Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non-li- 
quefying, motile  bacillus.  Spore  formation  not  observed.  Grows  in  the 
usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates,  at  the 
end  of  two  or  three  days,  punctiform,  yellowish  colonies  are  developed ; 
under  a  low  power  these  are  seen  to  be  granular,  pale-yellow,  and  spherical 
or  irregular  in  outline ;  upon  the  surface  the  colonies  are  elevated,  circular 
in  outline,  and  porcelain- white  in  color;  when  widely  separated  they  may 
finally  attain  the  size  of  a  two-franc  piece — with  very  irregular  margins ; 
under  a  low  power  these  large  colonies  are  seen  to  be  granular,  and  to  have 
a  yellowish  centre  with  pale  margins.  The  colonies  are  not  viscid  and  are 
easily  detached  from  the  surface  with  a  platinum  needle.  In  stick  cultures 
in  nutrient  gelatin  a  layer  is  developed  upon  the  surface  which  at  first  is 
nearly  transparent ;  later  this  has  a  grayish  color  and  extends  over  the  entire 
surface;  the  growth  along  the  line  of  puncture  extends  to  the  bottom,  but 
is  not  characteristic.  Upon  agar  a  grayish  layer  is  developed,  which  later 
sometimes  acquires  a  brownish  color,  especially  along  the  line  of  puncture. 
Upon  potato  a  moist,  yellowish  layer  is  developed ;  this  remains  smooth  and 
is  without  gas  bubbles.  In  bouillon,  at  373  C. ,  development  occurs  within 
five  or  six  hours,  causing  turbidity ;  when  milk  sugar  is  added  to  the  pepton- 
ized  bouillon  there  is  a  development  of  gas,  and  bubbles  are  given  off  in 
abundance  when  the  culture  is  agitated.  Culture  media  containing  sugar 
acquire  an  acid  reaction;  at  the  end  of  several  days  a  pellicle  is  formed  upon 
the  surface,  which  later  falls  to  the  bottom.  In  sterilized  milk  development 
is  not  abundant,  but  milk  filtered  through  porcelain  is  a  favorable  culture 
medium;  an  acid  reaction  is  produced,  but  coagulation,  as  a  rule,  does  not 
occur— sometimes  an  imperfect  coagulation  occurs.  This  bacillus  dies  out 
in  cultures  in  two  or  three  weeks,  and  does  not  resist  desiccation  longer  than 
forty-seven  to  fifty  days.  It  is  killed  by  a  temperature  of  70°  C.  maintained 
for  fifteen  minutes.  According  to  Freudenreich,  this  bacillus  closely  re- 
sembles Bacillus  coli  communis,  but  is  distinguished  from  it  by  the  fact  that 
it  is  actively  motile,  and  by  its  ability  to  grow  in  solutions  of  milk  sugar  in 
the  absence  of  oxygen,  also  by  not  being  pathogenic  for  guinea-pigs  when 
injected  into  the  peritoneal  cavity. 

470.  BACILLI  OP  GUILLEBEAU   (a,  6,  and  C). 
Obtained  by  Guillebeau  from  the  milk  of  cows  suffering  from  mastitis, 


720  ADDITIONAL    SPECIES    OF 

and  found  by  Freudenreich  to  produce  an  abnormal  fermentation  of  cheese, 
characterized  by  the  presence  of  large  cavities  ("  boursouflement  ")  and  by 
a  very  bad  taste. 

BACILLUS   «. 

Morphology. — Varies  considerably  in  size,  and  may  resemble  a  micrococ- 
cus  in  form ;  usually  1  /*  broad  and  1  to  2  V  long. 

Stains  with  the  usual  aniline  colors,  but  rather  feebly ;  does  not  stain  by 
Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  slightly 
motile,  non-liquefying  bacillus.  Spore  formation  not  observed.  Grows  in 
the  usual  culture  media  at  the  room  temperature.  Upon  gelatin  plates  the 
deep  colonies  are  spherical,  granular,  and  yellowish  in  color;  upon  the  sur- 
face they  are  round  and  granular  at  first,  later  they  become  opaque  and  re- 
semble a  drop  of  wax.  In  gelatin  stick  cultures  development  occurs  all 
along  the  line  of  puncture,  and  upon  the  surface  a  whitish  layer  is  formed. 
Upon  agar  a  grayish  white  layer  is  developed.  Upon  potato  a  thick,  yel- 
lowish layer  is  formed;  this  is  viscid  and  contains  numerous  gas  bubbles. 
In  milk  coagulation  is  produced  at  the  end  of  twenty-four  hours,  and  an. 
abundance  of  gas  is  given  off.  In  bouillon  containing  milk  sugar  it  mul- 
tiplies abundantly  and  a  large  quantity  of  gas  is  liberated.  Grows  best  at  a 
temperature  of  30°  to  35°  C.  Thermal  death-point  60°  C. — fifteen  minutes' 
exposure. 

BACILLUS  b. 

Morphology. — Resembles  bacillus  a;  bacilli  from  1  to  2  /*  long  and  about 
1  p  thick. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing, motile  bacillus.  Is  differentiated  from  a  by  the  fact  that  it  causes  lique- 
faction of  nutrient  gelatin  after  an  interval  of  several  weeks,  and  by  the  fact 
that  the  young  colonies  upon  gelatin  plates  are  quite  viscid.  Spore  forma- 
tion not  observed.  Thermal  death-point  80°  C. — five  minutes'  exposure. 
An  abundance  of  gas  is  given  off  from  cultures  containing  milk  sugar. 

BACILLUS   C. 

Morphology. — Short  bacilli ;  often  oval  or  even  spherical  in  form ;  about 
1  n  long. 

Biological  Characters. — An  aerobic,  non-liquefying  bacillus.  Spore 
formation  not  observed.  Upon  gelatin  plates  colonies  are  developed  which 
resemble  those  of  bacillus  a,  but  are  more  coarsely  granular ;  the  colonies 
are  very  adherent  and  difficult  to  remove  from  the  culture  medium.  Upon 
agar  a  viscous,  white  layer  is  developed.  Upon  potato  the  growth  is  of  a 
yellowish- white  color  and  similar  to  that  of  a  and  b,  with  gas  bubbles;  it  is 
very  adherent.  In  liquid  media  the  growth  of  this  bacillus  causes  the  cul- 
ture liquid  to  become  extremely  viscous  and  almost  gelatinous  in  consistence. 
In  milk  coagulation  occurs  at  the  end  of  sixty  hours  at  37°  C.,  and  the  rnilk 
then  loses  its  viscosity. 

471.  MICROCOCCUS  FREUDENREICHI  (Guillebeau). 

Obtained  from  milk  which  had  undergone  viscous  fermentation. 

Morphology. — Micrococci  having  a  diameter  of  2  /*,  solitary  or  in  chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  liquefy- 
ing micrococcus.  Grows  best  at  a  temperature  of  20°  C.  Upon  gelatin 
plates  made  with  milk  serum,  punctiform,  granular  colonies  are  developed 
at  the  end  of  thirty-six  hours ;  when  touched  with  the  platinum  needle  these 
may  be  drawn  out  into  long  threads;  soon  after  the  gelatin  commences  to 
liquefy  and  becomes  very  viscous.  Upon  potato  the  growth  is  sometimes 


BACTERIA,    NOT   CLASSIFIED.  .727 

in  the  form  of  a  thin  layer  having  numerous  vacuoles ;  sometimes  a  thick 
and  shining1  layer  is  developed  which  has  a  pale  sulphur-yellow  color  or  is 
of  a  dull-brown  mixed  with  yellow.  In  bouillon  a  cloudy  opacity  is  first 
developed ;  later  a  flocculent  deposit  is  seen  and  the  liquid  above  is  limpid ; 
it  is  slightly  viscid.  In  sterilized  milk  the  viscosity  produced  is  so  great 
that,  in  old  cultures,  threads  may  be  drawn  out  which  are  several  metres  in 
length.  Non-sterilized  milk  becomes  viscous  at  the  end  of  five  hours ;  later 
it  becomes  acid,  and  at  the  end  of  several  days  the  casein  is  coagulated  and 
is  seen  as  a  granular  precipitate,  above  which  is  a  limpid  and  viscous  serum ; 
at  this  time  the  milk  has  acquired  a  disagreeable  odor. 

472.  BACTERIUM  HESSii  (Guillebeau). 

Obtained  from  the  milk  of  a  cow  in  the  Alps,  at  an  altitude  of  twelve 
hundred  metres. 

Morphology. — Bacilli  from  3  to  5  jn  long  and  1.2  fi  thick  (from  potato  cul- 
tures) ;  shorter,  nearly  spherical  elements  are  also  seen  in  considerable  num- 
bers, and  occasionally  long  filaments ;  the  ends  are  round  and  stain  more 
deeply  than  the  central  portion. 

Biological  Characters. — An  aerobic,  liquefying,  motile  bacillus.  Forms 
spores.  Grows  in  the  usual  culture  media  at  the  room  temperature.  In 
nutrient  gelatin  containing  serum  from  milk,  colonies  are  developed  upon 
plates  at  the  end  of  a  few  hours ;  these  at  first  have  well-defined  outlines, 
but  later  are  made  up  of  interlacing  filaments ;  after  liquefaction  of  the  gela- 
tin the  colony  floats  upon  the  surface;  liquefaction  progresses  rapidly  and 
the  liquefied  gelatin  may  be  drawn  out  into  threads.  Upon  potato  a  shin- 
ing layer  is  developed  of  a  dull-white  color,  which  later  acquires  a  brownish 
tint.  Bouillon  without  sugar  is  rapidly  transformed  into  a  viscous  mass 
having  an  alkaline  reaction.  In  milk  an  acid  reaction  is  produced  and  the 
casein  is  precipitated  at  the  end  of  two  days.  The  viscosity  produced  in 
milk  is  less  than  that  produced  by  the  species  previously  described,  and  dis- 
appears at  the  end  of  two  days  in  milk  kept  at  a  temperature  of  35°  C.  In 
old  cultures  in  bouillon  a  disagreeable  odor  is  developed,  said  to  resemble 
trimethylamin. 

473.    BACILLUS   DENITRIFICANS. 

Obtained  by  Giltay  and  Aberson  from  the  soil  and  from  the  air.  Resem- 
bles Bacterium  denitrificans  of  Gayou  and  Dupetit. 

Morphology.— Bacilli,  usually  in  pairs,  1.5  n  to  3  ft  long  and  0.5  M  broad. 

Biological  Characters. — Completely  decomposes  nitrates,  producing  ni- 
trogen monoxide  as  well  as  pure  nitrogen.  The  reducing  action  of  the  fer- 
ment is  favored  by  the  presence  of  carbonate  of  lime  in  the  culture  medium. 
Grows  in  ordinary  nutrient  gelatin.  Also  cultivated  in  the  following  me- 
dium: Nitrate  of  potash  two  grammes,  glucose  two  grammes,  sulphate  of 
magnesia  two  grammes,  citric  acid  five  grammes,  monophosphate  of  potash 
two  grammes,  calcium  chloride  0.2  gramme,  two  drops  of  a  solution  of  per- 
chloride  of  iron,  and  one  litre  of  water. 

474.    BACILLUS  CYANO-FUSCUS. 

Obtained  by  Beyerinck  from  size  and  glue  and  Edam  cheese. 

Morphology. — Bacilli  from  0.2  to  0.6  /J.  long  and  one-half  as  thick. 

Biological  Characters. — An  aerobic,  chromogenic,  liquefying,  motile 
bacillus.  Grows  in  the  usual  culture  media  at  the  room  temperature. 
Spore  formation  not  observed.  When  cultivated  in  a  solution  containing 
one-half  per  cent  of  peptone  the  culture  medium  acquires  at  first  a  green 
color,  which  later  changes  to  blue,  brown,  and  black;  subsequently  the  color 
is  almost  entirely  lost.  In  nutrient  gelatin  containing  one-half  per  cent  of 
peptone  circular  colonies  are  developed  which  are  surrounded  by  a  zone  of 
black  pigment  and  in  which  crystals  of  lime  are  formed. 


ADDITIONAL  SPECIES   OF 

475.    BACILLUS  PYOGENES  SOLI. 

Obtained  by  Bolton  from  garden  earth  by  inoculation  into  a  rat.  Found 
in  association  with  the  tetanus  bacillus  in  pus  from  the  inoculation  wound. 

Morphology. — Closely  resembles  the  bacillus  of  diphtheria.  "  It  presents 
the  same  irregularities  of  shape,  and  the  transverse,  unstained  clear  spaces 
in  stained  preparations,  as  the  diphtheria  bacillus.  The  individual  bacilli 
vary  greatly  in  length  and  thickness,  and  many  of  them  are  bent  and  nar- 
rower through  the  middle  than  at  the  poles." 

Stains  readily  with  the  usual  aniline  colors,  but  takes  the  stain  irregularly, 
sometimes  showing  deeply  stained  spots  which  may  be  perfectly  round.  Does 
not  stain  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  bacillus.  Spore  formation  not  observed  with  cer- 
tainty—highly refractive  ovoid  bodies  are  sometimes  met  with,  but  these  do 
not  seem  to  be  specially  resistant  to  heat.  In  gelatin  roll  tubes  very  small, 
spherical  colonies  are  developed,  which  under  a  low  power  are  seen  to  be 
finely  granular  and  to  have  a  lemon-yellow  color.  Grows  best  in  a  slightly 
acid  medium — very  slowly  at  the  room  temperature.  In  gelatin  stick  cul- 
tures isolated  colonies  are  formed  along  the  line  of  puncture.  Scanty  growth 
on  potato  or  blood  serum.  Bolton  says :  "  I  have  rarely  succeeded  in  getting 
a  growth  in  agar." 

Pathogenesis. — Subcutaneous  inoculations  in  rats,  gray  mice,  rabbits, 
and  usually  in  white  mice  produce  an  abscess  at  the  point  of  inoculation. 
Injections  into  the  ear  veins  of  rabbits  sometimes  give  rise  to  multiple  ab- 
scesses, especially  in  the  joints  and  kidneys.  ' '  The  abscesses  following  sub- 
cutaneous inoculation  form  very  quickly,  within  twenty -four  hours,  and  run 
a  longer  or  shorter  course,  from  forty-eight  hours  to  eight  or  ten  days,1  in 
direct  proportion  to  the  amount  of  the  culture  introduced.  The  animals  do 
not  seem  to  suffer  any  inconvenience,  as  a  rule,  and  after  the  abscess  is 
opened  suppuration  ceases.  The  organism  is  found  aggregated  in  small  and 
large,  irregular  clumps  in  the  pus,  many  of  them  lying  in  the  pus  corpuscles. 
It  seems  to  form  metastatic  abscesses  only  under  exceptional  circumstances, 
such  as  when  injected  directly  into  the  blood.  Otherwise  the  abscess  remains 
strictly  confined  to  the  seat  of  inoculation  in  rabbits,  white  rats,  and  gray 
mice." 

476.   MICROCOCCUS  AQUATILIS  INVISIBILIS. 

Obtained  by  Vaughan  from  water. 

Morphology. — Oval  cocci. 

Biological  Characters. — An  aerobic,  non-liquefying  micrococcus.  Grows 
in  the  usual  culture  media  at  the  room  temperature,  but  feebly  at  38"  C.  On 
gelatin  plates  deep  brown  colonies  with  smooth  outline,  spreading  irregu- 
larly upon  the  surface.  In  gelatin  tubes  there  is  a  scanty  growth  along  the 
line  of  puncture  and  a  spreading  growth  upon  the  surface.  On  agar  a  thin, 
white  growth.  The  growth  upon  potato  is  invisible. 

Not  pathogenic. 

477.    BACILLUS   GRACILIS   ANAEROBIESCENS. 

Obtained  by  Vaughan  from  water. 

Morphology. — "Bacilli  three  times  as  long  as  broad,  often  growing  into 
long,  slender  rods." 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Grows  rapidly  in  the  usual  culture 
media  at  the  room  temperature — feebly  at  38°  C.  Upon  gelatin  plates  brown- 
ish colonies  are  developed,  "  spreading  irregularly."  In  gelatin  tubes  grows 
abundantly  along  the  line  of  puncture  and  also  spreads  over  the  surface.  On 
agar  a  thin,  white  layer  is  developed.  On  potato  an  abundant  and  promi- 


BACTERIA,    NOT   CLASSIFIED.  72!) 

nent  yellowish -white  layer.     Grows  in  Parietti's  solution,  but  not  in  Uffel- 
mann's  gelatin.     Forms  gas  abundantly  in  gelatin  stick  cultures. 
Not  pathogenic. 

478.   BACILLUS  FIGURANS. 

Obtained  by  Vaughan  from  water.  Crooksbank  has  described  a  Bacillus 
flguraiis  which  appears  to  be  identical  with  Bacillus  mesentericus  vulgatus. 

Morphology. — "  Bacilli  two  to  three  times  as  long  as  broad,  but  showing 
marked  variation  in  form.  Sometimes  they  appear  as  very  short  bacilli, 
while  at  other  times  they  grow  into  long  threads." 

Biological  Characters. — An  aerobic,  liquefying,  sluggishly  motile  ba- 
cillus. Spore  formation  not  mentioned.  Grows  rapidly  in  the  usual  cul- 
ture media  at  the  room  temperature— feebly  at  38°  C.  "  On  gelatin  plates 
the  deep  colonies  are  spherical  and  smooth;  the  superficial  growth  forms 
curved  and  interlacing  lines,  often  presenting  most  grotesque  figures.  Plates 
may  show  no  liquefaction  after  some  days."  in  gelatin  stick  cultures  does 
not  develop  along  the  line  of  puncture ;  liquefies  slowly,  and  sometimes  the 
fluid  is  lost  by  evaporation  as  fast  as  it  liquefies.  After  the  gelatin  has  been 
liquefied  half-way  down  the  tube,  the  bacteria  subside  to  the  bottom  and  fur- 
ther liquefaction  is  very  slow  or  does  not  occur.  On  agar  a  thin,  white 
layer  is  formed  upon  the  surface  and  a  heavy  deposit  in  the  water  of  con- 
densation. On  potato  an  abundant,  faintly  yellow,  mucilaginous  layer. 
Does  not  grow  either  in  Parietti's  solution  or  in  Uffelmann's  gelatin. 

Not  pathogenic. 

A 

479.    BACILLUS  ALBUS  ANAEROBIESCENS. 

Obtained  by  Vaughan  from  water. 

Morphology. — "  Bacilli  two  or  three  times  as  long  as  broad." 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  non-motile  ("only  an  oscillation  ")  bacillus.  Grows  rapidly  at 
the  room  temperature  in  the  usual  culture  media — also  at  38°  C.  Spore  for- 
mation not  mentioned.  On  gelatin  plates  forms  smooth,  spherical,  yel- 
lowish or  brownish  colonies.  In  gelatin  stick  cultures  grows  both  on  the 
surface  and  along  the  line  of  puncture.  On  agar  a  thick,  milk-white  layer 
is  developed.  On  potato  a  yellowish-white,  glistening  growth.  Grows 
both  in  Parietti's  solution  and  in  Uffelmann's  gelatin. 

Not  pathogenic. 

480.    BACILLUS  INVISIBILIS. 

Obtained  by=Vaughan  from  water. 

Morphology.  —Large  bacilli  with  rounded  ends,  from  two  to  five  times  as 
long  as  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  mentioned.  Grows  rap- 
idly in  the  usual  culture  media  at  the  room  temperature — also  at  38°  C.  On 
gelatin  plates  pale-yellow,  burr-like  colonies,  with  irregular  outlines  and 
spreading  slightly.  In  gelatin  tubes  grows  abundantly  along  the  line  of 
puncture  and  also  upon  the  surface,  spreading  slowly.  On  agar  a  thick, 
white  growth  with  but  little  tendency  to  spread.  On  potato  the  growth  is 
invisible.  Grows  both  in  Parietti's  solution  and  in  Uffelmann's  gelatin. 

Not  pathogenic. 

481.    BACILLUS   VENENOSUS. 

Obtained  by  Vaughan  from  water. 

Morphology. — Bacilli  with  rounded  ends,  two  to  four  times  as  long  as 
broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Spore  formation  not  mentioned.  Grows 


730  ADDITIONAL  SPECIES  OF 

rapidly  in  the  usual  culture  media  at  the  room  temperature — also  at  38°  C. 
On  gelatin  plates  small,  white,  spherical  colonies — sometimes  slightly  yel- 
low; the  superficial  colonies  are  elevated  above  the  surface  of  the  gelatin. 
In  gelatin  tubes  an  abundant  growth  occurs  along  the  line  of  puncture  and 
slowly  extends  upon  the  surface.  In.  cultures  from  the  spleen  of  an  inocu- 
lated animal  the  growth  upon  the  surface  is  less  marked.  On  agar  a  thin, 
white  layer  is  formed.  On  potato  a  light-brown,  moist  growth.  In  recent 
cultures  from  the  spleen  of  an  inoculated  animal  the  growth  upon  potato 
may  be  invisible.  Grows  abundantly  both  in  Parietti's  solution  and  in  Uf- 
felmann's  gelatin. 

Pathogenesis. — Pathogenic  for  rats,  mice,  guinea-pigs,  and  rabbits. 

482.    BACILLUS   VENENOSUS  BREVIS. 

Obtained  by  Vaughan  from  water. 

Morphology. — Short,  thick  bacilli,  about  twice  as  long  as  broad;  in  old 
cultures  grows  out  into  threads. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  actively  motile  bacillus.  Spore  formation  not  mentioned. 
Grows  rapidly  in  the  usual  culture  media  at  the  room  temperature— also  at 
38°  C.  On  gelatin  plates  forms  small,  round  colonies  with  concentric  rings: 
the  deeper  colonies  are  generally  yellowish  or  brown ;  the  surface  colonies 
are  elevated  and  spread  but  little.  In  gelatin  tubes  grows  along  the  line  of 
puncture  and  spreads  slowly  upon  the  surface,  finally  reaching  the  sides  of 
the  tube.  Upon  agar  a  thin,  white  layer  is  formed.  On  potato  a  thick  and 
moist,  light-brown  growth.  When  kept  for  fourteen  days  or  longer  at  40°  C. 
there  is  an  invisible  growth  upon  potato.  Grows  abundantly  in  Parietti's 
solution  and  slowly  in  Uffelmann's  gelatin. 

Pathogenesis. — Pathogenic  for  rats,  mice,  guinea-pigs,  and  rabbits. 

483.    BACILLUS  VENENOSUS  INVISIBILIS. 

Obtained  by  Vaughan  from  water. 

Morphology. — A  slender  bacillus  with  rounded  ends,  from  two  to  four 
times  as  long  as  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
liquefying,  motile  bacillus.  Spore  formation  not  mentioned.  Grows  slowly 
in  the  usual  culture  media  at  the  room  temperature — also  at  38°  C.  On  gela- 
tin plates  small,  granular,  yellowish  colonies  are  developed ;  the  superficial 
colonies  are  coarsely  granular  and  very  irregular  in  size  and  outline.  In 
gelatin  tubes  grows  slowly  both  on  the  surface  and  along  the  line  of  punc- 
ture ;  scarcely  visible  at  end  of  three  days.  On  agar  a  very  thin,  white 
growth.  On  potato  the  growth  is  sometimes  invisible;  on  some  potatoes  a 
light-brown  layer  may  be  developed.  Grows  well  both  in  Parietti's  solution 
and  in  Uffelmann's  gelatin. 

Pathogenesis. — Pathogenic,  but  in  less  degree  than  Bacillus  venenosus. 

484.    BACILLUS  VENENOSUS  LIQUEPACIENS. 

Obtained  by  Vaughan  from  water. 

Morphology. — Bacilli  with  rounded  ends,  one  and  one-half  to  twice  as 
long  as  broad. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  lique- 
fying, motile  bacillus.  Spore  formation  not  mentioned.  Grows  rapidly  in 
the  usual  culture  media  at  the  room  temperature — also  at  38°  C.  On  gelatin 
plates  the  deep  colonies  are  finely  granular,  sphei'ical,  and  yellowish  in 
color;  superficial  colonies  elevated  and  spread  over  the  surface.  In  gelatin 
tubes  grows  abundantly  along  the  line  of  puncture  and  spreads  slowly  over 
the  surface;  liquefaction  commences  in  from  four  to  six  weeks.  On  agar  a 


BACTERIA,    NOT   CLASSIFIED.  731 

thin,  white  growth.  On  potato  a  moist,  light-brown,  or  yellowish  growth. 
When  kept  for  fourteen  days  or  longer  on  spleen  tissue  it  forms  an  invisible 
growth  on  potato.  Grows  abundantly  both  in  Parietti's  solution  and  in 
Ulfelmann's  gelatin. 

Pathogenesis. — Pathogenic  for  mice,  rats,  guinea-pigs,  and  rabbits. 

485.    BACILLUS  AEROGENES   CAPSULATUS. 

Found  by  Welch  in  the  blood  vessels  of  a  patient  with  thoracic  aneurism 
opening  externally  ^  autopsy  made  in  cool  weather  eight  hours  after  death — 
the  vessels  found  full  of  gas  bubbles. 

Morphology. — Straight  or  slightly  curved  bacilli  with  slightly  rounded 
or  sometimes  square-cut  ends ;  a  little  thicker  than  Bacillus  anthracis,  and 
varying  in  length — average  length  3  to  6  /< ;  long  threads  and  chains  are  oc- 
casionally seen.  The  bacilli,  both  from  cultures  and  in  the  animal  body,  are 
enclosed  in  a  transparent  capsule. 

Biological  Ciiaracters. — An  anaerobic,  non-motile,  non-liquefying  ba- 
cillus. Does  not  form  spores.  Grows  in  the  usual  culture  media,  in  the  ab- 
sence of  oxygen,  at  the  room  temperature,  and  produces  an  abundant  de- 
velopment of  gas  in  all.  In  nutrient  gelatin  there  is  no  marked  liquefaction, 
but  the  gelatin  is  slightly  peptonized.  In  agar,  colonies  are  developed  which 
are  usually  one  to  two  millimetres  in  diameter,  but  may  attain  a  diameter  of 
one  centimetre ;  they  are  grayish- white  in  color  and  in  the  form  of  flattened 
spheres,  ovals,  or  irregular  masses,  beset  witli  little  projections  or  hair-like 
processes.  Bouillon  is  rendered  diffusely  cloudy,  with  an  abundant  white 
sediment.  Milk  is  coagulated  in  one  or  two  days.  The  cultures  in  agar  and 
bouillon  have  a  faint  odor,  comparable  to  that  of  stale  glue.  Upon  potato  a 
pale  grayish-white  layer  is  developed;  growth  occurs  at  18°  to  20°  C.,  but  is 
much  more  rapid  at  30°  to  37°  C.  Bouillon  cultures  are  sterilized  by  ex- 
posure to  a  temperature  of  58°  C.  for  ten  minutes. 

Pathogenesis. — "Quantities  up  to  2.5  cubic  centimetres  of  fresh  bouillon 
cultures  were  injected  into  the  circulation  of  rabbits  without  any  apparent 
effect,  except  in  one  instance  in  which  a  pregnant  rabbit  was  killed,  by  the 
injection  of  one  cubic  centimetre,  in  twenty -one  hours.  If  the  animal  is 
killed  shortly  after  the  injection  the  bacilli  develop  rapidly  after  death,  with 
an  abundant  formation  of  gas  in  the  blood  vessels  and  organs,  especially  the 
liver.  At  temperatures  of  18°  to  20°  C.  the  vessels,  organs,  and  serous  cavi- 
ties may  be  full  of  gas  in  eighteen  to  twenty-four  hours,  and  at  tempera- 
tures of  30°  to  32°  C.  in  four  to  six  hours,  when  one  cubic  centimetre  of  a 
bouillon  culture  has  been  injected  into  the  circulation  shortly  before  death." 

It  is  suggested  by  Welch  and  Nuttall  that  in  some  of  the  cases  in 
which  death  has  been  attributed  to  the  entrance  of  air  into  the  veins,  the  gas 
found  at  the  autopsy  may  not  have  been  atmospheric  air,  but  may  have  been 
produced  by  this  or  some  similar  microorganism  entering  the  circulation  and 
developing  after  death. 

486.    BACILLUS  OP  CANON  AND  PIELICKE. 

TY>und  by  Canon  and  Pielicke  (1892)  in  the  -blood  of  fourteen  patients 
with  measles,  and  supposed  to  be  the  etiological  agent  in  this  disease. 

Morphology. — Bacilli  varying;  greatly  in  size;  sometimes  the  length  is 
equal  to  the  diameter  of  a  red  l>lood  corpuscle,  others  are  quite  short  and 
resemble  diplococci;  often  united  in  pairs. 

Stained  by  Canon,  in  blood  drawn  from  the  finger,  by  the  use  of  the  fol- 
lowing solution :  Concentrated  aqueous  solution  of  methylene  blue,  forty 
cubic  centimetres ;  one-quarter-per-cent  solution  of  eosin  in  seventy-per-cent 
alcohol,  twenty  cubic  centimetres;  distilled  water,  forty  cubic  centimetres. 
The  preparations  were  first  placed  in  absolute  alcohol  for  five  to  ten  minutes, 
then  placed  in  the  staining  solution  in  the  incubating  oven  at  37°  C.  from 


732  ADDITIONAL   SPECIES   OF 

six  to  twenty  hours.     Some  of  the  bacilli  do  not  stain  uniformly,  but  present 
the  appearance  of  stained  spots  altei'nating  with  unstained  portions. 

Biological  Characters  not  determined.  Does  not  grow  in  glycerin-agar 
or  in  blood  serum.  In  bouillon  inoculated  with  blood  from  the  finger  of  a 
measles  patient,  bacilli  were  obtained  in  three  cultures  which  resembled  the 
bacillus  found  in  the  blood,  and  which  failed  to  grow  when  transplanted  to 
glycerin-agar,  blood  serum,  or  bouillon.  At  first  the  bouillon  remained 
clear,  with  a  sediment  at  the  bottom  partly  made  up  of  the  inoculated  blood ; 
after  several  days  a  faint  cloudiness  was  noticed  and  small  flocculi  formed. 
In  these  bouillon  cultures  the  bacilli  had  various  forms  and  dimensions, 
some  of  them  exceeding  in  length  those  found  in  stained  preparations  from 
the  blood.  They  appeared  to  have  a  slight  independent  motion.  The  bacilli 
in  these  bouillon  cultures  did  not  stain  by  Gram's  method.  The  bacilli  re- 
ferred to  were  found  in  the  blood  preparations  in  varying  numbers — some- 
times very  few,  and  at  others  the  first  field  examined  was  crowded.  They 
were  found  during  the  whole  course  of  the  disease,  and  in  one  case  three 
days  after  the  fever  had  disappeared.  They  were  also  found  in  the  secre- 
tions from  the  nose  and  conjunctiva  of  measles  patients. 

487.    BACILLUS   SANGUINIS    TYPHI. 

Obtained  (1892)  by  Brannan  and  Cheesrnan  from  the  blood  of  typhus- 
fever  patients.  "The  blood,  obtained  under  strict  antiseptic  precautions 
from  the  six  living  patients,  was  streaked  on  six-per-cent  glyceriii-agar 
plates,  arid  smeared  on  sterilized  cover  glasses  by  Dr.  Brannan  and  brought 
at  once  to  the  laboratory.  The  cover-glass  smears  from  all  the  cases,  being 
dried  at  once  in  the  air,  were  fixed  in  alcohol  and  stained  in  Czenzynski's 
solution  for  eighteen  hours  at  room  temperature.  Although  all  of  these 
covers  were  examined  throughout  with  a  one-sixteenth  homogeneous  immer- 
sion lens  in  the  most  careful  manner,  in  only  about  one-half  of  them  a  few 
blue-stained  bacilli  were  found,  never  more  than  eight  or  ten  on  a  cover." 

Morphology. — Bacilli  with  round  ends,  from  1  to  2. 5  n  long  and  0.5  to 
0.8  u  broad  ;  solitary  or  in  pairs,  and  occasionally  in  chains  containing  six 
to  eight  elements ;  often  club-shaped,  or  ovoid  in  recent  cultures. 

Stains  with  the  usual  aniline  colors  and  by  Gram's  method. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
motile  bacillus.  Does  not  form  spores.  Does  not  grow  at  a  lower  tempera- 
ture than  27°  C.  Grows  best  upon  blood  serum  at  37.5°  C.  Upon  glycerin- 
agar  plates  colonies  are  developed  which  at  the  end  of  eighteen  hours  appear 
as  minute,  bluish-gray,  translucent  spots,  the  diameter  of  which  does  not 
exceed  0.25  millimetre  ;  later  the  colonies  appear  dry  and  scaly,  they 
are  flat,  more  opaque,  and  whiter,  and  do  not  exceed  two  millimetres  in 
diameter.  Under  a  low  power  the  recent  colonies  are  seen  to  be  granular, 
to  have  a  sinuous  and  sharply  defined  margin  and  a  pale-brown  color  which 
is  more  intense  at  the  centre  and  in  scattered  points  upon  the  surface.  When 
magnified  one  hundred  diameters  the  surface  appears  to  be  coarsely  granular, 
and  coarse,  irregular  spiculae  are  seen  about  the  margin.  In  glycerin-agar 
tubes,  at  37. 5°  C.,  growth  occui-s  upon  the  surface  and  along  the  line  of 
puncture  as  small,  white,  isolated  colonies.  Upon  blood  serum  a  slightly 
elevated,  white,  shining  layer  is  developed.  In  milk  a  white  deposit  is 
formed  at  the  bottom  of  the  tube  and  the  milk  undergoes  no  apparent  change. 
On  potato  no  visible  growth  was  obtained. 

Pathogenesis. — "Inoculations  of  cultures  of  the  bacillus  obtained  from 
two  of  the  cases  were  made  in  eight  rabbits,  two  guinea-pigs,  and  two  white 
mice.  All  the  animals  showed  marked  emaciation,  and,  with  the  exception 
ot  two  rabbits,  all  the  animals  experimented  upon  died  in  from  ten  to  twenty- 
nine  days.  The  inoculated  bacillus  was  obtained  from  the  heart's  blood  of 
two  of  the  rabbits  that  died." 


BACTERIA,    NOT   CLASSIFIED. 


733 


488.    MICROCOCCUS   AGILIS   CITREUS. 

Obtained  by  Menge  (1882)  from  an  infusion  of  peas — probably  from  the 
air. 

Morphology.  — Micrococci,  usually  in  pairs,  but  sometimes  in  short  chains 
or  irregular  groups.  Has  a  flagellum  which  is  easily  demonstrated  by 
Lomer's  method  of  staining,  and  which  is  about  six  times  as  long  as  the 
diameter  of  the  micrococcus. 

Biological  Characters. — An  aerobic,  non-liquefying,  chromogenic,  motile 
micrococcus.  Forms  a  yellow  pigment.  Grows  in  the  usual  culture  media 
at  the  room  temperature.  Upon  gelatin  plates  a  diffuse  cloudiness  of  the 
gelatin  occurs  around  the  superficial  colonies  and  extends  over  the  plate,  ex- 
cept at  the  numerous  points  where  bundles  of  crystals  are  developed.  In 
gelatin  stick  cultures  a  scanty  growth  occurs  along  the  line  of  puncture, 
which  is  not  colored ;  upon  the  surface  a  round  layer  of  an  intense  yellow 
color  is  slowly  developed.  Upon  agar  a  pale  and  thin  layer  is  developed 
along  the  line  of  inoculation  by  the  end  of  the  third  day ;  this  increases  in 
breadth  and  thickness  and  acquires  a  yellow  color ;  the  growth  upon  agar 


FiG.  268. 
X  1,000.    From  a  photomicro- 


FIG. 267. 

Fio.  267.—  Bacillus  gracilis  cadaveris,  from  a  gelatin  culture. 
graph.    (Sternberg.) 

FIG.  258.  —  Bacillus  gracilis;  colonies  in  gelatin  roll  tube,  end  of  forty  -eight  hours. 
a  photograph.    (Sternberg  ) 


X  12.    From 


is  extremely  viscid  and  may  be  drawn  out  into  long  threads  when  touched 
with  a  platinum  needle.  In  bouillon  a  diffuse  cloudiness  occurs  and  a  yellow, 
viscid  deposit  accumulates  at  the  bottom  of  the  tube;  there  is  no  film 
formed  upon  the  surface.  Upon  potato  development  is  very  slow,  but  after 
a  time  an  abundant  bright-yellow  layer  is  formed,  and  around  this  the 
potato  acquires  a  slightly  bluish-gray  color.  Grows  in  milk  without  pro- 
ducing coagulation.  Grows  best  at  a  temperature  of  20°  C. 

489.  BACILLUS  GRACILIS  CADAVERIS  (Sternberg). 

Obtained  (1889)  from  a  fragment  of  liver,  of  man,  kept  for  forty-eight 
hours  in  an  antiseptic  wrapping. 

Morphology. — Bacilli  about  1  n  broad  and  2  /«  long,  associated  in  long 
chains. 

Biological  Characters. — An  aerobic  and  facultative  anaerobic,  non- 
motile,  non-liquefying  bacillus.  Spore  formation  not  observed.  In  gelatin 

63 


To!          ADDITIONAL   SPECIES   OF   BACTERIA,    NOT   CLASSIFIED. 

roll-tubes  the  deep  colonies  are  opaque  and  spherical ;  superficial  colonies 
circular  or  slightly  irregular  in  outline,  white  in  color,  and  opaque  or  slightly 
translucent.  In  gelatin  stick  cultures,  at  22°  C.,  at  the  end  of  five  days  a 
rather  thick,  white  mass  at  the  point  of  puncture,  covering  one-third  of  the 
surface,  and  closely  crowded,  opaque  colonies  at  bottom  of  line  of  puncture, 
with  slender,  branching  outgrowth  above.  In  nutrient  agar,  at  the  end  of 
five  days  at  22°  C.,  a  milk-white  growth  upon  the  surface  and  opaque 
growth  to  bottom  of  line  of  puncture.  On  potato,  at  end  of  five  days  at 
22°  C.,  rather  thick,  cream- white  growth  with  irregular  margins  along  the 
impfstrich.  Cultures  in  bouillon  have  a  milky  opacity  and  a  very  disagree- 
able odor.  Grows  in  aqua  coco  without  formation  of  gas. 

Pathogenic  for  rabbits  when  injected  into  the  cavity  of  the  abdomen. 


XIII. 
BACTERIOLOGICAL   DIAGNOSIS. 

THE  researches  made  by  bacteriologists  during  the  past  ten  years 
show  that  there  is  an  extensive  bacterial  flora,  especially  in  water 
and  in  the  soil,  and  that  many  of  the  species  known  are  widely  dis- 
tributed and  may  be  recognized  by  their  morphological  and  biologi- 
cal characters  wherever  they  may  be  found  ;  but  they  also  show  that 
we  cannot  depend  upon  morphology  alone  for  the  differentiation  of 
species,  and  that  in  many  cases  a  careful  study  of  the  mode  of 
growth  in  various  culture  media,  and  of  pathogenic  power  by  inocu- 
lations in  the  lower  animals,  shows  slight  differences  in  bacteria 
which  resemble  each  other  so  closely  in  form  and  in  certain  biologi- 
cal characters  that  a  less  careful  study  would  lead  to  the  belief  that 
they  were  identical.  That  there  are  true  species  among  the  bacte- 
ria, in  the  same  sense  as  among  the  higher  plants,  is  well  established; 
but,  as  among  the  higher  plants,  it.  is  often  difficult  to  determine 
whether  the  differences  observed  should  be  considered  sufficient  to 
justify  the  description  of  allied  forms  as  distinct  species,  or  whether 
they  should  simply  be  considered  as  varieties  of  a  single  species. 
For  example,  the  well-known  streptococcus  of  pus  has  morphologi- 
cal characters  which  enable  us  to  distinguish  it  from  many  other 
bacteria,  but  streptococci  have  been  obtained  from  various  sources 
which  present  slight  differences  as  to  their  growth  in  certain  media 
and  in  their  pathogenic  power.  The  question  arises  as  to  whether 
these  differences  are  to  be  considered  "specific"  or  otherwise.  If 
the  differences  noted  are  permanent,  and  enable  a  bacteriologist  to 
distinguish  one  streptococcus  from  the  other  wherever  it  may  be 
found,  we  are  justified  in  considering  them  as  two  distinct  micro- 
organisms. And  the  decision  as  to  whether  they  are  to  be  consid- 
ered as  different  species,  or  as  varieties  of  a  single  species,  need  not 
detain  us.  As  a  matter  of  fact,  nature  is  continuous,  and  specific 
lines  are  not  sharply  drawn  except  in  systematic  text  books  of  bot- 
any, etc.  The  more  complete  our  knowledge  of  any  class  of  animal 
or  vegetable  organisms,  the  less  sharply  differentiated  are  the  so- 
called  species  on  account  of  the  introduction  of  intermediate  forms 
in  a  series  having  common  characters. 


730  BACTERIOLOGICAL,  DIAGNOSIS. 

When  the  differences  noted  are  not  permanent  in  character,  de- 
scription under  a  distinct  name  only  leads  to  confusion.  Among  the 
bacteria,  as  among  higher  plants,  such  differences,  constituting  more 
or  less  permanent  varieties,  have  been  developed  by  cultivation  under 
various  conditions,  and,  without  doubt,  are  constantly  being  devel- 
oped under  natural  conditions  as  a  result  of  changes  in  the  environ- 
ment of  these  minute  plants.  Thus  we  have  artificial  varieties  of 
certain  common  chromogenic  species  in  which  no  pigment  is  pro- 
duced, non-pathogenic  varieties  of  pathogenic  species,  and  asporoge- 
nous  varieties  of  bacilli  which  usually  form  spores. 

The  attempt  to  classify  the  bacteria  in  a  systematic  manner  is 
attended  with  especial  difficulties,  owing  to  their  simple  structure, 
the  comparatively  slight  morphological  differences  which  they  pre- 
sent, and  also  because  of  the  tendency  to  variation  in  their  biological 
characters  above  referred  to.  But  bacteriologists  are  generally 
agreed  upon  the  importance  of  the  following  characters  for  their 
differentiation,  viz.  :  form — micrococci,  bacilli,  spirilla,  polymor- 
phous ;  relation  to  oxygen — aerobic,  facultative  anaerobic,  strict 
anaerobic  ;  growth  in  nutrient  gelatin — liquefy,  do  not  liquefy,  do 
not  grow  in  nutrient  gelatin  at  the  "room  temperature";  growth  on 
potato ;  groivth  in  milk — coagulate  milk,  do  not  coagulate,  etc.  ; 
color  of  growth — chromogenic,  non-chromogenic  ;  spore  forma- 
tion;  independent  movements  ;  pathogenic  power. 

It  is  upon  these  characters  that  we  must  rely  chiefly  in  our  bacte- 
riological diagnosis  of  known  species.  But  the  student  must  remem- 
ber that  the  lines  are  not  sharply  drawn  between  the  groups  formed 
when  we  classify  bacteria  with  reference  to  any  one  of  these  charac- 
ters. Thus  we  have  microorganisms  of  this  class  which  we  find  it 
difficult  to  classify  as  regards  form,  because  they  are  not  round,  and 
yet  are  so  slightly  elongated  in  one  diameter  that  it  is  difficult  to 
consider  them  bacilli.  If  we  follow  Cohn  and  group  these  short- 
oval  bacteria  under  the  generic  name  Bacterium,  we  have  not  re- 
moved the  difficulty,  but  have  made  two  arbitrary  and  artificial  lines 
instead  of  one.  Again,  liquefaction  of  gelatin  is  sometimes  so  slight, 
or  occurs  at  so  late  a  date,  that  it  may  be  a  question  whether  a  mi- 
croorganism of  this  class  should  be  included  among  the  liquefying 
or  non-liquefying  bacteria.  And  our  division  with  reference  to  the 
formation  of  pigment  must,  to  a  certain  extent,  be  arbitrary  ;  for 
many  species  which  are  not  decidedly  chromogenic  present  under 
certain  circumstances  a  slight  tint  of  yellow,  gray,  brown,  or  pink. 
A  slight  yellow  or  a  decided  brown  color  is  often  developed  in  potato 
cultures  of  bacteria  which  upon  other  culture  media  present  a  col- 
orless growth,  and  which  are  generally  included  by  bacteriologists 
among  the  non-chromogenic  species.  With  reference  to  independent 


BACTERIOLOGICAL   DIAGNOSIS.  737 

movements,  it  must  be  remembered  that  some  of  the  motile  bacteria, 
under  certain  circumstances,  do  not  exhibit  active  movements  ;  the 
question  of  motility  must  therefore  not  be  hastily  decided  in  the 
negative  from  a  single  examination.  Spore  formation  also,  in  many 
cases,  depends  upon  special  conditions,  and  great  care  will  often  be 
required  in  determining  this  character,  which,  indeed,  is  still  unde- 
termined for  some  of  the  best-known  species. 

We  have  endeavored  in  the  present  volume  to  include  all  bacteria 
which  have  been  described  by  competent  bacteriologists  with  suffi- 
cient detail  to  permit  of  their  recognition  when  carefully  studied  by 
the  usual  methods.  But  we  have  also  included  a  considerable  num- 
ber which  are  imperfectly  described  and  which  could  not  be  identi- 
fied by  the  descriptions  given.  And  no  doubt  a  certain  number  of 
those  which  have  been  described  under  different  names  are  in  fact 
identical  or  simply  varieties  of  a  single  species.  The  plan  adopted  of 
grouping  the  different  bacteria  described  with  reference  to  their  mor- 
phological and  biological  characters  will  bring  together  those  micro- 
organisms which  are  similar,  and  will,  we  trust,  be  of  assistance  to 
working  bacteriologists  in  determining  identity  or  non-identity.  Im- 
perfect descriptions,  if  not  completed  by  future  researches,  may  be 
eliminated  hereafter,  but  we  have  thought  it  best  to  give  them  a 
place  in  this  Manual,  as  most  of  them  are  included  in  systematic 
works  published  abroad — e.  g. ,  the  micrococci  found  by  Koch  in  his 
experimental  study  of  traumatic  infectious  diseases  (1878),  Bien- 
stock's  faeces  bacilli,  etc. 

LIST  OF  BACTERIA  DESCRIBED. 
PART   THIRD,    SECTION   IV. — PYOGENIC   BACTERIA. 

1.  Staphylococcus  pyogenes  aureus  (Rosenbach). 
Micrococcus  of  infectious  osteomyelitis  (Becker). 

2.  Staphylococcus  pyogenes  albus  (Rosenbach). 
Staphylococcus  epidermidis  albus  (Welch). 

o.  Staphylococcus  pyogenes  citreus  (Passet). 

4.  Micrococcus  pyogenes  tennis  (Rosenbach). 

5.  Streptococcus  pyogenes  (Rosenbach). 
Micrococcus  of  erysipelas  (Fehleisen). 
Streptococcus  of  pus. 
Streptococcus  longus  (Von  Lingelsheim). 

0.  Micrococcus  gonorrhceaa. 
Gonococcus  (Neisser). 

PART   THIRD,    SECTION   V. — BACTERIA   IN   CROUPOUS   PNEUMONIA. 

7.  Bacillus  of  Friedlander. 


738  BACTERIOLOGICAL   DIAGNOSIS. 

Pneumococcus  (Friedlander). 
Bacillus  pneumonias  (Fliigge). 

8.  Micrococcus  pneumonias  crouposae. 
Micrococcus  Pasteuri  (Sternberg). 
Micrococcus  of  sputum  septicaemia  (Frankel). 
Diplococcus  pneumonias  (Weichselbaum). 
Bacillus  septicus  sputigenus  (Fliigge). 
Bacillus  salivarius  septicus  (Biondi). 
Lancet-shaped  micrococcus  (Talamon). 
Streptococcus  lanceolatus  Pasteuri  (Gameleia). 

PART   THIRD,    SECTION   VI. — PATHOGENIC   MICROCOCCI   NOT 
DESCRIBED   IN   SECTIONS   IV.    AND   V. 

9.  Diplococcus  intercellularis  meningitidis  (Weichselbaum). 

10.  Staphylococcus  salivarius  pyogenes  (Biondi). 

11.  Micrococcus  of  progressive  tissue  necrosis  in  mice  (Koch). 

12.  Micrococcus  of  progressive  abscess  formation  in  rabbits  (Koch). 

13.  Micrococcus  of  pysemia  in  rabbits  (Kocl,i). 

14.  Micrococcus  of  septicaemia  in  rabbits  (Koch). 

15.  Micrococcus  salivarius  septicus  (Biondi). 
10.  Micrococcus  subflavus  (Fliigge). 

Yellowish-white  micrococcus  (Bumm). 

17.  Micrococcus  of  trachoma  ?  (Sattler). 

18.  Micrococcus  tetragenus  (Gaffky,  Koch). 

19.  Micrococcus  botryogenus  (Rabe). 
Micrococcus  of  "  Myko-desmoids  "  of  the  horse. 
Micrococcus  askoformans  (Johne). 
Micrococcus  Johnei  (Cohn). 

20.  Micrococcus  of  Manfredi. 

Micrococcus  of  progressive  granuloma  formation  (Manfredi). 
"21.  Micrococcus  of  bovine  mastitis  (Kitt). 

22.  Micrococcus  of  bovine  pneumonia  ?  (Poels  arid  Nolen). 

23.  Streptococcus  septicus  (Fliigge). 

24.  Streptococcus  bombycis. 
Microzyma  bombycis  (Bechamp). 

25.  Nosema  bombycis. 
Micrococcus  ovatus. 
Panhistophyton  ovatum. 

20.  Micrococcus  of  Heydenreich. 

Micrococcus  of  Biskra  button— "  Clou  de  Biskra,"  Fr.;  "  Pen- 

desche  Geschwur,"  Ger. 
27.  Micrococcus  of  Demme. 

Diplococcus  of  pemphigus  acutus  (Demme). 


BACTERIOLOGICAL   DIAGNOSIS.  739 

28.  Streptococcus  of  Manneberg. 

29.  Micrococcus  endocarditidis  rugatus  (Weichselbaum). 

30.  Micrococcus  of  gangrenous  mastitis  in  sheep  (Nocard). 

31.  Streptococcus  of  mastitis  in  cows  (Nocard  and  Mollereau). 

32.  Diplococcus  of  pneumonia  in  horses  (Schiitz). 

33.  Streptococcus  coryzae  contagiosa3  equorum  (Schiitz). 

34.  HEematococcus  bovis  (Babes). 

35.  Micrococcus  gingivse  pyogenes  (Miller). 

36.  Pseudodiplococcus  pneumonise  (Bononie). 

37.  Streptococcus  septicus  liquefaciens  (Babes). 

38.  Micrococcus  of  Kirchner. 

39.  Micrococcus  No.  II.  of  Fischel. 

40.  Streptococcus  of  Bonome. 

41.  Micrococcus  of  Almquist. 

42.  Staphylococcus  pyosepticus  (Hericourt  and  Richet). 

43.  Streptococcus  perniciosus  psittacorum. 
Micrococcus  of  gray  parrot  disease  (Eberth  and  Wolff). 

44.  Micrococcus  of  Forbes. 

PART   THIRD,    SECTION   VII. — THE   BACILLUS   OF    ANTHRAX. 

45.  Bacillus  anthracis. 
Milzbrandbacillus,  Ger. 

La  bacteridie  du  charbon,  Fr. 

PART   THIRD,    SECTION   VIII. — THE   BACILLUS   OF   TYPHOID   FEVER. 

4<!.  Bacillus  typhi  abdominalis. 
Bacillus  typhosus. 
Typhus  bacillus  (Eberth,  Gaffky). 

PART   THIRD,    SECTION  IX. — BACTERIA   IN   DIPHTHERIA. 

47.  Bacillus  diphtherias  (Klebs,  Loffler). 

48.  Pseudo-diphtheritic  bacillus  (Roux  and  Yersin). 

49.  Bacillus  diphtheriaB  columbrarum  (Loffler). 

50.  Bacillus  diphtherise  vitulorum  (Loffler). 

51.  Bacillus  of  intestinal  diphtheria  in  rabbits  (Ribbert). 

PART   THIRD,    SECTION    X. — BACTERIA   IN  INFLUENZA. 

52.  Bacillus  of  influenza  (Pfeiffer,  Canon). 

PART   THIRD,    SECTION   XL — BACILLI   IN  CHRONIC   INFECTIOUS 

DISEASES. 

53.  Bacillus  tuberculosis  (Koch). 
Tubercle  bacillus. 


740  BACTERIOLOGICAL   DIAGNOSIS. 

54.  Bacillus  tuberculosis  gallinarum  (Maffucci). 

55.  Bacillus  leprse  (Hansen,  Neisser). 
Leprosy  bacillus. 

50.  Bacillus  mallei  (Loftier  and  Schutz). 
Bacillus  of  glanders. 
Rotzbacillus,  Ger. 
Bacille  de  la  morve,  Fr. 

57.  Bacillus  of  Lustgarten. 
Syphilis  bacillus  ( ?) 

58.  Bacillus  of  rhinoscleroma  (?). 

59.  Bacillus  of  Koubasoff. 

60.  Bacillus  of  Nocard. 
Bacille  du  farcin  du  boeuf. 

PART  THIRD,  SECTION   XII.— BACILLI   WHICH   PRODUCE  SEPTICAEMIA 
IN   SUSCEPTIBLE   ANIMALS. 

01.  Bacillus  septicsemise  haemorrhagicae  (Hueppe). 
Bacillus  of  fowl  cholera. 
Microbe  du  cholera  des  poules  (Pasteur). 
Bacillus  cholerse  gallinarum  (Fliigge). 
Bacillus  der  Hiihnercholera. 
Bacillus  of  rabbit  septicaemia. 
Bacillus  der  Kaninchenseptikiimie  (Koch). 
Bacillus  cuniculicida  (Fliigge). 
Bacillus  der  Rinderseuche  (Kitt). 
Bacillus  der  Schweineseuche  (Loffler  and  Schutz). 
Bacillus  der  Wildseuche  (Hueppe). 
Bacillus  der  Biiffelseuche  (Oreste-^rmanni). 
Bacterium  of  Davaine's  septicaemia  ( ?) 

62.  Bacillus  of  cholera  in  ducks  (Cornil  and  Toupet). 

63.  Bacillus  of  hog  cholera  (Salmon  and  Smith). 
Bacillus  of  swine  plague  (Billings). 
Bacillus  of  swinepest  (Selander). 

64.  Bacillus  of  Belfanti  and  Pascarola. 

Impf tetanus  bacillus  (Belfanti  and  Pascarola). 

65.  Bacillus  of  swine  plague,  Marseilles. 

Bacillus  der  Schweineseuche  (Rietsch  and  Jobert). 
Bacillus  der  Frettenseuche  (Eberth  and  Schimmelbusch). 
Bacillus  der  americanischen  Rinderseuche  (Caneva). 
Bacillus  of  spontaneous  rabbit  septicaemia  (Eberth). 

66.  Bacillus  septicus  agrigenus  (Nicolaier). 

67.  Bacillus  erysipelatos  suis. 
Bacillus  of  hog  erysipelas. 

Bacillus  des  Schweinerothlauf  (Loffler,  Schutz). 


BACTERIOLOGICAL   DIAGNOSIS.  741 

Bacille  du  rouget  du  pore  (Pasteur). 
Bacillus  of  mouse  septicsemia. 
Bacillus  murisepticus  (Fliigge). 
Bacillus  des  Miiuseseptikamie  (Koch). 

68.  Bacillus  coprogenes  parvus  (Bienstock). 
Mauseseptikamieahnlicher  Bacillus  (Eisenberg). 

69.  Bacillus  cavicida  (Brieger). 
Brieger's  bacillus. 

70.  Bacillus  cavicida  Havaniensis  (Sternberg). 

71.  Bacillus  crassus  sputigenus  (Kreibohm). 

72.  Bacillus  pyogenes  foetidus  (Passet). 

73.  Proteus  hominis  capsulatus  (Bordoni-Uffreduzzi). 

74.  Proteus  capsulatus  septicus  (Banti). 

75.  Bacillus  enteritidis  (Gartner). 

76.  Bacillus  of  grouse  disease  (Klein). 

77.  Bacillus  gallinarum  (Klein). 

78.  Bacillus  smaragdinus  fcetidus  (Reimann). 

79.  Bacillus  pneumosepticus  (Babes). 

80.  Bacillus  capsulatus  (Pfeiffer). 

81.  Bacillus  hydrophilus  fuscus  (Sanarelli). 

82.  Bacillus  tenuis  sputigenus  (Pansini). 

83.  Bacillus  of  Laser. 

84.  Bacillus  typhi  murium  (Loffler). 

85.  Bacillus  of  Cazal  and  Vaillard. 

86.  Bacillus  of  Babes  and  Oprescu. 

87.  Bacillus  of  Lucet. 

88.  Capsule  bacillus  of  Loeb. 

PART     THIRD,    SECTION   XIII. — PATHOGENIC    AEROBIC     BACILLI     NOT 
DESCRIBED    IN   PREVIOUS   SECTIONS. 

89.  Bacillus  coli  comrmmis. 
Bacterium  coli  commune  (Escherich). 
Colon  bacillus. 

90.  Bacillus  lactis  aerogenes. 
Bacterium  lactis  aerogenes  (Escherich). 

91.  Bacillus  c  of  Booker. 

92.  Bacillus  acidiformans  (Sternberg). 

93.  Bacillus  cuniculicida  Havaniensis  (Sternberg). 

94.  Bacillus  leporis  lethalis  (Sternberg). 
Bacillus  of  Gibier. 

95.  Bacillus  pyocyanus  (Gessard). 
Bacillus  of  green  pus. 
Microbe  du  pus  bleu. 
Bacillen  des  griinblauen  Eiters. 


742  BACTERIOLOGICAL   DIAGNOSIS. 

Bacterium  aeruginosum. 

96.  Bacillus  of  Fiocca. 

97.  Proteus  vulgaris  (Hauser). 

98.  Proteus  of  Karlinsky. 

Bacillus  murisepticus  pleomorphus  (Karlinsky). 

99.  Proteus  mirabilis  (Hauser). 

100.  Proteus  Zenkeri  (Hauser). 

101.  Proteus  septicus  (Babes). 

102.  Proteus  lethalis. 

Proteus  bei  Lungengangran  des  Menschen  (Babes). 

103.  Bacillus  A  of  Booker. 

104.  Bacillus  endocarditidis  griseus  (Weichselbaum). 

105.  Bacillus  endocarditidis  capsulatus  (Weichselbaum). 

106.  Bacillus  of  Lesage. 

Bacillus  of  green  diarrhosa  of  infants  (Lesage). 

107.  Bacillus  of  Demme. 

Bacillus  of  erythema  nodosum  (Demme). 

108.  Bacillus  cedematis  aerobicus  (Klein). 

109.  Bacillus  of  Letzerich. 

Bacillus  of  nephritis  interstitialis  (Letzerich). 

110.  Bacillus  of  Schimmelbusch. 
Bacillus  nomse  (Schimmelbusch). 

111 .  Bacillus  foetidus  ozsense  (Hajek). 

112.  Bacillus  of  Lumnitzer. 

Bacillus  of  putrid  bronchitis  (Lumnitzer). 

113.  Bacillus  of  Tommasoli. 
Bacillus  of  sycosis  (Tommasoli). 

114.  Bacillus  of  Schou. 

Bacillus  of  vagus  pneumonia  (Schou). 

115.  Bacillus  necrophorus  (Loffler). 

116.  Bacillus  coprogenes  fretidus  (Schottelius). 
Darmbacillus  of  Schottelius. 

117.  Bacillus  oxytocus  perniciosus  (Wyssokowitsch). 

118.  Bacillus  saprogenes  No.  II.  (Rosenbach). 

119.  Bacillus  of  Afanassiew. 

Bacillus  of  whooping  cough  (Afanassiew). 

120.  Pneumobacillus  liquefaciens  bovis  (Arloing). 

121.  Bacillus  pseudotuberculosis  (Pfeiffer). 

122.  Bacillus  gingivse  pyogenes. 
Bacterium  gingivse  pyogenes  (Miller). 

123.  Bacillus  dentalis  viridans  (Miller). 

124.  Bacillus  pulpse  pyogenes  (Miller). 

125.  Bacillus  septicus  keratomalacise  (Babes). 

126.  Bacillus  septicus  acuminatus  (Babes). 


BACTERIOLOGICAL   DIAGNOSIS.  743 

127.  Bacillus  septictis  ulceris  gangrsenosi  (Babes). 

128.  Bacillus  of  Tricomi. 

Bacillus  of  senile  gangrene  (Tricomi). 

129.  Bacillus  albus  cadaveris  (Strassmami  and  Strieker). 

130.  Bacillus  varicosus  conjunctives  (Gombert). 

131.  Bacillus  meningitidis  purulentse  (Neumann  and  Schaffer). 

132.  Bacillus  septicus  vesicse  (Clado). 
Bacillus  of  cystitis  (Clado). 

133.  Bacillus  of  Gessner. 
Bacterium  tholoideum  (Gessner). 

134.  Bacillus  chromo-aromaticus  (Galtier). 

135.  Bacillus  canalis  capsulatus  (Mori). 

136.  Bacillus  canalis  parvus  (Mori). 

137.  Bacillus  indigogenus  (Alvarez). 

138.  Bacillus  of  Kartulis. 

Bacillus  of  Egyptian  ophthalmia  (Kartulis). 

139.  Bacillus  of  Utpadel. 

140.  Bacillus  alvei  (Cheshire  and  Cheyne). 
Bacillus  of  foul  brood  of  bees. 

141.  Bacillus  of  acne  contagiosaof  horses  (Dieckerhoff  and  Grawitz). 

142.  Bacillus  No.  I.  of  Roth. 

143.  Bacillus  No.  II.  of  Roth. 

144.  Bacillus  of  Okada. 

145.  Bacillus  of  purpura  hsemorrhagica  of  Tizzoni  and  Giovannini. 

146.  Bacillus  of  purpura  ha3inorrhagica  of  Babes. 

147.  Bacillus  of  purpura  hgemorrhagica  of  Kolb. 

148.  Bacillus  heminecrobiophilus  (Arloing). 

PART   THIRD,    SECTION   XIV. — PATHOGENIC   ANAEROBIC   BACILLI. 

149.  Bacillus  tetani  (Nicolaier). 
Tetanus  bacillus. 

150.  Bacillus  oedematis  maligni. 
Bacillus  of  malignant  oedema. 
Vibrion  septique  (Pasteur). 

151.  Bacillus  cadaveris  (Sternberg). 

152.  Bacillus  of  symptomatic  anthrax. 

Bacille  du  charbon   symptomatique   (Arloing,   Cornevin,  and 

Thomas). 
Rauschbrandbacillus. 

PART   THIRD,    SECTION   XV. — PATHOGENIC    SPIRILLA. 

15>3.  Spirillum  Obermeieri. 
Spirochsete  Obermeieri. 
Spirillum  of  relapsing  fever. 


744  BACTERIOLOGICAL   DIAGNOSIS. 

Recurrensspirochate. 

154.  Spirillum  anserum  (Sakharoff). 

155.  Spirillum  cholerce  Asiatics  (Koch). 
Spirillum  of  Asiatic  cholera. 
Comma  bacillus  of  Koch. 
Bacille-virgule  cholerigene. 

15G.  Spirillum  of  Finkler  and  Prior. 
Vibrio  proteus. 

157.  Spirillum  tyrogenum. 
Kasespirillen  (Deneke). 
Cheese  spirillum  of  Deneke. 

158.  Spirillum  Metschnikovi. 
Vibrio  Metschnikovi  (Gameleia). 

PART    FOURTH,    SECTION   VIII.—  NON-PATHOGENIC   MICROCOCCI. 

159.  Micrococcus  flavus  liquefaciens  (Fliigge). 

160.  Micrococcus  flavus  desidens  (Fliigge). 
1G1.  Micrococcus  agilis  (Ali-Cohen). 

162.  Micrococcus  fuscus  (Maschek). 

1G3.  Diplococcus  citreus  conglomeratus  (Bumm). 

104.  Diplococcus  citreus  liquefaciens  (Unna). 

105.  Diplococcus  flavus  liquefaciens  tardus  (Unna). 
1GG.  Diplococcus  fluorescens  foetidus  (Klamann). 
1G7.  Diplococcus  luteus  (Adametz). 

IGfS.  Diplococcus  roseus  (Bumm). 

100.  Micrococcus  cremoides  (Zimmermann). 

170.  Micrococcus  roseus  (Eisenberg). 

171.  Micrococcus  aurantiacus  (Colin). 
17^.  Micrococcus  cerasinus  siccus  (List). 
17o.  Micrococcus  versicolor  (Fliigge). 

174.  Micrococcus  of  Dantec. 

175.  Micrococcus  carneus  (Zimmermann). 
170.  Micrococcus  cinnabareus  (Fliigge). 

177.  Micrococcus  cereus  albus  (Passet). 

178.  Micrococcus  cereus  flavus  (Passet). 
170.  Micrococcus  citreus. 

Cremefarbiger  micrococcus  (List). 

180.  Micrococcus  fervidosus  (Adametz). 

181.  Micrococcus  flavus  tardigratus  (Fliigge). 

182.  Micrococcus  luteus  (Cohn). 

183.  Micrococcus  violaceus  (Cohn). 

184.  Staphylococcus  viridis  flavescens  (Guttmann). 

185.  Micrococcus  ochroleucus  (Prove). 

18G.  Micrococcus  acidi  lactici  liquefaciens  (Kreuger). 


BACTERIOLOGICAL   DIAGNOSIS.  745 

187.  Micrococcus  aerogenes  (Miller). 

188.  Micrococcus  albus  liquefaciens  (Von  Besser). 

189.  Micrococcus  fcetidus  (Klamann). 

190.  Micrococcus  radiatus  (Fliigge). 

191.  Diplococcus  albicans  amplus  (Bumm). 

192.  Micrococcus  candicans  (Fliigge). 

193.  Micrococcus  candidus  (Colin). 

194.  Micrococcus  acidi  lactici  (Marpmann). 

195.  Micrococcus  lactis  viscosus  (Conn). 

196.  Sphaerococcus  acidi  lactici  (Marpmann). 

197.  Micrococcus  aquatilis  (Bolton). 

198.  Micrococcus  concentricus  (Zimmermann). 

199.  Micrococcus  cumulatus  tenuis  (Von  Besser). 

300.  Micrococcus  plumosus  (Brautigam). 

301.  Micrococcus  rosettaceus  (Zimmermann). 

302.  Micrococcus  urese  (Pasteur). 

303.  Micrococcus  ureae  liquefaciens  (Fliigge). 

304.  Micrococcus  viticulosus  (Katz). 

305.  Diplococcus  albicans  tardissimus  (Eisenberg). 
Milk-white  diplococcus  (Bumm). 

306.  Diplococcus  albicans  tardus  (Unna). 

307.  Staphylococcus  albus  liquefaciens. 

White  liquefying  staphylococcus  (Escherich). 

308.  Micrococcus  ovalis  (Escherich). 

309.  Diplococcus  coryzse  (Hajek). 

310.  Micrococcus  Finlayensis  (Sternberg). 

311.  Micrococcus  of  Freire. 
Cryptococcus  xanthogenicus  (Freire). 

312.  Streptococcus  coli  gracilis  (Escherich). 

313.  Streptococcus  acidi  lactici  (Grotenfeld). 

314.  Streptococcus  giganteus  urethras  (Lustgarten). 

315.  Streptococcus  albus  (Maschek). 

216.  Streptococcus  vermiformis  (Maschek). 

217.  Streptococcus  brevis  (Von  Lingelsheim). 
Streptococcus  cadaveris  (Sternberg). 

218.  Streptococcus  Havaniensis  (Sternberg). 

219.  Streptococcus  liquefaciens  (Sternberg). 

230.  Micrococcus  tetragenus  versatilis  (Sternberg). 

331.  Pediococcus  albus  (Lindner). 

332.  Pediococcus  acidi  lactici  (Lindner). 

333.  Pediococcus  cerevisiss  (Balcke). 

334.  Micrococcus  tetragenus  mobilis  ventriculi  (Mendoza). 

335.  Micrococcus  tetragenus  subflavus  (Von  Besser). 
226.  Sarcina  aurantiaca. 


746  BACTERIOLOGICAL    DIAGNOSIS. 

227.  Sarcina  lutea  (Schroter). 

228.  Sarcina  flava  (De  Bary). 

229.  Sarcina  rosea  (Schroter). 

230.  Sarcina  alba  (Eisenberg). 

231.  Sarcina  Candida  (Reinke). 

232.  Sarcina  pulmonum  (Hauser). 

233.  Sarcina  ventriculi  (Goodsirj. 

234.  Micrococcus  amylovorus  (Burrill). 

235.  Ascococcus  Billrothii  (Cohn). 

236.  Leuconostoc  mesenteroides  (Cienkowski). 


PART   FOURTH,    SECTION   IX. — NON-PATHOGENIC   BACILLI. 

A.   Chromogenic,  Non-Liquefying  Bacilli. 

237.  Bacterium  luteum  (List). 

238.  Bacillus  aurantiacus  (Frankland). 

239.  Bacillus  brunneus  (Adametz). 

240.  Bacillus  aureus  (Adametz). 

241.  Bacillus  flavocoriaceus  (Eisenberg). 
Sulphur-yellow  bacillus  of  Adametz. 

242.  Bacillus  berolinensis  Indicus  (Classen). 

243.  Bacillus  constrictus  (Zimmermann). 

244.  Bacillus  fluorescens  aureus  (Zimmermann). 

245.  Bacillus  fluorescens  longus  (Zimmermann). 

246.  Bacillus  fluorescens  tenuis  (Zimmermann). 

247.  Bacillus  fluorescens  non-liquefaciens  (Eisenberg). 

248.  Bacillus  fluorescens  putidus  (Fliigge). 

249.  Bacillus  erythrosporus  (Eidam). 

250.  Bacillus  viridis  pallescens  (Frick). 

251.  Bacillus  virescens  (Frick). 

252.  Bacillus  iris  (Frick). 

253.  Bacillus  fuscus  (Zimmermann). 

254.  Bacillus  rubefaciens  (Zimmermann). 

255.  Bacillus  striatus  flavus  (Von  Besser). 

256.  Bacillus  subflavus  (Zimmermann). 

257.  Bacillus  cyanogenus  (Hueppe). 

258.  Bacillus  fuscus  limbatus  (Scheibenzuber). 

259.  Bacillus  latericeus  (Eisenberg). 
Ziegelroter  bacillus  (Adametz). 

260.  Bacillus  spiniferus  (Unna). 

261.  Bacillus  rubescens  (Jordan). 

262.  Bacillus  allii  (Griffiths). 


BACTERIOLOGICAL   DIAGNOSIS.  747 

B.   Cliromogenic,  Liquefying  Bacilli. 

263.  Bacillus  fulvus  (Zimmermann). 

264.  Bacillus  helvolus  (Zimmermann). 

265.  Bacillus  ochraceus  (Zimmermann). 

266.  Bacillus  plicatilis  (Zimmermann). 

267.  Bacillus  janthinus  (Zopf). 
Violet  bacillus. 

268.  Bacillus  violaceus  Laurentius  (Jordan). 

269.  Bacillus  tremelloides  (Schottelius). 

270.  Bacillus  cuticularis  (Tils). 

271.  Flesh-colored  bacillus  (Tils). 

272.  Bacillus  arborescens  (Frankland). 

273.  Bacillus  citreus  cadaveris  (Strassmann). 

274.  Bacillus  membranaceus  amethystinus  (Eisenberg). 

275.  Ascobacillus  citreus  (Unna). 

276.  Bacillus  cceruleus  (Smith). 

277.  Bacillus  fluorescens  liquefaciens  (Fliigge). 

278.  Bacillus  fluorescens  liquefaciens  minutissimus  (Unna). 

279.  Bacillus  fluorescens  nivalis  (Schmolck). 

280.  Bacillus  lactis  erythrogenes  (Hueppe). 

281.  Bacillus  glaucus  (Maschek). 

282.  Bacillus  lividus  (Plagge  and  Proskauer). 

283.  Bacillus  Indicus  (Koch). 

284.  Bacillus  prodigiosus. 
Micrococcus  prodigiosus. 
Monas  prodigiosa. 

285.  Bacillus  mesentericus  ruber. 
Rothen  Kartoffelbaciilus  (Globig). 

286.  Bacillus  pyocyanus  ft  (Ernst). 

287.  Bacillus  mycoides  roseus  (Scholl). 

288.  Bacillus  rosaceum  metalloides  (Dowdeswell). 

289.  Bacillus  viscosus  (Frankland). 

290.  Bacillus  violaceus. 

291.  Bacillus  sulfureum  (Holschewnikoff). 

292.  Bacillus  rubidus  (Eisenberg). 

293.  Bacterium  termo  of  Vignal. 

294.  Bacillus  buccalis  minutus. 
Bacillus  g  of  Vignal. 

295.  Bacillus  of  Canestrini. 
(Pathogenic  for  bees.) 


748  BACTERIOLOGICAL  DIAGNOSIS. 

C.  Non-chromogetiic,  Non-liquefying  Bacilli. 

296.  Bacillus  ubiquitus  (Jordan). 

297.  Bacillus  candicans  (Frankland). 

298.  Bacillus  albus  (Eisenberg). 

299.  Bacillus  acidi  lactici  (Hueppe). 

300.  Bacillus  limbatus  acidi  lactici  (Marpmann). 

301.  Bacillus  lactis  pituitosi. 

Bacillus  der  schleimigen  Milch  (Loftier). 

302.  Bacillus  aerogenes  (Miller). 

303.  Bacterium  aerogenes  (Miller). 

304.  Heliobacterium  aerogenes  (Miller). 

305.  Bacillus  aquatilis  sulcatus  No.  I.  (Weichselbaum). 

306.  Bacillus  aquatilis  sulcatus  No.  II.  (Weichselbaum). 

307.  Bacillus  aquatilis  sulcatus  No.  III.  (Weichselbaum). 

308.  Bacillus  aquatilis  sulcatus  No.  IV.  (Weichselbaum). 

309.  Bacillus  aquatilis  sulcatus  No.  V.  (Weichselbaum). 

310.  Bacillus  multipediculus  (Fliigge). 

311.  Bacillus  cystiformis  (Clado). 

312.  Bacillus  hepaticus  fortuitus  (Sternberg). 

313.  Bacillus  intestinus  motilis  (Sternberg). 

314.  Bacillus  caviee  fortuitus  (Sternberg). 

315.  Bacillus  coli  similis  (Sternberg). 

316.  Bacillus  filiformis  Havaniensis  (Sternberg). 

317.  Bacillus  Martinez  (Sternberg). 

318.  Bacillus  epidermidis  (Bizzozero). 

319.  Bacillus  nodosus  parvus  (Lustgarten). 

320.  Bacillus  hyacinthi  septicus  (Heinz). 

321.  Bacterium  gliscrogenum  (Malerba). 

322.  Bacillus  ovatus  minutissimus  (Unna). 

323.  Capsule  bacilli  of  Smith. 

324.  Bacillus  putrificus  coli  (Bienstock). 

325.  Bacillus  subtilis  simularis  No.  I.  (Bienstock). 

326.  Bacillus  subtilis  simulans  No.  II.  (Bienstock). 

327.  Bacillus  striatus  albus  (Von  Besser). 

328.  Bacillus  stolonatus  (Adametz). 

329.  Bacillus  ventriculi  (Raczynssky). 

330.  Bacterium  Zopfii  (Kurth). 

331.  Bacterium  Zurnianum  (List). 

332.  Bacillus  of  Colomiatti. 

333.  Bacillus  scissus  (Frankland). 

334.  Bacillus  No.  I.  of  Fulles. 

335.  Bacillus  No.  II.  of  Fulles. 

336.  Bacillus  phosphorescens  gelidus  (Forster). 


BACTERIOLOGICAL   DIAGNOSIS.  749 

337.  Bacillus  smaragdino-phosphoresceiis  (Katz). 

338.  Bacillus  argenteo-phosphorescens  No.  I.  (Katz). 

339.  Bacillus  argenteo-phosphorescens  No.  II.  (Katz). 

340.  Bacillus  argenteo-phosphorescens  No.  III.  (Katz). 

D.  Non-cliromogenic,  Liquefying  Bacilli. 

341.  Bacillus  cyaneo-phosphorescens  (Katz). 

342.  Bacillus  argenteo-phosphorescens  liquefaciens  (Katz). 

343.  Bacillus  phosphorescens  Indicus  (Fischer). 

344.  Bacillus  phosphorescens  indigenus  (Fischer). 

345.  Bacillus  circulans  (Jordan). 

346.  Bacillus  superficialis  (Jordan). 

347.  Bacillus  reticularis  (Jordan). 

348.  Bacillus  hyalinus  (Jordan). 

349.  Bacillus  cloacae  (Jordan). 

350.  Bacillus  delicatulus  (Jordan). 

351.  Bacillus  aquatilis  (Frankland). 

352.  Bacillus  diffusus  (Frankland). 

353.  Bacillus  liquidus  (Frankland). 

354.  Bacillus  vermicularis  (Frankland). 

355.  Bacillus  nubilus  (Frankland). 

356.  Bacillus  pestifer  (Frankland). 

357.  Bacillus  filiformis  (Tils). 

358.  Bacillus  devorans  (Zimmermann). 

359.  Bacillus  gracilis  (Zimmermann).  . 

360.  Bacillus  guttatus  (Zimmermann). 

361.  Bacillus  implexus  (Zimmermann). 

362.  Bacillus  punctatus  (Zimmermann). 

363.  Bacillus  radiatus  aquatilis  (Zimmermann). 

364.  Bacillus  vermiculosus  (Zimmermann). 

365.  Bacillus  aerophilus  (Liborius). 

366.  Bacillus  mycoides  (Fliigge). 

367.  Bacillus  mesentericus  vulgatus  (Fliigge). 
Kartoffelbacillus.  4f-«  «. 
Bacillus  mesentericus  fuscus  (Fliigge). 
Bacillus  megatherium  (De  Bary). 

Bacillus  albus  putidus  (De  Bary).  ,-,    • 

Bacillus  brassicse  (Pommer). 
Bacillus  butyricus  of  Hueppe. 
Bacillus  gasoformans  (Eisenberg). 
Bacillus  carabiformis  (Kaczynsky). 
Bacillus  graveolens  (Bordoni-Uffreduzzi). 
Bacillus  carotarum  (A.  Koch). 
64 


750  BACTERIOLOGICAL  DIAGNOSIS. 

377.  Bacillus  inflatus  (A.  Koch). 

378.  Bacillus  ramosus. 
Wurtzel  bacillus. 

379.  Bacillus  subtilis  (Ehrenberg). 

380.  Bacillus  subtilis  similis  (Sternberg). 

381.  Bacillus  leptosporus  (L.  Klein). 

382.  Bacillus  sessilis  (L.  Klein). 

383.  Bacillus  allantoides  (L.  Klein). 

384.  Bacillus  of  Scheurlen. 

385.  Bacillus  lactis  albus  (Loftier). 

386.  Bacillus  liodermos  (Loffler). 

387.  Bacillus  ulna  (Conn). 

388.  Bacillus  ulna  of  Vignal. 

389.  Bacillus  liquefaciens  (Eisenberg). 

390.  Bacillus  maidis  (Cuboni). 

391.  Proteus  sulfureus  (Lindenborn). 

392.  Bacillus  thormophilus  (Miquel). 

393.  Bacillus  tumescens  (Zopf). 

394.  Bacillus  buccalis  maximus  (Miller). 

395.  Leptothrix  buccalis  of  Vignal. 

396.  Bacillus  b  of  Vignal. 

397.  Bacillus  /  of  Vignal. 

398.  Bacillus  buccalis  fortuitus. 
Bacillus  j  of  Vignal. 

399.  Bacillus  Havaniensis  liquefaciens  (Sternberg). 

400.  Bacillus  liquefaciens  communis  (Sternberg). 

E.  Strictly  Anaerobic  Bacilli. 

401.  Bacillus  muscoides  (Liborius). 

402.  Bacillus  solidus  (Liideritz). 

403.  Bacillus  polypiformis  (Liborius). 

404.  Bacillus  butyricus  (Prazmowski). 
Bacillus  amylobacter. 
Clostridium  butyricum. 

405.  Clostridium  fostidum  (Liborius). 

406.  Bacillus  liquefaciens  magnus  (Liideritz). 

407.  Bacillus  liquefaciens  parvus  (Liideritz). 

408.  Bacillus  radiatus  (Liideritz). 

409.  Bacillus  spinosus  (Liideritz). 

410.  Bacillus  anaerobicus  liquefaciens  (Sternberg). 

PART  FOURTH,    SECTION  X. — NON-PATHOGENIC   SPIRILLA. 

411.  Spirillum  sputigenum  (Miller). 

412.  Spirillum  dentium. 


BACTERIOLOGICAL   DIAGNOSIS.  751 

Spirochsete  denticola. 

413.  Spirillum  plicatile. 
Spirochcete  plicatilis  (Ehrenberg). 

414.  Vibrio  rugula  (Miiller). 

415.  Spirillum  volutans  (Ehrenberg). 

416.  Spirillum  sanguineum  (Warming). 
Ophidomonas  sanguinea. 

417.  Spirillum  serpens  (Miiller). 

418.  Spirillum  undula  (Ehrenberg). 

419.  Spirillum  tenue  (Ehrenberg). 

420.  Spirillum  linguae. 
Vibrio  lingualis  (Weibel). 

421.  Spirillum  nasale. 
Vibrio  nasalis. 
Nasenschleim  vibrio  (Weibel). 

422.  Spirillum  a  of  Weibel. 
Vibrio  saprophiles  a.  (Weibel). 

423.  Spirillum  ft  of  Weibel. 
Vibrio  saprophiles  fi  (Weibel). 

424.  Spirillum  y  of  Weibel. 
Vibrio  saprophiles  y  (Weibel). 

425.  Spirillum  aureum. 
Vibrio  aureus  (Weibel). 

426.  Spirillum  flavescens. 
Vibrio  flavescens  (Weibel). 

427.  Spirillum  flavum. 
Vibrio  flavus  (Weibel). 

428.  Spirillum  concentricum  (Kitasato). 

429.  Spirillum  rubrum  (Von  Esmarch). 

430.  Spirillum  of  Smith. 

431.  Spirillum  of  Miller. 
Miller's  bacillus. 

PART   FOURTH,    SECTION  XI. — LEPTOTRICHEJE  AND 
CLADOTRICHE^E. 

432.  Crenothrix  Kiihniana  (Rabenhorst). 

433.  Beggiatoa  alba  (Vauch.). 

434.  Beggiatoa  roseo-persicina  (Zopf).  « 
Clathrocystis  roseo-persicina  (Cohn). 
Ophidomonas  sanguinea  (Ehrenberg). 
Bacterium  rubescens  (Lankester). 

435.  Beggiatoa  mirabilis  (Cohn). 

436.  Phragmidiothrix  multiseptata  (Engler). 


752  BACTERIOLOGICAL   DIAGNOSIS. 

437.  Cladothrix  dichotoma  (Colin). 

438.  Cladothrix  Foersteri. 
Streptothrix  Foersteri  (Cohn). 

439.  Cladothrix  intricata  (Russell). 


PART   FOURTH,    SECTION   XII. — ADDITIONAL  SPECIES  OF  BACTERIA, 

NOT   CLASSIFIED. 

440.  Nitromonas  of  Winogradsky. 

441 .  Nitrifying  bacillus  of  Winogradsky. 

442.  Streptococcus  conglomeratus  (Kurth). 

443.  Bacillus  thalassophilus  (Russell). 

444.  Bacillus  granulosus  (Russell). 

445.  Bacillus  limosus  (Russell). 
44G.  Spirillum  marinum  (Russell). 

447.  Bacillus  litoralis  (Russell). 

448.  Bacillus  halophilus  (Russell). 

449.  Bacillus  capsulatus  mucosus'  (Fasching). 

450.  Bacillus  of  potato  rot  (Kramer). 

451.  Bacillus  vacuolosis  (Sternberg). 

452.  Bacillus  of  Dantec. 

453.  Bacillus  Havaniensis  (Sternberg). 

454.  Bacillus  amylozyma  (Perdrix). 

455.  Bacillus  rubellus  (Okada). 

456.  Bacterium  urese  (Jaksch). 

457.  Sarcina  mobilis  (Maurea). 

458.  Bacillus  stoloniferus  (Pohl). 

459.  Bacillus  incanus  (Pohl). 
400.  Bacillus  inunctus  (Pohl). 

461.  Bacillus  flavescens  (Pohl). 

462.  Bacillus  butyricus  of  Botkin. 

463.  Urobacillus  Pasteuri  (Miquel). 

464.  Urobacillus  Duclauxi  (Miquel). 

465.  Urobacillus  Freudenreichi  (Miquel). 

466.  Urobacillus  Maddoxi  (Miquel). 

467.  Urobacillus  Schiitzenbergi  (Miquel). 

468.  Bacillus  of  Bovet. 

469.  Bacillus  Schafferi  (Freudenreich). 

470.  Bacilli  of  Guillebeau — a,  b,  c — (Freudenreich). 

471.  Micrococcus  Freudenreichi  (Guillebeau). 

472.  Bacterium  Hessii  (Guillebeau). 

473.  Bacillus  denitrificans  (Giltay  and  Aberson). 

474.  Bacillus  cyano-fuscus  (Beyerinck). 

475.  Bacillus  pyogenes  soli  (Bolton). 


BACTERIOLOGICAL   DIAGNOSIS.  753 

476.  Micrococcus  aquatilis  invisibilis  (Vaughan). 

477.  Bacillus  gracilis  anaerobiescens  (Vaughan). 

478.  Bacillus  figurans  (Vaughan). 

479.  Bacillus  albus  anaerobiescens  (Vaughan). 

480.  Bacillus  invisibilis  (Vaughan). 

481.  Bacillus  venenosus  (Vaughan). 

482.  Bacillus  venenosus  brevis  (Vaughan). 

483.  Bacillus  venenosus  invisibilis  (Vaughan). 

484.  Bacillus  venenosus  liquefaciens  (Vaughan). 

485.  Bacillus  aerogenes  capsulatus  (Welch). 

486.  Bacillus  of  Canon  and  Pielicke. 

487.  Bacillus  sanguinis  typhi  (Brannan  and  Cheesman). 

488.  Micrococcus  agilis  citreus  (Menge). 

489.  Bacillus  gracilis  cadaveris  (Sternberg). 

BACTERIOLOGICAL  DIAGNOSIS. 
MICROCOCCI. 

I.  Staphylococci — micrococci,  solitary,  in  pairs,  in  irregular  groups, 

and  occasionally  in  short  chains  or  in  groups  of  four. 
A.   Grow  in    nutrient  gelatin  at  the  room  temperature    (20°    to 

22°  C.)  and  liquefy  the  gelatin. 
a.  Chromogenic  ;  pigment  yellow: 

Staphylococcus  pyogenes  aureus  (1). 

Staphylococcus  pyogenes  citreus  (3). 

Micrococcus  flavus  liquefaciens  (159). 

Micrococcus  citreus  liquefaciens  (164). 

Micrococcus  flavus  desidens  (160). 

Micrococcus  cremoides  (169). 

Micrococcus  of  Almquist  (41). 

Micrococcus  Finlayensis  (210). 

Staphylococcus  salivarius  pyogenes  (10). 
a.  Pigment  red  or  pink  : 

Micrococcus  fuscus  (162). 

Micrococcus  roseus  (170). 

Micrococcus  agilis  (161). 
I)    Non-chromogenic  : 

Staphylococcus  pyogenes  albus  (2). 

Staphylococcus  pyosepticus  (42). 

Micrococcus  of  Freire  (211). 

Micrococcus  albus  liquefaciens  (188). 

Micrococcus  of  gangrenous  mastitis  in  sheep  (30). 

Micrococcus  urese  liquefaciens  (203). 

Micrococcus  aerogenes  (187). 


754  BACTERIOLOGICAL   DIAGNOSIS. 

Micrococcus  radiatus  (190). 
Micrococcus  foetidus  (189). 

B.  Grow  in  nutrient  gelatin  at  the  room  temperature  (20°  to  22°  C.), 

and  do  not  liquefy  the  gelatin. 

a.  Chromogenic  ;  pigment  yellow : 

Micrococcus  versicolor  (173). 

Micrococcus  aurantiacus  (171). 

Micrococcus  cereus  flavus  (178). 

Micrococcus  flavus  tardigratus  (181). 

Micrococcus  luteus  (182). 

Micrococcus  agilis  citreus  (488). 
a.  Pigment  greenish-yellow  : 

Staphylococcus  viridis  flavescens  (184). 
a.  Pigment  violet  : 

Micrococcus  violaceus  (183). 
a.  Pigment  red  or  pink  : 

Micrococcus  carneus  (175). 

Micrococcus  cinnabareus  (176). 

Micrococcus  cerasinus  siccus  (172). 

b.  Non-chromogenic  : 

Micrococcus  candicans  (192). 
Micrococcus  cereus  albus  (177). 
Micrococcus  concentricus  (198). 
Micrococcus  fervidosus  (180). 
Micrococcus  of  bovine  pneumonia  ?  (22). 
Micrococcus  acidi  lactici  (194). 
Micrococcus  aquatilis  (197). 
Micrococcug  cumulatus  tenuis  (199). 
Micrococcus  ureee  (202). 
Micrococcus  of  bovine  mastitis  (21). 
Micrococcus  salivarius  septicus  (15). 
Micrococcus  gingivsB  pyogeries  (35). 
Micrococcus  rosettaceus  (201). 
Micrococcus  aquatilis  invisibilis  (476). 

C.  Do  not  grow  in  nutrient  gelatin  at  the  room  temperature  : 

Micrococcus  endocarditidis  rugatus  (29). 
Nitromonas  of  Winogradsky  (440). 

D.  Biological  characters  not  determined  : 

Micrococcus  pyogenes  tenuis  (4). 

Micrococcus  of  progressive  abscess  formation  in  mice(12) 

Micrococcus  of  pysemia  in  rabbits  (13). 

Micrococcus  of  Forbes  (44). 

Nosema  bombycis  (25). 


BACTERIOLOGICAL   DIAGNOSIS.  755 

II.  Micrococci  united  in  zooglcea  masses  by  an  intercellular  substance: 

Micrococcus  viticulosis  (204). 
Micrococcus  plumosus  (200). 
Micrococcus  candidus  (193). 
Micrococcus  amylovorus  (234). 
Ascococcus  Billrothi  (235). 
Leuconostoc  mesenteroides  (236). 

III.  Micrococci  in  pairs — diplococci,  not  forming  chains. 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature  (20°  to  22° 

C.),  and  liquefy  the  gelatin. 

a.  Chromogenic  ;  pigment  yellow  : 

Diplococcus  subflavus  (16) — stains  by  Gram's  method. 

Micrococcus  botryogenus  (19). 

Diplococcus  flayus  liquefaciens  tardus  (165). 

a.  Pigment  red  : 

Diplococcus  roseus  (168). 

b.  Non-chromogenic  : 

Diplococcus  albicans  amplus  (191). 
Micrococcus  of  Heydenreich  (26). 

B.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  do  not 

liquefy  ;  non-chromogenic. 

a.  Stain  by  Gram's  method  : 

Micrococcus  of  Manfredi  (20). 
Micrococcus  of  trachoma  ?  (17). 

b.  Do  not  stain  by  Gram's  method  : 

Diplococcus  of  pneumonia  in  horses  (32). 
Hsematococcus  bovis  (34). 
Diplococcus  albicans  tardissimus  (205). 

c.  Staining  by  Gram's  method  not  determined  : 

Diplococcus  coryzse  (209). 

C.  Do  not  grow  in  nutrient  gelatin  at  the  room  temperature  ;  non- 

chromogenic  ;  do  not  stain  by  Gram's  method  : 
Diplococcus  intercellularis  meningitidis  (9). 
Micrococcus  gonorrhoeas  (6). 
Micrococcus  of  Kirchner  (38). 
Micrococcus  of  Demme  (27). 

D.  Biological  characters  imperfectly  determined  : 

Micrococci  of  Disse  and  Taguchi  (p.  404). 

IV.  Micrococci  which  multiply  by  division  in  one  direction  only, 

forming  diplococci  and  streptococci. 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature  (20°  to  22° 
C.),  and  liquefy  the  gelatin. 


756 


BACTERIOLOGICAL   DIAGNOSIS. 


a    Chromogenic  ,  pigment  yellow  : 
Diplococcus  luteus  (167). 

a.  Pigment  green  : 

Diplococcus  fluorescens  fcetidus  (166). 

b.  Non-chromogenic. 
1    Grow  on  potato  : 

Micrococcus  No.  II.  of  Fischel  (39). 

Micrococcus  lactis  viscosus  (195). 

Streptococcus  liquefaciens  (219). 

Streptococcus  of  Manneberg  (28). 

Streptococcus  coli  gracilis  (212). 

Micrococcus  Freudenreichi  (471). 

Streptococcus  albus  (215). 
2.  Does  not  grow  on  potato  : 

Streptococcus  septicus  liquefaciens  (37). 

B.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  do  not 
liquefy. 

a.  Chromogenic  ;  pigment  yellow  : 

Micrococcus  citreus  (179). 
Micrococcus  ochroleucus  (185). 

b.  Non-chromogenic. 

1.  Grow  on  potato  : 

j  Streptococcus  brevis  (217). 

(  Streptococcus  cadaveris. 
Pseudodiplococcus  pneumoniae  (36). 
Streptococcus  vermiformis  (216). 

2.  Do  not  grow  on  potato  •  coagulate  milk  : 

Streptococcus  pyogenes  (5). 
Streptococcus  of  mastitis  in  cows  (31). 

3.  Growth  on  potato  not  stated  : 

Streptococcus  coryzae  contagiosae  equorum  (33). 
Streptococcus  septicus  (23). 
Streptococcus  acidi  lactici  (213). 
Streptococcus  conglomeratus  (442). 

C.  Do  not  grow  in  nutrient  gelatin  at  the  room  temperature  : 

Micrococcus  pneumonias  crouposae  (8). 
Streptococcus  of  Bonome  (40). 
Streptococcus  giganteus  urethra  (214). 

D.  Biological  characters  imperfectly  known  : 

Streptococcus  perniciosus  psittacorum  (43). 

Streptococcus  bombycis  (24). 

Streptococcus  Havaniensis  (218). 

Micrococcus  of  progressive  tissue  necrosis  in  mice(ll). 


BACTERIOLOGICAL   DIAGNOSIS.  757 

V.  Micrococci  which  multiply  by  division  in  two  directions,  forming 

diplococci  and  tetrads. 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  liquefy 

the  gelatin. 

a.  Chromogenic  ;  pigment  yellow  : 

Diplococcus  citreus  conglomeratus  (163). 
Micrococcus  tetragenus  versatilis  (220). 

b.  Non-chromogenic  : 

Micrococcus  acidi  lactici  liquefaciens  (186). 
Pediococcus  albus  (221). 

B.  Grow  in  nutrient  gelatin  at  the  room  temperature  and  do  not 

liquefy. 
Non-chromogenic  : 

Pediococcus  acidi  lactici  (222). 

Micrococcus  tetragenus  mobilis  ventriculi  (224). 

Pediococcus  cerevisisB  (223). 

Micrococcus  tetragenus  (18). 

C.  Do  not  grow  in  nutrient  gelatin  at  the  room  temperature  : 

Micrococcus  tetragenus  subflavus  (225). 
Micrococcus  gonorrhoeas  (6). 

VI.  Micrococci  which  multiply  by  division  in  three  directions,  form- 

ing cubical  ' '  packets  " — sarcince. 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  liquefy 

the  gelatin. 

a.  Chromogenic  ;  pigment  yellow  : 
Sarcina  aurantiaca  (226). 
Sarcina  lutea  (227). 
Sarcina  flava  (228). 

a.  Pigment  red  : 

Sarcina  rosea  (229). 
Sarcina  mobilis  (457). 

b.  Non-chromogenic: 

Sarcina  alba  (230). 
Sarcina  Candida  (231). 

B.  GroAy  in  nutrient  gelatin  at  the  room  temperature,  and  do  not 

liquefy. 
Non-chromogenic  : 

Sarcina  ventriculi  (233). 
Sarcina  pulmonum  (232). 


758  BACTERIOLOGICAL   DIAGNOSIS. 

BACILLI. 

I.  Aerobic  bacilli  (many  of  the  bacilli  in  this  group  are  facultative1 

anaerobics). 
A.  Growin  nutrient  gelatin  at  the  room  temperature  (20°  to  22°  C. ),. 

and  liquefy  the  gelatin, 
a.  Chromogenic  ;  pigment  yellow  : 

1.  Motile  ;  grow  on  potato  : 

Bacillus  ochraceus  (365). 
Bacillus  buccalis  minutus  (294). 
Bacillus  plicatilis  (266), 
Bacillus  citreus  cadaveris  (273). 
Bacillus  fulvus  (263). 
Bacillus  arborescens  (272). 

2.  Non-motile  or  undetermined  ;  grow  on  potato  : 

Bacillus  cuticularis  (270). 
Bacillus  hydrophilus  fuse  us  (81). 
Ascobacillus  citreus  (275). 
Bacillus  helvolus  (264). 
Bacterium  termo  of  Vignal  (293). 
Bacillus  lactis  erythrogenes  (280). 
Does  not  grow  upon  potato  ;  phosphorescent : 

Bacillus  argenteo-phosphorescens  liquefaciens  (342). 
a.  Pigment  greenish-yellow  or  green  ;  grow  on  potato. 

1.  Motile  : 

Bacillus  fluorescens  liquefaciens  (277). 

Bacillus  fluorescens  liquefaciens  minutissimus  (278), 

Bacillus  fluorescens  nivalis  (279). 

Bacillus  chromo-aromaticus  (134). 

Bacillus  viscosus  (289). 

Bacillus  pyocyanus  (96). 

Bacillus  pyocyanus  ft  (286). 

2.  Non-motile  : 

Bacillus  smaragdinus  fcetidus  (78). 
a.  Pigment  violet  or  blue  ;  grow  on  potato. 

1.  Motile  : 

Bacillus  violaceus  (290). 
Bacillus  violaceus  Laurentius  (268). 
Bacillus  janthinus  (267). 
Bacillus  lividus  (282). 
Bacillus  cyano-fuscus  (474). 

2.  Non-motile  : 

Bacillus  membranaceus  amethystinus  (274). 
Bacillus  cceruleus  (276). 


BACTERIOLOGICAL   DIAGNOSIS.  759» 

a.  Pigment  red,  pink,  or  brown. 

1.  Motile. 

f  Form  spores  : 

Bacillus  of  Canestrini  (295). 

Bacillus  of  Dantec  (452). 

Bacillus  mesentericus  ruber  (285). 
*  Spore  formation  not  observed  : 

Bacillus  rubidus  (292). 

Bacillus  sulfureum  (291). 

Bacillus  rosaceum  metalloides  (288). 

Flesh-colored  bacillus  (271). 

Bacillus  Indicus  (283). 

2.  Non-motile  ;  spore  formation  not  observed  : 

Bacillus  mycoides  roseus  (287). 
Bacillus  glaucus  (28.1). 
Bacillus  prodigiosus  (284). 
Bacillus  tremelloides  (269). 

b.  Non-chromogenic. 
1.  Motile. 

f  Form  spores : 

Bacillus  subtilis  (379). 

Bacillus  subtilis  similis  (380). 

Bacillus  of  Scheuiieii  (384). 

Bacillus  Hessii  (472). 

Bacillus  circulans  (345). 

Bacillus  mycoides  (366). 

Bacillus  mesentericus  vulgatus  (367). 

Bacillus  mesentericus  fuscus  (368). 

Bacillus  tumescens  (393). 

Bacillus  alvei  (140). 

Bacillus  butyricus,  Hueppe  (372). 

Bacillus  liodermos  (386). 

Bacillus  ramosus  (378). 

Bacillus  megatherium  (369). 

Bacillus  of  potato  rot  (450). 

Bacillus  maidis  (390). 

Bacillus  inflatus  (377). 

Bacillus  gracilis  (359). 

Bacillus  lactis  albus  (385). 

Vibrio  rugula  (414). 

Bacillus  limosus  (445). 

Urobacillus  Maddoxi  (466). 

Bacillus  vacuolosis  (451). 

Urobacillus  Pasteuri  (463). 


BACTERIOLOGICAL   DIAGNOSIS. 

Urobacillus  Duclauxi  (464). 
Urobacillus  Freudenreichi  (465). 
*  Spore  formation  not  observed. 
x.  Grow  on  potato  : 

Bacillus  radiatus  aquatilis  (363). 

Bacillus  vermiculosus  (364). 

Bacillus  guttatus  (360). 

Bacillus  pestifer  (356). 

Bacillus  nubilis  (355). 

Bacillus  albus  putidus  (370). 

Bacillus  punctatus  (362). 

Bacillus  hyalinus  (348). 

Bacillus  cloacae  (349). 

Bacillus  liquefaciens  (389). 

Bacillus  liquidus  (353). 

Bacillus  diffusus  (352). 

Bacillus  delicatulus  (350). 

Bacillus  foetidus  ozaenoe  (111). 

Bacillus  septicus  ulceris  gangrsenosi  (127). 

Bacillus  albus  cadaveris  (129). 

Bacillus  leporis  lethalis  (94). 

Bacillus  liquefaciens  communis  (400). 

Bacillus  reticularis  (347). 

Proteus  vulgaris  (97)— polymorphous. 

Proteus  septicus  (101)— polymorphous. 

Proteus  mirabilis  (99)— polymorphous. 

Proteus  of  Karlinsky  (98)— polymorphous. 

Proteus  sulfureus  (391)— polymorphous. 

Urobacillus  Schiitzenbergi  (467). 

Bacillus  b  of  Guillebeau  (470). 

Bacillus  figurans  (478). 

Bacillus  venenosus  liquefaciens  (484). 

Bacillus  phosphorescens  Indicus  (343). 

Bacillus  litoralis  (447). 

Bacillus  halophilus  (448). 

Bacillus  stoloniferus  (458). 
y.  Do  not  grow  on  potato  : 

Bacillus  superficialis  (346). 

Bacillus  devorans  (358). 

Bacillus  aquatilis  (351). 
Bacillus  Havaniensis  liquefaciens  (399). 
Bacillus  cyaneo-phosphorescens  (341). 
Bacillus  phosphorescens  indigenus  (344). 


BACTERIOLOGICAL   DIAGNOSIS.  761 

z.  Growth  on  potato  not  determined  : 

Bacillus  gasoformans  (373). 

Bacillus  of  Schou  (114). 

Bacillus  carabiformis  (374). 
2.  Non-motile. 
f  Form  spores  : 

Bacillus  anthracis  (45). 

Bacillus  brassicaa  (371). 

Bacillus  carotarum  (37G). 

Bacillus  of  Tricomi  (128). 

Bacillus  vermicularis  (354). 

Bacillus  aerophilus  (365). 

Bacillus  of  Letzerich  (109). 

Bacillus  implexus  (361). 

Bacillus  filiformis  (357). 

Bacillus  granulosus  (444). 
*  Do  not  form  spores,  or  undetermined  : 

Bacillus  ulna  of  Vignal  (388). 

Leptothrix  buccalis  of  Vignal  (395). 

Bacillus/  of  Vignal  (397). 

Bacillus  b  of  Vignal  (396). 

Bacillus  buccalis  fortuitus  (398). 

Bacillus  varicosus  conjunctivas  (130). 

Bacillus  pulpee  pyogenes  (124). 

Bacillus  gingivse  pyogenes  (122). 

Bacillus  graveolens  (375). 

Pneumobacillus  liquefaciens  bo  vis  (120). 

Bacillus  incanus  (459). 

Bacillus  inunctus  (460). 
B.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  do  not 

liquefy, 
a.  Chromogenic  ;  pigment  yellow. 

1.  Motile  ;  grow  on  potato  ;  spore  formation  not  observed  : 

Bacillus  aurantiacus  (238). 
Bacillus  subflavus  (256). 
Bacillus  constrictus  (243). 
Bacillus  aureus  (240). 
Bacillus  fluorescens  aureus  (244). 
Bacillus  heminecrobiophilus  (148). 
Bacillus  flavescens  (461). 

2.  Non-motile  ;  spore  formation  not  observed  : 

Bacillus  spiniferus  (260) — grows  on  potato. 
Bacillus  of  cholera  in  ducks  (62) — grows  on  potato. 


BACTERIOLOGICAL,  DIAGNOSIS. 

Bacillus  fuscus  (253) — grows  on  potato. 
Bac.  of  Tizzoni  and  Giovannini  (145) — grows  on  potato. 
Bacillus  flavocoriaceus  (241). 
Bacillus  luteum  (237). 
•3.  Motility  not  determined  ;  grows  on  potato  : 

Bacillus  striatus  flavus  (255). 
•a.  Pigment  yellowish-green  or  green. 

1.  Motile  ;  grow  on  potato. 
f  Form  spores : 

Bacillus  of  Lesage  (106). 
Bacillus  erythrosporus  (249). 

*  Do  not  form  spores  : 

Bacillus  fluorescens  longus  (245). 
Bacillus  fluorescens  tenuis  (246). 
Bacillus  virescens  (251). 
Bacillus  fluorescens  putidus  (248). 
Bacillus  canalis  parvus  (136). 
Bacillus  dentalis  viridans  (123). 

2.  Non-motile  ;  do  not  form  spores  ;  grow  on  potato  : 

Bacillus  fluorescens  iion-liquefaciens  (247). 
Bacillus  iris  (252). 

-a.  Pigment  violet  or  blue  ;  grow  on  potato. 
1.  Motile. 

t  Forms  spores  ( ?)  : 

Bacillus  cyanogenus  (257). 

*  Do  not  form  spores,  or  undetermined. 

Bacillus  viridis  pallescens  (250). 
Bacillus  beroliniensis  Indicus  (242). 
Bacillus  cyanogenus  Jordaniensis  (257). 
<a.  Pigment  red,  pink,  or  brown. 

1.  Motile ;  grow  on  potato  ;  spore  formation  not  observed  : 

Bacillus  rubescens  (261). 
Bacillus  rubefaciens  (254). 
Bacillus  fuscus  limbatus  (258). 

2.  Non-motile. 

f  Forms  spores  : 

Bacillus  brunneus  (239). 

*  Do  not  form  spores  : 

Bacillus  latericeus  (259). 
Bacillus  Havaniensis  (453). 
b.  Non-chromogenic. 
1.  Motile. 
f  Form  spores : 

Bacillus  of  Afanassiew  (119). 


BACTERIOLOGICAL,   DIAGNOSIS.  763 

Bacillus  of  Koubasoff  (59). 
Bacillus  putrificus  coli  (324). 
Bacillus  septicus  vesicse  (132). 
:*  Spore  formation  not  observed  : 
x.  Grow  upon  potato  : 

Bacillus  endocarditidis  griseus  (104). 
Bacillus  meningitidis  purulentse  (131). 
Bacillus  pyogenes  fcetidus  (72). 
Bacillus  enteritidis  (75). 
Bacillus  cedematis  aerobicus  (108). 
Bacillus  hyacinthis  septicus  (320). 
Bacillus  gliscrogenum  (321). 
Bacillus  stolonatus  (328). 
Bacillus  albus  (298). 
Bacillus  aerogenes  (302). 
Bacterium  aerogenes  (303). 
Bacillus  aquatilis  sulcatus  No.  I.  (305). 
Bacillus  aquatilis  sulcatus  No.  II.  (306). 
Bacillus  aquatilis  sulcatus  No.  III.  (307). 
Bacillus  aquatilis  sulcatus  No.  V.  (309). 
Heliobacterium  aerogenes  (304). 
Bacillus  No.  I.  of  Fulles  (334). 
Proteus  lethalis  (102). 
Proteus  Zenkeri  (100). 
Bacillus  of  hog  cholera  (63). 
Bacillus  of  swine  plague,  Marseilles  (65). 
Bacillus  typhi  abdominalis  (46). 
Bacillus  cavicida  Havaniensis  (70). 
Bacillus  No.  I.  of  Roth  (142). 

Bacillus  coli  communis  (89).  >         Usually 

Bacillus  cuniculicida  Havaniensis  (93).  j"  not  motile. 
Booker's  bacilli,  d,  e,  f,  g,  h,  k,  n  (89).  )  Motility  not 
Bacillus  cavicida  (69).  j  stated- 

Bacillus  of  Bovet  (468). 
Bacillus  Schafferi  (469). 
Bacillus  a  of  Guillebeau  (470). 
Bacillus  c  of  Guillebeau  (470). 
Bacillus  gracilis  anaerobiescens  (477). 
Bacillus  invisibilis  (480). 
Bacillus  venenosus  (481). 
Bacillus  venenosus  brevis  (482). 
Bacillus  venenosus  invisibilis  (483). 
y.  Do  not  g'row  on  potato  : 

Bacillus  aquatilis  sulcatus  No.  IV.  (308). 


BACTERIOLOGICAL   DIAGNOSIS. 

Bacillus  argenteo-phosphorescens  No.  1  (338). 

Bacillus  argenteo-phosphorescens  No.  3  (340). 
z.  Growth  on  potato  undetermined  : 

Bacterium  Zopfii  (330). 

Bacillus  ventriculi  (329). 

Bacillus  of  Utpadel  (139). 

Bacillus  cystiformis  (311). 
2.  Non-motile, 
t  Form  spores  : 

Bacillus  of  Colomiatti  (332). 
Bacillus  acidi  lactici  (Hueppe)  (299). 

Bacillus  subtilis  simulans  No.  I.  (325). 

Bacillus  epidermidis  (318). 

Bacillus  coprogenes  fcetidus  (116). 
*  Spore  formation  not  observed. 
x.  Grow  on  potato  : 

Bacillus  diphtherise  (47). 

Bacillus  diphtherise  columbrarum  (49). 

Bacillus  septicsemise  hsemorrhagicse  (61). 

Bacillus  of  Tommasoli  (113). 

Bacillus  pyogenes  soli  (475). 

Bacillus  pneumosepticus  (79). 

Bacillus  acidiformans  (93). 

Bacillus  lactis  aerogenes  (91). 

Bacillus  capsulatus  mucosus  (449). 

Bacterium  urese  (456). 

Bacillus  ubiquitus  (296). 

Bacillus  scissus  (333). 

Bacillus  of  Gessner  (133). 

Bacillus  of  purpura  hsemorrhagica  of  Kolb  (147). 

Bacillus  of  purpura  hsemorrhagica  of  Babes  (146). 

Bacillus  albus  anaerobiescens  (479). 

Bacillus  tenuis  sputigenus  (82). 

Bacillus  No.  II.  of  Roth  (143). 

Bacillus  of  Schimmelbusch  (110). 

Bacillus  crassus  sputigenus  (71). 

Bacillus  Ziirnianus  (331). 

Bacillus  of  Fiocca  (96). 

Bacillus  of  intestinal  diphtheria  in  rabbits  (51). 

Bacillus  coli  similis  (315). 

Bacillus  limbatus  acidi  lactici  (300). 

Bacillus  multipediculus  (310). 

Bacillus  No.  II.  of  Fulles  (335). 

Bacillus  candicans  (297). 


a 

— 

c3 

o 


BACTERIOLOGICAL   DIAGNOSIS.  765 

Bacillus  lactis  pituitosi  (301). 

Bacillus  striatus  albus  (327). 

Bacillus  of  Belfanti  and  Pascarola  (64). 

Bacillus  hepaticus  fortuitus  (312). 

Bacillus  phosphorescens  gelidus  (336). 

Bacillus  smaragdino-phosphorescens  (337). 

Bacillus  of  Friedlander  (7). 

Bacillus  of  rhinoscleroma  (58). 

Capsule  bacilli  of  Smith  (323). 

Bacillus  capsulatus  (80). 

Bacillus  canalis  capsulatus  (135). 

Proteus  hominis  capsulatus  (73). 

Proteus  capsulatus  septicus  (74). 
y.  Do  not  grow  on  potato  : 

Bacillus  erysipelatos  suis  (67). 

Bacillus  gallinarum  (77). 

Bacillus  of  grouse  disease  (76). 

Bacillus  pseudotuberculosis  (121). 

Bacillus  of  Okada  (144). 

Bacillus  filiformis  Havaniensis  (316). 

Bacillus  nodosus  parvus  (319). 

Bacillus  Martinez  (317). 

Bacillus  argenteo-phosphorescens  No.  II.  (339). 
z.  Growth  on  potato  not  determined  : 

Bacillus  septicus  keratomalacise  (125). 

Bacillus  oxytocus  perniciosus  (117). 

Bacillus  of  acne  contagiosa  of  horses  (141). 

Bacillus  endocarditidis  capsulatus  (105). 

Pseudo-diphtheritic  bacillus  (48). 
3.  Motility  not  determined  : 

Bacillus  septicus  agrigenus  (66). 

Bacillus  ovatus  minutissimus  (322). 

C.  Do  not  grow  in  nutrient  gelatin  at  the  room  temperature,  but 
have  been  cultivated  in  other  media. 

1.  Motile: 

Bacillus  mallei  (56) — grows  on  potato. 
Bacillus  of  Lumnitzer  (112) — forms  spores. 

2.  Non-motile  : 

Bacillus  tuberculosis  (53). 

Bacillus  tuberculosis  gallinarum  (54). 

Bacillus  of  Demme  (107). 

Bacillus  of  Nocard  (60) — grows  on  potato. 

Bacillus  sanguinis  typhi  (487). 

3.  Motility  not  determined  : 

Bacillus  necrophorus  (115). 
65 


766  BACTERIOLOGICAL   DIAGNOSIS. 

Bacillus  of  Kartulis  (138). 
Bacillus  septicus  acuminatus  (126). 
Nitrifying  bacillus  of  Winogradsky  (441). 
Bac.  of  Canon  and  Pielicke — measles  bacillus  ?  (486). 
D.  Growth  in  nutrient  gelatin  not  determined,  but  have  been  cul- 
tivated in  other  media. 

a.  Chromogenic. 

f  Pigment  green  : 

Bacillus  allii  (262). 

*  Pigment  blue  : 

Bacillus  indigogenus  (137). 

b.  Non-chromogenic. 

1.  Motile. 

f  Form  spores  : 

Bacillus  leptosporus  (381). 
Bacillus  ulna  (387). 

*  Spore  formation  not  observed  : 

Bacillus  allantoides  (383). 

2.  Non-motile. 

f  Forms  spores  . 

Bacillus  sessilis  (382). 

*  Spore  formation  not  determined  : 

Bacillus  coprogenes  parvus  (68). 

II.  Strictly  anaerobic  bacilli. 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  liquefy 

the  gelatin. 

1.  Motile  ;  form  spores  : 

Bacillus  tetani  (149). 

Bacillus  of  symptomatic  anthrax  (152). 

Bacillus  cedematis  maligni  (150). 

Bacillus  spinosus  (409). 

Bacillus  rubellus  (455). 

Bacillus  butyricus  of  Botkin  (462). 

Clostridium  foetidum  (405). 

Bacillus  liquefaciens  magnus  (406). 

Bacillus  radiatus  (408). 

Bacillus  thalassophilus  (443). 

2.  Non-motile  ;  form  spores  : 

Bacillus  liquefaciens  parvus  (407). 
Bacillus  anaerobicus  liquefaciens  (410). 

B.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  do  not 

liquefy. 
1.  Motile  ;  form  spores  : 

Bacillus  polypiformis  (403). 


BACTERIOLOGICAL   DIAGNOSIS.  767 

Bacillus  solidus  (402). 
Bacillus  amylozyma  (454). 

2.  Non-motile  ;  forms  spores  : 

Bacillus  muscoides  (401). 

3.  Non-motile  ;  does  not  form  spores  : 

Bacillus  aerogenes  capsulatus  (485). 

C.  Growth  in  nutrient  gelatin  not  determined,  but  have  been  cul- 
tivated in  other  media. 

1.  Motile  ;  forms  spores  : 

Bacillus  butyricus  (404). 

2.  Non-motile  ;  spore  formation  not  observed  : 

Bacillus  cadaveris  (151). 
III.  Have  not  been  cultivated  in  artificial  media  : 

Bacillus  leprse  (cultivation  claimed)  (54). 
Bacillus  diphtherise  vitulorum  (50). 
Bacillus  of  Lustgarten  (57). 
Bacillus  buccalis  maximus  (394). 

SPIRILLA. 

Aerobic  spirilla  (many  of  the  species  are  also  facultative  anaerobics). 

A.  Grow  in  nutrient  gelatin  at  the  room  temperature,  and  liquefy 
the  gelatin. 

1.  Motile  ;   grow  upon  potato  ;    spore  formation  not  deter- 
mined : 

Spirillum  cholerse  Asiaticse  (155). 
Spirillum  of  Finkler  and  Prior  (156). 
Spirillum  tyrogenum  (157). 
Spirillum  Metschnikovi  (158). 
Spirillum  of  Miller  (431). 
Spirillum  marinum  (446). 

B.  Grow  in  nutrient  gelatin,  and  do  not  liquefy  : 

a.  Chromogenic  : 

f  Pigment  j^ellow ;  non-motile  : 

Spirillum  flavum  (427). 

Spirillum  aureum  (425). 
*  Pigment  yellowish-green  ;  non-motile  : 

Spirillum  flavescens  (426). 
I  Pigment  red ;  motile  : 

Spirillum  rubrum  (429). 

b.  Non-chromogenic  : 

f  Motile  : 
x.  Grow  on  potato  : 

Spirillum  saprophiles  a  (422). 


768  BACTERIOLOGICAL   DIAGNOSIS. 

Spirillum  saprophiles  0  (423). 

Spirillum  saprophiles  y  (424). 

Spirillum  of  Smith  (430). 
y.  Does  not  grow  on  potato  : 

Spirillum  concentricum  (428). 
*  Non-motile  : 

Spirillum  nasale  (421). 

Spirillum  linguae  (420). 
C.  Biological  characters  not  determined. 
Pathogenic  : 

Spirillum  Obermeieri  (153). 

Spirillum  anserum  (154). 
Non-pathogenic,  or  undetermined  : 

Spirillum  serpens  (417). 

Spirillum  sanguineum  (416). 

Spirillum  dentium  (412). 

Spirillum  tenue  (419). 

Spirillum  undula  (418). 

Spirillum  volutans  (415). 

Spirillum  sputigenum  (411). 

Spirillum  plicatile  (413). 


BIBLIOGRAPHY. 


PART  FIRST. 


I.  HISTORICAL. 

1.  MULLER,  O.  F.     Animalia  infusoria  fluv.  et  marina.     1786. 

2.  EHRENBERG.     Die  Infusionsthierchen  als  vollkommene  Organismen.     Leipzig, 

1838. 

3.  DUJARDIN.     Histoire  naturelle  des  zoophytes.    Paris,  1841. 

4.  ROBIN.     Histoire  des  vegetaux  parasites. 

5.  DAVAINE.    Dictionnaire  encyclop.  des  sciences  med.,  art.  Bacteries.    1868. 

6.  Recherches  sur  les  maladies  charbonneuses.     Compt.  rend.  Acad.  des  Sc., 

t.  Iviii.,  pp.  220,  351,  386,  and  lix.,  p.  393. 

7.  SPALLANZANI.    Opuscoli  di  fisica  animale  e  vegetabile.     Modena,  1776. 

8.  SCHULTZE.    Vorliiufige   Mittheilung  der  Resultate   einer   experimentellen    Be- 

obachtung  uber  Generatio  ^Equivoca.     Poggendorff's  Annaleu,  vol.  xxxix., 
p.  487. 

9.  SCHWANN.     Vorlaufige  Mittheilung  betreffend  Versuche  iiber  die  Weingahrung 

und  Faulniss.    Poggendorff's  Annalen,  vol.  xli.,  p.  184. 

10.  HELMHOLTZ.     Ueber  das  Wesen  der  Faulniss  und  Gahrung.     Archiv  filr  Ana- 

tomic, Physiologic  etc.,  Bd.  v.,  pp.  453-462. 

11.  SCHRODER  UND  VON  Duscn.     Ueber  Filtration  der  Luft  in  Beziehung  auf  Faul- 

niss und  Gahrung.     Annaleu  der  Chemie  und  Pharmacie,  vol.  Ixxxix. ,  p .  234. 

12.  PASTEUR.     Memoires  sur  les  corpuscles  organises  qui  existent  dans  I'atmosphdre. 

Compt.  rend.  Acad.  des  Sc.,  t.  xlviii.,  1859. 

13.  Del'origine  des  ferments.     Compt.  rend.  Acad.  des  Sc.,  t.  1.,  p.  849. 

14.  Etude  sur  la  maladie  des  vers  a  soie.     Paris,  1870. 

15.  Sur  les  maladies  virulentes,  et  en  particulier  sur   la    maladie    appelee 

vulgairement  cholera  des  poules.     Compt.  rend.  Acad.  des  Sc.,  t.  xc.,  1880, 
pp.  239-248. 

16.  Le  rouget  du  pore  ;  aveo  la  collaboration  de  MM.  Chamberlain,  Roux  et 

Thuillier.     Compt.  rend.  Acad.  des  Sc.,  t.  xcv  ,  p.  1120. 

17.  Nouveaux  fails  pour  servir  a  la  connaissance  de  la  rage;  avec  la  colla- 
boration de  MM.  Chamberlain,  Roux  et  Thuillier.   Bull.  Acad.  de  Med.,  2eme 
s.,  xi.,  pp.  1440-1445. 

18.  HOFFMANN.    Mykologische  Studien  ilber  Gahrung.     Annalen  der  Chemie  und 

Pharmacie,  vol.  cxv.,  1860,  p.  228. 


770  BIBLIOGRAPHY. 

19.  TYNDALL.    Essays  on  floating  matter  of  the  air.     London,  1881. 

20.  Coim.    Beitrage  zur  Biologic  der  Pflanzen,  vol.  ii.,  1876,  p.  263. 

21.  KOCH.     Die  ^Etiologie  der    Milzbrandkrankheit.     Beitrage   zur    Biologic   dcr 

Pflanzen,  vol.  ii.,  1876. 

22.  -  Ueber  Desinfektion.    Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1881. 

23. Zur  Untersuchung  von  pathogenen  Organismen.     Mitth.   aus  dem  K. 

Gesundheitsamte,  Bd.  i.,  1882,  pp.  1-48. 

24.  Wundinfektionskrankheiten.     Leipzig,  1878. 

25.  Die  yEtiologie    der  Tuberculose.      Berliner  klin.    Wochenschrift,  xix., 

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26. Ueber  die  Cholerabakterien.     Deutsche  med.  Wochenschrift,  1884. 

27.  WEIGERT.     Berliner  klin.  Wochenschrift,  Nos.  18  and  19,  1877. 

28.  OBERMEIER.     Vorkommen  feinster,  eigene  Bewegung  zeigender  Faden  im  Blute 

von  Recurrenskranken.     Berliner  klin.  Wochenschrift,  1873. 

29.  HANSEN.     Bacillus  leprse.     Nord.  med.  Ark.,  Stockholm,  xii.,  1880,  pp.  1-10. 

30.  NEISSER.     Centralbl.  filr  die  med.  Wiss.,  1879,  No.  28. 

31.  EBERTH.     Der  Bacillus  des  Abdominaltyphus.    Virchow's  Archiv,  Bd.  Ixxxi.  and 

Ixxxiii. 

32.  GAFFKY.     Zur  ^tiologie  des  Abdominaltyphus.     Mitth.   aus  dem  K.  Gesund- 

heitsamte, Bd.  ii.,  1884. 

33.  STERNBERG.     A  fatal  form  of  septicaemia  in  the  rabbit  produced  by  the  sub- 

cutaneous injection  of  human  saliva.     Nat.  Board  of  Health  Bull. ,  Wash- 
ington, vol.  ii.,  1881,  p.  781. 

34.  LOFFLER  UND  ScHUTZ.     Ueber  den  Rotzpilz.     Deutsche  med.  Wochenschrift, 

1882,  No.  52. 

35.  LOFFLER.     Untersuchungen  liber  die  Bedeutung  fur  die  Entstehung  der  Diph- 

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36.  ROSENBACH.     Mikroorganismen  bei  den  Wundinfektionskrankheiten  des  Men- 

schen.    Wiesbaden,  1884. 

37.  NICOLAIER.     Beitrage  zur  ^Etiologie  des    Wundstarrkrampfes.     Inaug.    Diss. 

Gottingen,   1885.      (First  publication    in   Deutsche    med.    Wochenschrift, 
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38.  PFEIFFER.     Vorlaufige  Mittheilungen  liber  den  Erreger  der  Influenza.    Deutsche 

med.  Wochenschrift,  1892,  Nos.  2  and  3. 

II.   CLASSIFICATION. 

39.  EHRENBERG.     Die  Infusionsthierchen  als  vollkommene  Organismen.     Leipzig 

1838. 

DUJARDIN.     Op.  cit.  (No.  3). 
DAVAINE.     Op.  cit.  (No.  5). 

40.  HOFFMANN.    Memoire  sur  les  bacteries.    Ann.  des  Sc.  Nat.  Bot.,  5eme  s.,  t.  xi., 

1869. 

41.  NAGELI.     Die  niederen  Pilze.     Munchen,   1877.     Untersuchungen  ilber  niedere 

Pilze,  Munchen,  1882. 

42.  SACHS.     Lehrbuch  der  Botanik.     Leipzig,  1874.     (English  edition,  1882.) 

43.  COHX.     Beitrage  zur  Biologic  der  Pflanzen,  Bd.  i.  (1873),  ii.  (1877),  iii.  (1879). 

44.  MAGNIN.    Les  bacteries.     Paris,  1878. 

45.  ZOPF.    Die  Spaltpilze.    Breslau,  1884. 

46.  DE  BARY.     Vergleichende  Morphologic  und  Biologic  der  Pilze,  Mycetozoen  und 

Bakterien.     Leipzig,  1834  ;  Vorlesungen  ilber  Bakterien,  1885. 


BIBLIOGRAPHY.  771 

47.  HUEPPE.     Die  Methoden  der  Bakterien- Forschung,  3d  ed.,  1886. 

48.  FLUGGE.     Die  Mikroorganismen,  2d  ed.,  Leipzig,  1886. 

49.  BAUMGARTEN.     Lehrbuch  der  pathologischeu  Mykologie.     Braunschweig,  1890. 


III.  MORPHOLOGY. 

See  Bibliography  previously  referred  to,  Nos'.  39  to  49. 

IV.   STAINING  METHODS. 

50.  WEIGERT.    Berliner  klia.  Wochenschrift,  1877,  Nos.  18  and  19. 

51.  Zur  Technik  der  ruikroskopischeii  Bakterieuuntersuchungen.     Virchow's 

Archiv,  Bd.  Ixxxiv.,  p.  275. 

52.  KOCH.     Verfahren  zur  Untersuchung,  zum  Conserviren  und  Photographiren  der 

Bakterien.  Cohii's  Beitrage  zur  Biologie  der  Ptianzen,  Bd.  ii.,  Heft  3. 
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Miinchener  arztl.  Intelligenzbl.,  1884,  No.  33. 
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54.  NEISSER'S  method  of  staining  spores.     Zeitschrift  fur  klin.  Med.,  1884,  p.  1. 

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deren  ihrer  Wimperhaare  und  Geisseln.  Centralbl.  fiir  Bakteriol.,  Bd.  vi., 
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56.  KUHNE.     Praktische  Anleitung  zum  mikroskopischen  Nachweis  der  Bakterien 

im  thierischen  Gewebe.     Leipzig,  1888. 

57.  NEISSEK.     Kleine  Beitrage    zur   bakterioskopischen  Technik.     Centralbl.   fiir 

Bakteriol.,  Bd.  iii.,  Nos.  16  and  17, 1888. 

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61.  BAUMGARTEN.     Ueber  ein  bequemes  Verfahren  Tubercle-Bacillen  in  phthisischen 

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65.  MOLLEK.     Ueber  eine  neue  Methode  der  Sporenfiirbung.     Centralbl.  fur  Bak- 

teriol., Bd.  x.,  1891,  p.  273. 

66.  HEIM.     Die  Neuerungen  auf  dem  Gebiete  der  bakteriologischen  Untersuchungs- 

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67.  PREGL.     Ueber  eine   neue   Karbolmethylenblau-Methode.     Centralbl.    fiir  Bak- 

teriol., Bd.  x.,  1891,  p.  826. 


772  BIBLIOGRAPHY. 

V.   CULTURE   MEDIA. 

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KOCH.     Op.  cit.  (No.  23). 

HUKPPE.     Op.  cit.  (No.  47). 

70.  Ueber  die  Verwendung  von  Eiern    zu  Kulturzwecken.     Centralbl.  fur 

Bakteriol.,  Bd.  iv.,  p.  80. 

71.  Roux  ET  NOCARD.     Sur  la   culture  du  bacille  de  la  tuberculose.     Annales  de 

1'Institut  Pasteur,  t.  i.,  p.  19. 

72.  KARLINSKY.     Eine  Vorrichtung  zum  Filtriren  vollstandig  klaren  Agar-Agars. 

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73.  KUHNE.    Zeitschrift  fur  Biologic,  Bd.  xxvii.,  p.  172. 

74.  WINOGRADSKY.     Annales  de  Hnstitut  Pasteur,  t.  iv.,  p.  213. 

75.  SELESKIN.     Die  Kieselsauregallerte  als  Nahrsubstrat.     Centralbl.  filr  Bakteriol., 

Bd.  x.,  1891,  p.  209. 

76.  BOLTON.     A  method  of  preparing  potatoes  for  bacterial  cultures.     Med.  News, 

vol.  i.,  1837,  p.  318. 

77.  RASKINA.     Bereitung  durchsichtiger  fester  Nahrboden  aus  Milch,  etc.     Abstract 

in  Baumgarten's  Jahresbericht,  Bd.  iii.,  p.  480. 

78.  VON  ROZSAHEGYI.     Ueber  das  Zilchten  von  Bakterien  in  gefiirbter  Nahrgelatine. 

Centralbl.  fur  Bakteriol.,  Bd.  ii.,  p.  418. 

79.  SPINA,   A.    Bakteriologische  Versuche    mit  gefiirbten  Nahrsubstanzen.      Cen- 

tralbl. filr  Bakteriol.,  Bd.  ii.,  p.  71. 

80.  VON  FREUDENREICH.    Zur  Bereitung  des  Agar-Agar.    Centralbl.  filr  Bakteriol., 

Bd.  iii.,  p.  797. 

81.  NOEGGERATH.     Ueber  eine  neue  Methode  der  Bakterienziichtung  auf  gefarbten 

Nahrmedien  zu  diagnostischen  Zwecken.    Fortschritte  der  Med.,  Bd     i.,  p.  1. 

82.  VAN  PUTEREN.     Ueber  Bereitung  von  festem  Nahrboden  aus  Milch,  etc.     Ab- 

stract in  Centralbl.  fur  Bakteriol  ,  Bd.  v.,  p.  181. 

83.  Roux.    De  la  culture  sur  pomme  de  terre.     Annales  de  1'Institut  Pasteur,  vol. 

ii.,  1888,  p.  28. 

84.  PUCCINELLI.     II  f  ucus  crispus  nella  preparazione  dei  terrani  nutritivi  dei  batteri. 

Bull.  d.  Reale  Accad.  Med.  di  Roma,  1890,  fasc.  iv.-v. 

85.  HELLER.     Der  Harn  als  bakteriologischer  Nahrboden.     Centralbl.  fur  Bakte- 

riol., Bd.  ix.,  p.  511. 

86.  STERNBERG.     Cocoanut  water  as  a  culture  fluid.     Med.    News,  Philadelphia, 

1890,  p.  262. 

87.  TISCHUTKLN.    Eine  vereinfachte  Methode  der  Bereitung  von  Fleisch-Pepton- 

Agar.     Centralbl.  filr  Bakteriol.,  Bd.  ix.,  p.  208. 

88.  UNNA.     Der  Dampftrichter.     Centralbl.  far  Bakteriol.,  Bd.  ix.,  p   749. 

89.  VAN  OVERBECK  DE  MEYER.     Ueber  die  Bereitung  des  Niihragars.     Centralbl. 

filr  Bakteriol.,  Bd.  ix.,  p.  163. 

90.  KAUFMANN.     Ueber  einen  neuen  Nahrboden  f  iir  Bakterien.     Centralbl.  f  ilr  Bak. 

teriol.,Bd.  x.,  1891,  p.  65. 

91.  SCHULTZ.     Zur  Frage  von  der  Bereitung  einiger  Nilhrsubstrate.     Centralbl.  fur 

Bakteriol.,  Bd.  x.,  1891,  p.  52. 

92.  LAGEUUEIM.     Macaroni  als  fester  Nahrboden.    Centralbl.  f  iir  Bakteriol.,  Bd   xi., 

1892,  p.  147. 


BIBLIOGRAPHY.  773 

VI.   STERILIZATION    OF  CULTURE  MEDIA. 

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94.  KOCH,   GAFFKY  TJND  LOFFLER.    Untersuchungen  ilber  die  Disinfektion  mit 

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95.  STERNBERG.    The  thermal  death  point  of  pathogenic  organisms.     Am.  Jour. 

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96.  GLOBIG.     Ueber  Bakterien-Wachsthuin  bei  50°  to  70°.    Zeitschrift  fur  Hygiene, 

Bd.  iii.,  p.  294.     Also :  Ueber  einen  Kartoffelbacillus  mit   ungewohnlich 
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97.  MIQUEL.     Les  organismes  vivants  de  1'atmosphere,  1883,  p.  182. 

98.  VAN  TIEGHEM.     Societe  botanique  de  France.    Bulletins,  t.  xxviii.,  p.  35. 

99.  HEYDENREICH.    Sur  la  sterilisation  des  liquides  au  moyen  de  la  marmite  de 

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100.  TYNDALL.     Philos.  Trans,  of  the  Royal  Soc.,  London,  1877. 

101.  PLADT.    Zur   Sterilisationstechnik.     Centralbl.  fiir  Bakteriol.,   Bd.  iii.,  1888, 

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102.  VIQUER.YT.     Ein  einfacher  kupferner  Sterilisirungsapparat.      Centralbl.    fur 

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103.  DOR.     De  la  sterilisation  de  1'eau  par  le  filtre  Chamberlain.     Lyon  Medical, 

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104.  BITTER.    Versuche  uber  das  Pasteurisiren  der  Milch.     Zeitschrift  fur  Hygiene, 

Bd.  viii. 

105.  BUJWID.     Eine  einfache  Filtervorrichtung  zum  Filtriren  sterilisirter  Fliissig- 

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106.  D'ARSONVAL.     Emploi  de  1'acide  carbonique  liquefie  pour  la  filtration  et  la 

sterilisation  rapide  des  liquides  organiques.     Compt.  rend.  Acad.  des  Sc., 
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VII.   CULTURES  IN  LIQUID  MEDIA. 

107.  PASTEUR.    Memoire  sur  la  fermentation  appelee  lactique.     Compt.  rend.  Acad. 

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110.  BREFELD.    Botanische  Untersuchungen   ilber  Schimmelpilze,  vol.  iv.,    1881, 

and  vol.  v.,  1883. 

111.  DUCLAUX.    Ferments  et  maladies.     Paris,  1883. 

112.  STERNBERG.    In  Bacteria,  Magnin  and  Sternberg,  1883,  pp.  175-179. 

113.  HUEPPE.     Die  Methoden  der  Bakterien-Forschung,  3d  ed.,  1886. 

VIII.   CULTURES  IN  SOLID  MEDIA. 

114.  KOCH.     Zur  Untersuchung  von  path.  Organismen.     Mitth.  aus  dem  K.  Gesund- 

heitsamte, Bd.  i.,  1881. 
115. Blutserum.    Berliner  klin.  Wochenschrift,  1882,  No.  15. 

116.  Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  1884. 

117.  SALOMONSON.    Zur  Isolation  differenter  Bakterien.    Bot.  Zeitung,  1879,  No.  39. 
118. Eine    einfache    Methode    zur    Reinkultur  versch.    Faulnissbakterien. 

Ibid.,  1880,  No.  28. 


774  BIBLIOGRAPHY. 

119.  BO.NCM.    Menschliches  Blutserum  als  Nahrboden  f ilr  pathogene  Mikroorganismen.. 

Deutsche  med.  Wochenschrift,  1885,  p.  910. 

120.  ESMARCH,  E.     Ueber  eine  Modification  dos  Koch'schen  Plattenverfahrens,  etc.. 

Zeitschrift  fur  Hygiene,  Bd.  i.,  1886,  p.  293. 

121.  Die  Bereitung  der  Kartoffel  als  Nahrboden  f  ilr  Mikroorganismen.     Cen- 

tralbl.  filr  Bakteriol.,  Bd.  i.,  1887,  p.  26. 

122.  PETRI,  R.  J.    Eine  kleine  Modification  des    Koch'schen   Plattenverfahrens. 

Centralbl.  filr  Bakteriol.,  Bd.  i.,  1887,  p.  279. 

123.  UNNA,  P.  G.    Ueber  eine  neue  Art  erstarrten  Blutserums  und  liber  Blutserum- 

platten.     Monatshefte  filr  prakt.  Dermatol.,  Bd.  v.,  18S6,  No.  9. 

124.  BOCKHART.     Ueber  eine  neue  Art  der  Zubereitung  von  Fleisch  als  fester  Nahr- 

boden  filr  Mikroorganismen.     Tagebl.  d.  60.  Versammlung  deutscher  Na- 
turforscher  und  Aerzte  in  Wiesbaden,  1887,  p.  347. 

125.  HUEPPE.     Ueber  Blutserumkulturen.     Centralbl.  furBakteriol.,  Bd.  i.,  1887,  p. 

607. 

126.  WILFARTII,  H.     Ueber  eine  Modification  der  bakteriologischen  Plattenkulturen. 

Deutsche  med.  Wochenschrift,  No.  28,  1887. 

127.  SCHIMMELBUSCFI,  C.      Eine  Modification  des   Koch'schen    Plattenverfahrens. 

Fortschr.  d.  Med.,  Bd.  vi.,  1838,  p.  616. 

IX.   CULTIVATION  OF   ANAEROBIC  BACTERIA. 

128.  PASTEUR.     Comptes  rend.  Acad.  des  So.,  t.  Hi.,  1861,  p.  344;  ibid.,  t.  Hi.,  p. 

1260;  ibid.,  t.  Ivi.,  1863,  p.  416;  ibid.,  t.  Ivi.,  p.  1189. 

129.  GRUBER.     Eine  Mcthode  der  Ktiltur  auagrobischer  Bakterien.     Centralbl.  filr 

Bakteriol.,  Bd.  i.,  1886,  p.  367. 

130.  Roux.     Sur  la  culture  des  microbes  anafirobies.     Annales  de  1'Institut  Pasteur^ 

vol.  i.,  1887,  p.  49. 

131.  BUCHNER.    Eine  neue  Methode  zur  Kultur  anaeTober  Mikroorganismen.     Cen- 

tralbl. furBakteriol.,  Bd.  iv.,  1888,  p.  149. 

132.  FRANKEL,  C.     Ueber  die  Kultur  anafirober  Mikroorganismen.     Centralbl.  fur 

Bakteriol.,  Bd.  iii.,  1888,  pp.  735  and  763. 

133.  BRAATZ.     Eine  neue  Vorrichtung  zur  Kultur  von  Anaeroben  im  hangenden 

Tropfen.    Centralbl.  fur  Bakteriol.,  Bd.  viii.,  p.  520. 

134.  KITASATO.     Ueber  den  Rauschbrandbacillus  und  sein  Kulturverfahren.     Zeit- 

schrift filr  Hygiene,  Bd.  vi.,  p.  105. 

135.  BLUCHER.     Eine  Methode  zur  Plattenkultur  anafirober  Bakterien.     Zeitschrift 

filr  Hygiene,  Bd.  viii.,  p.  499. 

136.  NIKIFOROFF.     Ein  Beitrag  zu  den  Kulturmethoden  der  Auagroben.     Zeitschrift 

filr  Hygiene,  Bd.  viii.,  p.  489. 

137.  BOTKIN.     Eine  einfache  Methode  zur  Isolirung  anaeTober  Bakterien.   Zeitschrift 

filr  Hygiene,  Bd.  ix.,  p.  383. 

138.  STERNBERG.    Report  on  etiology  and  prevention  of  yellow  fever.     Washing- 

ton, 1891,  p.  106. 

X.   INCUBATING  OVENS  AND  TIIERMO-REGULATORS. 

139.  ROHRBECK.    Ueber  Thermostaten,  Therrnoregulatoren,  und  das  Constanthal- 

ten  von  Temperaturen.    Deutsche  med.  Zeitung,  1886,  No.  56. 

140.  Ueber  storende  EinfTusse  auf  das  Constanthalten  der  Temperatur  bei 

Vegetationsapparaten  u»d    tlber  einen    neuen    Thermostaten.      Centralbl. 
filr  Bakteriol.,  Bd.  ii..  pp.  262  and  286. 


BIBLIOGRAPHY.  775- 

141.  HUEPPE.     Die  Methoden  der  Bakterien-Forschung-,  18S6. 

142.  VAN  ERMENGEM.     Manuel   technique   de   microbiologie,  Paris,  1887.     French 

edition  of  Hueppe,  with  additions  by  Van  Ermengem. 

143.  ROTH.     Ueber  ein  neues  Princip  zur  Erzeugung  constanter  Teraperaturen,  etc. 

Deutsche  med.  Wochenschrift,  1885,  p.  135. 

144.  ABEL,  C.    Ein  neuer  Thermostat  uud   Thermoregulator  zum  sofortigen  Ein- 

stellen  und  absoluten  Constanthalten  jeder  beliebigen  Temperatur    nach 
Lautenschlager.     Centralbl.  fur  Bakteriol.,  Bd.  v.,  p.  707. 

145.  KRASILTSCHICK.     Nouvelle  etuve,  chauffe  au  petrole,  ft  temperature  reglable  8, 

volonte.     Aunales  de  1'Institut  Pasteur,  t.  iii.,  1889,  p.  166. 

146.  ALTMANN.    Thermoregulator  neuer  Konstructiou.     Centralbl.  fur  Bakteriol., 

Bd.  ix.,  p.  791. 

147.  DESPEIGNES.     Nouveau  regulateur  pour  etuve  chauffe  au  petrole.     La  Province 

Med.,  1890,  p.  270. 

148.  Roux.     Sur  un  regulateur  de  temperature  applicable  aux  etuves.     Annales  de 

1'Institut  Pasteur,  t.  v.,  p.  158. 

149.  BABES.     Ueber  einige  Apparate  zur  Bakterienuutersuchung.     Centralbl.   fur 

Bakteriol.,  Bd.  iv.,  p.  19. 

XL  EXPERIMENTS  UPON  ANIMALS. 

150.  STRAUSS,  M.     Sur  une  seringue  hypodermique,  facile  a  steriliser.     Gaz.  heb- 

dom.  de  Med.  et  de  Chir.,  1886,  p.  115. 

151.  TURSINI.     Siringa  per  richerche  battcrioscopiche.     Morgagni,  1886. 

152.  PETRI.     Einfacher  Apparat  zum  Einspritzen  von  Fliissigkeiten  filr  bakteriolo- 

gische  Zwecke.     Centralbl.  filr  Bakteriol.,  Bd.  iv.,  p.  785. 

153.  STROSCHEIN.     Eine  Injectionsspritze  fur  bakteriologische  Zwecke.     Mitth.  aus 

Dr.  Brehmer's  Heilanstalt  f  lir  Lungenkranke,  Wiesbaden,  1889. 

154.  BUCIINER.     Einfacher    Zerstaubungsapparat     zu  InhalatioDsversuchen.     Cen- 

tralbl. fur  Bakteriol.,  Bd.  vi.,  No.  19. 

155.  CHEYNE.     Report  on  the  study  of  certain  of  the  conditions  of  infection.     British 

Med.  Journ.,  July  31st,  1886. 

XII.  PHOTOGRAPHING  BACTERIA. 

156.  WOODWARD,  J.  J.     Report  to  the  Surgeon-General  of  the  United  States  Army 

on  the  magnesium  and  electric   lights  as  applied  to    photomicrography. 
Washington,  1870. 

157.  KOCH.     Verfahren  zur  Untersuchung,  zum  Conserviren,  und  Photographiren 

der  Bakterien.     Cohn's Beitrage  zur  Biol.  der  Pflanz.,  Bd.  ii.,  Heft  3,  1877. 

158.  STERNBERG.    Photomicrographs,  and  how  to  make  them.     Boston,  1884,  204 

pages,  20  plates. 

159.  Photomicrography  by  gaslight.     Johns  Hopkins  University  Circulars, 

vol.  ix.,  No.  81,  p.  72. 

160.  Cox,  J.  D.     On  some  photographs  of  broken  diatom  valves,  taken  by  lamp- 

light.    Journ.  R.  M.  S.,  London,  1884,  p.  853. 

161.  CROOKSIIANK.     Photography  of  bacteria.    Illustrated  by  86  photographs  repro- 

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162.  ISRAEL.    Ueber  Mikrophotographie  mit  starken  Objectivsystemen.     Virchow's 

Arch.,  Bd.  cvi.,  p.  502. 

163.  NEUIIAUSS.     Anleitung  zur  Mikrophotographie  filr    Arzte,    Botaniker,    etc. 

Berlin,  1887. 


.776  BIBLIOGRAPHY. 

164.  NEUHAUSS.    Die  Entmckelung  der  Mikrophotographie,   etc.     Centralbl.   filr 

Bakteriol.,  Bd.  iv.,  pp.  81  and  111. 

165.  Verschiedenes  ilber  Mikrophotographie.     Zeitschr.  filr  wiss.  Mikroskopie 

und  fiir  mikrosk.  Teclmik,  Bd.  v.,  p.  484. 

166.  GUNTIIER.     Photogramme  der  pathogenen  Mikroorganismen.     Berlin,  1887. 

167.  KITT.     Ueber  Mikrophotographien.     Oesterr.  Monatschr.  filr  Thierheilk.,  1888 

p.  241. 

168.  FRANKEL  UND  PPEIFFER.     Mikrophotographischer  Atlas  der  Bakterienkunde. 

Berlin,  1889. 

169.  COMBER.     On  a  simple  form  of  heliostat,  and  its  appliances  in  photomicrography , 

Journ.  Roy.  Mic.  Soc.,  London,  August,  1890,  p.  429. 

170.  MARKTANNER  UND  TURNERETSCHER.     Die  Mikrophotographie.     Halle,  1890r 

344  pp.,  195  engravings. 


PART   SECOND. 


GENERAL  BIOLOGICAL  CHARACTERS. 


I.  STRUCTURE,   MOTIONS,   REPRODUCTION. 

171.  KOCH.    Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1881. 

172.  BREFELD.    Botan.  Untersuchungen  iiber  Schimmelpilze,  i.-iv.,  1881. 

173.  PRAZMOWSKI.     Untersuchungen  ilber  die  Entwickelungsgeschichte,  etc.,  einiger 

Bakteriumarten.     Leipzig,  1881. 

174.  LEHMANN.     Ueber  Sporenbildung  bei  Milzbrand.    Milnchener  med.  Wochen* 

schrift,  1887,  p.  485. 

175.  BEHRING.     Ueber  asporagenen  Milzbrand.     Zeilschrift  f ilr  Hygiene,  Bd.  vii., 

1889,  p.  171. 

176.  NENCKE.     Beitriige  zur  Biologic  der  Spaltpilze,  1880.     Also  :   Journ.  filr  prakt, 

Chem.,  Bd.  xxiii. 

177.  BRIEGER.    Zeitschrift  filr  physiol.  Chemie,  Bd.  ix. 

178.  TEXT  BOOKS  previously  referred  to  :  Nageli  (41),  Sachs  (42),  Magnin  (44),  Zopf 

(45),  De  Bary  (46),  Hueppe  (47),  Flilgge  (48),  Baumgarten  (49). 

179.  CORNEL  ET  BABES.     Les  bacteries.     3d  ed.,  Paris,  1890. 

II.  CONDITIONS  OF  GROWTH. 

180.  PASTEUR.     Animalcules  infusoire  vivants  sans  oxygene    libre,   etc.     Compt. 

rend.  Acad.  des  Sc.,  lii.,  1861. 

181.  BOLTON.     Ueber  das  verhalten  verschiedener  Bakterienarten  im  Trinkwasser. 

Zeitschrift  filr  Hygiene,  Bd.  i.,  1886,  p.  76. 

182.  MIQUEL.    Les  organistnes  vivants  de  1'atmosphere,  1883,  p.  182. 

183.  VAN  TIEGHE.M.     Societe  botanique  de  France.     Bulletins,  t.  xxviii.,  p.  35. 

184.  GLOBIG.     Ueber  Bakterien-Wachsthum  bei  50°  bis  70° .    Zeitschrift  fiir  Hygiene, 

Bd.  iii.,  p.  294. 

185.  FRISCH.    Ueber  den  Einfluss  niederer  Temperaturen  auf  die  Lebensfahigkeit 

der  Bakterien.    Sitzungsb.  der  K.  Akad.  Wissensch.,  Wien,  xxxv.,  1877, 
p.  257;  ibid.,lxxx.,  1879. 


BIBLIOGRAPHY.  <77 

186.  Roux.     Sur  la  culture  du  bacille  de  la  tuberculose.     Annales  de  1'Institut  Pas- 

teur, t.  i.,  p.  29. 

III.  MODIFICATIONS   OF  BIOLOGICAL  CHARACTERS. 

187.  KOSSIAKOPF.     Accommodation  aux  antiseptiques.   Annales  de  1'Institut  Pas- 

teur, t.  i.,  p.  465. 

189.  WASSERZUG.     Sur  la  formation  de  la  matiere  colorante  chez  le  bacillus  pyocya- 
nus.     Annales  de  1'Institut  Pasteur,  t.  i.,  p.  581. 

189.  KATZ.     Zur  Kenntuiss  der  Leuchtbakterien.     Centralbl.  filr  Bakteriol.,  Bd.  ix., 

p.  157. 

190.  ABBOTT.     Corrosive  sublimate  as  a  disinfectant  against  the  Staphylococcus  pyo- 

genes  aureus.     Bull.  Johns  Hopkins  Hosp.,  vol.  ii.,  p.  56. 

191.  PASTEUR.     De  1'attenuation  du  virus  du   cholera  des  poules.     Compt.   rend.. 

Acad.  des  Sc.,  t.  xci.,  1880,  p.  673. 

192.  Le  rougetdu  pore.     Compt.  rend.  Acad.  des  Sc.,  t.  xcv.,  1882,  p.  1120. 

193.  TOUSSAINT.     De  1'immunite  pour  le  charbon  aquise  a  la  suite  d'inoculations  pre- 

ventives.     Compt.  rend.  Acad  des  Sc.,  xci.,  1880,  p.  301. 

194.  CHAUVEAU.     De  1'attenuation  directe  et    rapide  des  cultures  virulentes  par 

1'action  de  la  chaleur.     Compt.  rend.  Acad.  des  Sc.,  xcvi.,  1883,  p.  553. 

195.  STERNBERG.     Experiments  with  disinfectants.     Johns  Hopkins  Univ.  Stud. 

Biol.  Lab.,  Baltimore,  vol.  ii.,  1882,  p.  205. 

196.  CHAMBERLAIN  ET  Roux.     Sur  1'attenuation  de  la  virulence  de  la  bacteridie 

charbonneuse,  sons  1'influence  des  substances  antiseptiques.     Compt.  rend. 
Acad.  des  Sc.,  xcvi.,  1883,  pp    1088-1091. 

197.  OGATA  AND  JASUHARA.    Ueber  die  Einflilsse  einiger  Thierblutarten  auf  Milz- 

brandbacillen.     Centralbl.  filr  Bakteriol.,  Bd.  ix.,  p.  25. 

IV.   PRODUCTS   OF  VITAL  ACTIVITY. 

PIGMENT   PRODUCTION. 

198.  SCHROTER.     Ueber  einige  von  Bakterien  gebildete  Pigmente.     Beitrage  zur 

Biol.  der  Pflanzen,  Bd.  i.,  Heft   2. 

199.  GESSARD.     De  la  pyocyaniue  et  de  son  microbe.     These  de  Paris,  1882. 

200.  •  Nouvelles  recherches  sur  le  microbe  pyocyanique.     Annales  de  1'Institut 
Pasteur,  t.  iv.,  p.  88. 

201.  SCHOTTELIUS.     Biologische  Untersuchungen  liber  den  Mikrokokkus  prodigio- 

sus.     Leipzig,  1887,  185  pp. 

202.  BABES.     Note  sur  quelques  matieres  colorantes  et  aromatiques  produites  par  le 

bacille  pyocyanique.     Compt.  read,  de  la  Soc.  de  Biol.,  1889,  p.  438. 

203.  FRICK.     Bakteriologische  Mittheilungen  iiber  das  grilne  Sputum  und  tiber  die 

grilnen  Farbstoff  producirenden  Bacillen.     Virchow's  Archiv,  Bd.    cxvi.,. 
1889,  Heft  2. 

PEPTONIZING   FERMENTS. 

204.  BITTER.     Ueber  Fermentausscheidung  von  Vibrio  Koch  und  Vibrio  Proteus. 

Archiv  fur  Hygiene.     Bd.  v.,  1886,  Heft  2. 

205.  STERNBERG.     The  liquefaction  of  gelatin  by  bacteria.     The  Medical  News, 

Philadelphia,  vol.  i.,  1887,  No.  14. 

206.  RIETSCH.     Contribution  a  1'etude  des  ferments  digestifs  secretes  par  les  bacte- 

ries.     Journ.  de  Pharm.  et  de  Chim.,  1887. 

207.  FERMI.     Weitere  Untersuchungen  liber  die  tryptischen  Enzyme  der  Mikroor- 

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778  BIBLIOGRAPHY. 

LACTIC   ACID   FERMENTATION. 

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212.  RidiiET.     De  la  fermentation  lactique  du  sucre  de  lait.     Compt.  rend.  Acad.  des 

Sc.,  Ixxxvi.,  1878,  p.  55. 

213.  DUCLAUX.     Memoire  sur  le  lait.     Annales  de  1'Institut  Agronomique,  1882. 

214.  j Le  lait.     Etudes  chimiques  et  microbiologiques.     Paris,  1887,   336  pp. 

215.  HUEPPE.     Untersuchungen  iiber  die  Zersetzungen  der  Milch  durch  Mikroor- 

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216.  HEYDUCK.     Ueber  Milchsauregilhrung.      Wochenschrift  fur    Brauerei,    1887, 

No.  17. 

217.  LOFFLER.     Ueber  Bakterien  in  der  Milch.     Berl.  klin.  Wochenschrift,  1887, 

Nos.  33  and  34. 

218.  FOKKER.     Ueber  das  Milchsaurefermente.     Fortschritte  der  Med.,  1890,  p.  401. 

219.  KABRHEL.     Ueber  das  Ferment  der  Milchsauregilhrung  in  der  Milch.     Allgem. 

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220.  BAGINSKY.     Zur  Biologie  der  normalen  Milchkothbakterien.     Zeitschrift  ftlr 

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221.  SCHOLL.     Ueber  Milchsauregahrung.    Fortschritte  der  Med.,  1890,  p.  41. 

222.  ADAMETZ.     Die  Bakterien  normaler  und  abnormaler  Milch.     Oesterreichische 

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"223.  VON  NENCKI  UND  SIEBER.  Ueber  die  Bildung  der  Paramilchsaure  durch  Giih- 
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ACETIC   FERMENTATION. 

224.  PASTEUR.     Mem.  sur  la  fermentation  acetique.     Ann.  de  1'Ecole  normale  supe- 

rieure,  t.  i.,  1864. 

225.  DUCLAUX.     Chimie  biologique  (t.  ix.,  lere  section  de  1'Encyclopedie  chimique). 

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226.  WURM.    Sur  la  fabrication  du  vinaigre  au  moyen  des  bacteries.    Dingler's  Polyt. 

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227.  BROWN.     Chemical  actions  produced  by  Bacterium  aceti.    Journal  of  the  Chemi- 

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"228.  GIUNTI.  Ueber  die  Wirkung  des  Lichtes  auf  die  Essiggahrung.  Le  Stazioni 
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BUTYRIC   ACID  FERMENTATION. 

229.  PASTEUR.  Animalcules  inf  usoires  vivant  sans  oxyg^ne  libre,  et  determinant  des 
fermentations.  Compt.  rend.  Acad.  des  Sc.,  t.  lii.,  p.  861. 

330.  -    —  Etudes  sur  la  biere.    Paris,  1876,  p.  282. 

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BIBLIOGRAPHY.  779 

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234.  PRAZMOWSKI.     Untersuclmngen   ilber  die  Entwickelungsgeschichte  und  Fer- 

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235.  BOTKIN.      Ueber  ein  neues  Bacillus  butyricus.     Zeitschrift  fiir  Hygiene,  Bd.  xi., 

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CAUCASIAN   MILK  FERMENT. 

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Imp.  des  Naturalistes  de  Moskau,  1881,  No.  3. 

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AMMONIACAL   FERMENTATION   OF   URINE. 

239.  PASTEUR.    Compt.  rend.  Acad.  des  Sc.,  1.,  1860. 
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241.  Bull,  de  1'Acad.  de  Med.,  1876,  No.  27. 

242.  PASTEUR  ET  JOUBERT.     Compt.  rend.  Acad.  des  Sc.,  Ixxxiii.,  1376. 

243.  BECHAMP.     Sur  les  microzymas  de  1'urine.     Montp.  Medical,  1874. 
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244.  GUBLER.     Fermentation  ammoniacale  de  1'urine.     Compt.  rend.  Acad.  des  Sc., 

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245.  FELZ  ET  RITER.     Etude  sur  1'alcalinite  des  urines,  etc.    Journ.  de  1'anat.  et  de 

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246.  VON  JACKSCH.    Studien  tlber  den  Harnstoffpilz.    Zeitschr.  fiir  physiol.  Chemie, 

Bd.  v.,  1881. 

247.  MIQUEL.     Annuaire  de  1'observatoire  de  Montsouri,  1882. 

248.  Etudes  sur  la  fermentation  ammoniacale,  etc.    Ann.de  Micrographie, 

t.  i.,  pp.  414,  417,  506,  552  ;  t.  ii.,  pp.  13,  53,  122, 145,  367,  488  ;  t.  iii.,  pp. 
275,  305. 

•249.  LEPINE  ET  Roux.     Compt.  rend.  Acad.  des  Sc.,  ci.,  1885. 

250.  LEUBE.     Ueber  die  ammoniakalische  Harngahrung.     Virchow's  Archiv,  Bd.  c., 

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252.  BILLET.     Sur  le  bacterium  urese.     Compt.  rend.  Acad.  des  Sc.,  c.,  p.  1252. 

253.  WARINGTON.     The  chemical  action  of  some  microorganisms.     London,  1888. 

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254.  SESTINI,   L.   UND  F.     Ueber  die  ammoniakalische   Gahrung  der  Harnsfture. 

Landwirthschaftliche  Versuchsstationen,  Bd.  xxxviii.,  p.  157. 

VISCOUS  FERMENTATION. 

255.  PASTEUR.    Bull,  de  la  Soc.  Chim.,  1861. 

256.  BECHAMP.     Compt.  rend.  Acad.  des  Sc.,  xciii. 

257.  MALERBA  E  SANNA-SALARIS.  Richerche  sul  Gliscrobatterio.    Estratto  dal  Rend. 

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258.  Archives  italiennes  de  biol.,  x. 

259.  ADAMETZ.     Ueber  einen  Erreger  der  schleimigen  Milch,  Bacillus  lactis  viscosus. 

Milch-Zeitung,   1889,  No.  48,    p.   941.     (Abstract  in   Centralbl.    fiir  Bak- 
teriol., Bd.  vii.,  p.  767.) 


780  BIBLIOGRAPHY. 

260.  ADAMETZ.     Untersuchungen  iiber  Bacillus  lactis  viscosus.    Berliner  landwirth- 

schaftliche  Jahrbticher,  1891. 

261.  VAN  LAER.     Note  sur  les  fermentations  visqueuses.     (Abstract  in  Centralbl.  fiir 

Bakteriol.,  Bd.  vii.,  1890,  p.  308.) 

262.  KRAMER.     Studien  iiber  die  schleimige  Gahrung.     Sitzungsber.  derK.  Akad.  der 

Wiss.  in  Wien.    Monatshefte  filr  Chemie,  Bd.  x.,  1889,  p.  467. 

CELLULOSE   FERMENTATION. 

263.  TAPPEINER.     Celluloseverdauung.     Fortsclir.  der  Med.,  Bd.  i.,  p.  151,  undBd. 

ii.,  pp.  377,  416. 

264.  VAN  TIEGHEM.     Sur  la  fermentation  de  la  cellulose.     Bull,  de  la  Soc.  Bot.  de 

France,  1879,  p.  25. 

265.  Compt.  rend.  Acad.  des  Sc.,  1884. 

FORMATION  OF  HYDROSULPHURIC  ACID. 

266.  GAYOU.     Sur  les  alterations  des  ceufs.     Compt.  rend.  Acad.  des  .Sc.,   Ixxxv. , 

1877. 

267.  HOLSCHEWNIKOFF.     Ueber  die  Bildung  von  Scliwefelwasserstoff  durch  Bakte* 

rien.    Fortschr.  der  Med.,  1889,  p.  201. 

268.  MIQUEL.     Fermentation  sulphydrique.     Bull,  de  la  Soc.  Chim.,  xxxii.,  1879, 

p.  127. 

269.  ROSENHEIM.     Demonstration  von  Bakterien  mit  der  Eigenschaft  H2S  zu  ent- 

wickeln.     Deutsche  med.  Wochenschr. ,  1887,  p.  530. 

PUTREFACTION. 

270.  DONNE.     Recherches  sur  la  putrefaction  spontanee  des  oeufs  couves.     Compt. 

rend.  Acad.  des  Sc.,  Iviii.,  1864. 

271.  Note  sur  la  putrefaction  des  O3ufs.     Ibid.,  Ixv.,  1867. 

272.  GAYOU.     Recherches  sur  les  alterations  spontanees  des  oeufs.     These.     Ann.  de 

1'Ecole  norm,  sup.,  1875. 

273.  GAUTIER  ET  ETARU.     Sur  le  mecanisme  de  la  fermentation  putride.     Compt. 

rend.  Acad.  des  Sc.,  1882. 

274.  KENCKI.     Ueber  den  chemischen  Mechanismus  der  Faulniss.     Journ.  f  iir  prakt. 

Chemie,  Bd.  xvii. 

275.  Ueber  die  Zersetzung  der  Gelatine  und  des  Eiweisses  bei  der  Faulniss 

mit  Pancreas.     Bern,  1876. 

276.  BERGMANN.     Das  putride  Gift  und  die  putride  Intoxication.     Dorpat,  Ib66. 

277.  GAUTIER.     Traite  de  chimie  physiologique.     Paris,  1873. 

278.  -       -  Bull,  de  1'Acad.  de  Med.,  1882. 

279.  JEANNERET.     Untersuch.  iiber  die  Zersetzung  von  Gelatine  und  Eiweiss.     In- 

aug.  Diss.,  Leipzig,  1877,  and  Journ.  fur  prakt.  Chem.,  1877. 

280.  SALKOWSKI.     Zur  Kenntniss  der  Eiweissfaulniss.    Ber.  der  deutschen  chem. 

Ges..  xii.,  pp.  106,  648;  xiii.,  p.  189. 

281.  BRIEGER     Zur  Kenntniss  der  Faulnissalkaloide.    Zeitschr.  fiir  physiol.  Chem.,, 

Bd.  vii.,  1883. 

282.  Ueber  Spaltungsprodukte  der  Bakterien.     Ibid.,  Bd.  viii.,  1884;  Bd.  ix.,. 

Heft  1. 

283.  SALOMONSON.     Die  Faulniss  des  Blutes.     Kopenhagen,  1877. 

284.  HAUSER.     Ueber  Faulnissbakterien.     Leipzig,  1885. 

285.  TAPPEINER.    Med.  Centralbl.,  1884. 

286.  PANUM.     Das  putride  Gift,  etc.     Virchow's  Archiv,  Bd.  lx.,  p.  328. 


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287.  SELMI.     Sulle  ptoma'iue  del  alcaloi'di  cadaverici.     Bologna,  1878. 

288.  SCHRANK.     Untersuchungen  uber  den  im  Hiihnerei  die  stinkende  Faulniss  her- 

vorrufenden  Bacillus.     Wiener  med.  Jahrb.,  1888,  p.  303. 

289.  STRASSMANN  UNO  STRECKER.    Bakterien  bei  der  Leichenfaulniss.    Zeitschr.  f ilr 

Medicinalbeamte,  1888. 

290.  TACKE.     Ueber  die  Entwickelung  von  Stickstbff  bei  Faulniss.     Landwirthsch. 

Jahrb.,  1887,  p.  917. 

291.  SANFELICE.      Contribute  alia  b'ologia  e  morfologia  dei    batterii     saprogeni 

aGrobi  e  anafirobi.     Atti  della  Accad.  Medic,  di  Roma,  Annoxvi.,  Serie  ii., 
vol.  v. 

292.  FLUGGE.     Die  Mikroorganismen,  pp.  493-500. 

293.  NENCKI  UNO  SIEBER.    Zur  Kenntniss  der  bei  Eiweissgilhrung  auftretenden 

Gase.     Sitzungsber.  der  K.  Akad.  der  Wissensch.  in  "Wien,  1889. 

294.  BOVET.     Des  gas  produits  par  la  fermentation  anae"robienne.     Ann.   de   Mi- 

crographie,  t.  ii.,  No.  7. 

SOLUBLE   FERMENTS   PRODUCED   BY   BACTERIA. 

295.  WORTMANN.     Ueber  das  diastatische  Ferment  der  Bakterien.     Zeitschrift  fur 

physiol.  Chemie,  Bd.  vi.,  1882. 

296.  BITTER.     Ueber  Ferine ntausscheidung    von  Vibrio  Koch  und  Vibrio  Proteus. 

Archiv  fur  Hygiene,  Bd.  v.,  1886,  Heft  2. 

297.  STERNBERG.     The  liquefaction  of  gelatine.     Med.  News,  Philadelphia,  vol.  1., 

1887. 

298.  RIETSCH.     Contribution  it  1'etude  des  ferments  digestifs  secretes  par  les  bacte- 

ries.     Journ.  de  Pharm.  et  de  China.,  1887  (July  1st). 

299.  VIGNAL.     Sur  1'action  des  micro-organismes  de  la  bouche  et  des  matieres  fecales 

sur  quelques  substances  alimentaires.     Compt.  rend.   Acad.  des  Sc.,   cv., 
1887,  p.  311. 

300.  WARINGTON.     Curdling  of  milk  by  microorganisms.    The  Lancet,  1888,  No. 

25. 

301.  MARCANO.     Compt.  rend.  Acad.  des  Sc.,  t.  xcv. 

302.  HUEPPE.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii. 

303.  MILLER.     Deutsche  med.  Wochenschr.,  1885,  No.  49. 

304.  DUCLAUX.     Compt.  rend.  Acad.  des  Sc.,  t.  xci. 

305.  MUSCULUS.     Ber.  der  chem.  Ges.,  1874,  S.  124. 

306.  KELLNER,   MORI  UNO  NAGAOKA.     Beitrage  zur  Kenntniss  der  invertirenden 

Fermente.     Zeitschrift  fiir  physiol.  Chemie,  1889,  p.  297. 

307.  WOOD.     Enzyme  action  in  lower  organisms.     Proc.  Roy.  Soc.   of  Edinburgh, 

vol.  xvii.,  1889,  p.  27. 
FERMI.     Op.  cit.  (No.  207). 

REDUCTION   OF   NITRATES   AND   NITRIFICATION. 

308.  MEUSEL.     Sur  la  formation  des  nitrites.    Compt.  rend.  Ac.  des  Sc. ,  Ixxxi. ,  1875. 

309.  GAYOU  ET  DUPETIT.     Sur  la  fermentation  des  nitrates.     Compt.  rend  Acad.  des 

Sc.,  xcv.,  1882. 

310.  Sur  la  transformation  des  nitrates  en  nitrites.     Ibid.,  xcv.,  p.  1365. 

311.  DEHERAIN  ET  MAQUENNE.     De  la  reduction  des  nitrates  dans  les  terres  arables. 

Compt.  rend.  Acad.  des  Sc.,  xcv.,  pp.  691,  732,  854. 

312.  SCHLOSING  UND  MUNZ.     Recherches  sur  la  nitrification  par  les  ferments  organi- 

ses.    Compt.  rend.  Acad.  des  Sc.,  Ixxxvi.,  1875,  p.  892. 

313.  Recherches  sur  la  nitrification.     Ibid.,  Ixxxix.,  p.  891  ;  1890,  p.  1074. 

66 


782  BIBLIOGRAPHY. 

314.  WARINGTON.     Nitrification.     Journ.  of  the  Chem.  Soc.,  1878,  p.  44,  and  1879, 

p.  429. 

315.  Chemical  News,  vol.  xxxv.,  p.  429,  and  vol.  xliv.,  p.  207. 

316    CELLI  AND  MARINO-ZUCO.     Sulla  nitrificazione.     Rend,  della  R.    Accad.   de 
Lincei,  1886. 

317.  LAURENT.    Experiences  sur  la  reduction  des  nitrates  par  les  vegetaux.     Ann. 

de  llnstitut  Pasteur,  t.  iv.,  1890,  p.  722. 

318.  WINOGRADSKY.     Recherches  sur  les  organismes  de  la  nitrification.    Ann.  de  1'In- 

stitut  Pasteur,  t.  iv.,  1890,  pp.  213,  257,  and  760  ;  t.  v.,  1891,  pp.  92  and  577. 

319.  FRANKLAND,  G.  C.  XJND  P.  F.    Ueber  einige  typische  Mikroorganismen  im 

Wasser  und  im  Boden.     Zeitschrift  fiir  Hygiene,  Bd.  vi.,  p.  373. 

320.  JORDAN  AND  RICHARDS.    Investigations  upon  nitrification  and  the  nitrifying 

organism.    Rep.  Mass.  State  B.  of  H.,   1890  (Purification  of  sewage  and 
water,  part  ii.,  p.  865) 

PHOSPHORESCENCE. 

321 .  FISCHER.     Bakteriologische  Untersuchungen  auf  einer  Reise  nach  Westindien. 

Zeitschrift  fur  Hygiene,  Bd.  ii.,  1887,  p.  54. 

322.  Ueber  einen  neuen  lichtentwickelnden  Bacillus.     Centralbl.  fiir  Bak- 

teriol.,  Bd.  iii.,  1888,  p.  105. 

323.  BEYERINCK.     Le  pholobacterium  luminosum,  bacterie  lumineuse  de  la  mer  du 

nord.     Archives  Neerlandaises,  xxiii.,  p.  401. 

324.  FORSTER.     Ueber  einige  Eigenschaften  leuchtender  Bakterien.     Centralbl.  filr 

Bakteriol.,  Bd.  ii.,  1887. 

325.  GIRARD  ET  BILLET.     Observations  sur  la  maladie  phosphorescente  des  talitres 

et  autres  crustaces.     Compt.  rend.  Soc.  de  Biol.,  1889. 

326.  GIRARD.    Nouvelles  recherches  sur  les  bacteries  lumineuses  pathogenes.    Compt. 

rend.  Soc.  deBiol.,  1890. 

327.  LEHMANN.     Studien  ilber  Bacterium  phosphorescens,  Fischer.     Centralbl.  fur 

Bakteriol.,  Bd.  v.,  1889. 

328.  LCTDWIG.    Die  bisherigen  Untersuchungen  iiber  photogene  Bakterien.    Centralbl. 

fiir  Bakteriol.,  Bd.  ii.,  1887. 

329.  KATZ.     Zur  Kenntniss  der  Leuchtbakterien.     Centralbl.  fiir  Bakteriol.,  Bd.  ix., 

1891,  pp.  157,  199,  229,  258,  811,  343. 

V.   PTOMAINES  AND  TOXALBUMINS. 

SELMI.     Op.  cit.  (No.  287). 
PANUM.     Op.  cit.  (No.  286). 
BERGMANN.     Op.  cit.  (No.  276). 
GAUTIER.     Op.  cit.  (No.  277). 

330.  BERGMANN  UND  SCHMIEDEBERG.    Med.  Centralbl.,  1869,  p.  497. 

331.  BRIEGER.     Ueber  Ptomaine.     Berlin,  1885-86.     Also  in  Berliner  klin.  Wochen- 

schr.,  1886,  p.  231 ;  1887,  pp.  311,  817 ;  1888,  No.  17. 

332.  BRIEGER  UND  FRANKEL.     Untersuchungen  iiber  Bakteriengif  te.    Berliner  klin. 

Wochenschr.,  1890,  Nos.  11  and  12. 

333.  FRANKEL.    Berliner  klin.  Wochenschr.,  1890,  p.  1133. 

334.  HANKIN.     Immunity  produced  by  an  albumose  isolated  from  anthrax  cultures. 

British  Med.  Journ.,  1889,  p.  810. 

335.  ZUELZER.     Wiener  med.  Wochenschr.,  1891,  No.  10. 

336.  KLEMPERER,  G.  UNDF.     Versuche  tiber  Immunisirung  und  Heilung  bei  der 

Pneumokokken-Infektion.      Berliner    klin.    Wochenschr.,    1891,    Nos.    34 
and  35. 


BIBLIOGRAPHY.  783 

337.  KOCH.     Weitere  Mittheilung  iiber  das  Tuberculin.     Deutsche  med.  Wochen- 

schr.,  1891,  No.  43. 

338.  EBER.     Ueber  Rotzlymphe  (Malleiu).     Centralbl.  filr  Bakteriol.,  Bd.  xi.,  1892, 

p.  20. 

339.  VAUGHAN  AND  Now.     Ptomaines  and  leucomaines.    2d  ed.,  Philadelphia,  1891. 

340.  WOODHEAD.     Bacteria  and  their  products.     London,  1891. 

VI.   INFLUENCE  OF  PHYSICAL  AGENTS. 

HEAT. 

341.  FRISCH.     Ueber  den  Einfluss  niederer  Temperaturen  auf  die  Lebensfahigkeit 

der  Bakterien.     Sitzungsber.  der  K.  Akad.   der  Wissensch.,  Wien,  Ixxv. , 
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342.  PRUDDEN.     On  bacteria  in  ice,  etc.     The  Medical  Record,  New  York,  1887. 

343.  CADEAC  ET  MALET.     Recherches  experimentales  sur  la  virulence  des  matieres 

tuberculeuses  desechees,  putrifiees  ou  congelees.     Rev.  veterinaire  de  Tou- 
louse, 1889. 

344.  KOCH  UND  WOLFFHUGEL.     Untersuclmngen  iiber  die  Desinfektion  mit  heissex- 

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345.  KOCH,  GAFFKY,  UND  LOFFLER.     Versuchc  liber  die  Verwerthbarkeit  heisser 

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346.  STERNBERG.    The  thermal  death-point  of  pathogenic  organisms.     Am.  Journ. 

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GLOBIG.    Op.  cit.  (No.  96). 

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351.  HEYDENREICH.    Sur  la  sterilisation  des  liquides  au  moyen  de  la  marmite  de  Papin. 

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352.  HUEPPE.     Ueber  das  Verhalten  ungef ormter  Fermente  gegen  holie  Temperatur. 

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353.  SCHILL  UND  FISCHER.     Ueber  die  Desinfektion  des  Auswurfs  des  Phthisiker. 

Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  1884. 

354.  VOELSCH.    Contribution  &  la  question  de  la  resistance  des  bacilles  tubercu- 

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355.  YERSIN.     Action  de  la  chaleur  sur  le  bacille  tuberculeux.     Ann.  de  1'Institut 

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356.  VON    ESMARCH.     Die    desinficirende    Wirkung   des  stromenden    uberhitzten 

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357.  TIZZONI  E  CATTANI.    Sulla  resistenza  del  virus  tetanico  agli  agenti  chimici 

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358.  HEIDER.     Ueber  die  Wirksamkeit  von  Desinfektionsmitteln  bei  hOherer  Tem- 

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DESICCATION. 

359.  KOCH.     Berliner  klin.  Wochenschr.,  1884,  No.  31. 


784  BIBLIOGRAPHY. 

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361.  LOFFLER.     Welche  Massregeln  erscheinen  gegen  die  Verbreitung  der  Diphtheric 

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366.  STRAUS.     Soc.  de  Biologie,  1886,  p.  473. 

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ELECTRICITY. 

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VII.  ANTISEPTICS  AND  DISINFECTANTS. 

GENERAL  ACCOUNT   OF  THE  ACTION   OF. 

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380.  Article  on  disinfection  in  Hare's  "System  of  Practical  Therapeutics," 

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VIII.   ACTION  OF  GASES  AND   OF  THE  HALOID   ELEMENTS. 

381.  STERNBERG.    Experiments  designed  to  test  the  value  of  certain  gaseous  and 

volatile  disinfectants.    Nat.  Board  of  Health  Bull.,  Washington,   vol.  i., 
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385.  FRANKEL.     Die  Einwirkung  der  Kohlensilure    auf  die   Lebensthatigkeit  der 

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387.  OBERDORFFER.     Ueber  die  Einwirkung    des    Ozons  auf  Bakterien.     Inaug. 

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388.  WYSSOKOWITSCH.     Die  "Wirkung  des  Ozons  auf  das  Wachsthum  der  Bakterien. 

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389.  KLEIN.     Chlorine  as  an  air-disinfectant.     Rep.  Med.  Off.  Local  Govt.  Board, 

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390.  SONNTAG.     Ueber  die  Bedeutung  des  Ozons  als  Desinficiens.     Zeitschr.  fur 

Hygiene,  Bd.  viii.,  1890,  p.  95. 

391.  ALTEHOFER.     Ueber   die   Desinfektionskraft  von    Wasserstoffsuperoxyd   auf 

Wasser.    Centralbl.  fur  Bakteriol.,  Bd.  viii.,  1890,  p.  129. 

392.  KLADAKIS.    Ueber  die  Einwirkung  des  Leuchtgases  auf  die  Lebensfahigkeit 

dei  Mikroorganismen.     Inaug.  Diss.,  Berlin,  1880. 

393.  SALKOWSKI.     Ueber  die  antiseptische  Wirkung  des  Chloroformwassers.     Deut- 

sche med.  Wochenschr.,  1888,  No.  16. 

394.  Zur  Kenntniss  der  Wirkungen  des  Chloroforms.     Virchow's  Archivt 

Bd.  cxv.,  1889. 

395.  KIKCHNER.    Untersuchungen  iiber  die  Einwirkung  des  Chloroforms  auf  die  Bak- 

terien.   Zeitschr.  f  tir  Hygiene,  Bd.  viii. ,  1890. 

396.  RIEDEL.     Versuche  liber  desinficirende  und  antiseptische  Eigenschaften  des  lod- 

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397.  TILANUS.     Neuere  Untersuchungeu  tiber  die  antiseptische  Wirkung  des  lodo- 

forms.    Miinchener  med.  Wochenschr.,  1889,  p.  262. 

398.  BUCHNER.     Ueber  die  Einwirkung  der  lodoform-Dampfe  auf   den  Cholera- 

Vibrio.     Miinchener  med.  Wochenschr.,  1887,  No.  25. 

399.  NEISSER.     Zur  Kenntniss  der  antibakteriellen  Wirkung  des  lodoforms.     Vir- 

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400.  CASH.    Report  on  the  disinfectant  properties  of  oxygen  and  ozone.     Rep.  Local 

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401.  GRAUER.     On  the  action  of  sulphuretted  hydrogen  on  certain  microorganisms. 

Medical  News,  Philadelphia,  vol.  li.,  p.  670. 

SULPHUR   DIOXIDE. 

402.  WERNITZ.    Ueber  die  Wirkung  der  Antiseptica   auf  ungeformte  Fermente. 

Dorpat,  1881. 

403.  WERNICH.      Action  of  dry  heat  and  of  sulphurous  acid  on  the  bacteria  which 

accompany  putrefaction.     Nature,  xii.,  p.  311.     (Abstr.  from  Centralbl.  fiir 
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404.  SCHOTTE  UND   GARTNER.    Viertelj.  fur   Oeff.  Gesundh.,  Bd.  xii.,  1880,   p. 

337. 

405.  KOCII.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  pp.  252-261. 


786  BIBLIOGRAPHY. 

406.  WOLFFHUGEL.     Ueber  den  Werth  der  schwefligen  Saure  als  Desinfektions- 

mittel.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  p.  188. 

407.  STERNBERG.     Sulphur  dioxide.    Rep.  of  Com.  on  Disinfectants,  A.  P.  H.  A., 

pp.  52-65. 

408.  BIGGS.     The  germicide  power  of  sulphur  dioxide.     The  Medical  News,  Dec., 

1887. 

409.  THOINOT.    Etude  sur  la  valeur  desinfectante  de  1'acide  sulfureux.     Ann.  de 

1'Institut  Pasteur,  vol.  iv.,  1890,  p.  500. 

IX.   ACIDS  AND  ALKALIES. 

410.  KOCH.    Ueber  Desinfektion.    Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1881, 

pp.  1-49. 

411.  MIQUEL.     Les  organismes  vivants  de  1'atmosphere.     Paris,  1883,  pp.  289-299. 

Also,  Bull.  gen.  de  Therap.,  cvii.,  1884,  pp.  80-95. 

412.  DE  LA  CROIX.     Das  Verhalten  der  Bakterien  des  Fleischwassers  gegen  einige 

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413.  ARLOING,   CORNEVIN  ET  THOMAS.     Compt.  rend.  Soc.  de  Biol.,  Paris,  iv.,  1883, 

p.  121. 

414.  SCHILL  UND  FISCHER.     Mitth.   aus  dem  K.   Gesundheitsamte,  Bd.   ii.,  1884, 

pp.  131-146. 

415.  STERNBERG.     Experiments  to  determine  the  germicide  value  of  certain  thera- 

peutic agents.     Am.   Journ.  Med.   Sc.,   Philadelphia,  Ixxxiv.,   1883,  pp. 
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416. Calcium  oxide.     Rep.  of  Com.  on  Disinfectants,  A.  P.  H.  A.,  p.  169. 

417.  VAUGHAN.     Disinfection  with  mineral  acids.     Rep.   of  the  Com.  on  Disinfec- 

tants, A.  P.  H.  A.,  p.  33. 

418.  ABBOTT.     The  germicide  value  of  some  of  the  vegetable  acids.     Med.  News, 

Philadelphia,  xlviii.,  1886,  p.  120. 

419.  KITASATO.     Ueber  das  Verhalten  der  Typhus-  and  Cholerabacillen  in  saure-  und 

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420.  BOER.     Ueber  die  Leistungsfahigkeit  rnehrerer  chemischer  Desinfektionsmittel 

bei  einigen  fur  den  Menschen  pathogenen  Bakterien.    Zeitschr.  fur  Hygiene, 
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421.  NICATI  ET  RIETSCH.     Revue  scientifique,  Nov.  22d,  1884. 

422.  SEITZ.     Bakteriologische  Studien  tiber  Typhus- ^Etiologie.     Munchen,  1886. 

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la  tuberculose.     Ann.  de  1'Institut  Pasteur,  vol.  ii.,  18^8,  p.  60. 

424.  JAGER.     Untersuchungen  ilber  die  Wirksamkeit  verschiedener  chemischer  Des- 

iufektionsmittel,  etc.     Arbeiten  aus  dem  K.  Gesundheitsamte,  1^89. 

425.  PFUHL.     Ueber  die  Desinfektion  der  Typhus-  und  Choleraausleerungen  mit 

Kalk.     Zeitschr.  filr  Hygiene,  Bd.  vi.,  1889. 

426.  Ueber  die  Desinfektion  der  Latrinen  mit  Kalk.     Ibid.,  Bd.  vii.,  1889. 

427.  LIBORIUS.     Einige  Untersuchungen  ilber  die  desiuflcirende  Wirkung  des  Kal- 

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428.  DE  GIAXA.     Sur  1'action   desinfectante  du  blanchiment  des  murs  au  lait  de 

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X.  ACTION  OF  SALTS. 

DE  LA  CROIX.     Op.  cit.  (No.  412). 
MIQUEL.    Op.  cit.  (No.  411). 
KOCH.     Op.  cit.  (No.  410). 


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STERNBERG.    Op.  cit.  (No.  415). 

SEITZ.     Op.  cit.  (No.  422). 

ARLOING,  CORNEVIN  ET  THOMAS.     Op.  cit.  (No.  413). 

JAGER.    Op.  cit.  (No.  424). 

KITASATO.     Op.  cit.  (No.  419). 

BOER.    Op.  cit.  (No.  420). 

YERSIN.     Op.  cit.  (No.  423). 

SCHILL  UND  FISCHER.    Op.  cit.  (No.  414). 

429.  VAN  ERMENGEM.     Le  microbe  du  cholera  Asiatique.    Paris  and  Brussels,  1885, 

p.  219. 

430.  BOLTON.    Chloride  of  lime.    Rep.  of  Com.  on  Disinfectants,  Am.  Public  Health 

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Hygiene,  Bd.  viii.,  p.  63. 

432.  STERNBERG.    Mercuric  chloride.     Rep.  of  Com.  on  Disinfectants,  A.  P.  H.  A., 

p.  41. 

433.  The  comparative  antiseptic  value  of  the  salts  and  oxides  of  mercury. 

Op.  cit.,  p.  51. 

434.  Potassium  permanganate.     Op.  cit. ,  p.  18. 

435.  GEPPERT.    Zur  Lehre  von  den  Antisepticis.     Berliner  klin.  Wochenschr. ,  1889, 

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436.  BEHRING.     Ueber  Quecksilbersublimat  in  eiweisshaltigen  Flilssigkeiten.     Cen- 

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437.  Ueber  den  entwickelungshemmenden  Werth  des  Auro-Kalium  cyana- 

tum  in  eiweisshaltigen  und  in  eiweissfreien  Nahrsubstraten.    Zeitschr.  fur 
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438.  Der    antiseptische  Werth   der    Silberlosungen    und    Behandlung  von 

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439.  ABBOTT.     Corrosive  sublimate  as  a  disinfectant  against  the  Staphylococcus 

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440.  The  disinfectant  value  of  stannous  chloride.    Med.  News,  Philadelphia, 

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444.  JEROSCH.    Experimentelle  Untersuchungen  uber  die  desinficirende  Wlrkung 

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XI.   ACTION  OF  COAL-TAR  PRODUCTS,   ESSENTIAL  OILS,  ETC. 

KOCH.    Op  cit.  (No.  410). 

SCHILL  UND  FISCHER.    Op,  cit.  (No.  414). 

STERNBERG.    Op.  cit.  (No.  415). 

VAN  ERMENGEM.    Op.  cit.  (No.  429). 

NICATI  AND  RIETSCH.     Op.  cit.  (No.  421). 

BOER.    Op.  cit.  (No.  420). 

SEITZ.     Op.  cit.  (No.  422). 

YERSIN.     Op.  cit.  (No.  423). 


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463.  MAXIMOWITSCH.    Des  proprietes  antiseptiques  du  naphthol  a.     Compt.  rend. 

Acad.  des  Sc.,  1888,  Jan.  30th. 

464.  MARPMANN.     Die    antiseptischen  Eigenschaften  des  Hydroxylamins.    Phar- 

maceut.  Centralhalle,  1889,  No.  16. 

465.  LUBBERT.     Die  a-Oxynaphtho8saure.     Fortschr.  der  Med.,  1888,  No.  2. 

466.  FRANKEL.     Die  desinficirenden  Eigenschafteu  der  Kresol.     Zeitschr.  fiir  Hy- 

giene, Bd.  vi.,  1889. 

467.  BEHRING.     Ueber  den  antiseptischen  Werth  des  Creolins.     Deutsche  militiir- 

arztliche  Zeitschr.,  1888. 

468.  HEINISCH.     Sur   les  proprietes  antiseptiques   de   1'hydroxylamine.     Ann.  de 

1'Institut  Pasteur,  vol.  iii.,  1889,  p.  438. 

469.  HUNERMANN.     Creoliu  als  Mittel  zur  Todtung  pathogener  Mikroorganismen. 

Deutsche  militararztliche  Zeitschr.,  1889,  p.  111. 

470.  HENLE.     Ueber  Creolin  und  seine  wirksamen  Bestandtheile.     Archiv  fiir  Hy- 

giene, Bd.  vi.,  1889,  p.  188. 

471.  GOTTSTEIN.     Sublimat-Lanolin    als  Antisepticum.     Therapeut.    Monatsschr., 

1889. 

472.  BEU.     Ueber  den  Einfluss  des  Rilucherns  auf  die  Faulnisserreger  bei  der  Con- 


BIBLIOGRAPHY.  789 

servirung  von  Fleischwaaren.  Centralbl.  filr  Bakteriol.,  Bd.  viii.,  1890, 
p.  514. 

473.  PETRI.     Ueber  die  Widerstandsfahigkeit  der  Bakteriea  des  Schweinerothlaufs 

in  Reiukulturen  und  im  Fleisch  rothlaufkranker  Schweine  gegen  Kochen, 
Schmoren.  Braten,  Salzen,  Eiupoken  und  Rauchern.  Arbeiten  aus  dem  K. 
Gesundheitsamte,  Berlin,  Bd.  vi.,  1890. 

474.  TASSINARI.    Experimental-Untersuchungen    tiber    die  Wirkung  des  Tabak- 

rauches  auf  die  Mikroorganismen,  etc.  Centralbl.  fur  Bakteriol.,  Bd.  iv., 
1888. 

475.  FESSLER.     Erfahrungen  ilber  die  bakterientodtende  Wirkung  der  Anilinfarben. 

Milnchener  med.  Wochenschr.,  1890,  No.  25. 

476.  PETERSEN.     Ueber  die  antibakterielle  Wirkung  der  Anilinfarben.     St.  Peters- 

burg med.  Wochenschr.,  1890,  No.  27. 

477.  LIEBREICH.     Das  Methylviolett.     Therapeut.  Monatshefte,  Bd.  iv.,  p.  344. 

478.  OMELTSCHENKO.     Ueber  die  Wirkung  der  Dampfe  atherischer  Oele  auf  die  Ab- 

dominaltyphus-,  Tuberkel-  und  Milzbrandbacillen.  Centralbl.  filr  Bakteriol., 
Bd.  ix.,  p.  813. 

XII.   ACTION  OF  BLOOD  SERUM  AND  OTHER  ORGANIC  LIQUIDS. 

479.  NUTTALL.    Experimente  ilber  die  bakterienfeindlichen  Einfliisse  des  thierischen 

Korpers.     Zeitschr.  fur  Hygiene,  Bd.  iv.,  1888,  p.  353. 

480.  VON  FODOR.     Neuere  Untersuchungen  ilber  die  bakterientodtende  Wirkung  des 

Blutes  und  ilber  Immunisation.  Centralbl.  filr  Bakteriol.,  Bd.  vii.,  1890, 
p.  753. 

481.  BEHRING  UND  NISSEN.     Ueber  bakterienfeindliche  Eigenschaf ten  verschiedener 

Blutserumarten.     Zeitschr.  filr  Hygiene,  Bd.  viii.,  1890. 

482.  STERN.     Ueber  die  Wirkung  des  menschlichen  Blutes  und  anderer  Korperfliis- 

sigkeiten'auf  pathogenen  Bakterien.  Zeitschr.  filrklin.  Med.,Bd.  xviii.,  1890. 

483.  BUCHNER.    Ueber  die  bakterientodtende  Wirkung  des  zellfreien  Blutserums. 

Centralbl.  fur  Bakteriol.,  Bd.  v.,  p.  817,  and  Bd.  vi.,  p.  1. 

484.  Ueber  die  nahere  Natur  der  bakterientodtenden  Substanz  im  Blutserum. 

Centralbl.  filr  Bakteriol.,  Bd.  vi.,  p.  561. 

485.  WURZ.     De  Faction  bactericide  du  blanc  d'oeuf.     La  Semaine  medicale,  1890, 

p.  21. 

486.  PRUDDEN.     On  the  germicidal  action  of  blood  serum  and  other  body  fluids. 

Medical  Record,  New  York,  1890  (Jan.  25th). 

487.  FOKKER.     Ueber  die  bakterienvernichtenden  Eigenschaften  der  Milch.     Fort- 

schr.  der  Medicin,  Bd.  viii..  p.  7. 

488.  HANKIN.    A  bacteria-killing  globulin.   Proc.  Roy.  Soc.,  London,  1890  (May  22d). 

489.  LEHMANN.     Ueber  die  pilztodtende  Wirkung  des  f  rischen  Harns  des  gesunden 

Menscheu.     Centralbl.  filr  Bakteriol.,  Bd.  vii.,  1890,  p.  457. 

490.  OGATA.     Ueber  die  bakterienfeindliche  Substanz  des  Blutes.     Centralbl.  fur 

Bakteriol.,  Bd.  ix.,  p.  597. 

XIII.  PRACTICAL  DIRECTIONS  FOR  DISINFECTION. 

491.  REPORT  OF  COMMITTEE  ON   DISINFECTANTS,  AM.  PUBLIC   HEALTH  ASSOCIA- 

TION, in  vol.  xiii.  of  Reports  and  Papers  of  the  A.  P.  H.  A.,  1887  ;  also  sep- 
arate volume  published  by  the  Association  in  1888,  266  pages. 

492.  ROHE.    Methods  of  practical  disinfection.     Rep.  of  Com.  on  Disinfectants, 

p.  208. 


790  BIBLIOGRAPHY. 

498.  ROHE.     Apparatus  for  the  application  of  dry  and  moist  heat   in  disinfection.. 
Op.  cit.,  pp.  89-115,  37  illustrations. 

494.  HOLT.     The  quarantine  system  of  Louisiana  ;  methods  of  disinfection  practised. 

Rep.  of  Com.  on  Disinfectants,  pp.  215-232,  9  illustrations. 

495.  RAYMOND.     Experiments  with  sulphurous  acid  gas.     Rep.  of  Com.  on  Dis- 

infectants, pp.  65-77. 

496.  VAUGIIAN.    Considerations  concerning  the  practical  use  of  mercuric  chloride  as- 

a  disinfectant.     Rep.  of  Com.  on  Disinfectants,  p.  47. 

497.  VON  ESMARCH.     Der   Henneberg'sche    Desinfektor.    Zeitschr.    fur  Hygiene, 

Bd.  ii.,  1887,  p.  342. 

498.  Der  Keimgehalt  der  Wande  und  ihre  Desinfektion.     Ibid.,  Bd.  ii.,  p.  491. 

499. Die  desinficirende  Wirkung  desstromendenuberhitztenDampfes.  Ibid., 

Bd.iv.,  1888,  p.  197. 

500.  '  Nachtrag  zu  der  Abhandlung  "Die  desinficirende  "Wirkung  des  stro- 
menden  iiberhitzten  Dampfes."    Ibid.,  p.  398. 

501.  AUBERT.     Nouvelles  experiences  sur  la  disinfection  des  habitations  privees  ou 

publiques  a  1'aide  de  1'acide  sulfureux,  et  sur  Faction  de  cet  agent  sur  les 
effets  meublants.    Bull.  gen.  de  Therap.,  Paris,  ex.,  1886,  pp.  397-408. 

502.  KOCH  UNO  WOLFFHUGEL.     Ueber  den  "Werth  der  schwefligen  Saure  als   Des- 

infektionsmittel.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  p.  188. 

503.  CHAUTEMPS.     L'organisation  sanitaire  de  Paris.     Hopitaux  d'isolement,   voi- 

tures  d'ambulances,  stations  de  desinfections.     Rapport  presente  au  Conseil 
municipal.     Paris,  1888,  142  pages,  5  pi.,  4to. 

504.  DOBROSLAVINE.     Etuve  selhydrique  pour  la  disinfection.     Revue  d'Hygiene, 

Paris,  1886,  viii.,  p.  487. 

505.  DUJARDIN-BEAUMETZ.     Experiences  sur  la  disinfection  des  locaux  ayant  ete 

occupes  par  les  malades  atteints  d'affections  contagieuses.     Bull.  Acad.  de 
Med.,  Paris,  xiii.,  1884,  p.  1261. 

506.  FLEISCHHAUER  UND  MITTENZWEIG      Priifung  des  Desinfektions-Apparatus  der 

Stadt  Dilsseldorf.     Vierteljahrsschr.  fiir  gerichtl.  Med.,  Berlin,  xliv.,  1886, 
p.  120. 

507.  FORD.     Report  of  the  Sanitary  Committee  of  the  Board  of  Health  of  Philadel- 

phia on  municipal  disinfection  of  clothing,  bedding,  etc.     Rep.  Board  of 
Health  of  Philadelphia,  1885,  p.  298. 

508.  FORSTER.     Wie  soil  der  Arzt  seine  Hiinde  reinigen  ?     Centralbl.  fur  klin.  Med.,. 

Leipzig,  vi.,  1885,  p.  297. 

509.  GUTTMANN.     Desinfektionsversuche  in  den  Apparaten  der  ersten  Offentlichen 

Desinfektionsanstalt  der  Stadt  Berlin.     Vierteljahrsschr.  filr  gerichtl.  Med., 
Berlin,  xiv.,  1886,  p.  161. 

510.  Ueber  Desinfektion  von  Wohnungen.     Archiv  filr  path.  Anat.,  Berlin, 

cvii.,  1887,  pp.  459-475. 

511.  HERSCIIER.     Note  sur  une  etuve  locomobile  it  desinfection.     Rev.  d'Hygiene,, 

Paris,  ix.,  1887,  p.  738. 

512.  HOFFMANN.     Moderne  Desinfektionstechnik  mil  besonderer  Beziehung  auf  off- 

entliche  Desinfektionsanstalten.     Deutsche  Vierteljahrsschr.  filr  offentliche 
Gesundheitspflege  xix.,  1887,  p.  117. 

513.  KREIBOHM.     Zur  Desinfektion  der  Wohnrilume  mit  Sublimatdampfen.     Zeit- 

schr. filr  Hygiene,  Bd.  i.,  p.  363. 

514.  MERKE.     Bemerkungen  ilber  den  fur  die  Stadt  Diisseldorf  bestimmten  Des- 

infektions-Apparat.     Vierteljahrsschr.  fiir  gerichtl.  Med.,  Berlin,  xliv.,  1886, 
p.  145. 

515.  Mittheilungen  ilber  Betriebsergebnisse  der  ersten  offentlichen  Desinfek- 


BIBLIOGRAPHY.  791 

tionsanstalt  der  Stadt  Berlin.     Deutsche  Vierteljahrsschr.  fur   offentliche- 
Gesundheitspflege,  xix.,  1887,  p.  311. 

516.  PARSONS.     Report  on  disinfection  by  heat.     Rep.  Med.  Off.  Local  Govt.  Board, 

London,  1885,  p.  218. 

517.  PROUST.     De  la  disinfection  a  bord.     Bull.  Acad.  de  Med.,  Paris,  xviii.,  1887, 

pp.  147-160. 

518.  DISINFECTION  OP  RAGS.     Report  of  the  Special  Com.  of  the  Am.  Public  Health 

Association,  in  annual  volume  of  A.  P.  II.  A.  for  1886,  vol.  xii. 

519.  SMITH,  W.  M.     Contagious  diseases  propagated  by  rags,  and  the  necessity  of 

disinfection.     Sanitarian,  New  York,  xv.,  1885,  pp.  481-524. 

520.  VALLIN.     Quelques  experiences  sur  les  etuves  a  disinfection  dans  les  hopitaux 

de  Paris.     Ann.  d'Hygiene,  Paris,  xi.,  1884,  p.  255. 

521.  Traite  des  desinf  ectants  et  de  la  desinfection.   Paris,  1883,  808  pages,  8vo. 

522.  VINAY.     De  la  valeur  pratique  des  etuves  a  desinfection.     Lyon  Medical,  1886, 

pp.  545-560. 

523.  -    —  Ibid.,  1887,  pp.  67-75. 

524.  WALZ  UND   WINDSCHEID.      Der  neue  Desinfektions-Apparat  in  Dusseldorf. 

Centralbl.  fur  allgemeine  Gesundheitspflege,  Bonn,  v.,  1836,  p.  426. 
535.  _    —  ibid.,  vi.,  1887,  p.  208. 

526.  WEISGERBER.     Le  lazeret  des  epidemics  a  Strasbourg,  et  le  nouvel  appareil  a 

desinfecter  de  M.  A.  Koch.     Revue  d'Hygiene,  Paris,  viii.,  1886,  p.  497. 

527.  WEUNICH.    Die  neuesten  Fortschritte  in  der   Desinf ektions-Praxis.     Wiener 

Klinik,  xiii.,  1887,  pp.  337-358. 

528.  BEHRING.     Ueber  Desinfektion,  Desinfektionsmittel  und  Desinfektionsmetho- 

den.    Zeitschr.  filr  Hygiene,  Bd.  ix.,  pp.  395-475. 

529.  WASSILJEW.     Die  Desinfektion  der  Choleradejektionen  in  Hospitalern.     Zeit- 

schr. fur  Hygiene  Bd.  in.,  1887,  p.  237 

530.  KUMMELL.    Wie    soil    der  Arzt  seine  Hande  desinficiren  ?    Deutsche  med. 

Wocheusch.,  1886,  p.  555. 

531.  WOLFFHUGEL.     Ueber    Desinfektion    mittels  Hitze.      Gesundheits-Ingenieur, 

1887,  No.  1. 

K32.  Du  MESNII,.  La  desinfection  par  la  vapeur  sous  pression  et  les  etuves  loco- 
mobiles dans  le  departement  de  la  Seine.  Ann.  d'Hygiene  publique,  1888, 
No.  6. 

533.  Roux  ET  REYNES.     Sur  une  nouvelle  methode  de  desinfection  des  mains  du 

chirurgieu.     Compt.  rend.  Acad.  des  Sc  ,  t.  cvii.,  1888,  p.  870. 

534.  LANDSBEKG.     Zur  Desinfektion  der  menschlichen  Haut  mit  besonderer  Beriick- 

sichtigung  der  Hande.     Breslau,  1SS8. 

535.  Zur  Desinfektion  der  Hande  des  Arztes.     Deutsche  med.Wochenschr., 

1889,  No.  2. 

536.  FiJRBRiXGER.     Untersuchungen  und  Vorschriften  ilber  die  Desinfektion   der 

Hande  des  Arztes,  etc.     Wiesbaden,  1888,  55  pages  (Bergmann). 

537.  Entgegnung  an  Dr.    Landsberg.     Deutsche  med.  Wochenschr.,  1889, 

No  2. 

538.  Zur  Desinfektion  der  Hande  des  Arztes.     Deutsche  med.  Wochenschr., 

1888,  No.  48. 

539.  SALOMONSON  UND  LEVISON.    "Versuche  mit  verschiedenen  Desinfektions-Appa- 

raten.     Zeitschr.  filr  Hygiene,  Bd.  iv.,  1883,  p.  94. 

540.  SOYKA.    Zur  Theorie  und  Praxis  der  Desinfektion.    Prager  med.  Wochenschr., 

1888,  Nos.  15  and  16. 

541.  BUDDE.    Neue  Konstruktion  f  ilr  Dampf desinfektious-Apparate  nebst  Versuchen 

ilber  ihre  Funktionsfahigkeit.     Zeitschr.  filr  Hygiene,  Bd.  vii.,  1869,  p.  269. 


792  BIBLIOGRAPHY. 

542.  EDSON.     Disinfection  of  dwellings  by  means  of  sulphur  dioxide.     New  York 

Med.  Record,  vol.  xxxvi.,  1839,  p.  533. 
5*43.  VON  GERLOCZY.     Versuche    ilber    die  praktische  Desinfektion   von    Abfall 

stoffen.    Deutsche  Viertel jahrsschr.  fur  offentl.  Gcsundheitspflege,  Band  xxi. , 

1889,  p.  433. 

544.  NOCHT.     Ueber  die  Verwendung  von  Kafbolseifenlosung  zu    Desinf ektions  • 

zwecken.     Zeitschr.  filr  Hygiene,  Bd.  vii.,  1890,  p.  521. 

545.  PFUHL.     Ueber  Desinfektion  der  Latrinen  mit  Kalk.     Zeitschr.  fur  Hygiene, 

Bd.  vii.,  1890,  p.  363. 

546.  ROHRBECK.     Zur  L5sung   der  Desinf ektionsf rage    mit    Wasserdampf.     Cen- 

tralbl.  filr  Bakteriol  ,  Bd.  vi.,  1689,  p.  493. 

547.  BOLL.    Zur  Desinfektion   der  Hande.     Deutsche  med.   Wochenschr.,    1890. 

No.  17. 

548.  DK  GIAXA.    Sur  I'actiondesinfectantedublanchimentdesmursau  lait  de  chaux 

Ann.  de  Micrograph.,  1890,  p.  305. 

549.  KIRCHNER.     Ueber  dieNothwendigkeit  und  diebeste  Art  der  Sputumsdesinfek- 

tion  bei  Lungentuberkulose.     Centralbl.  filr  Bakteriol.,  Bd.  ix.,  p.  41. 

550.  TEUSCHNER.     Beitrage    zur    Desinfektion  mit  Wasserdampf.     Zeitschr.    filr 

Hygiene,  Bd.  ix.,  p.  492. 

551.  ALBRECHT.     Die  erste  offentliche  Desinf  ektionsanstalt  der  Stadt  Berlin.     Anst. 

der  Stadt  Berlin  filr  die  offentl.  Gesundheitspflege,  1886,  pp.  174-184. 

552.  LOFFLER.     Welche  Massregeln  erscheinen  gegen  die  Verbreitung  der  Diph- 

theric geboten  ?    Centralbl  filr  Bakteriol.,  Bd.  viii.,  1890,  p.  663. 

553.  STERNBERG.     The  disinfection  of  excreta.    Journ.  of  the  Am.  Med.  Associa- 

tion, vol.  xvii.,  1891,  p.  289. 

554.  WELCH.     Conditions  underlying  the  infection  of  wounds  (disinfection  of  the 

hands).    Am.  Journ.  Med.  Sc.,  Philadelphia,  Nov.,  1891,  p.  461. 


PAET   THIRD. 


PATHOGENIC    BACTERIA. 


I.   MODES  OF  ACTION. 

555.  BOCKHART.     Ueber  secundiire  Infektion  bei  Harnrohrentripper.     Monatshefte 

fur  prakt.  Dermatol.,  1887,  No.  19. 

556.  BUMM.     Ueber  gonorrhoische  Mischinfektionen  beim  Weibe.     Deutsche  med. 

Wochenschr.,  1887,  p.  1057. 

557.  STERN  UND  HIRSCHLER.     Beitrag  zur  Lehre  der  Mischinfektion.     Wiener  med. 

Presse,  1888,  p.  973. 

558.  BABES.     Bakteriologische  Untersuchungen  iiber  septische  Processe  des  Kindes- 

alters.     Leipzig,  1889. 

559.  ANTON    UND    FUTTERER.      Untersuchungen   ilber  den  Typhus  abdominalis. 

Miinchener  med.  Wochenschr.,  1888,  p.  315. 

560.  WELCH.     The  histological  lesions  produced  by  the  toxalbumiu  of  diphtheria. 

Bull,  of  the  Johns  Hopkins  Hospital,  vol.  iii.,  1892,  p.  17. 


BIBLIOGRAPHY.  793 

II.   CHANNELS  OF  INFECTION. 

561.  SCHIMMELBUSCH.     Infektion  aus  heiler  Haut.    Tagebl.  der  61.  Versammlung 

deutscher  Naturforscher  und  Aerzte  in  Koln,  1888,  p.  127. 

562.  ROTH.     Ueber  das  Verhalten  der  Schleimhaute  und  der  ausseren  Haut  in  Bezug 

auf  ihre  Durchlassigkeit  fur  Bakterien.    Zeitschr.  filr  Hygiene,  Bd.  iv., 

1888,  p.  151. 

563.  BRAUNSCHWEIG.    Ueber  Allgemeininf ektion  von  der  unversehrten  Augenbinde- 

haut  aus.    Fortschr.  fur  Med.,  1889,  No.  24. 

564.  KORKUNOFF.     Beitrag  zur  Frage  der  Infektion  durch  Mikroorganismen  von 

Seiten  des  Darmkanals.     Abstract  in  Centralbl.   fur  Bakteriol.,  Bd.  vi., 

1889,  p.  445. 

565.  BUCHNER.     Untersuchungen  uber  den  Durchtritt  von  Infektionserregern  durch 

die  intakte  Lungenoberflache.     Archiv  filr  Hygiene,  Bd.  viii.,  p.  145. 

566.  HILDEBRANDT.     Experimentelle  Untersuchuugen  (iber  das  Eindringen  patho- 

gener  Mikroorganismen  von  den  Luftwegen  und  der  Lunge  aus.     Beitrage 
zurpathol.  Anat.  undPhysiol.,  Bd.  ii..  1888,  p.  143. 

567.  KORKUNOFF.     Zur  Frage  von  der  intestinalen  Infektion.     Archiv  fur  Hygiene, 

Bd.  x.,  p.  485. 

III.   SUSCEPTIBILITY  AND  IMMUNITY. 

568.  CHAUVEAU.     De    la  predisposition  et  de  1'immunite  pathologique.     Compt. 

rend.  Acad.  des  Sc.,  t.  Ixxxix.,  1879. 

569.  Du  role  de  1'oxygfine  de  1'air  dans  1'attenuation  quasi  instantanee  des 

cultures  virulentes  par  Faction  de  la  chaleur.    Ibid.,  xcvi.,  1883. 

570.  De  1'attenuation  des  cultures  virulentes  par  1'oxygene  comprime.     Gaz. 

hebdom.  de  Med.  et  de  Chir.,  1884. 

571.  Sur  la  resistance  des  animaux  de  1'esptice  bovine  au  sang  de  rate  et  sur 

la  preservation  de  ces  animaux  par  les  inoculations  preventives.     Compt. 
rend.  Acad.  des  Sc.,  xci.,  1880,  p.  648. 

572.  Nouvelles  experiences  sur  la  resistance  des  moutons  algeriens  au  sang 

de  rate.     Ibid.,  xc.,  p.  1396. 

573.  Des  causes  qui  peuvent  faire  varier  les  resultats  de  1'inoculation  char- 

bonneuse  sur  les  moutons  algeriens  ;  influence  de  la  quantite  des  agents  in- 
fectants  ;  applications  a  la  theorie  de  1'immunite.     Ibid.,  xc.,  p.  1526. 

574.  Nature  de  l'immunite  des  moutons  algeriens  centre  le  sang  de  rate;  est-ce 

une  aptitude  de  race  ?    Ibid  ,  xci.,  p.  33. 

575. De  1'attenuation  des  effets  [des  inoculations  virulentes  par  Temploi  de 

tres-petites  quantites  de  virus.     Ibid.,  xcii.,  1881,  p.  844. 

576.  Sur  le  mecanisme  de  1'immunite.    Ann.  de  Tlnstitut  Pasteur,  t.  ii.,  1888. 

577.  PASTEUR.    Sur  les  maladies  virulentes,  et  en  particulier  sur  la  maladie  appelee 

vulgairement  cholera  des  poules.     Compt.  rend.  Acad.  des  Sc.,  xc.,  1880, 
p.  239. 
578. De  1'attenuation  du  virus  du  cholera  des  poules.    Ibid.,  xci.,  p.  673. 

579.  Nou velles observations  sur  1'etiologieet  la prophylaxieducharbon.    Ibid., 

xci.,  p.  697. 

580.  De  1'attenuation  de  virus  et  de  leur  retour  a  la  virulence  ;  avec  la  collabo- 
ration de  MM.  Chamberlain  et  Roux.     Ibid,    xcii.,  1881,  p.  429. 

;j81. Le  rouget  de  pore  ;  avec  la  collaboration  de  MM.  Chamberlain,  Roux  et 

Thuillier.     Ibid.,  xcv.,  1882,  p.  1120. 
582. Une  statistique  au  sujet  de  la  vaccination  preventive  centre  le  charbon, 

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Beitrage,  Bd.  iv.,  188*.  pp.  127-222. 

708.  FRANKEL,  E.,  UND  SA'NGER.     Untersuchungen  liber  die  ^Etiologie  der  Endo- 

carditis.   Virchow's  Archiv,  Bd.  cviii.,  1887,  p.  286. 

709.  PRUDDEN.     An  experimental  study  of  mycotic  ulcerative  endocarditis.     Am. 

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710. On  the  etiology  of  diphtheria.     Atner.  Jouru.  of  the  Med.  Sc. ,  1889. 

711.  RIBBERT.     Ueber  experimentelle  Myo-  und  Endocarditis.     Fortschr.  der  Med., 

1886,  p.  1. 

712.  VON  EISELSBERG.     Nachweis  von  Erysipel-Kokkea  in  der  Luft  chirurgischer 

Krankenzimmer.     Von  Langenbeck's  Archiv,  Bd.  xxxv.,  1887. 

713.  FORTCNATI.     Azione  degli  stafilococchi  piogeni  nelle  ferite  della  cornea.     Boll. 

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722.  FRANKEL,  E.     Zur  Lehre  von  der  Identitilt  des  Streptococcus  pyogenes  und 

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730.  HAIJERMANN.     Zur  Pathogenese  der  eitrigen  Mittelohrentzundung.     Archiv  fiir 

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737.  FICK.     Ueber  Mikroorganismen  im  Conjunktivalsack.     Wiesbaden,  1887. 

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"740.  BOSSOWSKI.     Ueber    das    Vorkommeu    von    Mikroorganismen   in   Operations- 


800  BIBLIOGRAPHY. 

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750.  STEINSCHNEIDER.     Ueber  seine  in  Verbindung  mit  Dr.  Galewsky  vorgenom- 

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751.  Ueber  Vulvo-vaginitis  gonorrhoica  kleiner  Madchen.     Ibid.,  p.  170. 

752.  Zur  Differenzirung  der  Gonokokken.     Berliner  klin.  Wochenschr.,  1890, 

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755.  AUFUSO.     II  gonococco  di  Neisser.     LI&  Riforma  med.,  1891,  p.  328. 

V.  BACTERIA  IN  CROUPOUS  PNEUMONIA. 

756.  FRIEDLANDER.     Die  Schizomyceten  bei    der    akuten   fibrinosen  Pneumonie. 

Virchow's  Archiv,  Bd.  Ixxxvii. ,  1882. 

757.  Die  Mikrokokken  der  Pneumonie.    Fortschr.  der  Med.,  Bd.  i.,  1883. 

758.  Weitere  Arbeiten  liber  die  Schizomyceten  der    Pneumonie    und  der 

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762.  ZIEHL.     Ueber  das    Vorkommen    der    Pneumoniekokken    im  pneumonischen 

Sputum.     Centralbl.  fur  die  med.  Wissensch.,  1883. 

763.  FRIEDLANDER  UND  FROBENIUS.    Berliner  klin.  Wochensch.,  1883. 

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765.  MATRUY.     Ueber  Pneumoniekokken.     Wiener  med.  Presse,  June,  1883. 


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767.  KLEIN.     Etiology  of  acute  croupous  pneumonia,  etc.     Fourteenth  Annual  Re- 

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768.  STERNBERG.     A  fatal  form  of  septicaemia  in  the  rabbit  produced  by  the  subcu- 

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769.  Experiments  with  disinfectants.     Johns  Hopkins  University,  Stud.  Biol. 

Lab.,  Baltimore,  ii.,  1882,  pp.  201-212;   also  in  National  Board  of  Health 
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770.  Induced  septicaemia  in  the  rabbit.     American  Journal  of  the  Medical 

Sciences,  Philadelphia,  Ixxxiv.,  1882,  pp.  69-76. 

771.  Virulence  of  normal  human  saliva.     Medical  Times,  Philadelphia,  Nov. 

4th,  1882. 

772.  Germicide  value  of  therapeutic  agents.     American  Journal  of  the  Medi- 
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773.  Paper  in  the  American  Journal  of  the  Medical  Sciences,  July,  1885.    Ibid. , 

July,  1886. 

774.  The  etiology  of  croupous  pneumonia.     The  Medical  Record,  New  York, 

vol.  xxxv.,  1889,  p.  281. 

775.  Micrococcus  Pasteuri.     Journal  of  the  Royal  Microscopical  Society,  Lon- 
don, 1886. 

776. Micrococcus  pneumoniae  crouposse.    Centralblatt  filr  Bakteriol.,  Bd.  xii., 

1892,  p.  53  ;  also,  The  Medical  News,  Phil.,  vol.  lx.,  1892,  p.  153. 

777.  PASTEUR.     Sur  une  maladie  nouvelle  provoquee  par  la  salive  d'un  enfant  mort 

de  la  rage.     Compt.  rend.  Acad.  des  Sc.,  Paris,  xcii.,  1881,  pp.  159-165. 

778.  CLAXTON.     Virulence  of  normal  human  saliva.     Medical  Times,  Philadelphia, 

1882,  p.  627. 

779.  FRANKEL,  A.     Bakteriologische  Mittheilungen.     Verhandl.  des  Vereins  f iir  in- 

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p.  546. 
780. Zeitschrift  fur  klin.  Med.,  Bd.  x.  1886,  Heft  5  und  6. 

781.  Ueber  einen  Bakterienbefund  bei  Meningitis  cerebrospinalis,  nebst  Be- 

merkungen  uber  die  Pneumonie-Mikrokokken.     Deutsche  med.  Wochen- 
schr.,  1886,  No.  13. 

782.  Weitere  Beitrage  zur  Lehre  von  den  Mikrokokken  der  genuinen  fibrino- 

sen  Pneumonie.     Zeitschrift  filr  klin.  Med.,  Bd.  xi.,  1886,  Heft  5  und  6. 

783.  Ueber  die  bakterioscopische    Untersuchung   eitriger  pleuritischer  Er- 

giisse,  etc.     Charite-Annalen,  xiii.,  p.  147. 

784.  WEICHSELBAUM.     Ueber  die  ^Etiologie  der  akuten  Lungen-  und  Rippenfell- 

Entzilndungen.     Wiener  med.  Jahrbiicher,  1886,  p.  483. 

785.  Ueber  die  JEtiologie  der  akuten  Meningitis  cerebrospinalis.     Fortschritte 

der  Med.,  Bd.  v.,  1887,  Nos.  18  and  19. 

786.    Ueber  Endocarditis  pneumonica.     Wiener  med.    Wochenschr.,    1888, 

Nos.  35  and  36. 

787.  Ueber  seltenerere  Localisationen  des    pneumonischen  Virus.     Wiener 

klin.  Wochenschr.,  1888,  Nos.  28-32. 

788.  Der  Diplococcus  pneumoniae  als  Ursache  der  primareu,  akuten  Peritoni- 
tis.    Centralbl.  fur  Bakteriol.,  Bd.  v.,  1889,  p.  33. 

789. Bakteriologische  und  pathologisch-anatomische  Untersuchungen  uber 

Influenza    und  ihre    Komplikationen.     Wiener  klin.    Wochenschr.,   1890, 


802  BIBLIOGRAPHY. 

790.  WOLF.     Der  Nachweis  der  Pneumonie-Bakterien  in  Sputum.     Wiener  med. 

Blatter,  1887,  Nos.  10-14. 

791.  NETTER.     Du  microbe  de  la  pneumonic  dans  la  salive.     Compt.  rend,  hebdom. 

des  seances  de  la  Soc.  de  Biol.,  1887,  No.  34. 

792.    Du  microbe  de  Friedlander  dans  la  salive,  etc.     Ibid.,  December  24th, 

. 1887. 

793.  Recherches  sur  les  meningites  suppurees.     France  Med.,  1889,  No.  64. 

794.  De  la  pleuresie  metapneumonique  et  de  la  pleuresie  purulente  pneumo- 

coccique  primitive.     Bull,  et  memoires  de  la  Societe  Med.  des  Hopitaux  de 
Paris,  1889. 

795.  Recherches  bacteriologiques  sur  les  otites  moyennes  aigugs.     Annales 

des  Maladies  de  1'Oreille,  etc.,  1888,  p.  493. 

796.  GAMELEIA.     Etiologie  de  la  pneumonic  fibrineuse.     Ann.  de  1'Institut  Pasteur^ 

vol.  ii.,  p.  440. 

797.  MONTI.     Contributio    allo    studio    della  meningite    cerebrospinale.      Riforma 

medica,  1889,  Nos.  58  and  59. 

708. Sull'  eziologia  del  reumatismo  articolare  acuto.     Ibid. ,  1889,  No.  54. 

799.  FOA.     Weitere  Untersuchungen  liber  die  JEtiologie  der  Pneumonie.     Deutsche 

med.  Wochenschrift,  1889,  p.  21. 
800. Sulla  biologia  del  dipplococco  lanceolata.     Associazione  medica  italiana, 

Padova,  1889.     Abstract  in  Riforma  medica,  1889,  No.  233. 

801.  THUE.     Untersuchungen  liber  Pleuritis  und  Pericarditis  bei    der  crouposen 

Pneumonie.     Centralbl.  flir  Bakteriol.,  Bd.  v.,  1889,  p.  38. 

802.  ZAUFAL.     Neue  Falle  von  genuiner  akuter    Mittelohrentziindung   veranlasst 

durch  den  Diplococcus  pneumonias.     Prager  med.   Wochenschrift,   1889, 
Nos.  6-12.     Ibid.,  No.  15.     Ibid.,  No.  36. 

803.  GABBI.     Studio  sull'  artrite  sperimentale  da  virus  pneumonico.     Lo  Sperimen- 

tale,  1889. 

804.  JAKOWSKI.     Zur  ^Etiologie  der  akuten  crouposen  Pneumonie.     Zeitschrift  fiir 

Hygiene,  Bd.  vii.,  1889,  p.  237. 

805.  TESTI.     Di  una  rarissima  eomplicazione  della  pneumonite  fibrinosa.     Riforma 

medica,  1889,  Nos.  281  and  282. 

806.  BORDONI-UFFREDUZZI    UND    GRADENioo.     Ueber  die    ^Eti  'logic    der    Otitis 

media.     Centralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  pp.  529,  556,  695. 

807.  BORDONI-UFFREDUZZI.      Neuer  Streptococcus  oder  Diplococcus  lanceolatus  ? 

Centralbl.  fiir  Bakteriol.,  Bd.  vi.,  p.  670. 

808.  Ueber  die  Widerstandsfilhigkeit  des  pneumonischeu  Virus  in  den  Aus- 

wiirfen.     Ibid.,  Bd.  x.,  p.  305. 

809.  FOA   E    BORDONI-UFFREDUZZI.     Sulla    eziologia     della     meningite     cerebro- 

spinale epidemica.     Archivio  per  le  Sci.  med.,xi.,  1887,  p.  385. 

810.  GUARNIERI.     Studi  sull'  eziologia  della  polmonite.     Atti  della  R.  Accad.  med. 

di  Roma,  1888-89,  p.  447. 

811.  BONOMB.     Ueber  die  Unterscheidungsmerkmale  zwischen  clem   Streptococcus 

der  epidemischen    Cerebrospinal-Meningitis   und    dem    Diplococcus  pneu- 
moniae.     Centralbl.  flir  Bakteriol.,  Bd.  vii.,  1890,  p.  402. 

812.  NEUMANN.     1st  der  Mikrococcus  pyogenes  tenuis  (Rosenbach)  mit  dem  Pneu- 

moniekokkus  (Frankel-Weichselbaum)  identisch?    Centralbl.  fiir  Bakteriol., 
Bd.  vii.,  p.  177. 

813.  SCHEIBE.     Bakteriologiscb.es  zur  Otitis  media  bei  Influenza.  » Centralbl.    fiir 

Bakteriol.,  Bd.  viii.,  1890,  p.  225. 

814.  GABBI  TJND  PURITZ.     Beitrag  zur  Lehre  der  seltenen  Lokalisatiouen  dos  Virus 


BIBLIOGRAPHY.  803 

pneumoniaa  (Periarthritis,  Endocarditis,  und  Meningitis).  Centralbl.  fur 
Bakteriol.,Bd.  viii.,  1890,  p.  137. 

815.  ORTMANN  UND    SAMTER.     Beitrag  zur    Lokalisation    des    Diplococcus  pneu- 

moniaa.     Virchow's  Archiv,  Bd.  cxx.,  Heft  1. 

816.  DUPLAY.     Parotide  a  pneumocoques.     La  Semaine  med.,  1891,  No.  2. 

817.  KOPLIK.     The  etiology  of  empyema  in  children.     Archives  of  Pediatrics,  1890 

(October). 

818.  BANTI.     Sull'  eziologica  delle  pneumoniti  acute.     La  Sperimentale  xliv.,  1890, 

pp.  349,  461,  573. 

819.  EMMERICH.     Paper  read  at  Internal.   Med.  Congress,  London,  1891.     Abstract 

in  Journ.  Am.  Med.  Assoc.,  September  12th,  1891,  p.  418. 

820.  KLEMPERER,  G.  UND  F.     Versuche  liber  Immunisirung  und  Heilung  bei  der 

Pneumokokken-Infektion.  Berliner  klin.  Wochenschrift,  1891,  Nos.  34  and 
35. 

821.  KRUSE  TJND   PANSINI.     Untersuchungen  liber  den    Diplococcus     pneumonias 

und  verwandte  Streptokokken.  Zeitschrift  flir  Hygiene,  Bd.  xi.,  1892, 
p.  279. 

VI.   PATHOGENIC  MICROCOCCI  NOT   DESCRIBED  IN  SECTIONS 

IV.   AND   V. 

DIPLOCOCCUS  INTERCELLULARIS  MENINGITIDIS. 

822.  WEICHSELBAUM.     Ueber  die  ^Etiologie  der  akuten  Meningitis  cerebrospinalis. 

Fortschr.  der  Med.,  Bd.  v.,  1887,  Nos.  18  and  19. 

STAPHYLOCOCCU8   SALIVARIUS  PYOGENES. 

823.  BIONDI.     Die  pathogenen  Mikroorganismen    des    Speichels.     Zeitschrift    fur 

Hygiene,  Bd.  ii.,  1887,  p.  194. 

MICROCOCCUS   OF  PROGRESSIVE   TISSUE  NECROSIS   IN   MICE. 

824.  KOCH.     Wundinfektionskrankheiten.     Leipzig,  1878. 

MICROCOCCUS  OP  PROGRESSIVE   ABSCESS   FORMATION    IN   RABBITS.      Op.  tit.  (No.  824). 

MICROCOCCUS  OF   PY/EMIA   IN    RABBITS.       Op.  tit.  (No.  824). 

MICROCOCCUS  OF   SEPTICAEMIA   IN   RABBITS.       Op.  tit.  (No.  824). 

MICROCOCCUS   SALIVARIUS   SEPTICUS.       Op.  tit.  (No.  823). 

MICROCOCCUS   8UBFLAVUS. 

825.  BUMM.     Der  Mikroorganismus  der  gonorrhoischen  Schleimhauterkrankungen. 

Wiesbaden,  1885,  p.  20. 

MICROCOCCUS  OF  TRACHOMA  (?). 

826.  SATTLER.     Zehender's  klin.  Monatsblatter,  1881. 

827.  MICHEL.     Ueber  den  Mikroorganismus  bei  der  sog.  agyptischen  Augenentziln- 

dung  (Trachom).  Sitzungsber.  der  Wlirzburger  phys.-med.  Gesellschaft, 
23.  Januar,  1886.  Ibid.,  Archiv  filr  Augenheilkunde,  Bd.  xvi.,  1886,  p. 
367. 

828.  KARTULIS.     Zur  .^Etiologie    der  ilgyptischen    katarrhalischen    Conjunctivitis. 

Centralbl.  fur  Bakteriol.,  Bd.  i.,  1887. 


804  BIBLIOGRAPHY. 

MICROCOCCUS  TETRAGENUS. 

829.  KOCH.    Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  p.  42. 

830.  GAFPKY.     Von  Langenbach's  Archiv  fur  Chir.,  Bd.  xxviii.,  Heft  3. 

MICROCOCCUS  BOTRYOGENUS. 

831.  JOHNE.    Beitrage  zur  yEtiologie  der  Infektionsgeschwulste.     Bericht  viber  die 

Veterinarwesen  im  Kgrch.  Sachsen  filr  das  Jahr  1884,  p.  46. 

832. Ueber    mykotische   Bindegewebswucherung    bei    Pferden.     Deutsche 

Zeitschrift  filr  Thiermed.  und  Path.,  Bd.  xii.,  1886,  p.  137. 

MICROCOCCUS  OF  MANFREDI. 

833.  MANFREDI.     Ueber  eineu  neuen  Mikrokokkus  als  pathogenes  Agens  bei  infek- 

tiosen  Tumoren.     Fortschr.  der  Med.,  1886. 

MICROCOCCUS   OF   BOVINE   MASTITIS. 

834.  KITT.     Untersuchungen  uber  die  verschiedenen  Formeu  der  Euterentzundtmg. 

Deutsche  Zeitschrift  fiir  Thiermed.  und  Path.,  Bd.  xvii.,  1885,  p.  1. 

MICROCOCCUS  OF  BOVINE  PNEUMONIA  (?). 

835.  POELS  UND  NOLENS.     Das  Contagium  der  Lungenseuche.     Fortschr.  der  Med., 

1886,  No.  7. 

STREPTOCOCCUS  SEPTICUS. 

836.  FLUGGE.     Die  Mikroorgauismen.     2d  ed.,  1886,  p.  154. 

STREPTOCOCCUS  BOMBYCIS. 
NOSEMA   BOMBYCIS. 

837.  BECHAMP.    Micrococcus  bombycis.    Compt.  rend.  Acad.  des  Sc.,  Ixiv.,  1867. 

838.  PASTEUR.     Etudes  sur  les  maladies  des  vers  a  soie.    Paris,  1870. 

MICROCOCCUS  OF   HEYDENREICH. 

839.  HEYDENREICH.     Volume  of  116  pages,  published  in  St.  Petersburg,  1888  (Rus- 

sian).    Abstract  in  Ceutralbl  fur  Bakteriol.,  Bd.  v.,  1888,  p.  163. 

MICROCOCCUS  OF   DEMME. 

840.  DEMME.     Beitrage  zur  Kentniss  des  Pemphigus  acutus.     Verhandl.   des  V. 

Cong,  fiir  innere  Med.  in  Wiesbaden,  1886. 

STREPTOCOCCUS  OF  MANNEBERG. 

841.  MANNEBERG.     Zur  ^Etiologie  des  Morbus  Brightii  acutus.     Centralbl.  fiir  klin. 

Med.,  1888,  No.  30. 

MICROCOCCUS   ENDOCARDITIDIS   RUGATUS. 

842.  WEICHSELBAUM.    Beitrage  zur  ^Etiologie  und  path.  Anat.  der  Endocarditis. 

Ziegler's  Beitrage,  Bd.  iv.,  1888,  p.  127. 

MICROCOCCUS  OF   GANGRENOUS  MASTITIS  IN  SHEEP. 

843.  NOCARD.     Note  sur  la  mammite  gangreneuse  des  brebis  latieres.     Ann.   de 

1'Institut  Pasteur,  t.  i.,  1887,  p.  417. 

STREPTOCOCCUS  OF   MASTITIS  IN  COWS. 

844.  NOCARD  ET  MOLLERAU.     Sur  une  mammite  contagieuse    .des  vaches  latieres. 

Ann.  de  1'Institut  Pasteur,  t.  i.,  1887,  p.  109. 


BIBLIOGRAPHY. 


805 


STREPTOCOCCUS  CORYZ.E  CONTAGIOS.E   EQUORUM. 

845.  SCHUTZ.     Der  Streptokokkus  der   Druse  der  Pferde.     Archiv  f ttr  wissensch. 

undprakt.  Thierheilk. ,  1888,  p.  172. 

ELEMATOCOCCUS   BOVI8. 

846.  BABES.     Die  ^Etiologie  der  seuchenhaften   Hiimoglobiaurie  des  Rindes.     Vir- 

chow's  Archiv,  Bd.  cxv.,  1889. 

MICROCOCCUS  OINGIV^i   PYOGENES. 

847.  MILLER.     Die  Mikroorganismen  der  Mundhohle.     Leipzig,  1889,  p.  216. 

PSEUDODIPLOCOCCUS  PNEUMONI/E. 

848.  BONOME.    Pleuro-pericarditis  und  Cerebrospinal-Meningitis  sero-fibrinosa  durch 

einen  dem  Diplococcus  pneumonicus  sehr  ahnlichen  Mikroorganismus  er- 
zeugt.     Centralblatt  fi\r  Bakteriol.,  Bd.  iv.,  1888,  p.  321. 

STREPTOCOCCUS  SEPTICUS  LIQUEFACIENS. 

849.  BABES.     Bakteriologische  Untersuchungen  liber  septische  Prozesse  des  Kindes- 

alters.     Leipzig,  1889. 

MICROCOCCUS   OF   KIRCHNER. 

850.  KIRCHNER.     Bakteriologische  Untersuchungen  ilber  Influenza.     Zeitschr.  fur 

Hygiene,  Bd.  ix.,  1891,  p.  528. 

MICROCOCCUS  NO.   II.   OF  FISCHEL. 

851.  FISCHEL.     Eine  bakteriologische-experimentelle  Studie  liber  Influenza.     Zeit- 

schr. fur  Heilkunde,  Bd.  xii.,  1891. 

STREPTOCOCCUS  OF   BONOME. 

852.  BONOME.     Sull'  eziologia  della  meningite  cerebro-spiuale  epidemica.     Archive 

per  le  Scienze  mediche,  vol.  xiii.,  1890. 

MICROCOCCUS  OF  ALMQUIST. 

853.  ALMQUIST.     Pemphigus  neonatorum,  bakteriologisch  und  epidemiologisch  be- 

Ituchtet.     Zeitschr.  fur  Hygiene,  Bd.  x.,  1891,  p.  253. 

STREPTOCOCCUS   PYOSEPTICUS. 

854.  HERICOURT  ET  RICHET.     Compt.  rend.  Acad.  des  Sc.,  cvii.,  1888,  p.  690. 

STREPTOCOCCUS   PERNICIOSUS   PSITTACORUM. 

855.  EBERT.     Virchow's  Archiv,  ,Bd.  Ixxx. 

856.  WOLFF.     Virchow's  Archiv,  Bd.  xcii. 

MICROCOCCUS  OF  FORBES. 

857.  FORBES.    Studies  of  the  contagious  diseases  of  insects.     Bull.  111.  State  Lab.  of 

Nat.  Hist.   vol.  ii.,  1886,  p.  257. 

VII.   THE  BACILLUS  OF  ANTHRAX. 

858.  POLLENDER.     Viertcljahrsschr.  f ilr  ger.  Med.,  Bd.  viii.,  1855. 

859.  DAVAINE.     Recherches  sur  les  maladies  charbonneuses.     Compt.  rend.  Acad. 

des  Sc.,  Ivii.,  pp.  220,  351,  386,  et  lix.,  1863,  p.  393. 


806  BIBLIOGRAPHY. 

860.  DAVAINE.     Recherches  sur  la  nature  et  la  const,  anat.  de  la  pustule  maligne. 

Ibid.,  lx.,  1865,  p.  1296. 

861.  Sur  la  presence  constante  des  Bacteridies  dans  les  auimaux  infectes  de 

maladies  charbonneuses.     Ibid.,  Ixi.,  1886,  p.  368. 

862.  Action  de  la  chaleur  sur  le  virus  charbonneux.     Ibid.,  Ixxvii.,  1873. 

863. Rec.  de  Med.  vet.,  vol.  iv.,  1877. 

864.  PASTEUR,     Etiologie  du  charbon.     Bull.  Acad.  de  Med.,  Paris,  1879,  viii.,  pp. 

1222-1234. 

865.  Recherches  sur  1'etiologie  et  la  prophylaxie  de  la  maladie  charbonneuse 

dans  le  departement  d'Eure-et-Loire.     Rec.  de  Med.  vet.,  Paris,  1879,  pp. 
193^198. 

866. Sur  1'etiologie  du  charbon.     Compt.  rend.  Acad.  des  Sc.,  1880,  xci.,  pp. 

86-94. 

867.  Sur  1'etiologie  des  affections  charbonneuses.     Ibid.,  xci.,  pp.  455-459. 

868.  Sur  la  non-recidive  de  1'affection  charbonueuse.     Ibid.,  xci.,  p.  531. 

869.  Nouvelles  observations  sur  1'etiologie  et  la  prophylaxie  du  charbon. 

Ibid.,  xci.,  p.  697. 

870.  Sur  la  longue  duree  de  la  vie  des  germes  charbonneux  et  sur  leur  con- 
servation dans  les  terres  cultivees.     Ibid.,  xcii.,  1881,  p.  209. 

871.  -     —  Resultats  des  vaccinations  charbonneuses  pratiquees  pendant  les  mois  de 

juillet,  aout,  et  septembre,  1881.    Arch,  vet.,  Paris,  vii.,  1882,  p.  177. 

De  1'attenuation  de  virus  et  de  leur  retour  a  virulence;    avec  la  collabora- 


tion de  MM.  Chamberlain  et  Roux.     Ibid.,  xcii.,  pp.  429-435. 
873. De  la  possibilite  de  rendre  les  moutons  refractaires  au  charbon  par  la 

methode  des  inoculations  preventives;  avec  la  collaboration  de  MM.  Cham" 

berlain  et  Roux.    Ibid.,  xcii.,  1881,  pp.  662,  666. 
874. Une  statistique  au  sujet  de  la  vaccination  preventive  contre  le  charbou, 

portant  sur  quatre-vingt-cinq  mille  animaux.     Ibid.,  xcv.,  1882,  p.  1250. 
875. Reponse  au  docteur  Koch.     Rev.  scient.,  Paris,  xxxi.,  1883,  pp.  74-84. 

876.  TOTJSSAINT.     Recherches  experimentales  sur  la  maladie  charbonneuse.    Paris, 

1879. 

877.  De  I'immuuite  pour  le  charbon,  acquise  i  la  suite  d'inoculations  preven- 
tives.    Compt.  rend.  Acad.  des  Sc.,  xci.,  1880,  p.  135. 

878. Sur  quelques  points  relatifs  &  1'immunite  charbonneuse.     Ibid.,  xciii., 

p.  163. 

879.  CHATJVEAU.     Etudes   sur  le  sang  de  rate  en  Algerie.     Journ.  de  Med.  vet., 

Lyon,  1880,  pp.  449  and  505. 

880. Etude  experimentale  de  1'actiou  exercee  sur  1'agent  infectueux  par  1'or- 

ganisme  des  moutons  plus  ou  moins  refractaires  au  sang  de  rate.     Compt. 
rend.  Acad.  des  Sc.,  xci.,  1880,  p.  880. 

881.  Sur  la  resistance  des  animaux  de  1'espece  bovine  au  sang  de  rate,  etc. 

Ibid.,  xci.,  1880,  p.  648. 

882.  -    - —  Nouvelles  experiences  sur  la  resistance  des  moutons  algeriens  au  sang  de 

rate.     Ibid.,  xc.,  1880,  p.  1396. 

883.  -    —  Des  causes  qui  peuvent  faire  varier  les  resultats  de  1'inoculation  char- 

bonneuse sur  les  moutoas  algeriens;  influence  de  la  quantite  des  agents  in- 
fectants;  applications  a  la  theorie  de  rimmunite.     Ibid.,  xc.,  1880,  p.  1526. 

884.  Nature  de  1'immunite  des  moutous  algeriens  contre  le  sang  de  rate;  est- 

ce  une  aptitude  de  race  ?    Ibid.,  xci.,  p.  33. 

885.  De  1'attenuation  des  effets  des  inoculations  virulentes  par  1'emploi  de  tres- 

petites  quantites  de  virus.     Ibid.,  xcii.,  1881,  p.  844. 

886. Etude  experimentale  des  conditions  qui  permettent   de   rendre  iisuel 


BIBLIOGRAPHY.  807 

1'emploide  la  methode  de  M.  Toussuint  pour  attenuer  le  virus  charbonneux, 
etc.  Ibid.,  xciv.,  1882,  p.  1694. 

887. De  1'attenuation  directe  et  rapide  des  cultures  virulentes  par  1'action  de  la 

chaleur.  Ibid.,  xcvi.,  1883,  p.  553. 

888.  De  la  faculte  prolifique  des  agents  virulents  attenues  par  la  chaleur,  etc. 

Ibid.,  p.  612. 

889. Du  role  de  1'oxygSne  de  1'air  dans  1'attenuation,  etc.     Ibid.,  p.  678. 

890. Sur  le  transformation  en  microbiologie  pathogfene:  Des  limites,  des  con- 
ditions et  des  consequences  de  la  variabilite  du  Bacillus  anthracis.  Ibid., 
cix.,  1889,  p.  597. 

891.  KOCH.     Untersuchungen  iiber  Bakterien.     Beitrage  zur  Biologic  der  Pflanzen, 

Bd.  ii.,  Heft  2,  1876. 

892.  Zur  /Etiologie  des  Milzbrandes.     Mittb.  aus  dem  K.  Gesundheitsamte, 

Berlin,  Bd.  i  ,  1831. 

893.  Ucbcr  die  Milzbrandimpfung.     Eine  Entgegnung  auf  den  von  Pasteur 

in  Genf  gehaltenen  Vortrag.     Kassel  und  Berlin,  1882,  37  pages. 

894.  SEMMEU.     Der  Milzbraud  und  das  Milzbrandkontagium.     Jena,  1882. 

895.  ROLOPF.     Der  Milzbrand.     Berlin,  1883. 

896.  BOLLINGER.     Zur    ^Etiologie    des    Milzbrandes.     Sitzungsber.    der   Ges.    fiir 

Morphol.  und  Physiol.  zu  Milnchen,  1885. 

897.  Ueber  die  Rcgenwiirmer  als  Zwischentrager  des  Milzbrandgiftes.     Ar- 

beiten  aus  dem  path.  Institut  zu  Milnchen.     Stuttgart,  Itr86,  p.  209. 

898.  BUCHNER.     Die  Umwandlung  der  Milzbrandbakterien  in  unschadliche  Bakte- 

rieu.    Virchow's  Archiv,  Bd.  xci.,  1883. 

899. —  Neue  Versuche  iiber  Einathmung  von  Milzbrandsporen.     Miinchener 

med.  Wochenschr.,  1887,  No.  52. 

900.  -  Ueber  die  Ursache  der  Sporenbildung  beim  Milzbrandbacillus.     Cen- 

tralbl.  fiir  Bakteriol.,  Bd.  viii.,  p.  1. 

901.  KOCH,  GAFFKY  UND  LOFFLER.     Experimeutelle  Studien  iiber  Abschwilchung 

der  Milzbrandbacillen  durch  Filtterung.  Mitth.  aus  dem  K.  Gesundheits- 
amte, Bd.  ii.,  1884,  p.  147. 

902.  FALK.     Ueber  das  Verhalten    von    Infektiousstoffen    im    Verdauuugskanale. 

Virchow's  Archiv,  Bd.  xcii.,  1883. 

903.  ARLOING.     Influence  de  la  lumiere  blanche  et  des  ses  rayons  constituants  sur  le 

developpement  et  les  proprietes  du  Bacillus  anthracis.  Arch,  de  physiol. 
norm,  et  pathol.,  1886,  p.  209. 

904.  FRANCK.  Ueber  Milzbrand.     Ein  Beitrag  zur  Lehre  von  der  ortlichen  und 

zeitlichen  Disposition.     Zeitschr.  fiir  Hygiene,  Bd.  i.,  1886,  p.  369. 

905.  Roux.     De  1'action  de  la  lumiere  et  de  1'air  sur  les  spores  de  la  bacteridie  du 

charbon.     Ann.  de  1'Institut  Pasteur,  1887,  p.  445. 

906.  STRAUSS.     Le  charbon  des  animaux  et  de  riiomme.     Paris,  1887,  220  pp. 

907.  REINHOLD.     Zur  ^Etiologie  des  Milzbrandes.     Zeitschr.  fiir  Hygiene,  Bd.  iv., 

1888,  p.  498. 

908.  -        -  Weiterer  Beitrag  zur  Milzbrandatiologie.     Ibid.,  Bd.  v.,  1889,  p.  506. 

909.  BEHKING.     Ueber  die  Ursache  der  Immunitat  von  weissen  Ratten  gegen  Milz- 

brand.    Centralbl.  fur  klin.  Med.,  1888,  No.  38. 

910.  Beitrage  zur  ^Etiologie  des  Milzbrandes.    Zeitschrift  fiir  Hygiene,  Bd. 

vi.,  1889,  p.  117.     Ibid.,  Bd.  vii.,  1889,  p.  171. 

911.  HANKIN.     Immunity  produced  by  an  albumose  isolated  from  anthrax  cultures. 

British  Med.  Journ.,  1889,  p.  810. 

912.  KARLINSKY.     Zur  Kentniss  der  Verbreitungswege  des  Milzbrandes.     Centralbl. 

fiir  Bakteriol.,  Bd.  v.,  1889,  p.  5. 


808  BIBLIOGRAPHY. 

913.  WYSSOKOWITSCH.     Ueber  Schutzimpfungen    gegen    Milzbrand    in    Russland. 

Fortschr.  der  Med.,  1889,  p.  1. 

914.  PERRONCITO.     Studien  iiber  Immunitat  gegen  Milzbrand.     Centralbl.  fur  Bak- 

teriol.,  Bd.  v.,1889,  p.  503. 

915.  CZAPLEWSKI.     Untersuchungen  tiber  die  Immunitat  der  Tauben  gegeu  Milz- 

brand.     Beitr.  zur  allg.  Path.,  etc.  (Ziegler's),  Bd.  vii.,  1889,  p.  47. 

916.  FRANK.     Ueber  den  Untergang  von  Milzbrandbacillen  im  Thierkorper.     Cen- 

tralbl. fiir  Bakteriol.,  Bd.  iv.,  1888,  pp.  710,  737. 

917.  GAMELEIA.     Etude    sur    la    vaccination    charbonneuse.     Ann.    de  1'Institut 

Pasteur,  1888,  p.  517. 

918.  ROSENBLATH.     Beitriige  zur  Pathologic  des  Milzbrandes.     Virchow's  Archiv, 

Bd.  cxv.,  1889,  p.  371. 

919.  PHILIPOWICZ.     Ueber  das  Auftreten  pathogener  Mikroorganismen  im  Harne. 

Wiener  med.  Blatter,  1885,  p.  22. 

920.  TRAMBUSTI  E  MAFFUCCI.     Sull'  eliminazione  dei  virus    dall'  organismo  ani- 

male.     Rivista  internaz.  di  Med.  e  Chir.,  1886,  Nos.  9  and  10. 

921.  STRAUSS  ET  CHAMBERLAIN.     Archiv  de  Physiol.,  1883,  p.  436. 

922.  STRAUSS.     Sur  le  passage  de  la  bacteridie  charbonneuse  de  la  mere  au  foetus. 

Compt.  rend.  Soc.  de  Biol.,  1889,  pp.  409  and  498. 

923.  WOLFF.   Ueber  erbliche  Uebertragung  pathogener  Mikroorganismen.  Virchow's 

Archiv,  Bd.  cv.,  1886,  p.  192. 

924.  HOFFA.    Ueber  die  Natur  des  Milzbrandgiftes.     Wiesbaden,  1886. 

925.  WOLFFHUGEL  UND  RiEDEL.     Die  Vermehrung  der  Bakterien  im  Wasser.     Ar- 

beiten  aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  1836,  p.  455. 

926.  MARTIN.     The  chemical  products  of  the  growth  of  Bacillus  anthracis,  and  their 

physiological  action.     Proc.  of  the  Royal  Soc.,  London,  1890  (May  22d). 

927.  OSBORNE.     Die  Sporenbildung  des  Milzbrandbacillus  auf  Nahrboden  von  ver- 

schiedenen  Gehalt  an  Nahrstoffen.     Archiv  fur  Hygiene,  Bd.  xi.,  p.  51. 

928.  PETERMANN.    Recherches  sur  I'immunite  centre  le  charbon.    Ann.    de  1'In- 

stitut  Pasteur,  vol.  vi.,  1892,  p.  32. 


VIII.   THE   BACILLUS  OF  TYPHOID  FEVER. 

929.  EBERTH.     Der  Bacillus  des  Abdominaltyphus.     Virchow's  Archiv,  Bd.  Ixxxi., 

1880.  Ibid.,  Bd.  Ixxxiii.,  1881. 

930.  BRQWICZ.  Handbuch  der  path.  Anat.,  Birch-Hirschfeld,  1875. 

931.  FISCHEL.  Pragermed.  Wochenschr.,  1878,  p.  33. 

932.  GAFFKY.  Zur  ^Etiologie  des  Abdominaltyphus.     Mitth.  aus  dem  K.  Gesund- 

heitsamte, Bd.  ii.,  1884. 

933.  KOCH.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1881,  p.  46. 

934.  MEYER.     Uutersuchungen  iiber  den  Bacillus  des  Abdominaltyphus.     Inaug. 

Diss.,  Berlin,  1881. 

935.  KLEBS.     Archiv  fiir  exper.  Path,  und  Pharmakol.,  Bd.  xii.,  xiii.,  xv.,  1880-81. 

936.  Archiv  fiir  exper.  Path,  und  Pharm.,  Bd.  xiii. 

937.  HEIN.     Centralbl.  fur  die  med.  Wiss.,  October  4th,  1884. 

938.  LETZERICH.    Virchow's  Archiv,  Bd.  Ixviii.,  1876. 

939.  ALMQUIST.    Nord.med.  Ark  ,  Stockholm,  xiv.,  1882,  No.  10. 

940.  MARAGLIANO.     Centralbl.  fiir  die  med.  Wiss.,  1882,  No.  41. 

941.  TAYON.     Gaz.  med.  de  Montpellier,  May,  1885. 

912.  Sur  le  microbe  de  la  tievre  typhoide  de  rhomme  ;  culture  et  inocula- 
tion.    Compt.  rend.  Acad.  des  Sc.,  t.  c.  et  ci.,  1886. 


BIBLIOGRAPHY.  809 

943.  PFEIFFER.     Ueber  den  Nachweis  der  Typhusbacillen  im  Darminhalt  und  Stuhl- 

gang.     Deutsche  med.  Wocbenschr.,  1885,  p.  500. 

944.  KLEIN.    Rep.  Local  Govt.  Board,  London,  1875. 

945.  BAHRDT.    Arcbiv  der  Heilkunde,  1876,  p.  156. 

946.  VON  MOTSCHUKOFFSKY.     Centralbl.  fur  die  med.  Wiss.,  1876,  No.  11. 

947.  WALDER.     Inaug.  Diss.,  Zurich,  1879. 

948.  CORNIL  ET  BABES.     Les  Bacteries.    Paris,  1885,  p.  432. 

949.  BRIEGER.     Weitere  TJntersuchungen  uber  Ptomaine.     Berlin,  1885. 

950.  SEITZ.     Bakteriologische  Studien  zur  Typhusatiologie.     Munchen,  1886. 

951.  FRANKEL,  A.     Zur  Lehre  von  den  pathogenen  Eigenschaften  des  Typhusbacil- 

lus.     Centralbl.  fur  klin.  Med.,  1886,  No.  10. 

952.  MICHAEL.     Typhusbacillen  im  Trinkwasser.    Fortschr.   der  Med.,  1886,   No. 

11. 

953.  WOLFFHUGEL  UND  RiEDEL.    Die  Vermehrung  der  Bakterien  im  Wasser.     Ar- 

beiten  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1886,  p.  455. 

954.  BEUMER  UND  PEIPER.     Bakteriologische  Studien    uber   die    atiologische  Be- 

deutung    der   Typhusbacillen.     Zeitschrift  fur  Hygiene,  Bd.  i.,   1886,   p. 
489.     Ibid.,  Bd.  ii.,  1887,  p.  110  ;  ibid.,  p.  382. 

955.  FRANKEL,  E.,  UNO  SIMMONDS.     Zur  atiologischen  Bedeutung  des  Typhusbacil- 

lus.    Centralbl.  fur  klin.  Med.,  1886,  No.  39. 

956.  Weitere  Untersuchungen  ilber   die  JEtiologie    des    Abdominaltyphus. 

Zeitschrift  filr  Hygiene,  Bd.  ii.,  1887,  p.  138. 

957.  PHILIPOWICZ.    Ueber  die   diagnostische  Verwerthung  der    Milzfunktion    bei 

Typhus  abdominalis.     Wiener  med.  Blatter,  1886,  No.  6  and  7. 

958.  SIROTININ.     Die  Uebertragung  von  Typhusbacillen  auf  Versuchthiere.     Zeit- 

schrift filr  Hygiene,  Bd.  i.,  1886,  p.  465. 

959.  BiRCH-HiRSCHFELD.     Ueber  die  Zilchtung  von  Typhusbacillen  in  gefarbten 

Nahrlosungen.     Archiv  filr  Hygiene,  1887,  p.  341. 

960.  CHANTEMESSE  ET    WIDAL.     Recherches  sur  le  bacille  typhique  et  1'etiologie 

de  la  fiSvre  typhoide.     Arch,  de  Phys.  norm,  et  path.,  1887,  p.  217. 

961.  De  1'immunite  contre  le  virus  de  la  fievre  typhoide  conferee  par  les  sub- 
stances solubles.    Ann.  de  1'Institut  Pasteur,  t.  ii.,  1888,  p.  54. 

962.  STERNBERG.     The  bacillus  of  typhoid  fever.     The  Med.  News,  Phila.,  April 

30th,  1887. 

963.  The  thermal  death-point  of  the  typhoid  bacillus.     Rep.  of  Com.  on  Dis- 
infectants in  volume  published  by  the  American  Public  Health  Assoc.  in 
1888,  p.  140. 

964.  BUCHNER.    Ueber  die  vermeintlichen  Sporen  der  Typhusbacillen.     Centralbl. 

filr  Bakteriol.,  Bd.  iv.,  1S88,  p.  353. 

965.  KITASATO.   Ueber  das  Verhalteu  der  Typhus-  und  Cholerabacillen  zu  saure-  oder 

alkalihaltigen  Nahrboden.     Zeitschrift  filr  Hygiene,  Bd.  iii.,  1888,  p.  408. 

966.  PFUHL.     Zur  Sporenbildung  der  Typhusbacillen.     Centralbl.    filr  Bakteriol., 

Bd.  iv.,  1888,  p.  769. 

967.  THOINOT.     Sur  la  presence  du  bacille  de  la  fievre  typhoide  dans  1'eau  de  la 

Seine  3,  Ivry.     La  Semaine  med.,  1887,  p.  135. 

968.  MACE.     Sur  la  presence  du  bacille  typhique  dans  le  sol.     Compt.  rend.  Acad.  des 

Sc.,  cvi.,  p.  1564. 

969.  SEMMER.     Zur  Frage  uber  das  Vorkommen  des  Typhus  bei  Thieren.     Virchow's 

Archiv,  Bd.  cxii.,  1888,  p.  203. 

970.  VAUGHAN  AND  NOVY.     Experimental  studies  on  the  causation  of  typhoid  fever, 

with  special  reference  to  the  outbreak  at  Iron  Mountain,  Mich.     The  Medical 
News,  1888,  p.  92. 


810  BIBLIOGRAPHY. 

971.  DE  GIAXA.     Ueber  das  Verhalten  einiger    pathogenen    Mikroorganismen    im 

Meerwasser.     Zeitschrift  fiir  Hygiene,  Bd.  vi.,  p.  162. 

972.  GRANCHER  ET  DESCHAMPS.     Rechcrches  sur  le  bacille  typhique  dans  le  sol. 

Arch,  de  Med.  exp.  et  d'Anat.  path.,  vol.  i.,  1889,  p.  5. 

973.  HEIM.     Ueber  das  Verhalten  der  Krankheitserreger  der  Cholera,  des  Unterleibs. 

typhus,  und  der  Tuberculose  in  Milch,  Butter,  Molken  and  Kase.     Arbeiteu 
aus  dem  K.  Gesundheitsamte,  Bd.  v.,  1889,  p.  294. 

974.  HESSE.    Unsere  Nahrungsmittel    als  Nilhrboden   fur    Typhus  und    Cliolera. 

Zeitschrift  fur  Hygiene,  Bd.  v. ,  p.  527. 

975.  KARLINSKY.     Untersuchungen    fiber    das    Verhalten    der    Typhusbacillen    in 

typhosen  Dejektionen.     Centralbl.  fiir  Bakteriol.,  Bd.  vi.,  1889,  p.  65. 

976.  -       —  Ueber  das  Verhalten  einiger  pathogenen  Bakterien  im    Trinkwasser. 

Archiv  fiir  Hygiene,  Bd.  ix.,  p.  432      Ibid.,  Bd.  x.,  p.  464. 

977.  Untersuchungen  ilber  das  Vorkommen  der  Typhusbacillen  im  Harn. 

Prager  raed.  Wochenschr.,  1890,  Nos.  35  and  36. 

978.  NEUMANN.     Ueber  Typhusbacillen  im  Urin.     Berliner  klin.  Wochenschr.,  1890, 

No.  6. 

979.  SCHILLEK.     Zum  Verhalten  der  Erreger  der  Cholera  und  des  Unterleibstyphus 

in  dem  Inhalt  der  Abtrittsgruben  und  Abwasser.     Arbeiten  aus  dem  K.  Ge- 
sundheitsamte, Bd.  vi.,  1890. 

980. Beitrag  zum  Wachsthum  der  Typhusbacillen  auf  Kartoffeln.     Arbeiten 

aus  dem  K.  Gesundheitsamte,  Bd.  v.,  1889,  p.  312. 

981.  KITASATO.     Die  negative  Indolreaktion  der  Typhusbacillen  im  Gegensatz  zu 

anderen  ahnlichen  Bacillenarten.      Zeitschr.   fiir  Hygiene,  Bd.   vii.,  1889, 
p.  515. 

982.  MARTINOTTI  E  BARBACCI.     Presenza  dei  bacilli  del  tifo  nell'  acqua  potabile. 

Gioruale  della  R.  Accad.  di  Med.  di  Torino,  1889,  No.  8. 

983.  PETRUSCHKY.     Die  Anwendung  der  Lackmusreaktion  zur  Differenzirung  der 

Typhusbacillen  von  ahnlichen  Bakterienarten.  Centralbl.  fiir  Bakteriol., 
Bd.  vi.,  1889,  p.  660. 

984.  STRAUS  ET  DUBARRY.    Recherches  sur  la  duree  de  la  vie  des  microbes  patlio- 

genes  dans  1'eau.     Arch,  de  Med.  exper.  et  d'Anat.  pathol.,  t.  i.,  1889,  p.  5. 

985.  UFFELMANN.     Die  Dauer  derLebensfahigkeit  von  Typhus-  und  Cholerabacillen 

in  Fakalmassen.     Centralbl.  fiir  Bakteriol.,  Bd.  v  ,  1889,  p.  497. 

986.  GASSER.     Sur  un  nouveau    precede  de  diagnostique    differentiel  du    bacille 

d'Eberth.     La  Semaine  med..  1890,  No.  31. 

987.  Culture  du  bacille  typhique  sur  milieux  nutritifs  colores.     Arch,  de 

Med.  exper.  et  d'Anat.  path.,  1890.  No.  6. 

988.  JANOWSKY.     Zur    Biologic    der    Typhusbacillen.     Centralbl.     fiir  Bakteriol., 

Bd.  viii.,  1^90,  pp.  167,  193,  230,  262,  417,  449. 

989.  SMITH.     Einige  Bemerkungen  fiber  Saure-  und  Alkalibildung  bei  Bakterien. 

Centralbl  fttr  Bakteriol.,  Bd  viii.,  p.  389. 

990.  VINCENT.     Sur  un  uouveau  procede  d'isolement  du  bacille  typhique  clans  1'eau. 

Compt.  rend  Soc.  de  Biol..  1890,  No.  5. 

991.  CASSEDEBAT.     Sur  un  bacille  pseudo  typhique  trouve  dans  les  eaux  de  riviere. 

Compt.  rend.  Acad.  des  Sc.,  t.  ex.,  1889. 

992.  Le  bacille  d'Eberth-Gaffky  et  les  bacilles  pseudo-typhiques  dans  les  eaux 

de  riviere.     Ann.  de  1'Institut  Pasteur,  1890,  p.  625. 

993.  FINKELNBURG.     Ueber  einen  Befund  von  Typhusbacillen  im  Brunnenwasser, 

nebst  Bemerkungen  ilber  die  Sedimentirmethode  der  Untersuchung  auf 
pathogene  Bakterien  in  Flilssigkeiten.  Centralbl.  fiir  Bakteriol.,  Bd.  ix., 
1891,  p.  301. 


BIBLIOGRAPHY.  811 

994.  HOLZ.     Experimentale   Untersuchungen    liber  dea  Naclnveis  der  Typhusbacil- 

len.    Zeitschr.  fiir  Hygiene,  Bd.  viii.,  1890,  p.  143. 

995.  VINCENT.     Presence  du  bacille  typhique  dansl'eau  de  Seine  pendant  le  mois  de 

juillet,  1890.    Ann.  de  1'Institut  Pasteur,  1890,  p.  772. 

996.  JAEGER.     Zur  Kenntniss  der  Verbreitung  des  Typhus  durch  Kontagion  und 

Nutzwasser.     Zeitschr.  flir  Hygiene.  Bd.  x.,  1891,  p.  197. 

997.  LASER.     Ueber  das  Verhalten  von  Typhusbacillen,  Cholerabakterien  und  Tu- 

berkelbacillen  in  der  Butter.     Zeitschr.  fiir  Hygiene,  Bd.  x  ,  1891,  p.  513. 

998.  BABES.     Ueber  Variabilitat  und  Varietaten  des  Typhusbacillus.     Zeitschr.  fiir 

Hygiene,  Bd.  ix.,  1890,  p.  323. 

999.  FOOTE.     The  detection  of  the  Bacillus  typhosus  in  water.     Med.   Record,  New 

York,  1891,  p.  506. 

1000.  PARIETTI.     Metodo  di  ricerca  del  Bacillo  del  tifo  Jnelle  acque  potabili.     Ri- 

vista  d'igiene  e  sanita  pubblica.     1890. 

1001.  KAMEN.     Zum  Nachweise  der  Typhusbacillen  im  Trinkwasser.    Centralbl.  fiir 

Bakteriol.,  Bd.  xi.,  1892,  p.  33. 


IX.   BACTERIA  IN  DIPHTHERIA. 

1002.  KLEBS.    Arch,  f  ilr  exper.  Pathol.,  Bd.  iv.,  1875. 

1003.  — —  Medical  Congress  at  Wiesbaden,  1883. 

1004.  LOFFLER.     Uutersuchungen  ilber  die  Bedeutung  der  Mikroorganismen  fiir  die 

Entstehung  der  Diphtheritis  bei  Menschen,  etc.    Mitth.  aus  dem  K.  Ge- 
sundheitsamte,  Bd.  ii.,  1884,  p.  421. 

1005.  Die  Ergebuisse  weiterer  Untersuchungen  ilber  die  Diphtheriebacillen. 

Centralbl.  fiir  Bakteriol.,  Bd.  ii.,  1837,  p.  105. 

1006.  Der  gegenwiirtige  Stand  der  Frage  nach  der  Entstehung  der  Diph- 
theric.    Deutsche  med.  Wochenschr.,  1890,  Nos.  5  and  6. 

1007.  -  Bemerkungen  zu  der  Arbeit  von  Prof.  E.  Klein,   "  Zur  ^Etiologie  der 

Diphtheric."    Centralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  p.  528. 

1008. Welche  Massregeln  erscheinen  gegen  die  Verbreitung   der  Diphtheric 

geboten  ?    Centralbl.  fiir  Bakteriol.,  Bd.  viii.,  1890,  p.  663. 

1009.  VON  HOFFMANN.     Untersuchungen  iiber  den  LSffler'schen  Bacillus  der  Diph- 

therie  und  seine  pathogene  Bedeutung.    Wiener  med.  Wochenschr.,  1888, 
Nos.  3  and  4. 

1010.  PUTZ.    Ueber  croupos-diphtheritische  Erkrankungen  unserer  Hausthiere  und 

deren  Beziehungen  zur  Diphtheric  des  Menschen.     Oesterr.  Zeitschr.  fiir 
Veterinar-Wissenschaften,  Bd.  i.,  1887. 

1011.  ESSER.     1st  Diphtheritis  des  Menschen  auf  Kalber  ilbertragbar  ?    Thiermed- 

Rundschau,  1888,  No.  9. 

1012.  Roux  ET  YERSIN.     Contribution  a  1'etude  de  la  diphtheric.     Ann.  de  1'Institut 

Pasteur,  t.  ii.,  1838,  p.  629. 

1013. Ibid.,  t.  iii.,  1889,  p.  273. 

1014. Ibid.,  t.  iv.,  1890,  p.  385. 

1015.  PKUDDEN.     On  the  etiology  of  diphtheria.     Am.  Journ.  of  the  Med.  Sciences, 

1889. 

1016.  Studies  on  the  etiology  of  diphtheria,  2d  series.     Med.   Record,   New 

York,  vol.  xxxix.,  1891,  p.  445. 

1017.  BABES.     Croup  und  Diphtheric.     Wiener  klin.  Wochenschr.,  1889,  No.  14. 

1018.  Die  Gewebsveranderungen  bei  experimenteller  Diphtheric.     Centralbl. 

fur  Bakteriol.,  Bd.  viii.,  1890,  p.  741. 


812  BIBLIOGRAPHY. 

1019.  BABES.     Untersuchungen  liber  den  Diphtheriebacillus  und  die  experiinentelle 

Diphtheric.     Virchow's  Archiv,  Bd.  cxix..  1890,  p.  460. 

1020.  HOLZINGER.     Zur   Frage  der  Scharlachdiphtherie.     Inaug.  Diss.,  Munchen, 

1889. 

1021.  KOLISKO  UND  PALTAUF.     Zum  Wesen  des  Croups  und  der  Diphtheric.     Wiener 

klin.  Wochenschr.,  1889,  No.  8. 

1022.  ORTMANN.     Berliner  klin.  Wochenschr.,  1889.  No.  10. 

1023.  ZARNIKO.    Beitrag  zur  Kenntniss  des  Diphtheriebacillus.     (Inaug.  Diss.)     Cen- 

tralbl.  ftlrBakteriol.,  Bd.  vi.,  1889. 

1024.  WURZ  ET  BOURSES.     Arch,  de  Med.  experimeutale,  t.  ii.,  1890,  p.  341. 

1025.  ESCHERICH.     Zur  .Etiologie  der  Diphtheric.  Centralbl.  fur  Bakteriol. ,  Bd.  vii., 

1890,  p.  8. 

1026.  KLEIN.     Zur  ^Etiologie  der  Diphtheric.    Centralbl.    fiir  Bakteriol.,  Bd.  vii., 

1890,  pp.  489,  521. 

1027.  Nachtrag    zum   ';Weiteren  Beitrag  zur   ./Etiologie  der  Diphtheric." 

Centralbl.  fur  Bakteriol.,  Bd.  viii.,  1890,  p.  7. 

1028.  D'EspiNE.     Rev.  med.  de  la  Suisse  romande,  1888,  p.  49. 

1029.  BEHRING.     Untersuchungen  iiber  das  Zustandekommen  der  Diphtheric- Immu- 

nitat  bei  Thieren.     Deutsche  med.  Wochenschr.,  1890,  No.  50. 

1030.  BEHRING  UND  KITASATO.     Ueber  das  Zustandekommen  der  Diphtherie-Im- 

munitat  und  der  Tetanus-Immunitat  bei  Thieren.     Deutsche  med.  Wochen- 
schr., 18'JO,  No.  49. 

1031.  BRIEGER  UND  FRANKEL.    Untersuchungen  liber  Bakteriengifte.    Berliner  klin. 

Wochenschr.,  1890,  Nos.  11  and  12. 

1032.  Ueber  Immunisirungsversuche  bei  Diphtheric.     Berliner  klin.  Wochen- 
schr., 1890,  No.  49. 

1033.  WELCH  AND  ABBOTT.     The  etiology  of  diphtheria.    Bull.  Johns  Hopkins  Hos- 

pital, vol.  ii.,  1891,  p.  25. 

1034.  ABBOTT.     The  relation  of  the  pseudo-diphtheritic  bacillus  to  the  diphtheritic 

bacillus.     Ibid.,  vol.  ii.,  1891,  p.  110. 

1035. Further  studies  upon  the  relation  of  the  pseudo-diphtheritic  bacillus  to 

the  diphtheritic  bacillus.     Ibid.,  vol.  ii.,  1891,  p.  143. 

1036.  (No.  48.)  Roux  ET  YERSIN.     Ann.   del'Institut  Pasteur,  t.  iv.,  1890,  p.  409. 

1037.  (No.  49  and  No.  50.)  LOFFLER.     Mitth.   aus  dem  K.  Gesundheitsamte,  Bd.  ii., 

1884. 

1038.  (No.  51.)  RIBBERT.     Ueber    einen  bei    Kaninchen    gefundenen    pathogenen 

Spaltpilz.     Deutsche  med.  Wochenschr.,  1887,  No.  8. 

X.   BACTERIA  IN  INFLUENZA. 

1039.  BABES.     Vorlaufige  Mittheilungen  liber  eiuige  bei  Influenza  gefundene  Bak- 

terien.     Centralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  pp.  233,  460,  496,  533,  561, 
598. 

1040.  Ueber  die  bei  Influenza  gefundeue  f  einen  Bakterien.     Deutsche  med. 

Wochenschr.,  1892,  No.  6. 

1041.  BOUCHARD.     Recherches  bacteriologiques  sur  la  grippe  et  ses  complications. 

La  Semaine  med.,  1890,  No.  5. 

1042.  FISCHEL.     Beobachtungen     wahrend  der    lufluenzaepidemie.     Prager    med. 

Wochenschr.,  1890,  No.  9. 

1043.  Eine  bakteriologisch-experimentelle  Studie  liber  Influenza.     Zeitschrift 

flir  Heilkunde,  Bd.  xii.,  1891. 

1044.  JOLLES.     Zur  JStiologie  der  Influenza.     Wiener  med.  Blatter,  1890,  No.  4. 


BIBLIOGRAPHY.  813 

1045.  KIRCHNER.     Untersuchungen  liber  Influenza.     Centralbl.  fur  Bakteriol  ,  Bd. 

vii.,  1890,  p.  361. 

1046.  —    Bakteriologische     Untersuchungen     ilber  Influenza.     Zeitschrift  fur 

Hygiene,  Bd.  ix.,  1890,  p.  528. 

1047.  KLEBS.    Ein  Blutbefund  bei  Influenza.     Centralbl.  fur  Bakteriol.,   Bd.  vii., 

1890,  p.  145. 

1048.  Deutsche  med.  Wochenschr.,  1890,  No.  14. 

1049.  KOWALSKI.     Bakteriologische  Untersuchungen  ilber  die    Influenza.     Wiener 

klin.  Wochensch.,  1890,  Nos.  13  and  14. 

1050.  KRUSE,  PANSINI  UND  PASQUALE.     Influenzastudien.    Centralbl.  filr  Bakteriol., 

Bd.  vii.,  1890,  p.  657. 

1051.  LEVY.     Bakteriologische  Befunde  bei  Influenza.     Berliner  klin.  Wochenschr., 

1890,  No.  7. 

1052.  PRIOR.     Bakteriologische  Untersuchungen  liber  die  Influenza  und  ihre  Kompli- 

kationen.     Miinchener  med.  Wochenschr.,  1890,  Nos.  13-15. 

1053.  RIBBERT.     Anatomische  und  bakteriologische  Beobachtungen  liber  Influenza. 

Deutsche  med.  Wochenschr.,  1890,  No.  5. 

1054.  Weitere  bakteriologische  Mittheilungen  liber  Influenza.     Ibid.,  No.  15. 

1055.  VAILLARD.     Le  streptocoque  et  la  grippe.     La  Semaine  rned.,  1890,  No.  7. 

1056.  WEICHSELBAUM.     Bakteriologische  und  pathologisch-anatomische  Untersuch- 

ungen tiber  Influenza  und  ihreKomplikationeu.     Wiener  klin.  Wochenschr., 
1890,  Nos.  6-10. 

1057.  ZAUFAL.     Bakteriologisches  zur  Mittelohrentziindung  bei  Influenza.     Prager 

med.  Wochenschr.,  1890,  No.  9. 

1058.  FRIEDRICH.     Untersuchungen  liber  Influenza.     Arbeiten  aus  dein  K.  Gesund- 

heitsamte,  Bd.  vi.,  1890,  Heft  2. 

1059.  PRUDDEN.     Bacterial  studies  on  the  influenza  and  its  complicating  pneumonia. 

Medical  Record,  New  York,  1890,  p.  169. 

1060.  SCHEIBE.     Bakteriologisches  zur  Otitis  media  bei   Influenza.     Centralbl.    fiir 

Bakteriol.,  Bd.  viii.,  1890,  p.  225. 

1061.  BEIN.     Bakteriologische  Untersuchungen  liber  Influenza.     Zeitschrift  fiir  klin. 

Med.,  xvii.,  1890,  Heft  6. 

1062.  PFEIFPER.     Vorlaufige     Mittheilungen     liber     den  Erreger    der    Influenza. 

Deutsche  med.  Wochenschr.,  1892,  No.  2. 

1063.  CANON.     Ueber    einen  Mikroorganismus  im    Blute    von    Influenzakranken. 

Deutsche  med.  Wochenschr.,  1892,  No.  2. 

1064.  Ueber  Ziichtung  des  Influenzabacillus  aus  dem  Blute  von  Influenza- 
kranken.   Ibid.,  1892,  No.  3. 

1065.  KITASATO.     Ueber  den  Influenzabacillus  und  sein  Kulturverfahren.     Deutsche 

med.  Wochenschr.,  1892,  No.  2. 

XI.  BACILLI  IN   CHRONIC  INFECTIOUS  DISEASES. 

TUBERCULOSIS. 

1066.  VILLEMAN.    Etude  sur  la  tuberculose.     Paris,  1868. 

1067.  COHNHEIM.     Uebertragbarkeit  der  Tuberkulose.     Berlin,  1877. 

1068.  KOCH.     Die  ^Etiologie  der  Tuberkulose.     Berliner  klin.  Wochenschr.,  1882. 

1069. Mittheilungen  aus  demK.  Gesundheitsamte,  Bd.  ii.,  1884. 

1070.  -  Kritische  Besprechung  der  gegen  die  Bedeutung  der  Tuberkelbacillen 
gerichteten  Publicationen.     Deutsche  med.  Wochenschr.,  1883,  No.  10. 

1071.  Weitere  Mittheilung  liber  das  Tuberkulin.     Deutsche  med.   Wochen- 
schr., 1891,  No.  43. 


814  BIBLIOGRAPHY. 

1072.  DOUTRELPONT.     Die  ^Etiologie  des  Lupus  vulgaris.     Yierteljahresschr.    fiir 

Dermatol.  und  Syph.,  1884. 

1073.  CORNIL  ET  LELOIR.     Recherches,  etc.,    sur  la  natur  du  lupus.     Arch,    de 

Physiol.  norm,  et  path. ,  1884. 

1074.  GAFFKY.    Verhalten  der  Tuberkelbacillen  im  Sputum.     Mitth.  aus  dem  K. 

Gesundheitsamte,  Bd.  ii.,  1884. 

1075.  ZIEHL.     Bedeutung     der     Tuberkelbacillen     filr  Di'agnose    und    Prognose. 

Deutsche  med.  Wochenschr.,  1883,  No.  5. 

1076.  MALASSEY  ET  VIGNAL.     Sur  le  microorganisme  de  la  tuberculose  zoogloeique. 

Compt.  rend.  Acad.  desSc.,  t.  xcix.,p.  200. 

1077.  EHRLICH.     Deutsche  med.  Wochenschr.,  Bd.  viii.,  1882.     Ibid.,  Bd.  ix.,  1883. 

1078.  GIBBS.     Lancet,  London,  1883. 

1079.  BABES.     Der  erste  Nachweis  des  Tuberkelbacillus  im  Harn.     Centralbl.  fiir 

die  med.  Wissensch.,  1883. 

1080.  LUSTIG.    Ueber  Tuberkelbacillen   im  Blut   bei    an    allg.   akuter  Miliartub. 

Erkrankten.     Wiener  med.  Wochenschr.,  1884,  No.  48. 

1081.  WEIGERT.    Deutsche  med.  Wochenschr.,  1883,  No.  24. 

1082.  Zur  Theorie  der  tuberkulosen  Riesenzellen.     Deutsche  med.  Wochen- 
schr. ,  1885,  p.  599. 

1083.  MULLER.     Ueber  den  Befund  von  Tuberkelbacillen  bei  f unaijt  Knochen  und 

Gelenkaffektionen.     Centralbl.  fur  Chir.,  1884. 

1084.  BROUILLY.     Note  sur  la  presence  de  bacilles  dans  les  lesion^^R'urgicales  tuber 

culeuses.     Rev.  de  Chir.,  vol.  iii.,  1883. 

1085.  SCHILL  UND  FISCHER.     Mitth.  aus  dem  K.  Gesundheitsan^WBd.  ii.,  1884. 

1086.  JOHNE.     Zur  ^Etiologie  der  Htihnertuberkulose.     DeutscJ^Eeitschr.  filr  Thier- 

med.  und  vergl.  Pathol.,  Bd.  x.,  p.  155. 

1087.  Zur  Pathogenese  der  Tuberkulose  beim    Pfc  Jl.     Bericht    ilber   das 

Veterinarwesen  im  Kgrch.  Sachsen  fur  das  Jahr  18m,  p.  52. 

1088.  RIBBERT.     Ueber  die  Verbreitungsweise  der  Tube*elbacillen  bei  Hiihnern. 

Deutsche  med.  Wochenschr.,  1883,  No.  28.          M 

1089.  WEICHSELBAUM.    Tuberkelbacillen  im  Blut.     WJffner  med.  Jahrb.,  1883. 

1090.  kZusammenfassender    Bericht  iiber  die^Etiologie   der   Tuberkulose. 

Centralbl.  fur  Bakteriol.,  Bd.  iii.,  1888,  No^e. 

1091.  BANG.     Ueber  Eutertuberkulose  der  Milchkiihe.     Deutsche  Zeitschr.  fiir  Thier- 

med.  und  vergl.  Pathol.,  Bd.  xi. 

1092. Tuberkelbacillen  in  der  Milch  tuberkuloser  Kilhe.    Abstract  in  Cen- 
tralbl. fur  klin.  Med.,  1888,  p.  898. 

1093.  1st  die  Milch  tuberkuloser  Kilhe  virulent,  wenn  das  Enter  nicht  ergrif- 

fen  ist  ?    Internal.  Med.  Congress  in  Berlin,  1890.     Centralbl.  filr  Bakteriol., 
Bd.  ix.,  p.  144. 

1094.  STERNBERG.     Injection  of  finely  powdered  inorganic  material  into  the  abdo- 

minal cavity  of  rabbits  does  n0t  induce  tuberculosis;  an  experimental  re- 
search, with  pathological  notes  by  Wm.  T.  Councilman.  Amer.  Journ.  of 
the  Med.  Sci.,  Jan.,  1885. 

1095.  CORNIL  ET  MEGOIN.     Tuberculose  et  diphtheric  des  .^allinaces.     Journ.  de 

1'Anat.,  1885,  p.  268. 

1096.  KRASKE.     Ueber  tuberkulose  Erkrankung   von  Wunde.     Centralbl.  fiir  Chi- 

rurgie,  1885,  No.  4. 

1097.  NATHAN.     Ueber  das  Vorkommen  von  Tuberkelbacillen  bei  Otorrhoen.     Deut- 

sches  Archiv  fiir  klin.  Med.,  Bd   xxv.,  1835,  p.  491. 

1098.  NEELSEN.     Methode  zum  Nachweis  von  Tuberkelbacillen.    Fortschr.  der  Med., 

1885,  p.  200. 


BIBLIOGRAPHY.  815 

1099.  ORTMANX.     Ueber  Tuberkulose    der  weiblichen  Brustdrilse,  mit  besonderer 

Berilcksichtigkeit  der  Riesenzellenbildung.    Virchow's  Archiv,  Bd.  c.,  1885, 
p.  365. 

1100.  RUTIMEYER.     Ueber  das  Vorkommen  von  Tuberkelbacillen  im  Blut  und  Milz- 

saft  bei  allgemeiner  Miliartuberkulose.     Centralbl.  fiir  klin.  Med.,    1885, 

p.  353. 

r        0 

1101.  SIRENA  E  PERNICE.     Sulla  transmissibilita  della  tuberculosi  per  mezzo  degli 

sputi  dei  tisici.     Gaz.  degli  Ospitali,  1885,  No.  25. 

1 102.  STICKER.     Ueber  das  Vorkommen  von  Tuberkelbacillen  im  Blute  bei  der  akuten 

allgemeinen  Miliartuberkulose.     Centralbl.  fiir  klin.  Med.,  1885,  p.  441. 

1103.  TSCHERNING.    Inoculationstuberkulose  beim  Menschen.     Fortschr.   der  Med., 

1885,  p.  65. 

1104.  ULRICH.    Nachweis  der  Tuberkelbacillen  bei  Conjunktivaltuberkulose.     Cen- 

tralbl. filrprakt.  Augenheilk.,  1885,  Heft  12. 

1105.  VOLTOLINI.    Ueber  ein  besonderes  Erkennungszeichen  der  Tuberkelbacillen. 

Breslauer  arztl.  Zeitschr.,  1885,  No.  15. 

1106.  WESENER.    Kritische  und  experimentelle  Beitrage  zur  Lehre  von  der  Ftitter- 

ungstuberkulose.     Freiburger  akadeniische  Habilitationsschrift,  1885. 

1107.  BENDER.     Ueber   die   Beziehungen  des    Lupus   vulgaris    zur  Tuberkulose. 

Deuljgche  med.  Wochenschr.,  1886,  p.  396. 

1108.  BERGKAMMER.     Kasuistischer  Beitrag  zur  Verbreitung  der  Miliartuberkulose 

und  Etnwanderung  der  Tuberkelbacillen  in  die  Blutbahn.    Virchow's  Ar- 
chiv, Bfflkii.,  1886,  p.  397. 

1109.  BIEDERT.  Win  Verfahren,  den  Nachweis  vereinzelter  Tuberkelbacillen  zu 

sichern,  e»k     Berliner  klin.  Wochenschr.,  1886,  No.  42.     Ibid.,  1887,  No.  2. 

1110.  BOLLINGER.  WJeber  intestinale  Tuberkulose  bei  Huhnern  durch  Genuss  tuber- 

kuloser  SpulJL     Deutsche  med.  Zeitung,  1885,  No.  78. 

1111.  VON  BRUNN.    E^itrag  zur  Lehre  von  der  Uebertragbarkeit  der  Tuberkel- 

bacillen.    Deufltehe  med.  Wochenschr.,  1886,  p.  178. 

1112.  CAVAGNIS.     ContreVil  virus  tubercolare  e  contre  la  tuberculosi :    Tentativi 

sperimentali.     Atfl^del  R.  Institute  Veneto  di  Scienze,  Lett,  et  Arti,  t.  iii., 
iv.,  v.,  serie  vi.,  18$5-86. 

1113.  EHRLICH.     Beitrage  zurVTheorie  der  Bacillenfarbung.    Charite-Annalen,  1886. 

1114.  FRANKE.     Zur    Fiirbung    der     Tuberkelbacillen      in    Geweben    (Schnitten). 

Deutsche  med.  Wochenschr.,  1886,  p.  397. 

1115.  GARRE.    Zur  ^Etiologie  der  kalten  Abscesse,  etc.   Deutsche  med.  Wochenschr., 

1886,  p.  581. 

1116.  HANOT.     Contribution  a  1'etudede  la  tuberculose  cutanee.     Archiv.  de  Physiol. 

norm,  et  pathol.,  1886,  p.  25. 

1117.  KIRSTEIN.     Ueber  den  Nachweis  der  Tuberkelbacillen  im  Urin.     Deutsche 

med.  Wochenschr.,  1886,  p.  249. 

1118.  MULLER.     Experimentelle  Erzeugung  typischer  Knochentuberkulose.     Cen- 

tralbl. fiir  Chirurgie,  1886,  No.  14. 

1119.  Deutsche  Zeitschrift  fur  Chirurgie,  Bd.  xxiv.,  1886,  p.  37. 

1120.  NASSE.    Beitriige  zur  Kenntniss  der  Arterientuberkulose.     Virchow's  Archiv, 

Bd.  cv.,  1886,  p.  173. 

1121.  NEESE.    Ein  Beitrag  zur  Tuberkulose  des  Auges.     Archiv  filr  Augeuheil- 

kunde,  Bd.  xvi.,  1886,  Heft  3  and  4. 

1122.  NOCARD  ET  Roux.     Sur  la  culture  du  microbe  de  la  tuberculose.     Soc.  de 

Biol.,  seance  du  11  decembre,  1886. 

1123.  Sur  la  culture  du  bacille  de  la  tuberculose.     Ann.  de  1'Institut  Pasteur, 

1887,  p.  19. 


816  BIBLIOGRAPHY. 

1124.  ADAM.     Haufigkeit  der  Tuberkulose  bei  den  geschlachteten  Rindern  auf  dem 

Schlachthofe  zu  Augsburg.     Adam's  Wochenschr.  f  iir  Thierheilkunde,  1886, 
No.  17. 

1125.  CADEAC  ET  MALET.     Etude  experimentale  de  la  transmission  de  la  tuberculose 

par  1'air  expire  et  par  1'atmosphere.     Revue  de  Med.,  1887,  No.  7. 

1126. Compt.  rend.  Acad.  des  Sc..  t.  cv.,  1887,  p.  1190. 

1127. Recherches  experimentales  sur  la  virulence  des  matieres  tuberculeuses 

dessechees,  putriflees  ou  congelees.     Lyon  Med.,  1888,  p.  229. 

1128.  VON  EISELBERG.     Beitrage    zur  Impftuberkulose    beim  Menschen.     Wiener 

med.  Wochenschr.,  1887,  No.  53. 

1129.  ERNST.     Gabbet's     Farbung  der    Tuberkelbacillen.      Correspondenzbl.     fur 

Schweitzer  Aerzte,  Jahrg.  xvii.,  1887. 

1130.  ERNST.     How  far  may  a  cow  be  tuberculous  before  her  milk  becomes  danger- 

ous as  an  article  of  food?    Am.  Journ.  of  the  Med.  Sc.,  1889  (November). 

1131.  FINGER.     Lupus  und  Tuberkulose.     Zusammenfassende  Darstellung  des  jetzi- 

gen  Standes  dieser  Frage.     Centralbl.  filr  BakterioL,  Bd.  ii.,  1887,  p.  348. 

1132.  Ueber  die  sogenannte  Lichenwarze  und  ihre  Stellung  zu  Lupus  und  zu 

Tuberkulose.     Deutsche  med.  Wochenschr.,  1880,  No.  5. 

1133.  LELOIR.     Neue  Untersuchungen  tiber  die  Beziehung  zwischen  Lupus  und 

Tuberkulose.    Ann.  de  Dermatol.  et  de  Syph.,  vii.,  18B6,  p.  328. 

1 134.  PFEIPFER.     Ein  neuer  Fall  von  Uebertragung  der  Tuberkulose  des  Rindes  auf 

den  Menschen.     Zeitschrift  fiir  Hygiene,  Bd.  iii.,  1887,  p.  189. 

1135.  SOUZA.     Procede  rapide  de  coloration  a  froid  des  bacilles  tuberculeux  dans  les 

crachats.    Compt.  rend.  Soc.  de  Biol.,  1887,  No.  25. 

1136.  SPILMANN  ET  HAUSHALTER.     Dissemination  du  bacille  de  la  tuberculose  par 

les  mouches.     Compt.  rend.  Acad.  des  Sc.,  t.  cv.,  1887,  p.  352. 

1137.  VOLSCH.     Beitrag  zur  Frage  nach  der  Tenacitat  der  Tuberkelbacillen.     Zieg- 

ler's  Beitrage  zur  path.  Anat.  und  Physiol.,  Bd.  ii.,  Heft  11. 

1138.  DOR.    Methode  de  coloration  rapide  des  bacilles  de  la  tuberculose  et  de  la  lepre. 

Lyon  Med.,  1888,  No.  18. 

1139.  HEYDENREICH.     Die  Struktur  des  Tuberkelbacillus.     Wratch.,  1887,  No.  33. 

1140.  HOFFMANN.     Ueber  die  Verbreitung  der  Tuberkulose  durch  unsere  Stuben- 

fliege.     Correspondenzbl.  der  arztlichen  Kreis-  und  Bezirksvereine  im  Ko- 
nigreich  Sachsen,  1888,  No.  12. 

1141.  LUBIMOFF.     Zur  Technik  der  Farbung  von  Tuberkel- und  Leprabacillen.    Cen- 

tralbl. filr  BakterioL,  Bd.  iii.,  1888,  p.  540. 

1142.  PALOWSKI.     Culture  des  bacilles  de  la  tuberculose  sur  la  pomme  de  terre.    Ann. 

de  1'Institut  Pasteur,  1888,  p.  303. 

1143.  PEUCH.     Note  sur  la  contagion  de  la  tuberculose  par  le  lait  non-bouilli  et  la 

viande  crue.     Revue  veterin.,  \8^S,  pp.  649-653. 

1144.  STRAUS  UND  WURTZ.     Unempfanglichkeit  der  Hlihner  f  tir  Filtterungstuber- 

kulose.     (Tuberculosis    Congress  in  Paris,  1888.)    Referat   Wiener    med. 
Presse,  1888,  p.  1278. 

1145.  Einfluss  des  Magensaftes  auf  die  Tuberkelbacillen.     Ibid. 

1146.  TRUDEAU.     An  environment  experiment  repeated.     Med.  News,  Philadelphia, 

1888,  No.  17. 

1147.  Hydrofluoric  acid  as  a  destructive  agent  to  the  tubercle  bacillus.     Ibid., 

No.  18. 

1148.  -    —  Sulphuretted  hydrogen  vers"s  the  tubercle  bacillus.    Ibid.,   1887,  p. 

570. 

1149.  UTZ.    Die  Fiitterungstuberkulose  der  Sch weine.     Bad.  hierarztl.  Mitth. ,  1889, 

p.  7. 


BIBLIOGRAPHY.  817 

1150.  YILLEMIN.    Etudes  experimentales  de  1'action  de  quelques  agents  chimiques  sur 

le  developpement  du  bacille  de  la  tuberculose.     Bull,  general  de  therapeut., 
1888,  p.  550. 

1151.  YERSIN.     De  1'action  de  quelques  antiseptiques  et  de  la  chaleur  sur  le  bacille 

de  la  tuberculose.     Ann.  de  1'Institut  Pasteur,  t.  ii.,  1888,  p.  60. 

1152.  Etude  sur  le  developpement  du  tubercule experimental.    Ibid.,  p.  245. 

1153.  HAMMERSCHLAG.     Bakteriologisch-chemische  Untersuchungen  der  Tuberkel- 

bacillen.     Sitzungsber.  der  K.  Akad.  der  Wissensch.  in  Wien,  Dec.  13th, 
1888. 

1154.  HERMAN.     Precede  rapide  de  coloration  du   bacille  tuberculeux.     Ann.  de 

1  Institut  Pasteur,  t.  iii.,  1889,  p.  160. 

1155.  HIRSCHBEKGER.     Experimentelle  Beitrage  zur  Infektiositat  der  Milch  tuberku- 

lOser  Kilhe.     Inaug.  Diss.,  Miinchen,  1889. 

1156.  KASTNER.    Experimentelle  Beitrage  zur  Infektiositat  des  Fleisches  tuberku- 

loser  Kinder.     Milnchener  med.  Wochenschr.,  1889,  Nos.  34,  35. 

1157.  KITT.     Eine  vereinfachte  Tuberkelbacillenfarbung.     Monatsschr.   fiir  prakt. 

Thierheilkunde,  i  ,  p.  123. 

1158.  KRUGER.    Einige  Untersuchungen  des  Staubniederschlages  der  Luft  in  Bezug 

auf  seinen  Gehalt  an  Tuberkelbacillen.     Inaug.  Diss.,  Bonn,  1889. 

1159.  MAFFCCCI.     Richerche  sperimentali  sull'azione  dei  bacilli  della  cuberculosi  dei 

gallinacci  e  dei  mammiferi  nella  vita  embrionale  ed  adulta  del  polio.    Riforuaa 
medica,  1889,  Nos.  209  and  213, 

1160.  Sulla  infezione    tubercolare    degli  embrione  di  polio.     Giornale   di 

Anat.,  Fisiol.  e  Pathol.  degli  Animali,  1889,  fasc.  ii. 

1161.  Ueber  die  Wirkung  der  reinen,  sterilen  Kulturendes  Tuberkelbacillus. 

»          Centralbl.  fur  allg.  Path,  und  path.  Anat.,  1890,  No.  26. 

1162.  -   Die  Hiihnertuberkulose.     Zeitschr.    fur  Hygiene,   Bd.    xi.,   1892,   p. 

445. 

1163.  Di  MATTEL     Delia  presenza  del  bacillo  tubercolare  sulla  superficie  del  corpo 

dei  tisici.     Bull,  della  R.  Accad.  di  Roma,  1888-89,  fasc.  i. 

1164.  MARTIN.    Note  sur  la  culture  du  bacille  de  la  tuberculose.     Archiv  de  Med. 

exper.  et  d'Anat.  path.,  1889,  p.  77. 

116-j.  NEISSER.     Ueber  die  Struktur  der  Lepra-  und  Tuberkelbacillen,  etc.     1.  Con- 
gress der  Deutsch.  Dertnatol.  Gesellsch.  in  Prag,  1889. 

1166.  SCHILL.     Tuberkelbacillenfarbung    auf    dem    Objekttrager.     Centralbl.   fiir 

Bakteriol.   Bd  v.,  1889,  p.  340. 

1167.  SCHMIDT  MUHLHEIM.     Ueber  den  Nachweis  und  das  Verhalten  von  Tuberkel- 

keimen  in  der  Kuhmilch.     Archiv  fiir  anim.  Nahrungsmittelk.,  Jahrg.  v., 
1889,  Nos.  1  and  3. 

1168.  STEINHEIL.     Ueber  die  Infektiositat  des  Fleisches  bei  Tuberkulose.    Inaug 

Diss.,  Miinchen,  1889. 

1169.  GEBHARDT.     Experimentelle  Untersuchungen  fiber  den  Einfluss    der  Ver- 

dilnnung  auf  die  Wirksamkeit  des  tuberkulosen  Giftes.     Virchow's  Archiv, 
Bd.  cxix.,  p.  127. 

1170.  CADIOT,  GILBERT  ET  ROGER.     Tuberculose  des  volailles.     La  Semaine  med., 

x.,  1890,  No.  45. 

1171.  CZAPLEWSKI.     Zum  Nachweis  der  Tuberkelbacillen  im  Sputum.     Centralbl. 

fiir  Bakteriol.,  Bd.  viii.,  p.  685. 

1172.  FORSTER.     Ueber  den  Einfluss  des  Raucherns  auf  die  Infektiositat  des  Fleisches 

perlsiichtiger  Riuder.     Mi'mchener  med.  Wochenschr.,  1890,  No.  16. 

1173.  KUHNE.    Die  Untersuchung  von  Sputum  auf  Tuberkelbacillen.    Centralbl. 

fur  Bakteriol  ,  Bd.  viii.,  p.  293. 


818  BIBLIOGRAPHY. 

1174.  BOLLINGER.     Ueber  die  Infektionswege  des  tuberkul5sen  Giftes.     Internal. 

Med.  Congress  of  Berlin,  1890.     Centralbl.  fur  Bakteriol.,  Bd.  ix.,  p.  140. 

1175.  COURMONT  ET  DOR.     De  la  production,  chez  le  lapin,  des  tumeurs  blanches 

experimentales,  par  inoculation  intraveineuse  de  culture  du  bacille  de  Koch 
attenue.  La  Province  Med.,  1890,  p.  529. 

1176.  JOLLES  UNO  AD.     Zur  Kenntniss  der  chemischen  Natur  des  Kochins.     Inter- 

nal, klin.  Rundschau,  Bd.  v.,  1891,  p.  10. 

1177.  KOSTJURIN  UND  KRAiNSKi.     Ueber  die  Wirkung  von  Faulniss-  und  Tuberkel- 

toxinen  auf  Thiere,  etc.  Wratsch.,  1891.  Abstract  in  Centralbl.  filr  Bak- 
teriol., Bd.  ix.,  1891,  p.  445. 

1178.  NICKEL.    Zur  Biochemie  der  Bakterien.     Centralbl.  filr  Bakteriol.,  Bd.  ix., 

1891,  p.  333. 

1179.  Roux.    Quelques  remarques  a  propos  de  la  colorabilite  du  bacille  de  la  tuber- 

culose.    La  Province  Med.,  1891,  p.  37. 

1180.  SCHNIRER.     Zur  Frage  nach  der  Verb-reitung  der  Tuberkelbacillen  ausserhalb 

des  Korpers.     Wiener  med.  Presse,  1891,  p.  3. 

1181.  TIZZONI  UND  CATTANI.     Ueber  das  Vorhandensein  eines  gegen  Tuberkulose 

immunisirenden  Princips  im  Blute  von  Thieren,  welche  nach  der  Methode 
von  Koch  behandelt  worden  sind.  Centralbl.  filr  Bakteriol.,  Bd.  xi.,  1892, 
p.  82. 

1182.  NOCARD.     Application  des  injections  de  tuberculine  au  diagnostique  de  la 

tuberculose  bovine.     Ann.  de  1'Institut  Pasteur,  vol.  vi.,  1892,  p.  44. 

1183.  SAWIZKY.    Zur  Frage  tlber  die  Dauer  der  infektiosen  Eigenschaften  des  ge- 

trockneten  tuberkulosen  Sputunis.  Inaug.  Diss.,  St.  Petersburg,  1891.  Ab- 
stract in  Centralbl.  filr  Bakteriol.,  Bd.  xi.,  1892,  p.  153. 

1184.  PASTOR.     Eine  Methode  zur  Gewinnung  von  Reinkulturen  der  Tuberkelbacil- 

len aus  dem  Sputum.     Centralbl.  filr  Bakteriol.,  Bd.  xi.,  1892,  p.  233. 

1185.  KITASATO.     Gewinnung  von  Reinkulturen  der  Tuberkelbacillen  und  andere 

pathogener  Bakterien  aus  Sputum.  Zeitschrift  filr  Hygiene,  Bd.  xi.,  1892, 
p.  441. 

BACILLUS  LEPR^E. 

1186.  NEISSER.    Breslauer  arztl.  Zeitschrift,  1879. 

1187.  Weitere  Beitrage  zur  ^Etiologie  der  Lepra.    Archiv.  filr  path.  Anat., 

etc.,  Berlin,  Ixxxiv.,  1881,  p.  514.     Ibid.,  Bd.  ciii.,  1886,  p.  355. 

1188.  HANSEN,  A.    Bacillus  leprae.    Nord.  med.  Ark.,  Stockholm,  xii.,  1880,  p.  1. 

1189.  Virchow's  Archiv,  Bd.  Ixxix. 

1190.  Studien  tiber  Bacillus  leprae.    Virchow's  Archiv,  Bd.  xc.,  1882,  p.  542. 

1191.  Die  Lage  der  Leprabacillen.     Virchow's  Archiv,  Bd.  ciii.,  1886.  p.  388. 

1192.  BABES.     Etude  comparative  des  bacteries  de  la  lepre  et  de  la  tuberculose, 

Compt.  rend.  Acad.  des  Sc.,  t.  xcvi.,  1883. 

1193.  ARNING.     Ueber  das  Vorkommen  der  Bacillus  leprse  bei  Lepra  anaesthetica  s. 

nervorum.     Virchow's  Archiv,  Bd.  xcvii. 

1194.  DAMSCH.     Uebertragungsversuche  von  Lepra  auf  Thiere.     Virchow's  Archiv, 

Bd.  xcii.,  1883. 

1195.  KOBER.     Uebertragungsversuche  von  Lepra  auf  Thiere.     Virchow's  Archiv, 

1882. 

1196.  Vossius.     Uebertragungsversuche  von  Lepra  auf  Kaninchen.     Ber.  ilber  den 

Ophthalmologencongress  in  Heidelberg,  1881. 

1197.  UNNA.     Ueber  Leprabacillen.     Deutsche  med.  Wochenschr.,  1885,  No.  32. 
1198. Zur  Farbung  der  Leprabacillen.     Monatshefte  filr  prakt.  Dermatologie, 

redig.  v.  Uuna  in  Hamburg ;  Erganzungsheft,  1885,  p.  47. 


BIBLIOGRAPHY.  819 

1199.  UNNA.    Wo  liegeu  die  Leprabacillen  ?   Deutsche   med.  Wochenschr.,  1886, 

p.  123. 

1200.  Die  Bacillenklumpen  inder  Haut  sind  keine  Zellen.    Virchow's  Archiv, 

Bd.  ciii.,  1886,  p.  553. 

1201.  Die  Leprabacillen  in  ihrem  Verhaltniss  zum  Hautgewebe.    Dermatolog. 

Studien,  Heft  1,  Hamburg,  1886. 

1202.  GUTTMANN.     Ueber  Leprabacillen.     Berliner  klin.  Wochenschr.,  1885,  p.  81. 

1203.  VIRCHOW.     Demonstration  von  Lepra  laryngis.     Berliner  klin.  Wochenschr., 

1885,  p.  189. 

1204.  MELCHER  UND  ORTMANN.    Uebertragung  von  Lepra  auf  Kaninchen.    Berliner 

klin.  Wochenschr.,  1885,  p.  193. 

1205. •  Experimentelle  Darm-  und  Lymphdrilsen-Lepra  bei  Kaninchen.     Ber- 
liner klin.  Wochenschr.,  1886,  No.  9. 

1206.  CAMPANA.    Ancora  della  trapiantazione  della  lepra  negli  animal!  bruti.     Boll. 

della  Accad.  med.  de  Genova,  1886,  No.  7. 

1207.  Nochmals  die  Uebertragung  der  Lepra  auf  Thiere.     Vierteljahresschr. 

filr  Dermatol.  und  Syph.,  1887,  p.  435. 

1208.  Tentativi  ripetuti  ma  senza  risultato  positivo  nella  cultura  del  bacillo 

leproso.    Riforma  med.,  1889,  Nos.  243  and  244. 

1209.  Un  bacillo  simile  al  bacillo  leproso  aviluppatosi  in  tentativi  di  cultura 

di  tessuti  con  lepra  tubercolare.    La  Riforma  med.,  1891,  p.  159. 

1210.  BAUMGARTEN.    Ueber  die  Farbungsunterscheide  zwischen  Lepra-  und  Tuber- 

kelbacillen.    Centralbl.  fur  Bakteriol.,  Bd.  i.,  1887,  p.  573. 

1211.  Tuberkel-  und  Leprabacillen.    Jbid.,  Bd.  ii.,  1887,  p.  291. 

1212.  -    —  Replik.  (to  Bordoni-Uffreduzzi ;  see  No.  1214).     Berliner  kliu.  AVochen- 

schr.,  1889,  p.  217. 

1213.  BORDONI-UPFREDCZZI.     Ueber  die  Cultur    der  Leprabacillen.     Zeischr.   filr 

Hygiene,  Bd.  iii.,  1887,  p.  178. 

1214. Zur   Frage  der    Leprabacillen.     Berliner  klin.    Wochenschr.,    1888, 

p.  216. 

1215.  LELOIR.     Essais  d'inoculation  de  la  lepre  aux  auimaux.     Ann.  de  Dermatol. 

etdeSyph.,  1887,  p.  625. 

1216.  WESENER.    Zur  Farbung  der  Lepra-  und  Tukerkelbacillen.     Centralbl.   flir 

Bakteriol.,  Bd.  ii.,  1887,  p.  131.    Ibid.,  p.  450. 

1217. Uebertragungsversuche  von  Lepra  auf  Kaninchen.     Mi'mchener  med. 

Wochenschr.,  1887,  No.  18. 

1218.  CORNIL.     La  contagion  de  la  lepre.     Bull,  de  1'Acad.  de  Med.,  seance  du  19 

juin,  1888. 

1219.  LUBIMOFF.     Zur  Technik  der    Farbung  von  Tuberkel-  und  Leprabacillen. 

Centralbl.  fiir  Bakteriol.,  Bd.  ii.,  1888,  p.  540. 

1220.  BEAVEN  RAKE.    Trans.  Path.  Soc.  Lond.,  vol.  xxxviii.,  1887,  p.  439. 

1221.  British  Med.  Journal,  1888,  p.  215. 

1222.  Vossius.     Ueber  die  Uebertragbarkeit  der  Lepra  auf  Kaninchen.     Zeitschr. 

fiir  vergl.  Augenheilkunde,  Bd.  iv. 

1223.  DAUBLER.     Ueber  Lepra  und  deren  Contagiositiit.    Monatsschr.  filr  prakt. 

Dermatol.,  Bd.  viii.,  1889,  p.  123. 

1224.  NEISSER.     Ueber  die  Struktur  der  Lepra-  und  Tuberkelbacillen,  etc.     Archiv 

fiir  Dermatol.  und  Syph.,  1889,  p.  29.     Ibid.,  p.  42. 

1225.  STALLARD.    The  bacillus  of  leprosy.     Brit.  Med.  Journ.,  1889  (Dec.  21st). 

1226.  BABES  ET  KALINDERO.    Sur  la  reaction  produite  par  le  remede  de  Koch  chez 

les  lopreux.     La  Semaine  med.,  1891,  No.  3. 


820  BIBLIOGRAPHY. 

BACILLUS   MALLEI. 

1227.  LOFFLER  UND  ScHUTZ.     Ueber  den  Rotzpilz.     Deutsche  med.  Wockenschr. , 

1882,  No.  52. 

1228.  LOFFLER.     Die  ^tiologie  der  Rotzkrankheit.     Arbeiten  aus  dem  K.  Gesund- 

heitsamte,  Bd.  i.,  1886,  p.  141. 

1229.  ISRAEL.    Berliner  klin.  Wochenschr. ,  1883,  No.  11. 

1230.  BOUCHARD,  CAPITAN  ET  CHARRIN.    Bull,  de  1'Acad.  d.  Sc.,  1882,  No.  51. 

1231.  WEICHSELBAUM.     Zur  jEtiologie  der  Rotzkrankheit  des  Menschen.     "Wiener 

med.  Wochenschr.,  1885,  p.  21. 

1232.  KITT.     Versuche  ilber  die  Zuchtung  des  Rotzpilzes.     Jahresber.  der  Miinchen. 

Thierarzneisch.,  1883-84. 

1233.  Impfrotz  bei  Waldmausen.     Centralbl.  fiir  Bakteriol.,  Bd.  ii.,  1887, 

p.  241. 

1234.  CADEAC  ET  MALET.     Transmission  de  la  morve  de  mire  au  foetus.     Progres 

med.,  1886,  No.  4. 

1235.  La  resistance  du  virus  morveux  ft  1'action  destructive  des  agents  at- 

mospheriques  et  de  la  chaleur.     Ibid.,  1886,  No.  34. 

1236.  •  La  transmission  de  la  morve  sur  le  pore  et  de  mere  du  foetus.     Rec.  de 

med.  veterin.,  1886,  No.  5. 

1237.  Etude  experimental  de  la  transmission  de  la  morve  par  contagion 

mediate  ou  par  infection.     Revue  de  Med.,  1887,  No.  5. 

1238.  Ueber  Impfrotz  bei  Wiihlratten.     Oesterr.  Monatsschr.  fur  Thierheilk., 

1888,  No.  1. 

1239.  KRANZFELD.     Zur  Kenntniss  dea  Rotzbacillus.     Centralbl.  fur  Bakteriol.,  Bd. 

ii.,  1887,  p.  273. 

1240.  BABES.     Eindringen  der  Rotzbacillen  durch  die  unverletzte  aussere  Haut. 

Acad.  de  Med.,  Paris,  1888. 

1241.  BAUMGARTEN.     Zur  Frage  der   Sporenbildung  bei  den   Rotzbacillen.     Cen- 

tralbl. ftlr  Bakteriol.,  Bd.  iii.,  1888,  p.  397. 

1242.  KUHNE.     Ueber  Furbung  der  Bacillen  in  Malleusknoten.     Fortschr.  der  Med. , 

Bd.  vi.,  1888,  p.  860. 

1243.  STRAUS.     Sur  la  vaccination  contre  la  morve.     Compt.  rend.  Acad.  des.  Sc.,  t. 

cviii.,  p.  530. 

1244.  FINGER.     Zur  Frage  der  Immunitat  und  Phagocytose  beim  Rotz.     Ziegler's 

Beitrage  zur  pathol.  Anat.,  Bd.  vi.,  1889,  Heft  4. 

1245.  SALMON.     Glanders.     Reports  of  the  Bureau  of  Animal  Industry  for  the  years 

1887  and  1888  (Washington). 

1246.  SMITH.     On  the  influence  of  slight  modifications  of  culture  media  on  the  growth 

of  bacteria  as  illustrated  by  the  glanders  bacillus.     Journ.  of  Comp..  Med. 
and  Vet.  Archives,  March,  1890. 

1247.  CORNIL.     Sur  la  penetration  des  bacilles  de  la  morve  a  travers  la  peau  intact. 

La  Semaine  med..  1890,  No.  22. 

1248.  PREUSSE.     Versuche  mit  Rotzlymphe — Mallei'n.    Berliner  thierarztliche  Woch- 

enschr., 1891,  No.  29. 

1249.  EBER.     Ueber  Rotzlymphe— Malleiin.     Centralbl.  fiir  Bakteriol. ,  Bd.  xi.,  1892, 

p.  20. 

BACILLUS  OF   LUSTGARTEN. 

1250.  LUSTGARTEN.    Wiener  med.  Wochenschr.,  1884,  No.  47. 

1251.  Die  Syphilisbacillen.    Wien,  1885. 

1252.  DE  GIACOMI.     Neue  Farbungsmethode  der  Syphilisbacilleu.     Correspondenzbl. 

fiir  Schweitzer  Aerzte,  Bd.  xv. 


BIBLIOGRAPHY.  821 

1253.  ALVAREZ  ET  TAVEL.     Bull,  de  1'Acad.  de  Med.,  1885  (August). 

1254.  DOUTRELPONT  UND  ScHUTZ.     Deutsche  med.  Wochenschr.,  1885,  No  19. 

1255.  KLEMPERER.    Ueber  Syphilis- und  Smegmabacillen.     Deutsche  med.  Wochen 

schr.,  1885,  p.  809. 

1256.  BITTER.     Ueber  Syphilis-  und  Smegmabacillen.     Virchow's  Archiv,  Bd.  cvi., 

1886,  p.  209. 

1257.  DOUTRELPONT.     Ueber  die  Bacillen  bei  Syphilis.     Vierteljahresschr.  f l\r  Der- 

matol.  und  Syph.,  Bd.  xiv.,  1887,  p.  101. 

1258.  MATTERSTOCK.     Ueber  Bacillen  bei  Syphilis.    Mitt,  aus  der  med.  Klin,  der 

Univ.  Wilrzburg,  1886. 

1259.  VON  ZEISSEL.     Untersuchungen  ilber  den  Lustgarten'schen  Bacillus  in  Syphi- 

lisprodukten  und  Sekreten  derselben.     Wiener  med.  Presse,  1885,  No.  48. 

1260.  Die  Wesenheit  des  Syphiliscontagium.     Allg.  Wiener  med.  Zeitung, 

1887,  Nos.  32-34. 

1261.  BENDER.     Die  Bacillen  bei  Syphilis.     Centralbl.  fur  Bakteriol.,  Bd.  ii.,  1887, 

Nos.  11  and  12. 

1262.  TAVEL.     Zur    Geschichte  der    Smegmabacillen.     Centralbl.    fur  Bakteriol., 

Bd.  ii.,  1887,  p.  673. 

1263.  MARCUS.     Nouvelles  recherches  sur  le  microbe  de  la  syphilis.     These  de  Paris, 

1888. 

1264.  MARKUSE.     Ueber  den  jetzigen  Stand  der  Syphilis  und  Smegmabacillenfrage. 

Vierteljahresschr.  filr  Dermatol.  und  Syphilis,  1888,  p.  343. 

1265.  LEWY.    Ueber  Syphilis-  und  Smegmabacillen.     Inaug.  Diss.,  Bonn,  1889. 

BACILLUS   OF   EVE   AND    LINGARD. 

1266.  EVE  AND  LINGARD.     On  a  bacillus  cultivated  from  the  blood  and  tissues  in 

syphilis.    The  Lancet,  London,  1886  (April  10th). 

MICROCOCCI  OF  DI8SE  AND  TAGUCHI. 

1267.  DISSE  UND  TAGUCHI.     Deutsche  med.  Wochenschr.,  1886,  p.  235. 

BACILLUS  OF   RHINOSCLEROMA   (?). 

1268.  CORNIL  ET  ALVAREZ.    Sur    les   microOrganismes    du  rhinosclerome.    Bull. 

Acad.  de  Med.,  Paris,  1885. 

1269.  PALTAUF  UND  VON  EISELBERG.    Zur   ^Etiologie  des  Rhinoskleroms.     Fort- 

schr.  der  Med.,  1886,  Nos.  19  and  20. 

1270.  WOLKOWITSCH.     Zur    Histologie  und  parasitilren  Natur  des  Rhinoskleroms. 

Centralbl.  filr  die  Wissensch.,  1886,  No.  47. 

1271.  — : Das  Rhinosklerom.     Langenbeck's  Archiv,  Bd.  xxxviii.,  Heft  2  and 

3. 

1272.  DITTRICH.     Ueber  das  Rhinosklerom.     Zeitschrift  f  ilr  Heilkunde,  Bd.   viii., 

1887,  p.  251 . 

1273.  Entgegnung    auf    die    kritischen    Bemerkungen  des    Herrn   Babes. 

Centralbl.  filr  Bakteriol.,  Bd.  iii.,  1888,  p.  146. 

1274.  Zur  ^Etiologie    des  Rhinoskleroms.      Centralbl.   filr  Bakteriol.,   Bd. 

v.,  1889,  No.  5. 

1275.  BABES.     Antwort  auf  Herrn  Dittrich's  Entgegnung,     dessen    Artikel  ilber 

Rhinosklerom.     Centralbl.  filr  Bakteriol. ,  Bd.  ii.,  1887,  p.  617. 

1276.  MELLK.    Les  bacilles  du  rhiuosclerome.    Abstract  in  Baumgarten's  Jahresbe- 

richt,  Bd.  iv.,  1888,  p.  228. 

1277.  Neue  Fiirbemethode  filr  Rhinosklerombacillen.     Ibid. 


822  BIBLIOGRAPHY. 

1278.  STEPANOW.    Ueber  die  Impfungen  des  Rhinoskleroms.     Centralbl.  fur  Bak- 

teriol., Bd.  v.,  1889,  p.  549  (abstract). 

1279.  ZAGARI.     Richerche  etiologiche  sull'  rinoscleroma.     Giorn.  intern,  delle  Sci. 

mediche,  1889,  No.  4. 

1280.  PAWLOWSKI.     Ueber  die  JEtiologie  und  Pathologic  des  Rhinoskleroms,  etc. 

Centralbl.  filr  Bakteriol.,  Bd.  ix.,  1891,  p.  742. 

BACILLUS  OP  KOUBASOFF. 

1281.  KOUBASOFF.     Die  Mikroorganismen  der  krebsartigen  Neubildungen.     Abstract 

in  Centralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  p.  317. 

BACILLUS  OF  NOCARD. 

1282.  NOCARD.     Maladie  des  boaufs  de  la  Guadeloupe.     Ann.  de  1'Institut  Pasteur, 

vol.  ii.,  1888,  p.  293. 


XII.  BACILLI  WHICH  PRODUCE  SEPTICAEMIA  IN  SUSCEPTIBLE 

ANIMALS. 

BACILLUS   SEPTICAEMIA   H/EMORRHAGIC^E. 
BACILLUS   OF   CHOLERA   IN   DUCKS. 

BACILLUS   OF   HOG   CHOLERA. 

BACILLUS    OF    BELFANTI   AND   PASCAROLA. 

BACILLUS   OF   SWINE   PLAGUE   (MARSEILLES). 

BACILLUS  SEPTICUS  AGRIGENUS. 

1283.  DAVAINE.     Recherches,  etc.,  de  la  septicemie.     Bull,  de  fl'Acad.  de  Med.,  t. 

viii.,  1879,  p.  121. 

1284.  PASTEUR.     Sur  les  maladies  virulentes,  et  en  particulier  sur  la  maladie  appelee 

vulgairement  cholera  des  poules.     Compt.  rend.  Acad.  des  Sc.,  xc.,  1880, 
p.  239. 

1285.  De  1'attenuation  du  virus  du  cholera  des  poules.     Ibid.,  xci.,  p.  673. 

1286.  PERRONCITO.     Ueber  das  episootische  Typhoid  der  Hiihner.     Arcbiv  fur  wiss. 

und  prakt.  Thierheilk.,  1879. 

1287.  KITT.     Mittheilungen  ilber  die  Typhoidseuche  des  Geflilgels.     Allg.  deutsche 

Gefliigelzeitung,  1885  (Feb.  15th). 

1288.  — ^—  Beitrage  zur  l£enntniss  der  Geflilgelcholera  und  deren  Schutzimpfung. 

Deutsche  Zeitschr.  filr  Thiermedicin  und  vergl.  Pathol.,  Bd.  xiii.,  1886. 

1289.  KOCH.     ^Etiologie  der  Wundinfektionskrankheiten.     Leipzig,  1878,  p.  59. 

1290.  GAFFKY.     Experimentelle  erzeugte  Septikamie.     Mitth.  aus  dem  K.  Gesund- 

heitsamte,  Bd.  i.,  1881. 

1291.  Die    Geflugelcholera.     Zusammenfassender    Bericht.     Centralbl.    filr 

Bakteriol.,  Bd.  i.,  1887,  p.  305. 

1292.  KLEIN.     Report  on  infectious  pneumo-euteritis  of  the  pig.     Rep.  Med.  Off- 

Local  Govt.  Board,  London,  1878,  pp.  169-280,  26  pi. 

1293.  Bemerkungen  ilber  die  ./Etiologie  der  Schweineseuche.     Fortschr.  der 

Med.,  Bd.  vi.,  1888,  p.  929. 

1294.  BUCH.     Zur  Kenntniss  der  Schweineseuche.     Archiv   filr  wiss.    und  prakt. 

Thierheilk.,  Bd.  xiii.,  1887,  p.  332. 

1295.  CORNIL  ET  CHANTEMESSE.     Etiologie  de  la  pneumouie  contagieuse  des  pores- 

Le  Bulletin  medical,  1887,  p.  1363. 


BIBLIOGRAPHY.  823 

1296.  ORESTE  AND  ARMANNI.     Studii  e  richerche  intorno  al  barbone  dei  buffali. 

Atti  del  R.  Institute  d'Incoraggiamento  alle  Sci.  nat.,  econom.,  et  technol., 
1887. 

1297.  CORNIL  ET  TOUPET.     Sur  une  maladie  nouvelle  des  canards.     Bull,  de  la  Soc. 

nat.  d' Acclimation,  1888  (June  20th). 

1298.  HUEPPE.     Ueber  die  Wildseuche  und  ihre  Bedeutung  fiir  Nationalokonomie 

und  Hygiene.    Berliner  klin.  "Wochenschr. ,  1886,  p.  753. 

1299.  GAMELEIA.     Zur  ^Etiologie  der  Hilhnercholera.     Centralbl.   fiir  Bakteriol., 

Bd.  iv.,  1888,  p.  161. 

1300.  GRAFFUNDER.     Zur  Kenntniss  der  Schweineseuche.     Deutsche  Zeitschrift  fiir 

Thiermed.,  1888,  p.  391. 

1301.  SALMON  AND  SMITH.     The  bacterium  of  swine  plague.     Am.  Monthly  Mic. 

Journ.,  1886,  p.  204. 

1302.  SALMON.    On  swine  plague.     Second  An.  Rep.  of  the  Bureau  of  Animal  In- 

dustry, Washington,  1886  (for  the  year  1885).    Ibid..  1887,  p.  603. 

1303.  Further  investigations  on  the  nature  and  prevention  of  hog  cholera. 

Rep.  of  the  Com.  of  Agriculture  for  1887,  p.  481  (Washington,  1888). 

1304. : —  Hog  cholera  :  its  history,   nature,  and  treatment,   etc.     Washington, 

1889. 

1305.  Hog  cholera  in  other  countries.     Rep.  of  Bureau  of  Animal  Industry, 

1888,  p.  159. 

1306.  Investigations  of  fowl  cholera.     Rep.  Com.  of  Agriculture  for  1881  and 

1882. 

1307.  SMITH.     Contribution  to  the    study  of  the  microbe  of  rabbit   septictemia. 

Journ.  of  Comp.  Med.  and  Surg.,  vol.  viii.,  1887,  p.  24. 

1308.  Zur  Kenntniss  des  Hogcholerabacillus.     Centralbl.  fiir  Bakteriol.,  Bd. 

ix.,  1891,  pp.  253,  307,  339. 

1309.  Zur  Kenctniss    der  americanischen   Schweineseuche.     Zeitschrift  fiir 

Hygiene,  Bd.  x.,  1891,  p.  480. 

1310.  •  Special  report  on  the  cause  and  prevention  of  swine  plague.     U.  S. 

Dept.  of  Agriculture,  Bureau  of  Animal  Industry,  Washington,  1891. 

1311.  SCHUTZ.     Ueber  die  Schweineseuche.     Arbeiten  aus  dem  K.  Gesundheitsamte, 

1886,  Bd.  i.,  p.  376. 

1312. Die  Schweinepest  in  Danemark.     Archiv   fiir  wissensch.  und  prakt. 

Thierheilk.,  1888,  p.  376. 

1313.  EBERTH  UND  SCHIMMELBUSCH.    Der  Bacillus  der  Frettenseuche.     Virchow's 

Archiv,  Bd.  cxv.,  1889,  p.  282.     Ibid.,  cxvi.,  1889,  p.  327. 

1314.  FROHLING.     Ueber  amerikanische  Schweineseuche,  hog  cholera,  swine  plague. 

Schweiz.  Arch,  fiir  Thierheilk.,  xxx.,  p.  116. 

1315.  BILLINGS.     Dr.  Salmon's  latest :    Hog  cholera  and  swine  plague  two  distinct 

diseases.     The  Nebraska  Farmer,  1887,  p.  365. 

1316.  Swine  plague,  with  especial  reference  to  the  porcine  pests  of  the  world. 

Lincoln,  Neb.,  1888. 

1317.  The  Southern  cattle  plague  (Texas  fever)  of  the  United  States.     Lin- 
coln, Neb.,  1888. 

1318.  Dr.  E.  Salmon's  swine  plague  and  hog  cholera  critically  considered. 

Lincoln,  Neb.,  1889. 

1319. Are  the  German  "Schweineseuche"  and  the  "swine  plague  "of  the 

Government  of  the  United  States  identical  diseases  ?  American  Naturalist, 
1895  (March  12th). 

1320.  Evidence  showing  that  the  report  of  the  "  board  of  inquiry  concerning 

swine  diseases"  was  fixed.  Lincoln,  Neb.,  1890. 


824  BIBLIOGRAPHY. 

1321.  RIETSCH  ET  JOBERT.     L'epidemie  des  pores  &  Marseille  en     1887.     Compt. 

rend.  Acad.  des  Sc.,  t.  cvi.,  1888  (No.  15). 

1322.  SELANDER.     Ueber  die  Bakterien  der  Schweinepest.    Centralbl.  fur  Bakteriol., 

Bd.  iii.,  1888,  No.  12. 

1323.  BLEISCH  UND  FIEDELER.    Beitrag  zur  Kenntniss  der  Schweineseuche.     Zeit- 

schrift  filr  Hygiene,  Bd.  vi.,  1889,  p.  401. 

1324.  REPORT  OP  THE  U.    S.    BOARD   OF   INQUIRY  concerning  epizootic  diseases 

among  swine.     U.  S.  Department  of  Agriculture,  1889. 

1325.  RIECK.     Eine  infektiose  Erkrankung  der  Kanarienv5gel.    Deutsche  Zeitschrift 

filr  Thiermed.,  Bd.  xv.,  1889,  p.  68. 

1326.  SEMMER  UND  NONIEWICZ.    Die  Schweineseuche.     Oesterr.   Monatsschr.   filr 

Thierheilk.,  1889,  No.  4. 

1327.  WERTHEIM.     Bakteriologische  Untersuchungen  ilber  die  Cholera  gallinarum. 

Archiv  f&r  exp.  Pathol.  und  Pharm.,  Bd.  xxvi.,  1889,  p.  61. 

1328.  RACCUGLIA.     Ueber  die  Bakterien  der    amerikanischen  Swine-Plague  (Hog 

Cholera)  und  der  deutschen  Schweineseuche.  Centralbl.  f  ilr  Bakteriol. ,  Bd. 
viii.,  1890,  p.  289. 

1329.  BUNZL-FEDERN.     Bemerkungen  liber  Wild-  und  Schweineseuche.     Centralbl. 

fur  Bakteriol.,  Bd.  ix.,  1891,  p.  787. 

1330.  Untersuchungen  iiber  einige  seuchenartige  Erkrankungen  der  Schweine. 

Archiv  fiir  Hygiene,  1891. 

1331.  SCHWEINITZ.     A  preliminary  study  of  the  ptomaines  from  the  culture  liquids 

of  the  hog-cholera  germ.     Phila.  Med.  News,  1890,  p.  237. 

1332.  NOVY.     The  toxic  products  of  the  bacillus  of  hog  cholera.     Phila.  Med.  News, 

1890,  p.  231. 

1333.  CANEVA.     Ueber  die  Bakterien  der  hamorrhagischen  Septikamie  (Hueppe), 

Hog-Cholera  (Salmon),  Swineplague  (Billings),  Swinepest  (Selander),  Rin- 
derseuche  (Billings),  Biiffelseuche(Oreste-Armanni),  Marseille'sche  Schweine- 
seuche (Jobert,  Rietsch),  Frettenseuche  (Eberth).  Centralbl.  fiir  Bakteriol., 
Bd.  ix.,  1891,  p.  557. 

1334.  FROSCH.     Ein  Beitrag  zur  Kenntniss  der  Ursache  der  amerikanischen  Schweine- 

seuche, etc.     Zeitschrift  fiir  Hygiene,  Bd.  ix.,  1890,  p.  235.     Ibid.,  Bd.  x., 

1891,  p.  509. 

1335.  WELCH.    Johns  Hopkins  Hospital  Bulletin,  December,  1889. 


BACILLUS   ERYSIPELATOS   SUIS. 

1336.  KOCH.     Wundinfektionskrankheiten.     Leipzig,  1878. 

1337.  PASTEUR.     Le  rouget  du  pore;  avec  le  collaboration  du  MM.  Chamberlain, 

Roux  et  Thuillier.    Compt.  rend.  Acad.  des  Sc.,  xcv.,  1882,  p.  1120. 

1338.  PASTEUR  ET  THUILLIER.    Bull,  de  1'Acad.  de  Med.,  Paris,  xcvii.,  1883. 

1339.  LOFFLER.     Experimentelle  Untersuchungen  iiber  Schweinerothlauf .    Arbeiten 

aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1885. 

1340.  SCHUTZ.    Ueber  den  Rothlauf  der  Schweine  und  die  Impfung  desselben.     Ar- 

beiten aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1885,  p.  56. 

1341.  Archiv  fiir  wissensch.  und  prakt.  Thierheilk.,  Bd.  xii.,  1886,  Heft  1. 

1342.  LYDTIX  UND  SCHOTTELIUS.     Der  Rothlauf  der  Schweine.     Wiesbaden,  1885. 

1343.  LYDTIN.     Schutzimpfungen  gegen  den  Rothlauf  [der  Schweine.     Bad.  thier- 

arztl.  Mitth.,  1886,  p.  9. 

1344.  HESS  UND  GUILLEBEAU.    Zur  Schutzimpfung  gegen  Schweineseuche.   Schwei- 

zer  Archiv  fiir  Thierheilk.,  Bd.  xxviii.,  1886,  Heft  8. 


BIBLIOGRAPHY.  825 

1345.  KITT.    Beitrage  zur    Kenntniss  des  Stabschenrothlauf  der    Schweine   und 

dessen  Schutzimpfung.     Revue  fur  Heilk.  und  Thierzucht,  1886. 

1346.  Untersuchungen    ilber    dea    Stabschenrothlauf    und    dessen    Schutz- 
impfung.    Centralbl.  fur  Bakteriol.,  Bd.  ii.,  1887,  p.  693. 

1347.  PAMPOUKIS.    Les  bacilles  du  rouget.    Archiv  de  Physiol.  norm,  et  pathol., 

1886,  p.  89. 

1348.  HAFNER.     Die  Schutzimpfung  gegen  den    Rothlauf    der    Schweine.     Bad. 

thierarztl.  Mitth  ,  1889,  p.  17. 

1349.  HESS.     Der  Stabschenrothlauf  und  die  Schweineseuche.    Thiermed.  Vortrilge, 

herausgegeben  voii  Schneidemuhl,  Bd.  i.,  Heft  1. 

1350.  JAKOBI.     Beitrag  zur  Schutzimpfung  gegen  den  Rothlauf  der  Schweine.    Ber- 

liner thierarztl.  Wochenschr.,  1888,  No.  50. 

1351.  PETRI.     Ueber  die  Widerstandsfahigkeit  der  Bakterien  des  Schweinerothlaufs 

in  Reinkulturen  und  in  Fleisch  rothlaufkranker  Schweine  gegen  Kochen, 
Schmoren,  Braten,  Salzen,  Einpftkeln  und  Rauchern.  Arbeiten  aus  dem  K. 
Gesundheitsamte,  Bd.  vi.,  1890,  Heft  2. 

BACILLUS  COPROGENES  PARVUS. 

1352.  BIENSTOCK.    Zeitschr.  furklin.  Med.,  Bd.  viii.,  Heft  1. 

BACILLUS  CAVICIDA. 

1353.  BRIEGER.     Berliner  klin.  Wochenschr.,  1884,  No.  14. 

1354.  ESCHERICH.     Die  Darmbakterien  des  Sauglings.     Stuttgart,  1886,  p.  74. 

BACILLUS  CAVICIDA  HAVANIENSIS. 

1355.  STERNBERG.     Report  on  the  etiology  and  prevention  of  yellow  fever.     Wash- 

ington, 1891,  p.  202. 

BACILLUS   CRASSUS   8PUTIGENUS. 

1356.  FLUGGE.     Die  Mikroorganismen.     2d  ed.,  1886,  p.  260. 

BACILLUS  PYOGENES  FCETIDUS. 

1357.  PASSET.     Untersuchungen  ilber  die  eitrigen  Phlegmone  des  Menschen.     Ber- 

lin, 1885. 

PROTEUS  HOMINIS  CAPSULATUS. 
PROTEUS  CAPSULATUS  8EPTICUS. 

1358.  BORDONI-UFFREDUZZI.    Ueber  den    Proteus  hominis  capsulatus,  etc.     Zeit- 

schr. for  Hygiene,  Bd.  iii.,  1888,  p.  333. 

1359.  BANTI.     Sopra  quatro  nuove  specie  di  protei  o  bacilli  capsulati.     Dal.  Giornale 

medico  :  Lo  Sperimentali,  1888  (August). 

BACILLUS  ENTERITIDIS. 

1360.  GARTNER.     Correspondenzbl.  des  allg.  arztl.  Vereins  von  Thuringen,  1888. 

1361.  KAKLINSKY.     Zur  Kenntniss  des  Bacillus  enteritidis,   Gartner.     Centralbl.  f  iir 

Bakteriol.,  Bd.  vi.,  1889,  No.  14. 

BACILLUS  OF   GROUSE   DISEASE. 

1362.  KLEIN.     Ueber  eine  akute  infektiose  Krankheit  des  schottischen  Moorhuhnes 

(Lagopus  Scoticus).  Centralbl.  fur  Bakteriol.,  Bd.  vi.,  1889,  p.  36.  Ibid., 
p.  259. 


826  BIBLIOGRAPHY. 

BACILLUS  GALLINARtTM. 

1363.  KLEIX.     Ueber  eine  epidemische  Krankheit  der  Hiihner,  verursacbt  durch 

einen  Bacillus.     Centralbl.  fur  Bakteriol.,  Bd.  v.,  1889,  p.  689.     Ibid.,  Bd. 
vi.,  p.  259. 

BACILLUS   SMARAGDINUS   FCETIDUS. 

1364.  REIMANN.     Inaug.  Diss.,  Wilrzburg,  1887. 

BACILLUS  PNEUMOSEPTICUS. 

1365.  BABES.     Progres  medical  roumain,  1889  (April  6th). 

BACILLUS    CAPSULATUS. 

1366.  PFEIFFER.     Ueber  einen  neuen  Kapselbacillus.     Zeitschr.  fiir  Hygiene,  Bd. 

vi.,  1889,  p.  145. 

BACILLUS    HYDROPHILUS    PUSCUS. 

1367.  SANARELLI.     Ueber  einen  neuen  Mikroorganismus  des  Wasser,  welcher  flir 

Thiere  mit  veranderlicher  und  konstanter  Temperatur  pathogen  ist.     Cen- 
tralbl. fur  Bakteriol.,  Bd.  ix.,  pp.  193,  222. 

BACILLUS   TENUIS   SPUTIGENUS. 

1368.  PANSINI.     Bakteriologische  Studien    liber  den  Auswurf.     Virchow's  Archiv, 

Bd.  cxxii.,  1890. 

BACILLUS   OF   LASER. 

1369.  LASER.   Ein  neuer,  f ilr  Versuchsthiere  pathogener  Bacillus,  aus  der  Gruppe  der 

Fretten-Schweineseuche.     Centralbl.  fur  Eakteriol.,  Bd.  xi.,  1892,  p.  184. 

BACILLUS   TYPHI  MURIUM. 

1370.  LOFFLER.     Ueber  Epidemieen  unter  den  in  hygienischen  Institute  zu  Greifs- 

wald  gehaltenen  Miiusen,  und  liber  die  Bekilmpfung  der  Feldmausplage. 
Centralbl.  fttr  Bakteriol.,  Bd.  xi.,  1892,  p.  13). 

BACILLUS  OF   CAZAL   AND  VAILLARD. 

1371.  CAZAL  ET  VAILLARD.     Sur  une  maladie  parasitaire  de  I'homme  transmissible 

au  lapin.     Ann.  de  1'Institut  Pasteur,  vol.  v.,  1891,  p.  353. 

BACILLUS  OP  BABES  AND  OPRESCU. 

1372.  BABES  ET  OPRESCU.     Sur  un  bacille  trouve  dans  un  cas  de  septicemie  hemor- 

rhagique  presentant  certains  caracteres  du  typhus  exanthematique.     Ann. 
de  Tlnstitut  Pasteur,  vol.  v.,  1891,  p.  274. 

BACILLUS  OF   LUCET. 

1373.  LUCET.    Dysenteric  epizootique  des  poules  et  des  dindes.    Ann.  de  1'Institut 

Pasteur,  vol.  v.,  1891,  p.  312. 

CAPSULE  BACILLUS  OF  LOEB. 

1374.  LOEB.     Ueber  einen  bei  Keratomalacia  infantum  beobachteten  Kapselbacillus. 

Centralbl.  fur  Bakteriol.,  Bd.  x.,  1891,  p.  369. 


BIBLIOGRAPHY.  827 

XIII.  PATHOGENIC  AEROBIC  BACILLI  NOT  DESCRIBED  IN 
PREVIOUS  SECTIONS. 

BACILLUS   COLI   COMMUNIS. 

1375.  EMMERICH.     Die  Cholera  in    Neapel.     Deutsche    med.    Wochenschr.,  1884, 

No.  50. 

1376.  WEISSER.     Ueber  die  Emmerich'schen  sogenannten  Neapler  Cholerabakterien. 

Zeitschr.  fur  Hygiene,  Bd.  i.,  1886,  p.  315. 

1377.  ESCHERICH.     Die  Darmbakterien  des  Sauglings.     Stuttgart,  1886. 

1378.  BAGINSKY.  Ueber  GahrungsvorgangeimkindlichenDarmkanal,  etc.     Deutsche 

med.  Wochenschr.,  1888. 

1379.  BOOKER.     A  study  of  some  of  the  bacteria  found  in  the  dejecta  of  infants  af- 

flicted with  summer  diarrhoea.     Trans,  of  the  Ninth  Internat.  Med.  Con- 
gress, vol.  iii. 

1380.  Second  communication.     Trans,   of  the  Am.  Pediatric  Society,  1889, 

p.  198. 

1381.  STERNBERG.     Recent  researches  relating    to  the  etiology  of    yellow  fever. 

Trans.  Assn.  Am.  Physicians,  vol.  iii.,  1888,  p.  321. 

1382.  FRANKEL,  A.     Ueber  peritoneal  Infektion.     Wiener  klin.  Wochenschr.,  1891, 

Nos.  13-15. 

BACILLUS  LACTIS  AEROGENES. 

ESCHERICH.     Op.  cit.  (No.  1377). 
BAGINSKY.     Op.  cit.  (No.  1378). 
BOOKER.    Op.  cit.  (No.  1379). 

1383.  JEFFRIES.     A  contribution  to  the  study  of  the  summer  diarrhoeas  of  infancy. 

Trans.  Am.  Pediatric  Society,  vol.  i.,  1889,  p.  249. 

BACILLUS   ACIDIFORMANS. 

1384.  STERNBERG.     Report  on  the  etiology  and  prevention  of  yellow  fever.     Wash- 

ington, 1891,  p.  200. 

BACILLUS   CUNICULICIDA   HAVANIENSIS. 

STERNBERG.     Op.  cit.  (No.  1384),  p.  187. 

BACILLUS   LEPORIS   LETHALIS. 

STERNBERG.     Op.  cit.  (No.  1384),  p.  167. 

BACILLUS  PYOCYANUS. 

1385.  GESSARD.     De  l-a,  pyocyanine  et  de  son  microbe.     These  de  Paris,  1882. 

1386.  Nouvelles  recherches  sur  le  microbe  pyocyanique.     Ann.  de  1'Institut 

Pasteur,  vol.  iv.,  1890,  p.  89. 

1387.  FRICK.     Bakteriologische  Mittheilungen  liber  das  grilne  Sputum  und  ilber  die 

grilnen  Farbstoff  producirenden  Bacillen.     Virchow's  Archiv,  Bd.  cxvi., 
1889. 

1388.  WASSEUZUG.     Sur  la  formation  de  la  matiere  colorante  chez  le  Bacillus  pyocy- 

anus.     Ann.  de  1'Institut  Pasteur,  vol.  i.,  1887,  p  581. 

1389.  ERNST.     Ueber  einen  neuen  Bacillus  des  blauen  Eiters  (Bacillus  pyocyanus  ft). 

Zeitschrift  fur  Hygiene,  Bd.  ii.,  1887,  p.  369. 

1390.  LEDDERHOSE.     Ueber  den  blauen  Eiter.   Tagebl.  der  60.  Versamml.  Deutscher 

Naturf.  und  Aerzte  in  Wiesbaden,  1887,  p.  295. 


828  BIBLIOGRAPHY. 

1391.  LEDDERHOSE.    Deutsche  Zeitschrift  fur  Chirurg.,  1888. 

1392.  CHAUUIN.     La  maladie  pyocyanique.     Paris,  1889. 

1393.  BOUCHARD.    Influence  qu'exerce  sur  la  maladie  charbonneuse  1'inoculation  du 

bacille  pyocyanique.    Compt.  rend.  Acad.  des  Sc.,  t.  cviii.,  1889,  p.  713. 

1394.  BABES.    Note  sur  quelques  matieres  colorantes  et  aromatiques  produites  par  le 

bacille  pyocyanique.     Compt.   rend.  Soc.  de  Biol. ,  Paris,  1889,  p.  438. 

1395.  WOODHEAD  ET  WOOD.     De  1'action  antidotique  exercee  par  les  liquides  pyo- 

cyaniques  sur  le  cours  de  la  maladie  charbonneuse.     Compt.  rend.  Acad.  des 
Sc.,t.  cix.,  1889,  No.  26. 

1396.  ROGER.    Des  modifications  qu'on  peut  provoquer  dans  les  fonctions  d'un 

microbe  chromogene.     Compt.  rend.  Soc.  de  Biol.,  1887. 

PROTEUS   VULGARIS. 

1397.  HAUSER.     Ueber  Faulnissbakterien.     Leipzig,  1885,  94  pp.,  15  pi. 

1398.  CHEYNE.     Report  on  a  study  of  certain  of  the  conditions  of  infection.     British 

Med.  Journ.,  1886  (July  31st;. 

1399.  FOA  ET  BONOME.     Sur  les  maladies  causees  par  les  microorganismes  du  genre 

Proteus  (Hauser).     Archives  ital.  de  Biologic,  t.  viii.,  1887. 

1400.  -   Ueber  Schutzimpfungen.     Zeitschrift  fur  Hygiene,  Bd.  v.,  1888,  p.  415. 

1401.  BOOKER.     Trans.  Am.  Pediatric  Soc.,  vol.  i.,  1889,  p.  206. 

PROTEUS   OP   KARLINSKY. 

1402.  KARLINSKY.    Ein  neuer  pathogener  Spaltpilz  (Bacillus  murisepticus  pleomor- 

phus).     Centralbl.  fur  Bakteriol.,  Bd.  v.,  1889,  p.  193. 

PROTEUS   MIRABILIS. 

HAUSER.     Op.  cit.  (No.  1397). 

PROTEUS   ZENKERI. 

HAUSER.     Op.  cit.  (No.  1397). 

PROTEUS   SEPTICU8. 

1403.  BABES.    Bakteriologische  Untersuchungen  Tiber  septische  Prozesse  des  Kindes- 

alters.     Leipzig,  1889. 

PROTEUS   LETHALIS. 

1404.  BABES.     Progres  med.  roumain,  1889  (April  6th). 

BACILLUS  A   OP  BOOKER. 

BOOKER.     Op.  cit.  (No.  1379). 

BACILLUS  ENDOCARDITIDIS  GRISEUS. 

1405.  WEICHSELBAUM.    Beitrage  zur  JEtiologie  und  pathol.  Anatomic  der  Endocar- 

ditis.   Ziegler's  Beitrage,  Bd.  iv.,  1888,  p.  119. 

BACILLUS  ENDOCARDITIDIS  CAPSULATUS. 

WEICHSELBAUM.     Op.  cit.  (No.  1405),  p.  127. 

BACILLUS  OP  LESAGE. 

1406.  LESAGE.     De  la  diarrhee  verte  des  enf ants  du  premier  age.     Bull,  med.,  1887 

(Oct.  26th). 


BIBLIOGRAPHY.  829 

BACILLUS   OP  DEMME. 

1407.  DEXIME.     Zur  Kenntniss  der  schweren  Erytheme.     Fortschr.   der  Med.,  1888, 

No.  7. 

BACILLUS   (EDEMATIS  AEROBICUS. 

1408.  KLEIN.     Centralbl.  fiir  Bakteriol.,  Bd.  x.,  p.  186. 

BACILLUS  OF   LETZERICH. 

1409.  LETZERICH.     Untersuchungen  und  Beobachtungen   uber  Nephritis  bacillosa 

interstitialis  primaria  ;  eine  neue  Mykose.     Zeitschr.  fur  klin.  Med.,  Bd.  xiii., 
1887,  p.  33. 

BACILLUS   OP   SCHIMMELBUSCH. 

1410.  SCHIMMELBUSCH.     Ein  Fall  von  Noma.     Deutsche  med.  Wochenschr.,  1889> 

No.  26. 

BACILLUS   FOZTIDUS 


1411.  HAJEK.      Die  Bakterien  bei  der  akuten  und  chronischen  Coryza,  etc.     Berliner 

klin.  Wochenschr.,  1888,  No.  33. 

BACILLUS  OP   LUMNITZER. 

1412.  LUMNITZER.     Centralbl.  fiir  Bakteriol.,  Bd.  iii.,  p.  621. 

BACILLUS  OP  TOMMASOLI. 

1413.  TOMMASOLI.    Di  una  nuova  forma  di  sicosi.     Giornale  italiano  delle  mallattie 

veneree  e  delle  pelle,  1889,  No.  3. 

BACILLUS   OP   SCHOU. 

1414.  SCHOU.     Untersuchungen  liber  Vaguspneumonie.     Fortschr.  der  Med.,  1885, 

No.  15. 

BACILLUS  NECROPHORUS. 

1415.  LOFPLER.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  p.  493. 

BACILLUS  COPROGENES  FO3TIDUS. 

1416.  SCHOTTELIUS.     Der  Rothlauf  der  Schweine.     Wiesbaden,  1885. 

BACILLUS   OXYTOCUS  PERNICIOSUS. 

1417.  FLUGGE.     Die  Mikroorganismen.     2d  ed.,  Leipzig,  1886,  p.  268. 

BACILLUS   SAPROGENES   II. 

ROSENBACH.     Op.  cit.  (No.  674). 

BACILLUS  OP  AFANASSIEW. 

1418.  AFANASSIEW.     St.  Petersburger  med.  Wochenschr.,  1887,  Nos.  39^12. 

PNEUMOBACILLUS  LIQUEFACIBN8  BOVIS. 

1419.  ARLOING.     Compt.  rend.  Acad.  des  Sc.,  t.  cvi. 

BACILLUS  PSEUDOTUBERCULOSIS. 

1420.  PFEIPPER.     Ueber  die  bacillure  Pseudotuberculose  bei  Nagethiere.     Leipzig, 

1889. 

BACILLUS   GINGIV.*   FYOGENES. 

1421.  MILLER.     Die  Mikroorganismen  der  Mundhohle.     Leipzig,  1889,  p.  216. 

69 


830  BIBLIOGRAPHY. 

BACILLUS  DENTALIS   VIRIDANS. 

MILLER.     Op.  cit.  (No.  1421),  p.  218. 

BACILLUS  PULP^E   PYOGENES. 

MILLER.     Op.  cit.  (No.  1421),  p.  219. 

BACILLUS   SEPTICUS  KERATOMALACLiE. 

BABES.     Op.  cit.  (No.  1403). 

BACILLUS  SEPTICUS  ACUMINATUS. 

BABES.     Op.  cit.  (No.  1403). 

BACILLUS  SEPTICUS  ULCERIS  GANGR.ENOSI. 

BABES.     Op.  cit.  (No.  1403). 

BACILLUS  OP  TRICOMI. 

1422.  TRICOMI.     II  micro- parassita  della  gangrena  senile.     Atti  della  Soc.  italiana  di 

Chirurgia,  1887  (April  20th). 

BACILLUS   ALBUS   CADAVERIS. 

1423.  STRASSMANN  UND  STRECKER.     Bakterien  bei  der  Leichenfaulniss.     Zeitsclir. 

fiir  Medicinalbeamte,  1888,  No.  3. 

BACILLUS  VARICOSITS   CONJUNCTIVE. 

142 1.  GOMBERT.     Reciierches  experiment,  sur  les  microbes  des  conjunctives.     Mont- 
pellier;  Paris,  1889. 

BACILLUS  MENINGITIDIS  PURULENT^E. 

1425.  NEUMANN  UWD  SCHAEFFER.     Zur  ^Etiologie  der  eitrigen  Meningitis.     Vir- 

chow's  Archiv,  Bd.  cix.,  1887,  p.  477. 

BACILLUS   SEPTICUS   VESIC.E. 

1426.  CALDO.     Deux  nouveaux  bacilles  dans  les  urines  pathologiques.     Bull,  de  la 

Soc.  anatom.  de  Paris,  1887,  p.  339. 

BACILLUS   OF   GESSNER. 

1427.  GESSNER.     Archiv  filr  Hygiene,  Bd.  ix.,  p.  129. 

BACILLUS   CHROMO-AROMATICUS. 

1428.  GALTIER.     Sur  un  microbe  pathogene  chromo-aromatique.      Compt.   rend. 

Acad.  des  Sc.,  t.  cvi.,  1888,  p.  1368. 

BACILLUS  CANALIS  CAPSULATUS. 

1429.  MORI.     Ueber  die  pathogenen  Bakterien  des  Kanalisationswassers.    Zeitschr. 

ftlr  Hygiene,  Bd.  iv.(  1888,  p.  97. 

BACILLUS  CANALIS   PARVUS. 

MORI.     Op.  cit.  (No.  1429). 

BACILLUS   INDIGOGENUS. 

1430.  ALVAREZ.     Compt.  rend.  Acad.  des  Sc.,  t.  cv.,  1887,  p.  286. 


BIBLIOGRAPHY.  831 

BACILLUS   OF   KARTULIS. 

1431.  KARTULIS.    Zur  JEtiologie    der  agyptischen  katarrhalischen  Conjunctivitis. 

Centralbl.  filr  Bakteriol.,  Bd.  i.,  1887,  p.  289. 

1432.  WEEKS.     Der  Bacillus  des  akuten  Bindehautkatarrhs.     Arch,  filr  Augenheilk., 

Bd.  xvii.,  1887,  p.  318. 

BACILLUS   OF    UTPADEL. 

1433.  UTPADEL.     Ueber  eiuen  pathogenen  Bacillus  aus  Zwischendeckf  illlung.     Ar- 

chiv  fur  Hygiene,  Bd.  vi.,  1887. 

1434.  GESSNER.     Ueber  die  Bakterien  in  Duodenum  des  Menschen.     Archiv  fiir  Hy- 

giene, Bd.  ix.,  1889,  p.  128. 

BACILLUS  ALVEI. 

1435.  CHESHIRE  AND  CHEYNE.     The  pathogenic  history,  and  history  under  cultiva- 

tion, of  a  new  bacillus,  the  cause  of  a  disease  of  the  hive  bee  hitherto  known 
as  foul  brood.    Journ.  of  the  Royal  Mic.  Soc.  of  London,  1885  (March). 

1436.  KLAMANN.     Ueber  die  Faulbrut  der  Bienen.     Bienenwirthschaftl.  Centralbl. 

(Hannover),  1888,  Nos.  18  and  19. 

BACILLUS   OF   ACNE   CONTAGIOSA   OF   HORSES. 

1437.  DIECKERHOFF  UND  GRAWiTZ.     Die    Acne  contagiosa  des  Pferdes  und  ihre 

yEtiologie.     Virchow:s  Archiv,  Bd.  cii.,  1885,  p.  148. 

BACILLUS  NO.    I.    OF  ROTH. 

1438.  ROTH.    Ueber   pathogene    Mikroorganismen  in  den  Harden.     Zeitschr.   filr 

Hygiene,  Bd.  viii.,  1890,  p.  296. 

BACILLUS  NO.    II.    OF  ROTH. 

ROTH.    Op.  cit.  (No.  1438). 

BACILLUS   OF   OKADA. 

1439.  OKADA.     Ueber  einen  neuen  pathogenen  Bacillus  aus  Fussbodenstaub.     Cen- 

tralbl. filr  Bakteriol.,  Bd.  ix.,  1891,  p.  442. 

BACILLUS    OF   PURPURA   H^EMORRHAGICA   OF   TIZZONI   AND   GIOVANNINI. 

1440.  TIZZONI  E  GIOVANNINI.    Recherche  batteriologiclre  e  sperimentali  sulla  genesi 

dell'  infezione  emorragica.     Atti  della  R.  Accad.  delle  Sci.  di  Bologna,  1889. 

1441.  Ziegler's  Beitrage,  Bd.  vi.,  1889,  p.  300. 

BACILLUS  OF   PURPURA   H^ESfORRHAGICA   OF   BABES. 

1442.  BABES.     Ueber  Bacillen  des  hiimorrhagischen  Infektion  des  Menschen.     Cen- 

tralbl. filr  Bakteriol.,  Bd.  ix.,  1891,  p.  719. 

BACILLUS   OF   PURPURA   H^EMORRHAGICA   OF   KOLB. 

1443.  KOLB.     Arbeiten  aus  dem  K.  Gesundsheitsamte,  Bd.  viii.,  1891. 
BABES.     Op.  cit.  (No.  1442). 

BACILLUS    HEMINECROBIOPHILUS. 

1444.  ARLOING.    Compt.  rend.  Acad.  des  Sc.,  cvi.,  p.  1365.    Ibid.,  cvii.,  p.  1167. 


832  BIBLIOGRAPHY. 


XIV.   PATHOGENIC  ANAEROBIC  BACILLI. 

BACILLUS   TETANI. 

1445.  NICOLAIEK.     Deutsche  med.  Wochenschr. ,  1884,  No.  42. 

1446.  Beitrage  zur  ^Etiologie  des  Wundstarrkrampfes.     Inaug.  Diss.,  Got- 

tingen,  1885. 

1447.  CARL  E  RATTONE.    Studio  sperimentale  sull'  etiologia  del  tetano.     Gior.  della 

R.  Accad.  di  Med.  di  Torino,  1884  (March). 

1448.  ROSENBACH.     Zur    JEtiologie     des     Wundstarrkrampfes     beim     Menschen. 

Archiv  fur  klin.  Chirurgie,  Bd.  xxxiv.,  1886,  p.  306. 

1449.  BEUMER.     Zur  atiologischen  Bedeutung  der  Tetanusbacillen.     Berliner  kliu. 

Wochenschr.,  1887,  No.  30. 

1450.  Zur  ^tiologie  des  Trismus  sive  Tetanus  neonatorum.     Zeitschrift  fur 

Hygiene,  Bd.  iii.,  1887,  p.  242. 

1451.  BONOME.     Sull'  eziologia  del  tetano.     Giorn.  del  R.  Accad.  di  Med.  di  Torino, 

1886. 
1452. Fortschr.  der  Med.,  Bd.  v.,  1887,  p.  690. 

1453.  BRIEGEU.     Zur  Kenntniss  der  ^Etiologie  des  Wundstarrkrampfes.     Berliner 

klin.  Wochenschr.,  1887,  p.  311. 

1454.  Ueber  das  Vorkommen  von  Tetanin  bei  einem  an  Wundstarrkrampf 

erkrankten  Individuum.     Berliner  klin.  Wochenschr.,  1888,  No.  17. 

1455.  FERRARI.    Le  microbe  du  tetanus.     La  Semaine  med.,  1887,  No.  15. 

1456.  GIORDANO.     Contribute  all'  eziologia  de  tetano.     Giorn.  della  Accad.  di  Med. 

di  Torino,  1887,  Nos.  3  and  4. 

1457.  HOCHSINGER.     Zur  .^Etiologie  des  menschlichen  Wundstarrkrampfes.     Cen- 

tralbl.  fur  Bakteriol.,  Bd.  ii.,  1887,  Nos.  6  and  7. 

1458.  MORISANI.     Richerche  sperimentali  sulla  eziologia  del  tetano  traumatico.     Na- 

poli,  1887. 

1459.  OHLMULLER  TJND  GOLDSCHMIDT.     Ueber  einen  Bakterienbef  und  bei  mensch- 

lichen Tetanus.     Centralbl.  filr  klin.  Med.,  1887,  No.  31. 

1460.  PEIPER.     Zur  yEtiologie  des  Trismus  sive  Tetanus  neonatorum.   Centralbl.  f  iir 

klin.  Med.,  1887,  No.  42. 

1461.  SHAKESPEARE.     Preliminary  report  of  experimental  researches  concerning  the 

infectious  nature  of  traumatic  tetanus.     Trans.  IX.  Internal.  Med.  Congress. 

1462.  BOSSANO.     Attenuation  du  virus  tetanique  par  le  passage  sur    le    cobaye. 

Compt.  rend.  Acad.  des  Sc.,  t.  cvii.,  1888,  p.  1172. 

1463.  VON   EISELBERG.     Experimented   Beitrage  zur  ^Etiologie  des    Wundstarr- 

krampfes.    Wiener  klin.  Wochenschr.,  18S8,  Nos.  10-13. 

1464.  FRIEDBERGER.     Starrkrampf  beim  Pferde,  Ueberimpfung  auf  weisse  Mause. 

Jahresbericht  der  K.  Central-Thierarztneisch.  in  Miinchen,  1887-88,  p.  53. 

1465.  LAMPIASI.     Richerche  sull'  etiologia  del  tetano.     Giorn.  intern,  delle  Scienze 

med.,  1888. 

1466.  RAUM.     Zur  ^Etiologie  des  Tetanus.     Zeitschrift  flir  Hygiene,  Bd.  v.,  1889,  p. 

509. 

1467.  RIETSCH.     Sur  le  tetanos  experimentale.     Compt.  rend.  Acad.  des  Sc.,  t.  cvii., 

1888,  p.  400. 

1468.  WIDENMANN.     Beitrag  zur  ^Etiologie  des  Wundstarrkrampfes.     Zeitschrifl  f  iir 

Hygiene,  Bd.  v.,  1889,  p.  522. 

1469.  BAERT  ET  VERHOOGEN.     Sur  le  bacille  de  Nioolaier  et  son  role  dans  la  patho- 

genic du  tetanos.     Bull,  de  la  Soc.  Beige  de  Microscopic,  t.  xv.,  1889. 


BIBLIOGRAPHY.  833 

1470.  BELFAXTI  E  PASCAROLA.    Nuovo    contribute  allo  studio  batteriologico    del 

tetano.    Riforma  medica,  1889,  No.  71.    Ibid.,  1890,   No.   94.    Ibid.,  1890, 
No.  155. 

1471.  BOSSANO  ET  STEULLET.     Resistance  des  germes  tetaniques  a  Faction  de  cer- 

tains antiseptiques.     Compt.  rend.  Soc.  de  Biol.,  1889,  p.  614. 

1472.  DALL'  ACQUA  E  PARIETTI.     Contributo  sperimentale  all'  eziologia  del  tetano 

traumatico.     Riforma  medica,  1890  (March). 

1473.  KITASATO.     Ueber  den  Tetanuserreger.     Deutsche  med.  Wochenschr.,  18b9, 

No.  31. 

1474.  Ueber  den  Tetanusbacillus.     Zeitschrift   fur  Hygiene,  Bd.  vii.,  1889, 

p.  225. 

1475.  Experimentelle  Untersuchungen  ilber  das  Tetanusgift.     Zeitschrift  filr 

Hygiene,  Bd.  x.,  1891,  p.  267. 

1476.  BEHRING.     Ueber  Immunisirung   und  Heilung  von    Versuchsthieren     beim 

Tetanus.     Zeitschrift  fur  Hygiene,  Bd.  xii.,  1X92,  p.  45. 

1477.  SORMANI.     Ancora  sui  neutralizzanti    del   virus    tetanigens,  etc.     Rendiconti 

del  R.  Instituto  lombardo,  1889  (November  21st). 

1478. Ueber  ^Etiologie,   Pathogenese  und  Prophylaxie  des  Tetanus.     Trans. 

X.  Internat.  Med.  Congress.     Abstract  in  Centralbl.  filr  Bakteriol.,  Bd.  x., 
1891,  pp.  421,  580. 

1479.  TIZZONI  E  CATTANI.     Recherche  batteriologiche    sul    tetano.     Riforma  me- 

dica,. 1889,  No.  86. 

1480.  Sui  caratteri  morfologica  del  bacillo  di  Rosenbach  e  Nicolaier.     Ibid., 

1889,  No.  126. 

1481. Richerche  sull'  eziologia  del  tetano.     Ibid.,  1889,  No.  142. 

1482.  -       -  Ulteriori  richerche  sul'  tetano.     Ibid.,  1889,  No.  148. 

1483.  -    —  Sulla  diffusione  del  virus  tetanico  nell'  organismo.   Ibid.,  1889,  No.  162. 

1484.  -  — -  Ulteriori  richerche   sui  caratteri  delle  colture  del  bacillo  del    tetano. 

Ibid.,  1889,  No.  293. 

1485.  -       -  Ueber  das  Tetanusgift.     Centralbl.  filr  Bakteriol.,  Bd.  viii.,  1890,  p.  69. 

1486.  Sulla  resistenza  del  virus  tetanico  agli  agenti  chimici  e  fisici.     Riforma 

med.,  1890,  No.  83. 

1487.  Ueber  die  Art  einem  Thiere  die  Immunitat  gegen  Tetanus  zu  iiber- 

tragen.     Centralbl.  filr  Bakteriol..  Bd.  ix.,  1891,  p.  189. 

1488.  Ueber  die  Eigenschaften  des  Tetanus- Antitoxins.     Ibid.,  p.  685. 

1489.  Fernere  Untersuchungen  ilber  das  Antitoxin  des  Tetanus.     Ibid.,  Bd. 

x.,  1891,  p.  33. 

1490.  -       -  Sull' attenuazione  del  bacillo  del  tetano.     La  Riforma  med.,  1891,  p.  157. 

1491.  WIDENMANN.     Beitrag  zur  ^Etiologie  des  Wundstarrkrampfes.     Zeitschrift 

fur  Hygiene,  Bd.  v.,  1889. 

1492.  TIZZONI,  CATTANI  UND  BAGNIS.     Bakteriologische  Untersuchungen  liber  den 

Tetanus.     Zicgler's  Beitrage,  Bd.  vii  ,  Heft  4. 

1493.  BABES  UND  PUSCARIN.     Versuche  ilber  Tetanus.     Centralbl.   fur  Bakteriol., 

Bd.  viii.,  1890,  p.  74. 

1494.  BEHRING  UND  KITASATO.     Ueber  das  Zustandekommen  der  Diphtherie-Im- 

munitat  und  der  Tetanus-Immiinitat  bei  Thieren.     Deutsche  med.  Wochen- 
schr., 1890,  No.  49. 

1495.  SANCHEZ-TOLEDO  ET  VEILLON.     De  la  presence  du  bacille  du  tetanos  dans  les 

excrements  du  chevalet  du  boeuf  i\  1'etat  sain.     La  Semaine  med.,  1890,  No. 
45. 

1496.  Recherches  microbiologiques  et  experimentales  sur  le  tetanos.     Arch. 

de  Med.  experiment,  et  d'Anat.  path.,  1890,  p.  11. 


834  BIBLIOGRAPHY. 

1497.  PEYRAUD.    Etiologie  du  tetanos ;  sa  vaccination  chimique  par  la  strychnine. 

La  Semaiue  med.,  1890,  No.  44. 

1498.  RENVERS.     Zur  ^Etiologie  des  Wundstarrkrampfes.     Deutsche  med.  "Wochen- 

schr.,  1890,  No.  32. 

1499.  VAILLARD   ET   VINCENT.     Recherches  experimentales   sur   le  tetanos.      La 

Semaine  med.,  1891,  No.  5. 

1500.  r-  Contribution  3,1'etude  du  tetanos.     Ann.  de  1'Institut  Pasteur,  1891, 

No.  1. 

1501.  TURCO.     Alcune  richerche  sperimentali  sulla  diffusione  del  virus  tetanico  e  sulla 

sua  resistenza  agli  agenti  esterni.    La  Riforma  med.,  1891,  No.  236. 

1502.  VAILLARD.     Sur  1'immunite  contre  le  tetanos.     Compt.  rend,  de  la  Soc.  de 

Biol.,  1891,  No.  7. 

BACILLUS  (EDEMATIS  MALIGNI. 

1503.  PASTEUR.     Sur  le  vibrion  septique.    Bull.  Acad.  de  Med.,  1887  and  1881. 

1504.  KOCH.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  i.,  1881,  p.  54. 

1505.  GAFFKY.    Experimented  erzeugte  Septikamie,  etc.    Mitth.  aus  dem  K.  Ge- 

suudheitsamte,  Bd.  i.,  1881,  p.  12. 

1506.  TRIFAUD.    De  la  gangrene  gazeuse  foudroyante.     Rev.  de  Chir.,  t.  iii. 

1507.  LUSTIG.     Zur  Kenntniss  bakteriamischer  Erkrankuugen  bei  Pferden  (malignes 

Oedem).     Jahresber.  der  K.  Thierarzneischule  zu  Hannover,  1883-84. 

1508.  KITT.     Untersuchungen  liber  malignes  Oedem  und   Rauschbrand  bei  Haus- 

thieren.     Jahresber.  der  K.  Thierarzneischule  in  Miinchen,  1883-84. 

1509.  HESSE,  W.  UND  R.     Ueber  Zuchtung   der  Bacillen  des  malignen  Oedems. 

Deutsche  med.  Wocheoschr.,  1885,  No.  14. 

1510.  CHAUVEAU  ET  ARLOING.     Etudeexperimentalesur  la  septicemie  gangreneuse. 

Arch,  veter.,  1884,  pp.  366,  817. 

1511.  Bull.  Acad.  de  Med.,  1884  (May  6th  and  Aug.  19th). 

1512.  Roux  ET  CHAMBERLAXD.     Immunite  contre  la  septicemie  conferee  par   les 

substances  solubles.    Ann.  de  1'Institut  Pasteur,  vol.  i.,  1887,  p.  562. 

1513.  ROGER.    Quelques  effets  des  associations  microbiennes.     Compt.  rend.  Soc. 

deBiol.,  1889,  p.  35. 

1514.  KITASATO  UND  WEYL.     Zur  Kenntniss  der  AnaGroben.     Zeitschr.  fur  Hygiene, 

Bd.  viii.,  1890,  p.  41. 

1515.  VAN  COTT.     Untersuchungen  liber  das  VorkomYnen  der  Bacillen  des  malignen 

Oedems  in  der  Moschustinktur.     Centralbl.  flir  Bakteriol.,  Bd.  ix.,  1891, 
p.  303. 

1516.  VERNEUIL.     Note  sur  les  rapports  de  la  septicemie  gangreneuse  et  du  tetanos, 

etc.     La  Semaine  med.,  vol.  x.,  1890,  No.  48. 

BACILLUS  CADAVERIS. 

STERNBERG.     Op.  cit.  (No.  1384),  p.  212. 

BACILLUS   OF   SYMPTOMATIC  ANTHRAX. 

1517.  FESER.     Studium  tlber  den  sog.    Rauschbrand  des  Rindes.     Zeitschrift  fur 

prakt.  Veterinarwissensch.,  Bern,  1876. 

1518.  BOLLINGER  UND  FESER.     Wochenschr.  f  lir  Thierheilkunde,  1878. 

1519.  ARLOING,  CORNEVIN  ET  THOMAS.     Sur  I'inoculabilite  du  charbon  symptoma- 

tique  et  les  caracteres  qui  le  differencient  du  sang  de  rate.     Compt.  rend. 
Acad.  des  Sc.,  Paris,  xc.,  1880,  pp.  1302-1305. 

1520.  De  1'inoculation  du  charbon  symptomatique  par  injection  intraveineuse. 


BIBLIOGRAPHY.  835 

et  de  1'immunite  conferee  au  veau,  au  mouton  et  a  la  chevre  par  ce  proc6de. 
Compt.  rend  Acad.  des  Sc.,  Paris,  xci.,  1880,  pp.  734-736. 

1521.  ARLOING,  CORNEVIN  ET  THOMAS.     Sur  la  cause  de  I'immunite  des  adultes  et 

de  1'espece  bovine  contre  le  charbon  symptomatique  ou  bacterien,  dans  les 
locaiites  ou  cette  maladie  est  frequente.  Compt.  rend.  Acad.  des  Sc.,  Paris, 
xciii.,  1881,  pp.  605-609. 

1522.  Mecanisme  de  1'infection  dans  les  differents  modes  d'inoculation  du 

charbon  symptomatique  ;  application  a  1'interpretation  des  faits  cliniques  et 
&  la  metkode  des  inoculations  preventives.    Compt.  rend.  Acad.  des  Sc. ,  Paris, 
xcii.,  1881   pp.  1246-1248. 

1  528.  Nouvelles  reckerches  experimentales  sur  la  maladie  inf ectieuse  appelee 

charbon  symptomatique.    Journ.  de  Med.  vet.  et  de  ZoOtech.,  Lyon,  1881, 

3s.,  vi.,pp.  290-300. 
1524.  Experiences  publiques  sur  la  vaccination  du  charbon  symptomatique. 

Arch,  vet.,  Paris,  vi.,  1881,  pp.  721-727. 
1525. Note  relative  a  la  conservation  et  a  la  destruction  de  la  virulence  du 

microbe  du  charbon  symptomatique.     Rec.  de  Med.   vet.,   Paris,    1882,  6 

s.,  ix.,  pp.  467-472. 

1526.  Moyen  de  conf erer  artificiellement  1'iinmunite  contre  le  charbon  symp- 
tomatique ou  bacterien  avec  du  virus  attenue.     Compt.  rend.  Acad.  des  Sc., 
Paris,  xcv.,  1882,  pp.  189-191. 

1527.  Le  charbon  symptomatique  ;    troisieme  rapport  a  M.    le  Ministre  de 

1'Agriculture  sur  le  resultat  des  inoculations  preventives.     Arch,  vet.,  Paris, 
vii.,  1882,  pp.  767-771. 

1528. Modifications  que  subit  le  virus  du  charbon  symptomatique  ou  bac- 

terieu  sous  1'influence  dequelques  causes  de  destruction.  Compt.  rend.  Soc. 
de  Biol.,  Paris,  7  s.,  iv.,  1883,  pp.  121-128. 

1529.  Le  charbon  symptomatique  du  bceuf .     2eme  ed.,  Paris,  1887. 

1530.  EHLERS.    Untersuchungen  liber  den  Rauschbraudpilz.    Inaug.  Diss.,  Rostock, 

1884. 

1531.  KITT.     Untersuchungen  liber  malignes  Oedem   und  Rauschbrand  bei  Haus- 

thieren.     Jahresber.  der  K.  Thierarzneischule  in  Miinchen,  1883-84. 

1532. YersucheubereinmaligeRauschbrand-Schutzimpfung.    Ibid.,  1886-87, 

p.  91. 

1533.  Ueber  Abschwachung  des  Rauschbrandvirus  durch  stromende  Wasser- 

dampfe.     Centralbl.  filr  Bakteriol.,  Bd.  iii.,  1888,  pp.  572,  605. 

1534.  HESS.     Bericht  liber  die  Schutzimpf  ungen  gegen  Rauschbrand,  etc. ,  im  Kanton 

Bern  wiihrend  der  Jahre  1886-88.     Bern,  1889. 

1535.  HAFNER.     Die  Rauschbrandimpfungen  in  Baden.     Bad.   thierarztl.  Mitth., 

1887,  p.  33.     Ibid.,  1889,  No.  2. 

1536.  ROGOWITSCH.     Zur  Kenntniss  der  Wirkung  des  Rauschbrandbacillus  auf  den 

thierischen  Organismus.     Ziegler's  Beitrage,  Bd.  iv.,  1888,  Heft  4. 

1537.  Roux.    Immunite  contre  le  charbon  symptomatique,    confere    par  les  sub- 

stances solubles.     Ann.  de  1'Iustitut  Pasteur,' vol.  ii.,  1888,  p.  49. 

1538.  STREBEL.     Resultat  der  Rauschbrand-Schutzimpfung  im   Kanton  Freiburg. 

Schweizer  Archiv  fur  Thierheilk.,  Bd.  xxx.,  p.  87. 

1539.  SUCHANKA.    Resultate  der  Rauschbrandimpfungen  des  Jahres  1887  im  Her- 

zogthume  Salzburg- Oesterreich.  Monatsschr.  filr  Thierheilk.,  1888,  p.  161. 
Ibid.,  1889,  No.  3. 

1540.  WOLFF.     Schutzimpfungen'  gegen  Rauschbraud.    Berliner  Archiv  filr   wis- 

sensch.  und  prakt.  Thierheilk.,  1883,  p.  191. 

1541.  KITASATO.     Ueber  den  Rauschbrandbacillus  und  sein  Kulturverfahren.    Zeit- 

schr.  fur  Hygiene,  Bd.  vi.,  1889,  p.  105.    Ibid.,  Bd.  viii.,  p.  55. 


836  BIBLIOGRAPHY. 

1542.  ROGER.    Inoculation  du  charbon  symptomatique  au  lapin.     Corapt.  rend.  Soc. 

de  Biol.,  1889,  pp.  77  and  242. 

1543.  De  quelques  causes  qui  modifient  1'immunite  naturelle.     Ibid.,  p.  476. 

1544.  WILDNER.    Die  Resultate  der  im  Jahre  1888  in  Niederosterreich  vorgenom- 

menen  Rauschbrand-Schutzimpfungen.     Oesterr.   Monatsschr.   fiir    Thier- 
heilk.,  1889,  No.  12. 

1545.  BOVET.    Des  gaz  produits  par  la  fermentation  anaerobienne.     Ann.  de  Micro- 

graphic,  t.  ii.,  1890,  No.  7. 


XV.   PATHOGENIC  SPIRILLA 

SPIRILLUM    OBERMEIERI. 

1546.  OBERMEIER.     Vorkommen  feinster,  eigene  Bewegung  zeigender  Faden   im 

Blutevon  Recurrenskranken.    Centralbl.  filr  die  med.  Wissensch.,  1873, 
No.  10. 

1547.  Weitere  Mittheilungen  ilber  Febris  recurrens.     Berliner  klin.  Wochen- 

schr.,  1873,  No.  35. 

1548.  ENGEL.    UeberdieObermeier'schenRecurrensspirillen.    Berliner  klin.  Wochen- 

schr.,  1873,  No.  35. 

1549.  MOCZUTOWSKY.     Experimeutaluntersuchung  tlber  die    Inoculationsflihigkeit 

der  Typhen.     Deutsches  Archiv  fiir  klin.  Med.,  Bd.  xxiv.,  1876. 

1550.  HEYDENREICH.     Der  Parasit  des  Rilckfallstyphus.     Berlin,  1877. 

1551.  Kocn.    Deutsche  med.  Wochenschr.,  1879. 

1552.  WEIGERT     Zur  Technik  der  mikroskopischen  Bakterienuntersuchungen.    Vir- 

chow's  Archiv,  Bd.  Ixxxiv.,  1881,  p.  292. 

1553.  CARTER.     Contribution  to  the  experimental  pathology  of  spirillum  fever  ;  its 

communicability  by  inoculation  to  the  monkey.     Med.  Chir.  Trans. ,  Lon- 
don, 1880,  2d  series,  xlv.,  pp.  7,  148. 

1554.  -       -  Aspects  of  the  blood  spirillum  in  relapsing  fever.     Trans.  Internal. 

Med.  Congress,  London,  1881,  p.  334. 

1555.  METSCHNIKOPP.    Ueber  den  Phagocytenkampf  beim  Ruckfallstyphus.    Vir- 

chow's  Archiv,  Bd.  cix.,  1887,  p.  176. 

1556.  SOUDAKEWITCH.    Recherches  sur    la    fievre    recurrente.    Ann.  de  1'Institut 

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SPIRILLUM  ANSERUM. 

1557.  SAKHAROFP.    Spirochseta  anserina  et  la  septicemie  des  oies.     Ann.  de  1'In- 

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SPIRILLUM   CHOLER^E   ASIATIC/E. 

1558.  KOCH.     Ueber  die  Cholerabakterien.    Deutsche  med.  Wochenschr.,  1884.  Ibid., 

1885,  Nos.  19,  20,  37a,  38,  39. 

1559.  VAN   ERMENGEM.     Recherches  sur  le  microbe  du  cholera  asiatique.     Paris 

and  Brussels,  1885. 

1560.  Note  sur  1'inoculation  des  produits  de  culture  du  bacille-virgule.     Bull. 

de  1'Acad.  Roy.  de  Med.  de  Belgique,  3eme  serie,  xviii. 

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Acad.  des  Sc.,  t.  ci.,  1885. 

1562.  PPEIPPER.     Ueber  die  Cholera  in  Paris.     Deutsche  med.  Wochenschr.,  1885, 

No.  2. 


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Wochenschr.,  1885,  No.  9. 

1578.  EMMERICH.    Die  CholerainNeapel.    Deutsche  med.  Wochenschr.,  1884,  No.  50. 

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pathol.,  1885,  p.  72. 

1581.  Compt.  rend.  Acad.  des  Sc.,  t.  xcix.,  p.  928. 

1582.  Recherches  sur  le  cholera.     Paris,  1886. 

1583.  KLEBS.     Mittheilungen  zur  JEtiologie  der  Cholera.     Correspondenzblatt  fiir 

Schweizer  Aerzte,  1885. 

1584.  BABES.     Untersuchungen  liber  Koch's   Kommabacillus.     Virchow's  Archiv, 

Bd.  xcix.,  1885,  p.  148. 

1585.  EMMERICH.     Untersuchungen  liber  die  Pilze  der  Cholera    asiatica.     Archiv 

fiir  Hygiene,  1885,  p.  291. 

1586.  BUCHNER    UND    EMMERICH.     Die  Cholera  in  Palermo.     Aerztl.  Intelligenz- 

blatt,  Munchener  med.  Wochenschr.,  1885,  No.  44. 

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med.  Wissensch.,  1886,  p.  769. 

1589.  CUNNINGHAM.     Relation  of  cholera  to  schizomycetic  organisms.     Scientific 

memoirs  of  the  medical  officers  of  the  army  of  India.     Calcutta,  1885. 

1590.  LUSTIG.     Bakteriologische  Studien  iiber  Cholera.     Centralbl.    fiir  die    med. 

Wissensch.,  1887,  Nos.  16  and  17. 

1591.  —    _  Zeitschrift  fiir  Hygiene,  Bd.  iii.,  1887,  p.  146. 

1592.  GAFFKY.    Bericht  liber  die  Thatigkeit  der  zur  Erforsclmng  der  Cholera  im 

Jahre  1883  nach  Egypteu  und  Indien  entsandten  Kommission.  Unter  Mit- 
wirkung  von  Dr.  R.  Koch.  Arbeiten  aus  dem  K.  Gesundheitsamte,  Ber- 
lin, Bd.  iii.,  1887. 


838  BIBLIOGRAPHY. 

1593.  FERRAN.    Sur    1'action  pathogene    et  prophylactique    du    bacillus-virgule 

Compt.  rend.  Acad.  des  Sc.,  t.  c.,  p.  959. 

1594.  Revendication  de  la  priorite  de  la  decouverte  des  vaccins  du  cholera 

asiatique  faite  sous  les  auspices  de  la  municipalite  de  Barcelone.     Barcelone, 
1888. 

1595.  VAN  ERMENGEM.     Die  Ferran'schen    Impfungen.     Deutsche  med.  Wochen- 

schr.,  1885,  No.  29. 

1596.  BITTER.     Ueber  Fermentausscheidung  von  Vibrio  Koch  und  Vibrio  proteus. 

Inaug.  Diss.,  Milnchen,  1886. 

1597.  BUJWID.     Eine  chemische  Reaktion  fur  die  Cholerabakterien.     Zeitschrift  fiir 

Hygiene,  Bd.  ii.,  1887,  p.  52. 

1598.  Centralbl.  fur  Bakteriol.,  Bd.  iii.,  1888,  p.  169. 

1599.  Neue  Methoden   zum  Diagnosticiren  und  Isoliren  der  Cholerabakte- 
rien.    Centralblatt  fur  Bakteriol.,  Bd.  iv.,  1888,  p.  494. 

1600.  WEISSER   UND    FRANK.     Mikroskopische    Untersuchungen  von  an  Cholera 

asiatica  verstorbenen  Indiern.     Zeitschr.  filr  Hygiene,  Bd.  i.,  1886,  p.  379. 

1601.  ALI-COHEN.     Zur  Bedeutung  des  sog.   Cholerarothes.    Fortschr.  der  Med., 

1887,  No.  17. 

1602.  Ibid.,  1888,  No.  6. 

1603.  ALMQUIST.    Einige  Bemerkungen  uber  die  Methoden  der  Choleraforschung. 

Zeitschrift  fur  Hygiene,  Bd.  iii.,  1887,  p.  281. 

1604.  BRIEGER.     Ueber  die  Entstehung  des  Cholerarothes  sowie  liber  Ptomaine  aus 

Gelatine.    Deutsche  med.  Wochenschr. ,  1887,  No.  22. 

1605.  Zur  Kenntniss  des  Stoffwechselprodukte  des  Cholerabacillus.    Berliner 

klin.  Wochenschr.,  1887,  p.  8L7. 

1606. Choleraroth  und   Cholerablau.     Berliner  klin.  Wochenschr.,  1887,   p. 

500. 

1607.  Ueber  die  Cholerafarbstoffe.     Virchow's  Archiv,  Bd.  ex.,  1887,  p.  614. 

1608.  CANESTRINI  E  MORPURGO.    Resistenza  del  bacillus  komma  in  culture  vecchie 

al  calore.    Atti  di  R.  Institute  di  Scienze,  Lettere  ed  Arti,  t.  v.,  1887. 

1609.  STERNEEHG.     The  thermal  death-point  of  pathogenic  microorganisms.     Am. 

Journ.  of  the  Med.  Sc.,  1887  (July) ;  also  in  Rep.  of  Com.  on  Disinfectants, 
A.  P.  H.  A.,  1887,  p.  138. 

1610.  DUNHAM.     Zur  chemischen  Reaktion  der  Cholerabakterien.     Zeitschrift  fiir 

Hygiene,  Bd.  ii.,  1887,  p.  337. 

1611.  HUEPPE.     Ueber  Fortschritte    in  der  Kenntniss  der  Ursachen  der  Cholera 

asiatica.    Berliner  klin.  Wochenschr. ,  1887,  Nos.  9-12. 

1612. Ueber  Thierversuche  bei  Cholera  asiatica.     Berliner  klin.  Wochenschr., 

1887,  No.  22. 

1613.  Einige     Bemerkungen     liber    Thierversuche     bei    Cholera     asiatica. 

Deutsche  med.  Wochenschr.,  1887,  No.  30. 

1614.  Sur  la  virulence  des  parasites  du  cholera.     Compt.  rend.  Acad.  des  Sc., 

t.  cviii.,  1889,  p.  105. 

1615.  Zur  ^Etiologie  der  Cholera  asiatica.     Prager  med.  Wochenschr.,   1889, 

No.  12. 

1616.  KITASATO.   Die  Widerstandfahigkeit  der  Cholerabakterien  gegen  dasEintrock- 

nen  und  Hitze.     Zeitschrift  fiir  Hygiene,  Bd.  v.,  1888,  p.  134.     Ibid.,  Bd. 
vi.,  1889,  p.  11. 

1617.  Ueber  das  Verhalten  der  Typhus-  und  Cholerabacillen  zu  saure-  und 

alkalihaltigen  Nahrboden.     Zeitschrift  fiir  Hygiene,  Bd.  iii.,  1888,  p.  404. 

1618.  Das  Verhalten  der  Cholerabakterien  im  menschlichen  Koth.     Ibid.,  Bd. 

v.,  1888,  p.  487. 


BIBLIOGRAPHY. 

1619.  KITASATO.     Das  Verhaltcn  der  Cholerabakterieu  in  der  Milch.     Ibid.,  Bd.  v., 

18S8,  p.  491. 

1620.  Zeitschrift  fiir  Hygiene,  Bd.  vi.,  1889,  p.  1. 

1621.  BOLTON.     Ueber  das  Verhalten  verschiedener  Bakterienarten  im  Trinkwasser. 

Zeitschrift  fur  Hygiene,  Bd.  i.,  1886,  p.  76. 

1622.  ROY,  BROWN,  AND  SHERRINGTON.     Preliminary  report  on  the  pathology  of 

cholera  Asiatica.     Proc.  Roy.  Soc.,  London,  vol.  xli.,  p.  173. 

1623.  SALKOWSKI.     Ueber  das  Choleraroth  und  das  Zustandekommen  der  Cholera- 

reaktion.     Virchow's  Archiv,  Bd.  ex.,  1887,  p.  366. 

1624.  WEICHSELBAUM.     Ueber  JEtiologie  der  Cholera.     Wien,  1887. 

1625.  TIZZONI  UND  CATTANI.     Untersuchungen  uber  Cholera.     Centralbl.  fiir  die 

med.  Wissensch.,  1887,  No.  8  ;  ibid.,  No.  26 ;  ibid.,  No.  29  ;  ibid.,  No.  33  ; 
ibid.,  Nos.  39  and  40  ;  ibid.,  No.  51. 

1626.  VINCENZI.     Ueber    intraperitonaale   Einspritzung  von    Koch'schen   Komma- 

bacillen  bei  Meerschweinchen.     Deutsche  med.  Wochenschr.,  1887,  Nos.  17 
and  26. 

1627.  WASSILJEW.     Die  Desinfektion  der  Choleradejektionen  in  Hospi'iilern.     Zeit- 

schr.  fiir  Hygiene,  Bd.  iii.,  1837,  p.  237. 

1628.  ZASLEIN.    Ueber  den  praktischen  Nutzen  der  Koch'schen  Plattenkultureu  in  der 

Choleraepidemie  des  Jahres  1886  in  Genua.     Deutsche  Med.-Zeitung,  1887, 
p.  389. 

1629.  Was  wSchst  aus  alten  Cholerakulturen  ?     Ibid.,  No.  52. 

1630.  Beitrag  zur  chemischen  Reaktion  des  Cholerabacillus.     Ibid.,  No.    72. 

1631.  Ueber  die  Varietaten  des  Koch'schen  Kommabacillus.     Deutsche  Med.- 
Zeitung,  1888,  Nos.  64  and  65. 

1632.  SIRENA  E  ALLESSI.    Azione  della  creolina  sulbacillo-virguladi  Koch.    Riforma 

med.,  1888,  Nos.  257  and  258. 

1633.  LOEWENTHAL.     Experiences    biologiques  et  therapeutiques    sur  le  cholera. 

Compt.  rend.  Acad.  des  Sc.,  t.  cvii..  1888,  p.  1169. 

1634.  Sur  la  virulence  du  bacille  cholerique  et  1'action  que  le  salol  exerce  sur 

cette  virulence.     Compt.  rend.  Acad.  des  Sc.,  t.  cTiii.,  1889,  p.  192. 

1635.  HESSE.     Unsere  Nahrungsmittel  als  Nahrboden   fiir  Typhus  und   Cholera. 

Zeitschr.  fiir  Hygiene,  Bd.  v.,  1889,  p.  527. 

1636.  BERCKHOLTZ.     Untersuchungen  liber  den  Einfluss  des  Eiutrockuens  auf  die 

Lebensfahigkeit  der  Cholerabacillen.     Arbeiten  aus  dem  K.  Gesundheits- 
amte,  Bd.  v.,  1888. 

1637.  GAMELEIA.     Ueber  Priiventivinipfung  gegen  Cholera  asiatica.     Compt.  rend. 

Acad.  des  Sc.,  1888  (Aug.  20th). 

1638.  Sur  la  vaccination  cholerique.     Compt.    rend.    Soc.    de  BioL,  1889, 

No.  38. 

1639.  Ueber  die  Resistenz  der  Kaninchen  gegenilber  den  Cholerabakterien. 

Centralbl.  fiir  Bakteriol.,  Bd.  ix.,  1891,  p.  807. 

1640.  HOVORKA  UNO  WINKLER.     Ein  neues  Unterscheidungsmerknwl  zwischen  dem 

Bacillus  choleras  asiaticae  Koch  und  dem  von  Finkler  und  Prior  entdeckten 
Bacillus.     Allgem.  "Wiener  med.  Zeitung,  1889. 

1641.  NEUHAUSS.     Ueber  die  Geisseln  an  den  Bacillen  der  asiatischen  Cholera.     Cen- 

tralbl.  fur  Bakteriol.,  Bd.  v.,  1889,  p.  81. 

1642.  PKTRI.     Reduktion  von  Nitraten  durch  die  Cholerabakterien.     Centralbl.  fiir 

Bakteriol.,  Bd.  v.,  1889,  p.  561. 

1643.  Ueber  die  Verwerthung  der  rothen   Salpetrigsiiure-Indolreaktion  zur 

Erkennung  der  Cholerabakterien.     Arbeiten  aus  dem  K.   Gesundheitsamte, 
Bd.  vi.,  p.  1. 


840  BIBLIOGRAPHY. 

1644.  PFEIFFER  UND  NOCHT.     Ueber  das  Verhalten  der  Choleravibrionen  im  Tau- 

benkorper.     Zeitschrift  fur  Hygiene,  Bd.  vii.,  1889,  p.  259. 

1645.  PPUHL.     Ueber  die  Desinfektion  von  Typhus-  und  Choleraausleerungen  mit 

Kalk.    Zeitschrift  fur  Hygiene,  Bd.  vi.,  1889,  p.  97. 

1646.  UFFELMANN.    Die  Dauer  der  Lebensfiihigkeit  von  Typhus-  und  Cliolerabacillen 

in  Fakalmassen.     Central bl.  fiir  Bakteriol.,  Bd.  v.,  1889,  pp.  497,  529. 

1647.  DOWDESWELL.     Note  sur  les  flagella  du  microbe  du  cholera.     Ann.  de  Micro- 

graphic,  vol.  ii.,  1890,  No.  8. 

1648. Sur  quelques  phases  du  developpement  du  microbe  du  cholera.     Ibid. , 

No.  12. 

1649.  DE  GIAXA.     Le  bacille  du  cholera  dans  le  sol.     Ann.  de  Micrographie,  1890. 

1650.   Sur  1'action  desinfectante  du  blanchiment  des  murs  au  lait  de  chaux. 

Ann.de  Micrographie,  1890,  p.  305 

1651.  KARLINSKY.     Zur  Kenntniss  der  Tenacitilt  der  Choleravibrionen.     Central bl. 

fur  Bakteriol.,  Bd.  viii.,  1890,  p.  40. 

1652.  SCHILLEK.     Zum  Verhalten  der  Erreger  der  Cholera  und  des  Unterleibstyphus 

in  dem  Inhalt  der  Abtrittsgruben  und  Abwasser.     Arbeiten  aus  dem  K. 
Gesundheitsamte,  Bd.  vi.,  1890,  Heft  2. 

1653.  SIRENA.     Sulla  resistenza  vitale  del  bacillo  virgola  nelle  acque.     Riforma  med., 

1890,  No.  14. 

1654.  WINTER    ET    LESAGE.     Contribution  si  1'etude  du  poison  cholerique.     Bull. 

med.,  1890,  p.  328. 

1655.  BOER.     Ueber  die  Leistungsfahigkeit  mehrer  chemischer  Desinfektionsmittel 

bei  einigen    fur    den    Menschen    pathogenen    Bakterien.     Zeitschrift    filr 
Hygiene,  Bd.  ix.,  1890. 

1656.  BRUCE.     Bemerkung    liber  die   Virulenzsteigerung  des  Choleravibrio.     Cen- 

tralbl.  filr  Bakteriol.,  Bd.  ix.,  1891,  p.  786. 

1657.  CUNNINGHAM.     On  some  species  of  choleraic  comma  bacilli  occurring  in  Cal- 

cutta.    The  scientific  memoirs  by  the  medical  officers  of  the  Army  of  India, 
partvi.,  Calcutta,  1891. 

1658.  KAUPE.     Untersuchungen  uber  die  Lebensdauer  der  Cliolerabacillen  in  mensch- 

lichen  Koth.     Zeitschrift  fur  Hygiene,  Bd.  ix.,  1890. 

1659.  MANFREDI  UND  SERAFINI.     Ueber  das  Verhalten  von  Milzbrand-  und  Clio- 

lerabacillen in  reinen     Quarz-     und     reinen    Marmorboden.     Archiv    fill- 
Hygiene,  Bd.  xi.,  p.  1. 

1660.  SHAKESPEARE.     Report  on  cholera  in  Europe  and  India.     Washington,  1890. 

SPIRILLUM   OF   FINKLER   AND   PRIOR. 

1661.  PINKLER  UND  PRIOR.     Untersuchungen  tiber  Cholera  nostras.     Deutsche  med. 

Wochenschr.,  1834,  No.  36. 

1662.  Forschungen  uber  Cholerabaciilen.      Ergiinzungshefte  zum  Central - 

blatt  fur  allgemeine  Gesundheitspflege,  Bd.  i.,  1885,  Hefte  5  und  6. 

1663.  BUCHNER.     Ueber  die  Koch'schen  und  Finkler-Prior'schen  Konimabacilleu. 

Sitzungsber.  der  Gesellsch.  fur  Morphol.  und  Physiol.   in  Mllnchen,  1885, 

.    P.  21- 

1664.   Archiv  fur  Hygiene,  1885,  p.  361. 

1665.  GRUBER.     Ueber  die  als  ';  Kommabacillen  "  bezeichneteu  Vibrionen  von  Koch 

und  Finkler-Prior.     Wiener  med.  Wochenschr.,  1885,  p.  262. 

1666.  SMITH.    Spirillum  Finkler  and  Prior  in  hepatized   lung  tissue.     Med.  News, 

Philadelphia,  1887,  p.  536. 

1667.  FRANCK.    Ueber  Cholera  nostras.    Zeitschr.  fiir  Hygiene,  Bd.  iv.,  1888,  p.  205. 


BIBLIOGRAPHY.  841 

16C8.  FIRTSCH.     Untersuchungen  ilber  Variationserscheinuugen  bei  Vibrio  Proteus. 
Archiv  fur  Hygiene,  Bd.  viii.,  1883,  p.  369. 

1669.  KARTULIS.     Zur  .Etiologie  der  Cholera  nostras,  etc.     Zeitschr.  ftir  Hygiene, 

Bd.  vi.,  1889,  p.  62. 

1670.  Dr  MATTEL     Iljmethodo  Schottelius  nella  diagnoSi  batterioscopica  del  colera 

asiatico  et  del  colera  nostras.    Bull.  R.  Accad.  med.  di  Roma,  1888-89,  No.  1. 

SPIRILLUM  TYROGENUM. 

1671.  DENEKE.    Ueber  eine  neue,  den  Choleraspirillen  ahnliche  Spaltpilzart.     Deut- 

sche med.  Wochenschr. ,  1885,  No.  3. 

1672.  FLUGGE.     Die  Mikroorganismen.     2d  ed.,  1886,  p.  386. 

SPIRILLUM   METSCHNIKOVI. 

1673.  GAMELEIA.    Vibrio  Metschnikovi  (n.  sp.)  et  ses  rapports  avec  le  microbe  du 

cholera  asiatique.    Ann.  de  1'Institut  Pasteur,  vol.  ii.,  1883,  p.  482. 
1674. .  Vibrio  Metschnikovi,  son  mode  naturelle  d'infection.     Ibid.,  p.  552. 

1675.  Vibrio  Metschnikovi,  vaccination  chimique.     Ibid.,  vol.  Hi.,  p.  542. 

1676.  Exaltation  de  la  virulence.    Ibid.,  p.  609. 

1677.   Localisation  intestinale.     Ibid.,  p.  625. 

1678.  PFEIFFEK.     Ueber  dea  Vibrio  Metschnikoff  und  sein  Verhaltniss  zur  Cholera 

asiatica.     Zeitschr.  ftir  Hygiene,  Bd.  viii.,  1889,  p.  347. 

XVI.   BACTERIA  IN  DISEASES  NOT  PROVED  TO  BE  DUE  TO 
SPECIFIC  MICROORGANISMS. 

ALOPECIA. 

1679.  ROBINSON.    Pathologic   und  Therapie  der    Alopecia  areata.     Monatsh.   fur 

prakt.  Dermatol.,  1888,  Nos.  9-16. 

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BERI-BERI. 

1682.  DE  LACERDA.     O  microbio  do  Beriberi.     Rio  de  Janeiro,  1887,  pp.   200,  5 
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1686.  PEKELHARING   UND  WINKLER.     Mitth.  ilber  die  Beri-Beri.     Deutsche  med. 

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1687.  Recherches  sur  la  nature  et  la  cause  du  beri-beri  et  sur  les  moyens  de  le 

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842  BIBLIOGRAPHY. 

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BRONCHITIS. 

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1691.  PICCHINI.     Rivista  clinica,  1889,  p.  121. 

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1696.  SCHEURLEN.     Die  ^Etiologie  des  Carcinoms.     Deutsche  med.  Wochenschr., 

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1697.  Zur  Carcinomfrage.     Deutsche  med.  Wochenschr.,  1888,  No.  30. 

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1699.  VAN  ERMENGEM.     Etiologie  du  cancer.     Bull,  de  la  Soc.  beige  de  Microscopic, 

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1700.  LAMPIASI-RUBINO.     Sulla  natura  parasitaria  del  tumori  cancerosi.    La  Riforma 

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1702.  NEPVEU.     Contribution  a  1'etude  des  baeteries  dans  les  tumeurs.     Gazette 

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1704.  ROSENTHAL.     Untersuchungen  iiber  das  Vorkommen  von  Mikroorganismen  in 

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1705.  SENGER.     Studien  zur  ^Etiologie  des  Carcinoms.     Berliner  klin.  Wochenschr. , 

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1706.  THOMA.     Ueber  eigenartige  parasitare  Organismen  in  den  Epithelzellen  der 

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CHANCROID. 

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CHOLERA   NO8TRAS. 
FlNKLER   AND   PllIOR.      Op.  cit.  (No.   1661) 

FRANCK.     Op.  cit.  (No.  1667). 
KARTULIS.     Op.  cit.  (No.  1669). 


CONJUNCTIVITIS. 

1721.  SATTLER.     Untersuchungen  liber  das  Trachom.     Bericht  tiber  die  Ophthalmo- 

logencongress  zu  Heidelberg,  1882. 

1722.  Ueber  die  Naturder  Jequirity- Ophthalmic.    Zehender's  klin.  Monatsbl., 

1883  (June). 

1723.  SATTLER  ET  DE  WECKER.     L'ophthalmie  jequiritique.     Paris,  1883. 

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sels, 1884. 

1727.  GIFFORD.     Beitrag  zur  Lehre  von  der  sympathischen  Ophthalmic.     Archiv 

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1728.  Ueber  das  Vorkommen  von  Mikroorgauismcn  bei  Conjunctivitis  ecze- 

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1729.  KNAPP.     Versuche  ilber  die  Einwirkung  von   Bakterien    auf   Augenopera- 

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844  BIBLIOGRAPHY. 

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1731.  FRANKEL,  EUG.,  UND  FKANKE.     Ueber  den  Xerosebacillus  und  seine  atiolo- 

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1732.  KAKTULIS.     Zur  yEtiologie  der  agyptischen  katarrhalischen   Conjunctivitis. 

Centralbl.  fur  Bakteriol.,  Bd.  i.,  1887,  p.  289. 

1733.  WEEKS.     Xerosis  conjunctivse  bei  Sauglingen  und  bei  Kindern.     Archiv  fiir 

Augenheilkunde,  Bd.  xvii.,  1887,  p.  193. 

1734.  Der  Bacillus  des  aku ten  Bindehautkatarrhs.     Ibid.,  p.  318. 

1735.  MONTI.     Richerche  batteriologiche  sulla  xerosi  congiuntivale  e  sulla  panoftal- 

mite.     Archivio  per  le  Scienze  mediche,  Bd.  xi.,  1887,  No.  4. 

1736.  ANDREWS.     Contagious  conjunctivitis  ;  its  causes,  prevention,  and  treatment. 

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1737.  GOLDSCHMIDT.     Zur  ^Etiologie  des  Trachotns.     Centralbl.  fur  klin.  Med.,  1887, 

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1739.  SCIILAFKE.     Der  Trachomakokkus.     Centralbl.  fiir  Bakteriol. ,  Bd.  ii.,  1887, 

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1740.  ERNST.     Ueber  den  Bacillus  xerosis  und  seine  Sporenbildung.     Zeitschr.  fiir 

Hygiene,  Bd.  iv.,  1888,  p.  25. 

1741.  SCHREIKER.     Ueber  die  Bedeutung  der  sogenannten  Xerosebacillen.    Fortschr. 

der  Med.,  1888,  p.  650. 

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CORYZA. 

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1749.  PASQUALE.     Ulterior!  richerche  sugli  streptococchi  delle  mucose  a  contribuo 

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CYSTITIS. 

1752.  SCHOTTELIUS  UND  RsiNHOLD.     Ueber  Bakteriurie.     Centralbl.  fiir  klin.  Med., 

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70 


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/ 

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Beriicksichtigung  der  experimentellen  Ergebnisse.     Deutsche  med.  Wochen- 
schr.,  1887,  Nos.  32  and  33. 

1803.  STERN  UND  HIRSCHLER.     Beitrage  zur  ^Etiologie  und  Symptomatologie  der 

ulcerosen  Endocarditis.     Wiener  med.  Presse,  1887,  Nos.  27  and  28. 

1804.  GILBERT  ET  LION.     Compt.  rend.  Soc.   de  B'ol.,  1883  (Bacilli  in  ulcerative 

endocarditis). 

1805.  Deuxieme  note.     Ibid.,  1889,  p.  21. 

1806.  GIRODE.     Quelques  faits  d'endocardite  maligne.     Compt.  rend.  Soc.  de  Biol., 

1889,  p.  622. 

1807.  PERRET  ET  RODET.     Sur  1'endocardite  infectieuse.     Compt.   rend.   Soc.   de 

Biol.,  1889,  p.  724. 

ERYTHEMA. 

1808.  CORDUA.     Zur  ^Etiologie  des  Erythema  multiforme.     Deutsche  med.  Wochen- 

schr.,  1885,  p.  576. 

1809.  DEMME.    Zur  Kenntniss  der  schweren  Erytheme  und  der  multiplen  Hautgan- 

gran.    Fortschr.  der  Med.,  1888,  No.  7. 

GRANULOSA  FONGOIDES. 

1810.  AUSPITZ.    Ein  fall  von  Granulosa  f ungoides.     Vierteljahresschr.  fur  Dermat. 

und  Syph.,  1885,  p.  123. 

1811.  RINDFLEISCH.    Mykosis  f  ungoides.    Deutsche  med.  Wochenschr.,  1885,  p.  233. 

HYDROPHOBIA. 

1812.  PASTEUR.     Nouvelle  communication  sur  la  rage.     Ann  de  Med.  veterin.,  1884. 

1813.  Lettre  sur  la  rage.    Ann.  de  1'Institut  Pasteur,  vol.  i.,  1887,  p.  1. 

1814.  Lettre  &  M.  Duclaux.     Ann.  de  1'Institut  Pasteur,  vol.  ii.,  1888,  p.  117. 

1815.  8ur  la  methode  de  prophylaxie  de  la  rage  apres  morsure.    Compt. 

rend.  Acad.  des  Sc.,  t.  cviii.,  1889,  p.  1228. 

1816.  PASTEUR,  CHAMBERLAND,  Roux  ET  THUILLIER.    Nouveaux  faits  pour  servir 

a  la  connaissance  de  la  rage.   Compt.  rend.  Acad.  des  Sc.,  t.  xcv.,  1882,  No. 
24. 

1817.  PASTEUR,  CHAMBERLAND  ET  Roux.     Methode  pour  prevenir  la    rage  apres 

morsure.     Compt.  rend.  Acad.  des  Sc.,  1885  (October  26th). 

1818.  GIBIER.     These  de  doctorat,  July  26th,  1884. 

1819.  BERT.     Contribution  a  1'etude  de  la  rage.     Compt.  rend.  Acad.  des  Sc.,  1882. 

1820.  FOL.     Sur  un  microbe,  dout  la  presence  parait  liee  &  la  virulencera  bique. 

Compt.  rend.  Acad.  des  Sc.,  1885,  No.  24. 

1821.  BABES.     Untersuchungen    iiber  die    Hundswuth.     Centralbl.   filr  die  med. 

Wissensch.,  1887,  No.  37. 

1822.  Studien  ttber  die  Wuthkrankheit.     Virchow's  Archiv,  Bd.  ex.,  18S7. 


848  BIBLIOGRAPHY. 

1823.  BARDACH.     Sur  la  vaccination  intensive  des  chiens  inocules  de  la  rage  par 

trepanation.    Ann.  de  1'Institut  Pasteur,  vol.  i.,  1887,  p.  84. 

1824.  Nouvelles  recherches  sur  la  rage.     Ibid.,  vol.  ii.,  1888,  p.  9. 

1825.  STERNBERG.     Experiments  on  the  temperature  destructive  of  the  virus  of 

hydrophobia.    In  Rep.  of  the  Com.  on  Disinfectants  of  the  A.  P.  H.  A. 
(Concord,  1888),  p.  147. 

1826.  ERNST.     An  experimental  research  upon  rabies.     Am.  Journ.  of  the  Med.  Sc. 

1887,  p.  321. 

1827.  VON  FRISCH.     Pasteur's  Untersuchungen  tlber  das  Wuthgift  und  seine  Pro- 

phylaxe  der    Wuthkrankheit.     Internal,   klin.   Rundschau,    1887,   No.   1. 
Also,  Mitth.  der  K.  Akad.  der  Wissensch. ,  Bd.  xxvii.,  1886. 

1828.  GAMELEIA.     Etude  sur  la  rage  paralytique  chez  1'homme.     Ann.  de  1'Institut 

Pasteur,  vol.  i.,  1887,  p.  63. 

1829.  Vaccination  antirabique  des  animaux.     Ibid.,  pp.  127  and  296. 

1830.  •  Vaccination  preventives  de  la  rage.     Ibid.,  p.  226. 

1831.  MOTTET  UND  PROTOPOPOFF.     Ueber  einen  Mikroben  der  bei  Kaninchen  und 

Hunden  eine  der  paralytischen  Tollwuth  ganz  ahnlichen  Krankheit  hervor- 
ruft.     Centralbl.  filr  Bakteriol.,  Bd.  ii.,  1887,  No.  20. 

1832.  PETER.     Les  vaccinations  antirabiques.     Journ.  de  Micrographie,  1887,  p.  449. 

1833.  DE  RENZI  E  AMOROSO.     Richerche  sperimentale  sulla  rabia.     Rivista  clin.  e 

therap.,  1887,  Nos.  2  and  5. 

1834.  RIVOLTA.    II  virus  rabido  (Coccobacterium  lyssae,  Rivolta).     Giorn.  di  Anat. 

fls.,  1886. 

1835.  SUZOR.    Hydrophobia :  an  account  of  M.  Pasteur's  system,  containing  a  trans- 

lation of  all  his  communications  on  the  subject,  the  technique  of  his  method, 
and  the  latest  statistical  results.    London,  1887,  231  pp. 

1836.  ULL.MANN.     Ein  Beitrag  zur  Frage  ilber  den  Werth  der  Pasteur'schen  Schutz. 

impfungen  am  Menschen.     Wiener  med.  Blatter,  1887,  p.  1260. 

1837.  VULPIAN.    Nouvelle  statistique  des  personnes  qui  ont  ete  traitees  a  1'Institut 

Pasteur,  etc.     Compt.  rend.  Acad.  des  Sc.,  1887  (January  28th). 

1838.  GALTIER.     Nouvelles  experiences  sur  1'inoculation  antirabique  en  vue  de  pre. 

server  les  animaux  mordus  par  les  chiens  enrages.   Compt.  rend.  Acad.  des 
Sc.,  t.  cvi.,  1888,  p.  1189. 

1839.  Persistance  de  la  virulence  rabique  dans  les  cadavres  enfouis.     Ibid., 

cvii.,  p.  364. 

1840.  Nouvelles  experiences  tendant  a  demontrer  1'efflcacite  des  injections 

intraveineuses  de  virus  rabique,  etc.     Ibid.,  cvii.,  1888,  p.  798. 

1841.  HELMAN.     Etudes  sur  les  formes  furieuses  et  paralytiques  de  la  rage  chez  les 

lapins.     Ann.  de  1'Institut  Pasteur,  vol.  ii.,  1888,  p.  274. 

1842.  Action  du  virus  rabique  introduit,  soit  dans  le  tissu  cellulaire  sous- 

cutane,  soit  dans  les  autres  tissus.     Ann.  de  1'Institut  Pasteur,  1889,  p.  15. 

1843.  HOGYES.     Le  virus  rabique  des  chiens  des  rues  dans  ses  passages  de  lapin  a 

lapin.    Ann.  de  1'Institut  Pasteur,  vol.  ii.,  1888,  p.  133. 

1844.  Contribution  experimentale  a  1'etude  de  quelques  questions  pendantes 

ausujet  de  la  rage.     Ann.  de  1'Institut  Pasteur,  vol.  iii.,  1889,  p.  429. 

1845. Vaccinations  contre  la  rage  avact  et  apres  infection.     Ibid.,  p.  449. 

1846.  NOCARD  ET  Roux.     Experience  sur  la  vaccination  des  ruminants  contre  la  rage 

par  injections  intraveineuses  de  virus  rabique.     Ann.  de  1'Institut  Pasteur, 
vol.  ii.,  1888,  p.  341. 

1847.  PROTOPOPOFF.     Zur  Immunitat  filr  Tollwuthgift  bei  Hunde.n.     Centfalbl.  fur 

Bakteriol.,  Bd.  iv.,  1888,  p.  85. 

1848.  Ueber  die  Vaccination  der  Hunde  gegen  Tollwuth.     Ibid.,  p.  787. 


BIBLIOGRAPHY.  849 

1849.  PROTOPOPOFF.     Ueber  die  Hauptursache  der  Abschwachung  des  Tollwuth- 

giftes.     Ibid.,  Bd.  vi.,  1889,  p.  129. 
1850. EinigeBoinerkungeu  iiberdie  Hundswuth.     Ibid.,  Bd.  v.,  1889,  p.  721. 

1851.  Roux.     Note  sur  UQ  inoyen  de  conserver  les  moelles  rabiques  avec  leur  viru- 

lence.   Ann.  de  1'Institut  Pasteur,  vol.  i.,  1887,  p.  87. 

1852.  Note  de  laboratoire  sur  la  presence  du  virus  rabique  dans  les  nerfs. 

Ibid.,  vol.  ii.,  p.  18. 

1853.  •  Note  de  laboratoire  sur  rimmunite  conferee  aux  chiens  centre  la  rage, 

par  1'iujection  intraveineuse.     Ibid.,  p.  479. 

1854.  ZAGARI.    Esperienze  iutorno  alia  transmissione  della  rabbia  dalla  madre  al 

feto  attraversa  la  placenta  e  per  mezzo  del  latte.     Ibid.,  1888. 

1855.  BABES  ET  LEPP.    Recherches  sur  la  vaccination  antirabique.     Ann.  de  1'In- 

stitut  Pasteur,  vol.  iii.,  1889,  p.  384. 

1856.  BAGNIS.    VirulenzadeFumor  acqueo  negli  animali  rabbiosi.     Riforma  medica, 

1889,  No.  225. 

1857.  BAREGGI.    II  nuovo  metodo  antirabbico  Ferran  e  la  sua  interpretazione  speri- 

mentale,  etc.    Riforma  medica,  1889,  Nos.  43  and  44. 

1858.  DE  BLASI  E  RUSSO-TRAVALI.     Rendiconti  delle  vaccinazioni  profllattiche  ed 

esperimenti  esequiti  nell'  Instituto  antirabbico  e  di  microscopia  cliuica  della 
citta  di  Palermo.     Palermo,  1889. 

1859.  BUJWID.    La  methode  Pasteur  3,  Varsovie.    Ann.  de  1'Institut  Pasteur,  1889, 

p.  177. 

1860.  FERREIRA  DOS  SANTOS.     Statistique  du  traitement  preventive  de  la  rage,  du 

9  fevrier,  1888,  au  15  septembre,  1889,  a  1'Institut  Pasteur  de  Rio  de  Jan- 
eiro.    Compt.  rend.  Acad.  des  Sc.,  t.  cix.,  1889,  p.  694. 

1861.  GASPARETTI.     Relazione  sull' Instituto  antirabbico  di  Padova.     Riforma  medi- 

ca, 1889  (January). 

1862.  HORSLEY.    On  rabies  :  its  treatment  by  M.  Pasteur,  and  on  the  means  of  de- 

tecting it  in  suspected  cases.     Brit.  Med.  Journ.,  1889,  p.  342. 

1863.  RUSSO-TRAVALI  ET  BRANCALEONE.    Sulla  resistenza  del  virus  rabbico  alia 

putrefazione.    Riforma  medica,  1889,  No.  127. 

1864.  Di   VESTEA   E   ZAGARI.    Sulla  transmissione    della  rabbia  per  la  via    dei 

nervi.    Giornale  internaz.  della  Sci.  med.,  1887. 

1865.  Nuove  richerche  sulla  rabia.     Ibid.,  1889,  No.  2. 

1866.  Sur  la  transmission  de  la  rage  par  voie  nerveuse.    Ann.  de  1'Institut 

Pasteur,  vol.  iii.,  1889,  p.  237. 

1867.  PERDRIX.    Les  vaccinations  antirabiques  a  1'Institut  Pasteur.     Aon.  de  1'In- 

stitut  Pasteur,  vol.  iv.,  1890,  p.  129. 

1868.  Roux  ET  NOCARD.     A  quel  moment  le  virus  rabique  apparait-il  dans  la  bave 

des  animaux  enrages.     Ann.  de  1'Institut  Pasteur,  vol.  iv.,  1890,  p.  163. 

1869.  BOMBICCI.    Sulla  virulenza  delle  capsule  surrenali  del  coniglio,  nella  rabbia. 

La  Riforma  med.,  1890,  p.  471. 

1870.  BRUSCHETTINI.     Sur  la  maniere  dont  se  comporte  le  virus  de  la  rage  dans  le 

vide  et  dans  plusieurs  gaz.     Ann.  de  Micrographie,  t.  iii.,  1890,  No.  1. 

1871.  TIZZONI  ET  SCHWARZ.     La  prophylaxie  et  la  guerison  de  la  rage  par  le  sang 

des  animaux  vaccines  contre  cette  maladie.    Ann.  de  Micrographie,  t.  iv., 
1892,  p.  169. 

ICTERUS. 

1872.  KARLINSKY.     Zur  Kenntniss  des  fieberhaften  Icterus.     Fortschr.  der  Med., 

Bd.  viii.,  1890,  No.  5. 

1873.  DUCAMP.     Une  petite  epidemic  d'ictere  infectieux.     Revue  de  Med.,    1890 

(June). 


850  BIBLIOGRAPHY. 

MALARIA. 

1874.  KLEBS  UND  TOMMASI-CRUDELI.     Studien  iiber  die  Ursache  des  Wechselfiebers 

und  iiber  die  Natur  der  Malaria.  Archiv  fur  exper.  Path,  und  Pharmakol., 
Bd.  xi.,  1879,  pp.  311-398,  3  pi.  Also,  Reale  Accademia  dei  Lincei,  1879> 
(June). 

1875.  STERNBERG.     Special  report  to  National  Board  of  Health :  experimental  in- 

vestigations relating  to  the  etiology  of  the  malarial  fevers.  Nat.  Bd.  Health 
Bull.,  Washington,  vol.  iii.,  1881-82. 

1876.  CECI.    Bacillus  malarise.     Archiv  fur  exper.  Path.,  Bd.  xv.  and  xvi. 

1877.  ZIEHL.    Deutsche  med.  Wochenschr. ,  1883. 

1878.  MARCHIAFAVA.     Studi  sulla  malaria.     Salute,  Bd.  xiv.,  1880,  p.  225. 

1879.  MARCHAND.     Bacillus  malarias.     Virchow's  Archiv,  Bd.  Ixxxviii.,  1882,  p.  104. 

1880.  TOMMASI-CRUDELI.    The  Practitioner,  London,  1880,  p.  321. 

1881.  Richerche  sulla  natura  della  malaria,  esequite  dal  Dr.  Bernardo  Schia- 

vuzzi  in  Pola.     Rendiconti  della  R.  Accad.  dei  Lincei,  1886  (December  5th). 

1882.  CUBONI  UND  MARCHIAFAVA.    Archiv  fiir  exper.  Pathol.,  Bd.  xiii.,  p.  265. 

1883.  MAUREL.    L'etiologie  et  la  nature  du  paludism.     Ann.  d' Hygiene,  1883. 

1884.  GOLGI.     TJeber  den  angeblichen  Bacillus  mnlariae  von  Klebs,  Tommasi-Cru- 

deli  und  Schiavuzzi.    Ziegler's  Beitriige,  Bd.  iv.,  1888,  p.  419. 

MEASLES. 

1885.  COZB  ET  FELTZ.    Recherches  exper.  sur  la  presence  des  infus.  dans  les  mala- 

dies infectieux.     Paris  and  Strassburg,  1866. 

1886.  Recherches  cliniques  et  exper.  sur  les  maladies  infectieux.     Paris,  1872. 

1887.  BRAIDWOOD  AND  VACHER.    Reports  of  the  Scientific  Grants  Committee  of  the 

British  Med.  Assn.     London,  1882. 

1888.  KEATING.    The  presence  of  micrococci  in  the  blood  of  malignant  measles. 

The  Medical  Times,  Philadelphia,  vol.  xii.,  1882,  p.  766. 

NEPHRITIS. 

1889.  MICOLI.     Nefriti  micotiche  primitive  in  bambini.     La  Riforma  medica,  1887. 

1890.  LETZERICH.    Untersuchungen  und  Beobachtungen  uber  Nephritis  bacillosa 

interstitialis  primaria.     Zeitschrift  filr  klin.  Med.,  Bd.  xiii.,  1887,  p.  33. 

1891.  RIVOLTA.     Da  una  nefrite  bacillare  nei  bovini.     Giorn.  d'Anat.  e  Fisiol.,  1887.. 

1892.  LUSTGARTEN   UND  MANNEBERG.     In  Vierteljahresschr.   fur  Dermatol.  und 

Syph.,  Bd.  xiv.,  1887,  p.  905. 

1893.  MANNEBERG:    Zur  ^Etiologie  des  Morbus  Brightii  acutus.     Centralbl.  fiirklin. 

Med.,  1888,  No.  30. 

1894.  Loos.     Beitrage  zur  Lehre  von  der  primaren  Nephritis  filr  Kinder.     Jahrb. 

far  Kinderheilk.,  Bd.  xxx.,  1890,  Heft  4. 

1895.  KOMPE.     Nephritis  im  Gefolge  des  Unteileibstyphus.     Miinchener  med.  Wo- 

chenschr., 1890,  No.  11. 

OTITIS. 

1896.  ZAUFAL.     Mikroorganismen  im  Secrete  der  Otitis  media  acuta.     Prager  med. 

Wochenschr.,  1887,  No.  16. 

1897.  Weitere  Mittheilungen  iiber  das  Vorkommen  von  Mikroorganismen  im 

Secrete  der  Otitis  media  acuta.     Ibid.,  1888,  No.  8. 


BIBLIOGRAPHY.  851 

1898.  ZAUFAL.    Der  eiterbildende  Kettenkokkus  (Streptococcus  pyogenes)  bei  Otitis 

media  und  ihre  Folgenkrankheiten.     Ibid.,  Nos.  20  and  21. 

1899.  Neue  Falle  von  genuiner  akuter  Mittelohrentziindung  veranlasst  durch 

den  Diplococcus  pneumonioe.     Ibid.,  1889,  Nos.  6-12  ;  ibid.,  No.  15;  ibid., 
No  36. 

1900.  Bakteriologisches  zur  Mittelohrentziindung  bei  Influenza.     Ibid.*  1890, 

No.  9. 

1901.  Centralbl.  fiir  Bakteriol. ,  Bd.  ix.,1891,  pp.  326,  357. 

1902.  WEICHSELBAUM.     Ueber  eine  von  einer  Otitis  media  suppurativa  ausgehende 

und  durch  den  Bacillus  pneumoniae  (Friedlander)  bedingte  Allgemeininfek- 
tion.     Monatsschr.  f  iir  Ohrenheilkunde,  1888,  Nos.  8  and  9. 

1903.  LEVY  UND  SCHRADER     Bakteriologisches  iiber  Otitis  media.     Archiv  f  ilr  exp. 

Pathol.  und  Pharmakol.,  Bd.  xxvi.,  p.  223. 

1904.  GRADENIGO.     Contribution  &  1'etude  bacteriologique  des  otitis  moyennes  puru- 

lentes.    Ann.  des  Maladies  de  1'Oreille,  1889,  No.  9. 

1905.  BORDONI-UFFREDUZZI    UND    GRADENIGO.     Ueber  die    ^Etiologie    der    Otitis 

media.     Centralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  pp.  529,  556,  695. 

1906.  MAGGIORA    UND    GRADENIGO.    Bakteriologische    Beobachtungen    liber  den 

Inhalt  der  Eustachischen  Trompete  bei  chronischen  katarrhalischen  Mittel- 
ohrentzundung.     Centralbl.  fur  Bakteriol.,  Bd.  viii.,  1890,  p.  582. 

1907.  SCHEIBE.    Bakteriologisches  liber  Otitis  media  bei  Influenza.     Centralbl.  fur 

Bakteriol.,  Bd.  viii.,  1890,  p.  225. 

OSTEOMYELITIS. 

1908.  BECKER.     Vorlaufige    Mittheilungen  liber    den  die  akute  infekti5se  Osteo- 

myelitis   erzeugenden    Mikroorganismus.     Deutsche    med.    Wochenschr., 
November,  1883. 

1909.  KRAUSE.     Ueber  einen  bei  derakuten  infektiosen  Osteomyelitis  vorkommenden 

Mikrokokkus.     Fortschr.  der  Med  ,  Bd.  ii.,  1884. 

1910.  ROSENBACH.     Vorliiufige  Mittheilungen  iiber  die  die  akute  Osteomyelitis  beim 

Menschen  erzeugenden  Mikroorganismen.     Centralbl.  fiir  Chirurgie,  1884, 
No.  5. 

1911.  RODET.    fitude  experimental  sur  1'osteomyelite  infectieuse.     Compt.  rend. 

Acad.  des  Sc. ,  t.  xcix.,  p   569. 

1912.  KRASKE.     Zur  JEtiologie  und  Pathogenese  der  akuten  Osteomyelitis.    Berliner 

klin.  Wochenschr.,  1886,  p.  262. 

1913.  GIORDANO.    I  microbii  piogeni  nella  eziologia  della  osteomiellite  infettiva  acuta. 

Tesc.  Torino,  1888. 

1914.  LANNELONGUE  ET  ACHARD.     Les  microbes  de  1'osteomyelite  aigue  dite  infec- 

tieuse.   La  Semaine  med.,  1890,  No.  11. 

1915.  Des  osteomyelites  a  streptocoques.     Ibid.,  1890,  No.  23. 

1916.  Des  osteomyelites  a  streptocoques.     Compt.  rend.  Soc.  de  Biol.,  1890, 

No.  19. 

1917.  COLZI.     Sulla  eziologia  della  osteomiellite  acuta.     Lo  Sperimentale,  vol.  Ixiv., 

1890,  pp.  471,  561. 

1918.  COURMONT  ET  JABOULAY.     Sur  les  microbes  de  l'osteomyelite  aiguS  infec- 

tieuse.    Compt.  rend.  Soc.  de  Biol.,  1890,  No.  18 

OZ^ENA. 

1919.  KLAMANN.     Allg.  med.  Centralzeitg.,  1885,  August  22d 

1920.  THOST.     Pneumoniekokken  in  der  Nase.     Deutsche  med.  Wochenschr.,  1886, 

p.  161. 


852  BIBLIOGRAPHY. 

1921.  LOWENBERG.     Zur  Prioritat  betreffs  Ozaenakokkus.     Deutsche  med.  Wochen- 

schr., 1886,  p.  446. 

1922.  HAJEK.     Ueber  Ozsena.     Milnchener  med.  Wocbenschr.,  1887,  No.  47. 

1923.  Die  Bakterien  bei  der  akuten  und  chronischea  Coryza,  sowie  bei  der 

Ozaena  und  deren  Beziehungen  zu  den  genannten  Krankheiten.     Berliner 
klin.  Wochenschr.,  1888,  No.  33. 

1924.  REIMANN.    Ueber  Mikroorganismen  im  Nasensecret  bei  Ozsena.    Inaug.  Diss., 

Wiirzburg,  1887 

1925.  ROHRER.     Bakteriologische  Beobachtungen  bei  affectionen  des  Obres  und  des 

Nasen-Rachenraumes.     Centralbl.  fiir  Bakteriol..  Bd.  iii.,  1888,  p.  644. 

1926.  BERLINER.     Ueber  Ozama  und  ihre  Behandlung  und  Prophylaxe.     Deutscbe 

med.  Wochenschr.,  1889,  No.  51. 

1927.  MARANO.     Sulla  natura  dell'  ozena.     Archiv  ital.  di  Laringologia,  1890  (Jan.). 

PAROTITIS. 

1928.  HANAN.     Ueber  eitrige  Entzilndung  der    Speicheldrusen.     Correspondenzbl. 

filr  Schweizer  Aerzte,  Bd.  xviii.,  1888. 

1929.  STERN  UND   HIRSCHLER.    Beitrag  zur  Lehre  der  Mischinfektion.     Wiener 

med.  Presse,  1888,  No.  28. 

1930.  TESTI.     Parotite  suppurativa  determinata  dal  diplococco  di  Frankel.     Lavori 

dei  Cong,  di  Med.  interna,  secondo  congresso  tenuto  in  Roma  nell'  ottobre, 
1889. 

1931.  DUPLAY.     Parotide  &  pneumocoques     La  Semaine  med.,  1891,  No.  2. 

PEMPHIGUS. 

1932.  DEMME.    Beitrage    zur  Kenntniss  des  Pemphigus  acutus.     Verhandl.    des 

V.  Cong,  fur  innere  Medicin  in  Wiesbaden.     Wiesbaden,  1886. 

1933.  DAHNHARDT.     Beitrag  zur  Kenntniss  des  Pemphigus  chronicus.     Deutsche 

med.  Wochenschr.,  1887,  No.  32. 

1934.  STRELITZ.    Bakteriologische  Untersuclmngen  ilber  den  Pemphigus  neonato- 

rum.     Archiv  fur  Kinderheilk. ,  Bd.  xi.,  1889. 

PERITONITIS. 

1935.  PERNICE.     Sulla  peritonite  sperimentale.    Rivista  internaz.  di  Med.  e  Chir., 

1887. 

1936.  PAWLOWSKY.    Beitrage  zur  ^Etiologie  und  Entstehungsweise  der  akuteu  Peri- 

tonitis.    Centralbl.  fur  Chirurgie,  1887,  No.  48. 

1937.  Ueber  die  ^Etiologie  und  die  Formen  der  akuten  Peritonitis.     Abstract 

in  Centralbl.  fur  Bakteriol.,  Bd.  v.,  1888,  p.  715. 

1938. Virchow's  Archiv,  Bd.  cxvii.,  1889,  p.  469. 

1939.  CLIVIO  E  MONTI.     SuLL'  eziologia  delle  peritonite  puerperale.     Estratto  degli 

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1940.  WEICHSELBAUM:.     Der  Diplococcus    pneumonia  als  Ursache   der  primaren, 

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1911.  LAMELLE.     Etude  bacteriologique  sur  les  peritonites  par  perforation.      La 
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1942.  BUMM.     Zur  JEtiologie  der  septischen  Peritonitis.     Milnchener  med.  Wochen- 

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1943.  FRANKEL,  E.     Zur  vEtiologie  der  Peritonitis.     Milnchener  med.  Wocheuschr. 

1890,  Nos.  10  and  11. 


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YELLOW  FEVER. 

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individus  morts  de  la  flevre  jaune. 

2015.  BABES.     Fievre  jaune.     In  Les  Bacteries.     2d  ed.,  Paris,  1886,  p.  521. 

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PART  FOURTH. 


SAPROPHYTES. 


I.   BACTERIA  IN  THE  AIR. 

"2022.  POUCHET.     Compt.  rend.  Acad.  des  Sc.,  xlvii.,  1858. 

2023.  PASTEUR.    Memoire  sur  les  corpuscles  organises  qui  existent  en  suspension 

dans  1'atmosphere.     Compt.  rend.  Acad.  des  Sc.,  lii.,  1862. 
"2024.  MADDOX.     Monthly  Mic.  Journ.,  1870. 
2025.  CUNNINGHAM.     Microscopic  examination  of  the  air  of  Calcutta.     Rep.  to  San. 

Com.  with  Govt.  of  India,  1872.     Calcutta,  1874. 
'2026.  TYNDALL.    Essays  on  the  floating  matter  of  the  air  in  relation  to  putrefaction 

and  infection.     New  York,  1882,  537  pp.  (D.  Appletou  &  Co  );  also  London, 

1881. 
•2027.  MIPLET.     Untersuchungen    ilber     die  in    der  Luft  suspendirten  Bakterien. 

Cohn's  Beitrage  zur  Biol.  der  Pflanzen,  Bd.  in.,  1879. 
2028.  KLEBS  UNO  TOMMASI-CRUDELI.     Untersuchungen  der  Luft  auf  die  Mikroor- 

ganismen  der  Malaria.     Archiv  f  lir  Exper.  Path.,  Bd.  ii.,  1879. 
5029.  BUCHNER.     Die  Bedingungen  des  Uebergangs  von  Pilzen  in  die  Luft.     Vor- 

trage  im  Aerztl.  Verein  zu  Milnchen,  1881. 

2030.  VON  FODOR.     Hygienische  Untersuchungen  ilber  Luft,  Boden  und  Wasser. 

Braunschweig,  1882. 

2031.  MIQUEL.     Les  organismes  vivants  de  1'atmosphere.     Paris,  1883. 

2032.  Annuaire  de  1'Observatoire  de  Montsouris,  1877-1888. 

2033.  Dixieme  memoire  stir  les  poussieres  organisees  de  1'air  et  des  eaux. 

Annuaire  de  Montsouris  pour  1888. 

2034.  De  1'analyse  microscopique  de  1'air  au  moyen  de  flltres  solubles.     Ann. 

de  Micrographie,  t.  i.,  1889,  p.  146. 


BIBLIOGRAPHY.  857 

/ 

2035.  EMMERICH.     Ueber  die  Bestimmung  der  entwicklungsfahigen  Luftpilz.     Ar- 

chiv  flir  Hygiene,  Bd.  i.,  Heft  2. 

2036.  HESSE.     Ueber  quantitative  Bestimmung  der  in  der  Luft  enthaltendeu  Mikro- 

organismen.     Mitth.  ausdemK.  Gesundheitsamte,  Bd.  ii.,  1884. 

2037.  Ueber  Abscheidung  der  Mikroorganismen  aus  der  Luft.      Deutsche 

med.  Wochenschr.,  No.  2,  1884. 

2038.  -    —  Weitere  Mitth.  ilber  Luftfiltration.     Ibid.,  1884,  No.  51. 

2039.  GIACOSA.     Les  corpusc.  organ,  de  1'air  des  liautes  montagnes.     Arch.  ital.  de 

Biol  ,  Bd.  iii. 

2040.  FREUDENREICH.     Les  microbes  de  1'air  des  montagnes.     Rev.   scientifique, 

t.  ii.,  p.  384. 

2041.  Les  variations  horaires  des  bacteries  et  la  purete  de  1'air  de  la  cam- 

pagne.     Arch,  des  Sc.  phys.  et  naturelles,  t.  xvi.,  1886,  p.  572. 

2042.  PETRI.     Eiue  neue  Methode,  Bakterien  und  Pilzsporen  in  der  Luft  nachzu- 

weisen  und  zu  zahlen.     Zeitschr.  fiir  Hygiene,  Bd.  iii.,  1887,  p.  1. 

2043.  FRANKLAND.    Methode    der  bakteriologischen  Luftuntersuchung.    Zeitschr. 

fur  Hygiene,  Bd.  iii.,  1887,  p.  287. 

2044.    The  distribution  of  microorganisms  in  air.     Proc.  of  the  Roy.  Soc., 

London,  1885,  p   509. 

2045.  CONDORELLI-MANGERI.    Variazioni  numeriche  dei  microorganismi  nell'  aria  di 

Catania.    Atti  dell'  Accad.  Gioenia  di  Sci.  nat.  in  Catania,  vol.  xx.,  1888, 
p.  111. 

2046.  FISCHER.    Bakteriologische  Untersuchungen  auf  einer  Reise  nach  Westindien. 

Zeitschr.  fur  Hygiene,  Bd.  i.,  1886,  p.  421.     Ibid.,  Bd.  ii.,  1887,  p.  54. 

2047.  NEUMANN.     Ueber  den  Keimgehalt  der  Luft  im  stadtischen  Krankenhaus 

Moabit.     Vierteljahresschr.  fur  gerichtl.  Med.  und  offentl.  Sanitatswesen, 
Bd.  xlv.,  1886,  p.  310. 

2048.  CADEAC  ET  MALET.     Sur  la  transmission  des  maladies  infectieuses  par  1'air  ex- 

pire.   Lyon  Medical,  1887,  No.  14. 

2049.  ROBERTSON.     A  study  of  the  microorganisms  in  air,  especially  those  in  sewer 

air,  and  a  new  method  of  demonstrating  them.     Brit.  Med.  Journ.,  1888, 
Dec.  15th. 

2050.  STRAUS.     Sur  1'absence  de  microbes  dans  1'air  expire.    Ann.  de  1'Institut  Pas- 

teur, 1888,  p.  181. 

2051.  UFFELMANN.     Luftuntersuchungen,  ausgefilhrt  im  hygienischen  Institut  der 

Universitiit  Rostock.     Archiv  fur  Hygiene,  Bd.  viii.,  1888,  p.  262. 

2052.  SEDGWICK  AND  TUCKER.    A  new  method  for  the  biological  examination  of 

air  (preliminary  communication).     Proc.  of  the  Soc.  of  Arts,  Boston.,  Jan. 
12th,  1888. 

2053.  A  new  method  for  the  biological  examination  of  air,  with  a  description 

of  an  aerobioscope.     Nat.  Acad.  of  Sc.,  Washington,  April  18th,  Ib88. 

2054.  WELZ.    Bakteriologische  Untersuchungen  der  Freiburger  Luft.     Zeitschr.  ftir 

Hygiene,  Bd.  xi.,  p.  121. 

II.   BACTERIA  IN  WATER. 

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2118.  FINKLENBUKG.     Ueber  einen  Befund  von  Typhusbacillen  im  Brunnenwasser, 

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2131.  Milzbrandbacillen  im  Boden.    Ibid.,  p.  65. 

2132.  FRANCK.     Ueber  die  chemischen  Umsetzungen  im  Boden  und  dem  Einflusse 

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2183.  LAURENT.     Les  microbes  du  sol.    Journal  de  Pharmacie  et  de  Chimie,  1886, 
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2134.  PFEIFFER.     Die  Beziehungen  der  Bodencapillaritat  zum  Transport  von  Bak- 

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2135.  Antwort  auf  die  Engegnung  des  Herrn  Soyka  bezilglich  meines  Auf. 

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2137.  Die  Lebensthatigkeit  niederer    Organismen  bei  wechselnder    Boden- 

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fur  Bakteriol.,  Bd.  i.,  1887  p.  441.     Ibid.,  Bd.  ii.,  1887,  No.  15. 

2140.  FRANKEL,  C.     Untersuchungen  liber  das  Vorkommen  von  Mikroorganismen  im 

verschiedenen  Bodenschichten.     Zeitschr.  fur  Hygiene,  Bd.  ii.,  1887,  p.  521. 

2141.  MAGGIORA.     Richerche  quantitative  sui  microorganism!  del  suolo,  etc.    Giorn 

della  R.  Accad.  di  Med.,  1887,  No.  3. 

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Wochenschr.,  1886,  No.  27. 

2143.  KLEMENTIEFF.     Versuch  einer  quantitativen  Bestimmung  der  Mikroorganis- 

men im  Boden  von  Kirchhofen.     Inaug.  Diss.    St  Petersburg  1887. 

2144.  SMOLENSKI.    Bakteriologische  Untersuchungen  des  Bodens  im    Lager   der 

Avantgarde  bei  Krasnoje  Selo.     Wratsch.,  1887,  No.  10. 

2145.  ADAMETZ.     Ueber  die  niederen  Pilze  der  Ackerkrume.     Inaug.  Diss.,  Leipzig, 

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2146.  KRAMER.     Die    Bakteriologie  in    ihren  Beziehungen   zur  Landwirthschaft. 

Wien,  1890. 

2147.  FRANKLAND,  G.  C.  UND  P.  F.     Ueber  einige  typische  Mikroorganismen  im 

Wasser  und  Boden.     Zeitschrift  filr  Hygiene,  Bd.  vi.,  1889,  p.  373. 

2148. The  nitrifying  process  and  its  special  ferment.     Pro*;.  R.  Soc.,  London, 

vol.  xlvii.,1890*,  p.  296. 

2149.  GRANCIIER  UND  RICHARD.     Ueber  den  Einfmss  des  Bodens  auf  die  Krank- 

heitserreger.     Centralbl.  filr  Bakteriol.,  Bd.  vii.,  1889,  p.  578. 

2150.  REIMERS.     Ueber  den  Gehalt  des  Bodens  an  Bakterien.    Zeitschrift  filr  Hy- 

giene, Bd.  vii.,  1889,  p.  307. 

2151.  SACHSSE.     Die  Mikroorganismen  des  Bodens.     Chemisches  Centralbl.,  Bd.  ii., 

1889,  Hefte  4  und  5. 

2152.  DE  GIAXA.     Le  bacille  du  cholera  dans  le  sol.     Ann.  de  Micrographie,  1890. 

71 


863  BIBLIOGRAPHY. 

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p.  92. 

2154.  DOWD.     A  study  of  the  hygienic  condition  of  our  streets.     Medical  Record, 

New  York,  1890,  p  700. 

2155.  MANFREDI  UNO  SERAFINI.    Ueber  das  Verhalten  von  Milzbrand-  und  Cholera- 

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2156.  JORDAN  AND  RICHARDS,  ELLEN  H.    Investigations  upon  nitrification  and  the 

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IV.  BACTERIA  OF  THE  SURFACE  OF  THE  BODY  AND  OF  EXPOSED 
MUCOUS  MEMBRANES. 

2158.  BORDONI-UFPREDUZZI.    Ueber  die  biologischen  Eigenschaften  der  normalen 

Hautmikrophyten.     Fortschr.  der  Med.,  1886,  No.  5. 

2159.  KUMMELL,  FORSTER,  FtJRBRiNGER.     Disinfection  of  the  hands.     See  Nos.  508, 

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2160.  MAGGIORA.    Contribute  allo  studio  dei  microfiti  della  pelle  umana  normale  e 

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2161.  UNNA  UND  SEHLEN.    Flora  dermatologica.    Monatsh.   fiir  prakt.  Dermat., 

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2162.  FICK.     Ueber  Mikroorganismen  im  Conjunktivalsack.     Wiesbaden,  1887. 

2163.  G  A  YET.    Asepsie  methodique.    LaSemaine  med.,  1887,  p.  199. 

2164.  FELSER.     Die  Mikroorganismen  des  Conjunktivalsackes  und  die  Antisepsis 

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2166.  HAJEK.     Ueber  Ozsena.    Munchener  med.  Wochenschr.,  1887,  No.  47. 

2167.  REIMANN.     Ueber  Mikroorganismen  im  Nasensecret  bei  Ozsena.    Inaug.  Diss., 

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2168.  VON  BESSER.    Ueber  die  Bakterien  der  normalen  Luftwege.     Ziegler's  Bei- 

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2169  WEIBEL      Untersuchungen  tiber  Vibrionen.     Centralbl.   fiir  Bakteriol.,  Bd. 
ii.,1887,  p.  465. 

2170.  -    —  Ibid    Bd.  iv  ,  1888,  p.  225. 

2171.  ROHRER      Bakteriologische  Beobachtungen  bei  Affektionen  des  Ohres  und  des 

Nasen-Rachenraumes.     Centralbl.  fur  Bakteriol.,  Bd.  iii.,  1888,  p.  644. 

2172.  THOST.    Pneumoniekokken  in  der  Nase.     Deutsche  med.  Wochenschr.,  1886, 

p.  161. 

2173.  WRIGHT.    Nasal  bacteria  in  health.     New  York  Med.  Journ.,  1889  (July  27th). 

2174.  PAULSEN.    Mikroorganismen  in  der  gesunden  Nasenhohle  und   beim  akuten 

Schnupfen.     Centralbl.  fur  Bakteriol.,  Bd.  viii.,  1890,  p.  344. 

2175.  STERNBERG.    A  fatal  form  of  septicaemia  in  the  rabbit  produced  by  the  sub- 

cutaneous injection  of  human  saliva.    Johns  Hopkins  Univ.  Stud.   Biol. 
Lab.,  Baltimore,  vol.  ii.,  1882,  p.  183. 

2176. A  contribution  to  the  study  of  the  bacterial  organisms  commonly  found 

upon  exposed  mucous  membranes,  etc.     Proc.  Am.  Assn.  Adv.  Sc.,  vol. 
xxx.,  1881,  p.  83. 


BIBLIOGRAPHY.  863 

2177.  VIGNAL.     Recherches  sur   les   microorganismes    de     la    bouche.     Arch,    de 

Physiol.  norm,  et  path.,  1886,  No.  8. 

2178.  MILLER.     Zur  Kenntniss    der    Bakterien    der    Mundhohle.     Deutsche  med. 

Wochenschr.,  1884,  No.  47. 

2179.  The  microorganisms  of  the  human  mouth.     Philadelphia,  1890,  364 

pp. 

2180.  BIONDI.     Die  pathogenen  Mikrcorganismen    des  Speichels.    Zeitschrift    fur 

Hygiene,  Bd.  ii  ,  1887,  p.  194. 

2181.  KREIBOHM.     Ueber  das  Vorkommen  pathogener  Mikroorganismen  im  Mund- 

secrete.     Inaug.  Diss.,  Gottingen,  1889. 

2182.  NETTER.    Microbes  pathog&nes  contenus  dans  la  bouche  de  sujets  sains,  etc. 

Revue  d'Hygiene,  1889,  No.  6. 

2183.  PODBIELSKY.     Untersuchungen  der  Mikroben  der  Mundhohle  von  Erwach- 

senen  und  Kindern  im  gesunden  Zustand.      124  pp.  8vo,  Katzan,  1890. 
Russian.    Abstract  in  Centralbl.  far  Bakteriol.,  Bd.  ix.,  1891,  p.  617. 

2184.  SANARELLI.     Der  menschliche  Speichel  und  die  pathogenen  Mikroorganismen 

der  Mundh5hle.     Centralbl.  fur  Bakteriol.,  Bd.  x.,  1891,  p.  817. 

2185.  DODERLEIN.    Ueber  das  Vorkommen  von  Spaltpilzen  in  der  Lochien  des 

Uterus  und  der  Vagina  gesunder  und  kranker  Wochnerinnen.    Archiv  fur 
Gynakol.,  Bd.  xxi.,  1887,  p.  412. 

2186.  WINTER.    Die  Mikroorganismen  im  Genitalkanal  der  gesunden  Frau.    Zeit- 

schrift fur  Geburtshulfe  und  Gynakol.,  Bd.  xiv.,  1888,  Heft  2. 

2187.  VON  OTT.    Zur  Bakteriologie  der  Lochien.  Archiv  fur  Gynakol.,  Bd.  xxxi., 

1888,  p.  436. 

2188.  CZERNIENSKY.     Zur  Frage  der  Puerperalerkrankungen.     Archiv  filr  Gynakol., 

Bd.  xxxiii.,  1888,  p.  73. 

2189.  STEFFECK.    Bakteriologische  Begrilndung  der  Selbstinfektion.    Zeitschr.  fur 

Geburtshulfe  und  Gynakologie,  Bd.  xx.,  p.  339. 


V.    BACTERIA  OF  THE  STOMACH  AND  INTESTINE. 

2190.  FALKENHEIM.    Ueber  Sarcine.    Archiv  fur  experim.  Pathologic  und  Pharma- 

kologie  Bd.  xix.,  1885,  p.  1. 

2191.  DE  BARY.    Beitrag  zur  Kenntniss  der  niederen  Mikroorganismen  im  Magen- 

inhalt.   Archiv  filr  experim.  Pathol.  und  Pharmakol.,  Bd.  xx.,  1886,  p.  243. 

2192.  MILLER.    Ueber  einige  gasbildende   Spaltpilze  des  Verdauungstraktus,  ihr 

Schicksal  im  Magen  und  ihre  Reaktion  auf  verschiedene  Speisen.    Deutsche 
med.  Wochenschr.,  1886,  No.  8. 

2193.  VAN  PUTEREN.    Ueber   die   Mikroorganismen   im    Magen  von  SSuglingen. 

Wratch.,  1888,  No.  22.     Abstract  in  Zeitschr.  filr  Mikroskopie,  Bd.  v.,  1888, 
p  539. 

2194.  STRAUS  ET  WURTZ.     De  1'action  du  sue  gastrique   sur  quelques  microbes 

pathogenes.    Arch,  de  Med.  exper.  et  d'Anat.  pathol.,  1889,  No.  3. 

2195.  KURLOW  UND  WAGNER.     Ueber  die  Wirkung  des  menschlichen  Magensaftes 

auf  pathogenen  Mikroorganismen.     Wratsch.,  1689,  p.  926. 

2196.  CAPITAN   ET    MORAN.     Recherches  sur  les  microorganismes  de    1'estomac 

Compt.  rend.  Soc.  de  Biol.,  1889,  p.  25. 

2197.  ABELOUS.     Recherches  sur  les  microbes  de  I'estomac  a  1'etat  normal,  et  leur 

action  sur  les  substances  alimentaires.     Compt.  rend.  Soc.  de  Biol.,  1889, 
p  86. 


864  BIBLIOGRAPHY. 

2198.  RACZTNSKI.     Zur   Frage  liber  die   Mikroorganismen  des  Verdauungskanals. 

Inaug.  Diss.,  St.  Petersburg,  1888.     Abstract  in  Centralbl.   fiir  Bakteriol., 
Bd.  vi.,  1889,  p.  112. 

2199.  HAMBURGER.     Ueber  die  Wirkung  des  Magensaftes  auf  pathogene  Bakterien. 

Centralbl.  filr  klin.  Med.,  1890,  No.  24. 

2200.  KIANOWSKI.    Zur  Frage  ilber  die  antibakteriellen  Eigenschaften  des  Magen- 

saftes.    Wratsch.,  1890,  Nos.  38-41.     Abstract  in  Centralbl.  filr  Bakteriol., 
Bd.  ix.,  1891,  p.  420. 

2201.  NOTHNAGEL.    Niedere  Organismen  in  den  menschlichen  Darmentleerungen, 

Zeitschr.  fur  klin.  Med.,  Bd.  iii.,  1884. 

2202.  BRIEGER.    Ueber  Spaltungsprodukte  der  Bakterien.    Zeitschr.  ftlr  physiolog, 

Chemie,  Bd.  viii.  and  ix. 

2203.  STAHL.    Mikroorganismen  in    den    Darmentleerungen.     Verhandlungen  des 

3  Congr.  f  Sir  innere  Med.,  1884. 

2204.  BIENSTOCK.    Ueber  die  Bakterien  der  Faces.    Zeitschr.  filr  klin.  Med.,  1884, 

Bd.  viii. 

2205.  KUISL.    Beitrage  zur  Kenntniss  der  Bakterien  im  normalen  Darmtraktus. 

Inaug.  Diss.,  Munchen,  1885. 

2206.  ESCHERICH.    Die  Darmbakterien  des  Sauglings.     Stuttgart,  1886,  177  pages. 

Also,  Fortschr.  der  Med.,  1885,  Nos.  16  and  17. 

2207.  BeitrSge  zur  Kenntniss  der  Darmbakterien.    Milnchenermed.  Wochen- 

schr.,  1886,  Nos.  1,  43,  and  46. 

2208.  Ueber  Darmbakterien  im  Allgemeinen  und  diejenigen  der  Sauglinge 

im  besonderen,  etc.    Centralbl.  fiir  Bakteriol.,  Bd.  ii.,  1887,  Nos.  24  and  25. 

2209.  SUCKSDORP.    Das  quantitative  Vorkommen  von  Spaltpilzen  im  menschlichen 

Darmkanale.    Archiv  fiir  Hygiene,  Bd.  iv.,  1886. 

2210.  BAGINSKY.    Zur  Biologic  der  normalen  Milchkothbakterien.    Zeitschr.   far 

physiol.  Chemie,  Bd.  xii.,  p.  434;  Bd.  xiii.,  p.  352. 

2211.  BOOKER.    A  study  of  some  of  the  bacteria  found  in  the  dejecta  of  infants  af- 

flicted with  summer  diarrhoea.     Trans.  Ninth  Internat.  Med.  Cong.,  vol.  iii. 

2212.  Second  communication.     Trans,   of  the  Am.  Pediatric  Soc.,  vol.   i., 

1889,  p.  198. 

2213.  JEFFRIES.    The  bacteria  of  the  alimentary  canal,  especially  in  the  diarrhoea  of 

infancy.     Boston  Med.  and  Surg.  Journ.,  1888,  Sept.  6th. 

2214.  — — — •  A  contribution  to  the  study  of  the  summer   diarrhoeas  of  infancy. 

Trans.  Am.  Pediatric  Soc.,  vol.  i.,  1889,  p.  249. 

2215.  STERNBERG.    Report  on  the  etiology  and  prevention  of  yellow  fever.     Wash- 

ington 1891,  p.  115. 

2216.  DE  GIAXA.     Del  quantitative  di  batteri  nel  contenuto  del  tubo  gastrico-enterico 

di  alcuni  animali.     Giorn.  intern,  delle  Sci.  med.,  1888. 

VI.   BACTERIA  OF  CADAVERS  AND   OF  PUTREFYING    MATERIAL 
FROM  VARIOUS  SOURCES. 

2217.  COHN.     Untersuchungen  iiber  Bakterien.     Beitr.  zur  Biol.  der  Pflanz.,  Bd.  i., 

1872,  p.  202. 

2218.  FLUGGE.     Fermente  und  Mikroparasiten.     Handb.  der  Hygiene  von  Petten- 

kofer  und  von  Ziemssen,  1883,  p   112. 

2219.  BRIEGER.     Ueber    giftige  Produkte   der   Faulnissbakterien.      Berliner   klin. 

Wochenschr.,  1884,  No.  14. 

2220.  HAUSER.     Ueber  Faulnissbakterien.     Leipzig,  1885. 


BIBLIOGRAPHY.  805 

2221.  HACSER.     Ueber  das  Vorkommen  von  Mikroorganismen  im  lebenden  Gewebe 

gesunder  Thiere.    Archiv  fur  exper.  Pathol.  und  Pharmakol.,  Bd.  xx.,  1885, 
p.  162. 

2222.  ZWEIFEL.     Gibt    es    im     gesuaden    lebenden    Organismus     Faulnisskeime  ? 

Tagebl.  der  58.  Versamml.   Deutscher  Naturforscher  und  Aerzte  in  Strass- 
burg,  1885,  p.  303. 

2223.  HUEPPE.     Ueber  die  Beziehungen  der  Faulniss  zu  den  Infektionskrankheiten. 

Berliner  klin.  Wochenschr.,  1887,  p.  721. 

2224.  SCHRANK.     Untersuchungen  ilber  den  im  Hilhnerei  die  stinkende  Faulniss 

hervorrufenden  Bacillus.     Wiener  med.  Jahrb. ,  18S8,  p.  303. 

2225.  STRASSMANN  CJND  STRECKER.     Bakterien  bei  der  Leichenfaulniss.     Zeitschr. 

fUr  Medicinalbeamte,  1888,  No.  3. 

2226.  FACKE.     Ueber  die  Entwicklung  von  Stickstoff  bei  Faulniss.     Abstract  in 

Centralbl.  fur  Bakteriol.,  Bd.  iii.,  1888,  p.  588. 

2227.  STERNBERG.     Report  on  etiology  and  prevention  of  yellow  fever.     Washing- 

ton, 1891,  p.  121. 

VII.  BACTERIA  IN  ARTICLES  OF  FOOD. 

MILK 

2228.  LISTER.     The  cause  of  putrefaction  and  lactic  fermentation.     The  Pharm. 

Journ.,  1887. 

2229.  HUEPPE.     Untersuchungen  tlber  die  Zersetzungen  der   Milch  durch  Mikro- 

organismen.    Mitth.  aus  dem  K.  G-esundheitsamte,  Bd.  ii.,  1884. 

2230.  -    Deutsche  med.  Wochenschr.,  1884,  No.  48. 

2231.  DUCLAUX.     Memoire  sur  le  lait.     Ann.  de  1'Institut  agronomique,  1882. 

2232.  Chimie  Biologique,  chapitre  lix.  (Lait,  crgme,  et  beurre).     Paris,  1883. 

2233.  Le  lait.     Etudes  chimiques  et  microbiologiques.     Paris,  18S7,  336  pp. 

2234.  SCHMIDT-MUHLHEIM.     Untersuchungen  ilber  fadenziehenden  Milch.     Archiv 

f lir  die  ges.  Physiol.,  Bd.  xxvii.,  pp.  490-510. 

2235.  KERN.     Ueber  ein  neues  Milchferment  aus  dem  Kaukasus.     Bull,  de  la  Soc. 

Imp.  des  Naturalists  de  Moskau,  1881,  No.  3. 

2236.  Dispora  caucasica,  eine  neue  Bakterienform.     Biolog.  Centralbl.,  Bd. 

ii.,  p.  137. 

2237.  HEYDUCK.     Ueber    Milchsauregahrung.     Wochenschr.    filr    Brauerei,    1887, 

No.  17. 

2238.  LINDNER.     Ueber  ein  neues,  in  Malzmaischen  vorkommendes  Milchsaure  bil- 

dendes  Ferment.     Wochenschr.  filr  Brauerei,  1887,  No.  23. 

2239.  LOFFLER.     Ueber  Bakterien  in  der  Milch.     Berliner  klin.  Wochenschr.,  1887, 

Nos.  33  and  34. 

2240.  ADAMETZ.     Ueber  einen  Erreger  der  schleimigen  Milch,  Bacillus  lactis  vis- 

cosus.     Milchzeitung,  1889,  p.  941. 

2241.  Die  Bakterien  normaler  und  abnormaler  Milch.     Oesterr.  Monatsschrift 

filr  Thierheilk.  und  Thierzucht,  Bd.  xv.,  1890,  No.  2. 

2242.  Untersuchungen   ilber  Bacillus  lactis  viscosus,   eine  weitverbreiteten 

milchwirthschaftlichen    Schadling.     Berliner     landwirthschaftliche    Jahr- 
bucher,  1891. 

2243.  BAGINSKY.     Rothe  Milch.     Deutsche  Medicinalztg.,  1889,  No.  9. 

2244.  CNOPF.     Spaltpilzuntersuchungen  in  der  Kuhmilch.     Tagebl.   der  62.  Ver- 

samtnlung  Deutscher  Naturf.  und  Aerzte  in  Heidelberg,  1889,  p.  493. 

2245.  FOKKER.     Ueber  das  Milchsaureferment.     Fortschr.  der  Med.,  1890,  p.  401. 


866  BIBLIOGRAPHY. 

2246.  GROTENFELT.     Studien  liber  Zersetzungen  der  Milch.     Fortschr.  der  Med., 

1889,  p.  41.     Ibid.,  p.  121. 

2247.  KABHHEL.     Ueber  das  Ferment  der  Milchsauregahrung  in  der  Milch.    Allgem. 

Wiener  med.  Zeitung,  1889,  Nos.  52  and  53. 

2248.  MENGE.     Ueber  rothe  Milch.     Centralbl.  filr  Bakteriol.,  Bd.  vi.,  1889,  p.  593, 

2249.  SCROLL.     Beitrage  zur  Kenntniss  der  Milchzersetzung  durch  Mikroorganis- 

men.     I.  Ueber  blaue  Milch.     Fortschr.  der  Med.,  1889. 
2250. II.  Ueber  Milchsauregahrung.     Ibid.,  1890,  p.  41. 

2251.  KREUGER.     Beitrage  zum  Vorkommen  pyogener  Kokken  in  Milch.     Centralbl. 

filr  Bakteriol.,  Bd.  vii.,  1890,  pp.  425,  464,  493. 

2252.  ERNST.     How  far  may  a  cow  be  tuberculous  before  her  milk  becomes  danger- 

ous as  an  article  of  food  ?    Am.  Journ.  of  the  Med.  Sci.,  18S9  (Nov.). 

2253.  HIRSCIIBERGER.     Experimentelle  Beitrage  zur  Infektiositat  der  Milch  tuber- 

kulOser  Kline.     Archiv  filr  klin.  Med.,  Bd.  xliv.,  18S9,  p.  500. 

2254.  SEDGWICK  AND  BATCHELDER.     A  bacteriological  examination  of  the  Boston. 

milk  supply.     Boston  Med.  and  Surg.  Journ.,  1892,  p.  25. 

2255.  HEIM.     Versuche  liber  blaue  Milch.     Arbeiten  aus  dem  K.  Gesundheitsamte, 

Bd.  v.,  p.  518. 

2256.  CONN.     Ueber  einen  bittere  Milch  erzeugenden  Mikrokokkus      Centralbl.  fiir 

Bakteriol.,  Bd.  ix.,  1891,  p.  653. 

BREAD,  BUTTER,  CHEESE,  MEATS,  BEER,  ETC. 

2257.  JOHNE.     Ein  mikroskopisch-bakteriologischer  Beitrag  zur  Frage  der  Fleisch- 

vergiftungen.  Ber.  liber  das  Veterinarwesen  im  Konigr.  Sachsen,  1886, 
p.  40. 

2258.  EHRENBERG.    Ueber  einige  in  einem  Falle  von  sog.  "  Wurstvergiftung  "  aus 

dem  schadlichen  Materiale  Faulnissblasen,  sowie  liber  einige,  durch  die 
Thatigkeit  eines  besonderen,  im  gleichen  Materiale  auf gefundenen  Bacillus 
gebildete  Zersetzungsprodukte.  Zeitschrift  filr  physiol.  Chemie,  Bd.  xi., 
1887. 

2259.  NAUWERCK.     "Wurstvergiftung.      Med.    Correspondenzbl.    des    wilrttemberg. 

arztl.  Landesvereins,  1886,  No.  20. 

2260.  BENECKE.     Ueber  die  Ursachen  der  Veriinderung,  welche  sich  wiihrend  des 
•        Reifungsprocesses  im  Emmenthaler  Kase  vollziehen.     Centralbl.  fiir  Bakte- 
riol., Bd.  ii.,  1887,  No.  18. 

2261.  PEUCH.     Note  sur  la  contagion  de  la  tuberculose  par  le  lait  non  bouilli  et  la 

viande  crue.     Revue  veterin.,  1888,  p.  649. 

2262.  GARTNER.    Ueber  die  Fleischvergif tung  in  Frankenhausen  am  Kyff  hauser  und 

den  Erreger  derselben.  Correspondenzbl.  des  allg.  arztl.  Vereins  von  Thii- 
ringen,  1888,  No.  9. 

£263.  DE  VRIES.     Ueber  blauen  Kase.     Petersen's  Milchzeitung,  Bel.   xvii.,   1888, 
Nos.  44  and  45. 

2264.  ADAMETZ.     Bakteriologische  Untersuchungen  liber  den  Reifuugsprocess  des- 

Kase.     Landwirthsch.  Jahrbiicher,  1889,  p.  227. 

2265.  JSRGENSEN.     Die  Mikroorganismen  der  Gahrungsindustrie,  2d  ed. ,  1889. 

2266.  KRATSCHMER  UND  NIEMILOWICZ.     Ueber  eine  eigeiithiimliche  Brotkrankheit. 

Wiener  klin.  Wochenschr.,  1889,  No.  30. 

2267.  VAN  LAER.     Note  sur  les  fermentations  visqueuses.     Abstract  in  Centralbl. 

fiir  Bakteriol.,  Bd.  vii.,  1890,  p.  308. 

2268.  PETERS.     Die  Organismen  des  Sauerteigs  und  ihre  Bedeutung  fiir  die  Brot- 

gahrung.     Botan.  Zeitung,  Jahrg.  xlvii.,  1889,  Nos.  25-27. 


BIBLIOGRAPHY.  867 

2269.  BERNHEIM.     Die  parasitiiren  Bakterieu  der  Cerealieu.     Milncheuer  med.  Wo- 

chenschr.,  1888,  p.  748. 

2270.  BUCHNER.     Notiz  betreffend  die  Frage  des  Vorkommens  von  Bakterien  im 

normalen  Pflanzeagewebe.     Mlinchener  med.  Wochenschr.,  1888,  No.  52. 

2271.  FERNBACH.     De  1'absence  des  microbes  dans  les  tissus  vegetaux.     Ann.  de 

1'Institut  Pasteur,  1888,  p.  567. 

2272.  HILTNER.     Die  Bakterien  der  Futtermittel  und  Saamen.     Laudwirthsch.  Ver- 

suchsstationen,  Bd.  xxxiv.,  1887,  p.  391. 

2273.  Di  VESTEA.     De  1'absence  des  microbes  dans  les  tissus  vegetaux.     Ann.  de 

Tlnstitut  Pasteur,  1888,  p.  670. 

2274.  FAZIO.     I  microorganismi  nei  vegetati  usati  f  reschi  nell'  alimentazione.    Rivista 

internazionale  d'Igiene,  1890,  Nos.  1-3. 

2275.  KREUGER.     Bakteriologisch  chemische  Untersuchung  kasiger  Butter.      Cen- 

tralbl.  fur  Bakteriol.,  Bd.  vii.,  1890,  pp.  425,  464,  493. 

2276.  BEU.     Ueber  den  Einfluss  des  Raucherns  auf  die  Filulnisserreger  bei  der  Kon- 

servirung  von  Fleischwaaren.     Centralbl.  filr  Bakteriol.,  Bd.  viii.,  1890,  pp. 
513,  545. 

2277.  FORSTER.     Ueber  den  Einfluss  des  Raucherns  auf  die  Inf  ektiositat  des  Flei- 

sches  perlsiichtiger  Rinder.     Mlinchener  med.  Wochenschr.,  1890,  No.  16. 

2278.  FREUDENREICH.     Sur  quelques  bacteries  produisant  le  boursouflement    des 

fromages.     Ann.  de  Micrographie,  t.  ii.,  1890,  No.  8. 

2279.  GAFFKY  UND  PAAK.     Ein  Beitrag  zur  Frage  der  sogenannten  Wurst-  und 

Fleischvergiftung.     Arbeiten  aus  dem  K.  Gesundsheitsamte,  Bd.  vi.,  1890, 
Heft  2. 

2280.  UFFELMANN.     Verdorbenes  Brot.     Centralbl.  fur  Bacteriol.,  Bd.  viii.,  1890,  p. 

481. 

2281.  POPOFP.     Sur  un  bacille  anaerobic   de  la  fermentation  pannaire.     Ann.  de 

1'Institut  Pasteur,  1890,  p.  674. 

2282.  ZIEDLER.     Beitrilge  zur  Kenntniss  einiger  in  Wiirze  und  Bier  vorkommenden 

Bakterien.     Wochenschr.  fur  Brauerei,  1890,  Nos.  47,  48. 

2283.  KASTNER.     Experimentelle  Beitrage  zur  Infektiositat  des  Fleisches  tubercu- 

loser  Rinder.     Milnchener  med.  Wochenschr.,  18?9,  Nos.  84,  35. 

2284.  KRATSCHMER  UND  NIEMILOWICZ.     Ueber  eine  eigenthiimliche  Brotkrankheit. 

Wiener  klin.  Wochenschr.,  1889,  No.  30. 

2285.  STEINHEIL.     Ueber  die  Infektiositat  des  Fleisches  bei  Tuberculose.     Munch- 

ener  med.  Wochenschr.,  1889,  Nos.  40,  41. 

VIII.   NON-PATHOGENIC    MICROCOCCI. 

2286.  Micrococcus  flavus  liquefaciens.     FLUGGE,  Die  Mikroorganismen,  2d  ed.,  p. 

174. 

2287.  Micrococcus  flavus  desidens.     FLUGGE,  ibid.,  p.  177. 

2288.  Micrococcus  agilis.     ALI-COHEN,  Centralbl.  fur  Bakteriol.,  Bd.  vi.,  p.  33. 

2289.  Micrococcus  fuscus.     ADAMETZ,   Die  Bakterien  der  Nutz  und  Trinkwasser, 

Vienna,  1888. 

2290.  Diplococcus  citreus  conglomeratus.     BUMM,  Der  Mikroorganismus  der  Gon. 

Schleimhauterkrankungen.     Wiesbaden,  1885,  p.  17. 

2291.  Diplococcus  citreus  liquefaciens.     TOMMASOLT,  Monatshefte  f  ilr  prakt.  Derma- 

tol.,  Bd.  ix.,  p.  56. 

2292.  Diplococcus  flavus  liquefaciens  tardus.     TOMMASOLI,  op.  cit.  (No.  2291). 
?3293.  Diplococcus  fluorescens  fujtidus.     KLAMANN,   Allgemeine  medizin.    Central- 

zeitung,  1887,  p.  1347. 


868  BIBLIOGRAPHY. 

2294.  Diplococcus  luteus.     ADAMETZ,    Die   Bakterien   der  Nutz   und  Trinkwasser, 

Vienna,  1888. 

2295.  Diplococcus  roseus.     BUMM,    Der  Mikroorganismus  der    Gou.   Schleimhaut- 

erkrankungen,  1885,  p.  25. 

2296.  Micrococcus  cremoides.     ZIMMERMANN,    Die  Bakterien   unserer    Nutz-  und 

Trinkwasser.     Chemnitz,  1890. 

2297.  Micrococcus  roseus.     EISENBERG,  Bakteriologische  Diagnostik,  3ded.,  p.  408. 

2298.  Micrococcus  aurantiacus.     ADAMETZ,  op.  cit.  (No.  2289).     TILS,  Zeitschr.  fur 

Hygiene,  Bd.  ix.,  p.  301. 

2299.  Micrococcus  cerasinus  siccus.     ADAMETZ,  op.  cit.  (No.  2289). 

2300.  Micrococcus  versicolor.     FLUGGE,  Die  Mikroorganismen,  2d  ed.,  1886.    TILS, 

Zeitschr.  fur  Hygiene,  Bd.  ix.,  p.  299. 

2301.  Micrococcus  of  Dantec.     DANTEC,   Etude  de  la.  morue  rouge,  Ann.  de  1'In- 

stitut  Pasteur,  t.  v.,  1891,  p.  659. 

2302.  Micrococcus  carneus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2303.  Micrococcus  cinnabareus.     FLUGGE,  op.  cit.  (No.  2300),  p.  174. 

2304.  Micrococcus  cereus  albus.     PASSET,  Fortschr.  der_Medicin,  Bd.  iii.,  1885.    TILS, 

Zeitschr.  fur  Hygiene,  Bd.  ix.,  p.  300. 

2305.  Micrococcus  cereus  flavus.     PASSET,  op.  cit.  (No.  2304). 

2306.  Micrococcus  citreus.    ADAMETZ,  op.  cit.  (No.  2294).    TILS,  op.  cit.  (No.  2304). 

2307.  Micrococcus  fervidosus.   ADAMETZ,  op.  cit.  (No.  2294).   TILS,  op.  cit.  (No.  2304). 

2308.  Micrococcus  flavus  tardigratus.     FLUGGE,  op.  cit.  (No.  2300),  p.  175. 

2309.  Micrococcus  luteus.     ADAMETZ,  op.  cit.  (No.  2294).    TILS,  op.  cit.  (No.  2304). 

2310.  Micrococcus  violaceus.     ADAMETZ,  op.  cit.  (No.  2294). 

2311.  Staphylococcus   viridis  flavescens.     GUTTMANN,  Virchow's  Archiv  fiir  path. 

Anat.,  Bd.  cvii.,  p.  261. 

2312.  Micrococcus  ochroleucus.     PROVE,  Beitrage  xur  Biologic  der  Pflanzen,  Bd.  iii., 

p.  409. 

2313.  Micrococcus  acidi  lactici  liquefaciens.     KRUGER,  Centralbl.  fiir  Bakteriol.,  Bd. 

vii.,  p.  464. 

2314.  Micrococcus  aGrogenes.     MILLER,  Deutsche  med.  Wochenschr.,  1886,  No.  8. 

2315.  Micrococcus  albus  liquefaciens.     VON  BESSER,  Beitrage  zur  path.  Anat.,  etc., 

Bd.  vi.,  p.  346. 

2316.  Micrococcus  foetidus.     KLAMANN,  Allg.  med.  Centralzeitung,  1887,  p.  1344. 

2317.  Micrococcus  radiatus.     FLUGGE,  op.  cit.  ^No.  2300),  p.  176. 

2318.  Diplococcus  albicans  amplus.     BUMM,  op.  cit.  (No.  °295). 

2319    Micrococcus  candicans.     FLUGGE,  op.  cit.  (No.  2300).    TILS,  op.  cit.  (No.  2298), 
p.  299. 

2320.  Micrococcus  candidus.     TILS,  op.  cit.  (No.  2298),  p.  299. 

2321.  Micrococcus  acidi  lactici.     MARPMANN,  Ergilnzungshefte   des  Centralbl.  fiir 

allg.  Gesundheitspflege,  Bd.  ii.,  Heft  2,  p.  22. 

2322.  Micrococcus  lactis  viscosus.     CONN,  Centralbl.  fiir  Bakteriol.,  Bd.  ix.,  p.  653. 
2323    Streptococcus  acidi  lactici.     MARPMANX,  op.  cit.  (No.  2321),  p.  121. 

2324.  Micrococcus  aquatilis.     BOLTON,  Zeitschrift  fiir  Hygiene,  Bd.  i.,  p.  94. 

2325.  Micrococcus  concentricus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2326.  Micrococcus  cumulatus  tenuis.     VON  BESSER,  op.  cit.  (No.  2315),  p.  347. 

2327.  Micrococcus  plumosus.     ADAMETZ,  op.  cit.  (No.  2294). 

2328.  Micrococcus  rosettaceus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2329.  Micrococcus  urece.    PASTEUR,   Compt.   rend.  Acad.  des  Sc.,  t.  Ixxxiii.,  1876. 

VON  JACKSCII,  Zeitschrift  fiir  physiol.  Chemie,  Bd.  v.,  1881.  LEPINE  ET 
Roux,  Compt.  rend.  Acad.  des.  Sc.,  t.  ci.,  1835.  LEUBE  UND  GRASSER, 
Virchow's  Archiv,  Bd.  c.,  p.  556. 


BIBLIOGRAPHY.  869 

2330.  Micrococcus  ureae  liquefaciens.    FLUGGE,  op.  cit.  (No.  2300),  p.  170. 

2331.  Micrococcus  viticulosus.    FLUGGE,  op.  cit.  (No.  2300),  p.  178. 

2332.  Diplococcus  albicans  tardissimus.     BOMM,  op.  cit.   (No.  2295).    TOMMASOLI, 

Monatsheft  filr  prakt.  Dermatol.,  Bd.  ix.,  p.  54. 

2333.  Diplococcus  albicans  tardus.     TOMMASOLI,  op.  cit.  (No.  2332),  p.  49. 

2334.  Staphylococcus  albus  liquefaciens.     ESCHERICH,  Die  Darmbakterien  des  Sau- 

glings.    Stuttgart,  18S6,  p.  88. 

2335.  Micrococcus  ovalis.     ESCHERICH,  op.  cit.  (No.  2334),  p.  90. 

2336.  Diplococcus  coryzse.     HAJEK,  Berliner  klin.  Wochenschr.,  1888,  No.  83. 

2337.  Micrococcus  Finlayensis.     STERNBERG,  Report  on  etiology  and  prevention  of 

yellow  fever,  Washington,  1891,  p.  219. 

2338.  Micrococcus  of  Freire.     STERNBERG,  op.  cit.  (No.  2337),  p.  163. 

2339.  Streptococcus  coli  gracilis.     ESCHERICH,  op.  cit.  (No.  2334). 

2340.  Streptococcus  acidi  lactici.     GROTENFELT,   Fortschr.   der  Med.,  Bd.   vii.,  p. 

124. 

2341.  Streptococcus  giganteus  urethrae.    LUSTGARTEN    UND  MANNEBERG,  Viertel- 

jahresbericht  fur  Dermatol.  und  Syph.,  1887,  p.  918. 

2342.  Streptococcus  albus.    TILS,  op.  cit.  (No.  2298),  p.  302. 

2343.  Streptococcus  vermiformis.    TILS,  op.  cit.  (No.  2298),  p.  302. 

2344.  Streptococcus  brevis.  VON  LINGELSHEIM,  Zeitschr.  filr  Hygiene,  Bd.  x.,  p.  331. 

2345.  Streptococcus  cadaveris.     STERNBERG,  op.  cit.  (No.  2837),  p.  218. 

2346.  Streptococcus  Havaniensis.     STERNBERG,  op.  cit.  (No.  2337),  p.  219. 

2347.  Streptococcus  liquefaciens.     STERNBERG,  op.  cit.  (No  2337),  p.  219. 

2348.  Micrococcus  tetragenus  versatilis.   STERNBERG,  op.  cit.  (No.  2337),  p.  164. 

2349.  Pediococcus  albus.    LINDNER,  Die  Sarcineorganismen  der  Gahrungsgewebe, 

Berlin,  1888. 

2350.  Pediococcus  acidi  lactici.     LINDNER,  op.  cit.  (No.  2349). 

2351.  Pediococcus  cerevisise.     LINDNER,  op.  cit.  (No.  2349). 

2352.  Micrococcus  tetragenus  mobilis  ventriculi.     MENDOZA,  Centralbl.  fur  Bakte- 

riol.,Bd.  vi.,  p.  506. 

2353.  Micrococcus  tetragenus  subflavus.     VON  BESSER,  op.  cit.  (No.  2315),  p.  347. 

2354.  Sarcina  aurantiaca.     Mitth.  aus  dem  K.  Gesundheitsamte,  Bd.  ii. 

2355.  Sarcina  lutea.    EISENBERG,  op.  cit.  (No.  2297),  p.  15. 

2356.  Sarcina  flava.     LINDNER,  op.  cit.  (No.  2349). 

2357.  Sarcina  rosea.     LINDNER,  op.  cit  (No.  2349). 

2358.  Sarcina  alba.    EISENBERG,  op.  cit.  (No.  2297),  p.  26. 

2359.  Sarcina  Candida.     LINDNER,  op.  cit.  (No.  2349). 

2360.  Sarcina  pulmonum.     HAUSER,  Deutsches  Archiv  fiir  klin.  Medizin,  Bd.  xlii., 

p.  131. 

2361.  Sarcina  ventriculi.     FALKENHAIM,  Archiv  fur  exper.  Pathol.  und  Pharmakol. , 

Bd.  xix.,  p.  339. 

2362.  Micrococcus  amylovorus.     BURRILL,  Proc.  Am.  Assoc.  Adv.  Sc.,  vol.  xxix., 

1880,  p.  583 ;  Am.  Naturalist,  vol.  xv.,  1881,  p.  527.  ARTHUR,  Report 
New  York  Agric.  Exper.  Station,  1884,  p.  357  ;  Proc.  Am.  Assn.  Adv.  Sc., 
vol.  xxxiv. ,  1885,  p.  295 ;  History  and  biology  of  pear  blight,  Proc.  Acad. 
Nat.  Sc.,  Philadelphia,  1886. 

2363.  Ascococcus  Billrothii.     COHN,  Beitrage  zur  Biologic  der  Pflanzen.     FL  GGE, 

op.  cit.  (No.  2300),  p.  184. 

2364.  Leuconostoc  mesenteroides.     CIENKOWSKI,  Die  Gallertbildungen  des  Zucker- 

riibensaftes,  Charkow,  1878.     ZOPF,  Die  Spaltpilze,  2ded.,  p.  45. 


870  BIBLIOGRAPHY. 

IX.   NON-PATHOGENIC  BACILLI. 

2365.  Bacterium  luteum.     ADAMETZ,  op.  cit.  (No.  2294). 

2366.  Bacillus  aurantiacus.     FKANKLAND,  Zeitschr.  fur  Hygiene,  Bd.  vi.,  p.  390. 

2367.  Bacillus  brunneus.     ADAMETZ,  op.  cit.  (No.  2294). 

2368.  Bacillus  aureus.    ADAMETZ,  op.  cit.  (No.  2294).    TOMMASOLI,  Monatsheft  fur 

prakt.  Dermatol.,  Bd.  ix.,  p.  57. 

2369.  Bacillus  flavocoriaceus.     ADAMETZ,  op.  cit.  (No.  2294). 

2370.  Bacillus  berolinensis  Indicus.     CLASSEN,  Centralbl.  fiir  Bakteriol.,  Bd.  vii.,. 

p.  13. 

2371 .  Bacillus  constrictus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2372.  Bacillus  fluorescens  aureus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2373.  Bacillus  fluorescens  longus.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2374.  Bacillus  fluorescens  teuuis.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2375.  Bacillus  fluorescens  non-liquefaciens.     EiSENBEiia,  op.  cit.  (No.  2297),  p.  145. 

2376.  Bacillus  fluorescens  putidus.     FLUGGE,  op.  cit.  (No.  2300),  p.  288. 

2377.  Bacillus  erythrosporus.    FLUGGE,  op.  cit.  (No.  2300),  p.  288. 

2378.  Bacillus  viridis  pallescens.     FRICK,  Virchow's  Archiv  fiir  path.  Anat.,  Bd, 

cxvi.,  p.  292. 

2379.  Bacillus  virescens.    FRICK,  op.  cit.  (No.  2378),  p.  292. 

2380.  Bacillus  iris.     FRICK,  op.  cit.  (No.  2378),  p.  292. 

2381.  Bacillus  fuscus.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2382.  Bacillus  rubefaciens.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2383.  Bacillus  striatus  flavus.     VON  BESSER,  op.  cit.  (No.  2315),  p.  249. 

2384.  Bacillus  subflavus.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2385.  Bacillus  cyanogenus.     FLUGGE,  op.  cit.  (No.  2300),  p.  291.     HUEPPE,  Mitth. 

aus  dem  K.  Gesundheitsamte,  Bd.  ii.,  p.  335.  NEELSEN,  Beitrage  zur  Biol. 
derPflanzen,  Bd.  iii.,  Heft  2.  HEIM,  Arbeitenaus  dem  K.  Gesundheitsamte, 
Bd.  v.,  p.  518.  JORDAN,  Rep.  Mass.  State  Board  of  Health,  1890,  Purifica- 
tion of  Water  and  Sewage,  vol.  ii.,  p.  883. 

2386.  Bacillus  fuscus  limbatus.     SCBTEIBENZUBER,  Allgemeine  Wiener  med.  Zeitung,r 

1889,  p.  171. 

2387.  Bacillus  latericeus.     ADAMETZ,  op.  cit.  (No.  2294). 

2388.  Bacillus  spiniferus.     TOMMASOLI,  op.  cit.  (No.  2368),  p.  58. 

2389.  Bacillus  rubescens.    JORDAN,  op.  cit.  (No.  2335),  p.  835. 

2390.  Bacillus  allii.     GRIFFITHS,  Proc.  Roy.  Soc.,  Edin.,  vol.  xv.,  p.  40. 

2391.  Bacillus  fulvus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2392.  Bacillus  helvolus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2393.  Bacillus  ochraceus.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2394.  Bacillus  plicatilis.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2395.  Bacillus  janthinus.     ZOPF,    Die  Spaltpilze,   Breslau,   1884,  p.  62.     PLAGGE 

TJND  PROSKAUER,  Zeitschrif  t  f  iir  Hygiene,  Bd.  ii.,  p.  463.  JORDAN,  op.  cit. 
(No.  2385),  p.  840. 

2396.  Bacillus  violaceus  Laurentius.     JORDAN,  op.  cit.  (No.  2385),  p.  838. 

2397.  Bacillus  tremelloides.     TILS,  Zeitschrift  fiir  Hygiene,  Bd.  ix.,  p.  292. 

2398.  Bacillus  cuticularis.     TILS,  op.  cit.  (No.  2397),  p.  293. 

2399.  Flesh-colored  bacillus.     TILS,  op.  cit.  (No.  2397),  p.  294. 

2400.  Bacillus  arborescens.    FRANKLAND,  op.  cit.  (No.  2366),  p.  379. 

2401.  Bacillus  citreus  cadaveris.     STRASSMAN  UND  STRECKER,  Zeitschrift  fiir  Medi- 

cinalbeamte,  1888,  No.  3. 

2402.  Bacillus  membranaceus  amethyst  inus.     EISENBERG,  op.  cit.  (No.  2297),  p.  421. 

2403.  Ascobacillus  citreus.     TOMMASOLI,  op.  cit.  (No.  2332),  p.  60. 


BIBLIOGRAPHY.  871 

2404.  Bacillus  cceruleus.     SMITH,  The  Medical  News,  1887,  rol.  ii.,  p.  758. 

2405.  Bacillus  fluorescens  liquefaciens.     FLUGGE,  op.  cit.  (No,  2300),  p.  239.     STERN- 

BEBG,  op.  cit.  (No.  2337),  p.  208. 

2406.  Bacillus  fluorescens  liquefaciens  minutissimus.    TOMM  ASOLI,  op.  cit.  (No.  2332),. 

p.  57. 

2407.  Bacillus  fluorescens  nivalis.     SCHMOLCK,  CentralbL  fur  Bakteriol.,  Bd.  iv.,. 

p.  545. 

2403.  Bacillus  lactis  erythrogenes.     GROTENFELT,  Fortschr.  der  Med.,  1889,  No.  2, 
p.  41. 

2409.  Bacillus  glaucus.     ADAMETZ,  op.  cit.  (No.  2294). 

2410.  Bacillus  lividus.     PLAGGE  UND  PROSKAUER,  Zeitschrift  fur  Hygiene,  Bd.  ii., 

p.  463.     EISENBERG,  op.  cit.  (No.  2297),  p.  81. 

2411.  Bacillus  Indicus.     EISENBERG,  op.  cit.  (No.  2297),  p.  79. 

2412.  Bacillus    prodigiosus.     EHRENBERG,    Verhandl.    der    Berliner  Acad.,  1839. 

SCHOTTELIUS,    Biologische  Untersuchungen  ilber   den  Micrococcus  prodir- 
giosus,  185  pp.,  Leipzig,  1887. 

2413.  Bacillus  mesentericus  ruber     GLOBIG,  Zeitschrift  filr  Hygiene,  Bd.  iii.,  p.  3221. 

2414.  Bacillu^  pyocyanus  ft.     ERNST,  Zeitschrift  fur  Hygiene,  Bd.  ii.,  365. 

2415.  Bacilluo  mycoides  roseus.     SCROLL,  Fortschr.  der  Med.,  Bd.  vii.,  p.  46. 

2416.  Bacillus  rosaceum  metalloides.     DOWDESWELL,  Ann.  de  Micrographie,  vol.  ii.r 

p.  310. 

2417.  Bacillus  viscosus.     FRANKLAND,  op.  cit.  (No.  2366),  p.  391. 

2418.  Bacillus  violaceus.     FRANKLAND,  op.  cit.  (No.  2366),  p.  394. 

2419.  Bacillus  sulfureum.     HOLSCIIEWNIKOFF,  Fortschr.  der  Med.,  Bd.  vii.,  p.  202. 

2420.  Bacillus  rubidus.     EISENBERG,  op.  cit.  (No.  2297),  p  88.    TILS,  op.  cit.  (No^. 

2397),  p.  307. 
2421    Bacterium  termoof  Vignal.     VIGNAL,  Archiv  de  Physiol.,  t.  viii.,  1886,  p.  842.. 

2422.  Bacillus  buccalis  minutus.     VIGNAL,  op.  cit.  (No.  2422),  p  365.. 

2423.  Bacillus  of  Canestrini.     CANESTRINI,  Atti  Soc.  Ven, -Trent.  Sci.  Nat.,  xii.,  p.. 

134. 

2424.  Bacillus  ubiquitus.     JORDAN,  op.  cit.  (No.  2385),  p.  830. 

2425.  Bacillus  candicans.     FRANKLAND,  op.  cit.  (No.  2366),  p.  398. 

2426.  Bacillus  albus.    EISENBERG,  op.  cit.  (No.  2497),  p.  171. 

2427.  Bacillus  acidi  lactici  (Hueppe).     HUEPPE,  Mittheilungen  aus  dem  K.  Gesund- 

heitsarate,  Bd.  ii.,  p.  337.    GROTENFELT,  Fortschr.  der  Medicin,  Bd.  viii,, 
p.  121. 

2428.  Bacillus  limbatum  acidi  lactici.     MARPMANN,  op.  cit.  (No.  2321),  p.  122. 

2429.  Bacillus  lactis  pituitosi.     LOFFLER,  Berliner  klin.  Wochenschr.,  1887,  p.  631.. 

2430.  Bacillus  aerogenes.    MILLER,  Deutsche  med.  Wochenschr.,  1886,  No.  8. 

2431.  Bacterium  aerogenes.     MILLER,  op.  cit.  (No.  2430). 

2432.  Heliobacterium  a<5rogeues.     MILLER,  op.  cit.  (No.  2430). 

2433    Bacillus  aquatilis  sulcatus,  Nos.  1,  2,  3,  4,  and  5.     WEICHSELBAUM,  Das  oster- 
reichische  Sanitatswesen,  1839,  Nos.  11-23. 

2434.  Bacillus  multipediculus.     FLUGGE,  op.  cit.  (No.  2300),  p.  323. 

2435.  Bacillus  cystiformis.     CLADO,  Bull,  de  la  Soc.  d'Anat.  de  Paris,  1887,  p.  339.. 

2436.  Bacillus  hepaticus  fortuitus.     STEUNBERG,  op.  cit.  (No.  2337),  p.  205. 

2437.  Bacillus  intestinus  motilis.     STERNBERG,  op.  cit.  (No.  2337),  p.  205. 

2438.  Bacillus  caviae  fortuitus.     STERNBERG,  op.  cit.  (No.  2337),  p.  206. 

2439.  Bacillus  coli  similis.     STERNBERG,  op.  cit.  (No.  2337),  p.  218. 

2440.  Bacillus  flliformis  Havaniensis.     STERNBERG,  op.  cit,  (No.  2337),  p.  21L 

2441.  Bacillus  Martinez.     STERNBERG,  op.   cit.  (No.  2337),  p.  214. 


872  BIBLIOGRAPHY. 

2442.  Bacillus  epidermidis.     BIZZOZKRO,  Virchow's  Archiv,  Bd.  xcviii.,  p.  455.     BOR- 

DONI-UFFREDUZI,  Fortschritt  der  Med.,  1886,  p.  156. 

2443.  Bacillus  nodosus  parvus.     LUSTGARTKN,    Vierteljahresschr.    filr  Derm.    und 

Syph.    1887,  p.  914. 

2444.  Bacillus  hyacinthi  septicus.     HEINZ,  Centralbl.  filr  Bakteriol.,  Bd.  v.,  p.  535. 

2445.  Bacterium  gliscrogenum.     MALERBA,  Giornale  intern   delle  Sci.  med.,  Naples, 

1888,  fasc.  li. 

2446.  Bacillus  ovatus  minutissimus.     TOMMASOLI,  op.  cit.  (No.  2332),  p.  59. 
2147.  Capsule  bacilli  of  Smith      SMITH,  Centralbl.  fiir  Bakteriol.,  Bd.  x.,  p.  181. 

2448.  Bacillus  putrificus  coli.     Bacillus  subtilis  simulans  Nos.  1  and  2.     BIENSTOCK, 

Zeitschr.  f  ur  klin.  Med.,  Bd.  viii. 

2449.  Bacillus  striatus  albus.     VON  BESSER,  op.  cit.  (No.  2315),  p.  349. 
2450    Bacillus  stolonatus.     ADAMETZ,  op.  cit.  (No.  2294). 

2451.  Bacillus  ventriculi.     RACZYNSSKY,  Diss.  der  militarisch-medicinischen  Akad., 

St.  Petersburg,  1888. 

2452.  Bacillus  Zopfli.     KUUTH,  Bot.  Zeitung,   1883.    CROOKSHANK,  Manual  of  bac- 

teriology, 3d  ed.,  p.  344. 

2453.  Bacterium  Ziirnianum.     ADAMETZ,  op.  cit.  (No.  2294). 

2454.  Bacillus  of  Colomiatti.     KUSCHBERT  UND    NEISSER,   Breslauer  arztliche  Zeit- 

schrift,  1883,   No.  4.     FRANKEL  UND  FRANKE,  Knapp-Schweiger's  Archiv, 
Bd.  xvii.,p   176. 

2455.  Bacillus  scissus.     FRANKLAND,  op.  cit.  (No.  2366),  p.  398. 

2456.  Bacilli  of  Fulles.     FULLES,  Zeitschrift  fur  Hygiene,  Bd.  x.,  p.  250. 

2457.  Bacillus  phosphorescens  gelidus.    FORSTER,  Centralbl.  filr  Bakteriol.,  Bd.  ii., 

p.  337. 

2458.  Phosphorescent  bacilli  of  Katz.     KATZ,  Centralbl.  filr  Bakteriol.,  Bd.  ix. 

2459.  Bacillus  phosphorescens  Indicus.     FISCHER,  Zeitschrift  fur  Hygiene,  Bd.  ii., 

p.  54 ;  Centralbl.  fur  Bakteriol.,  Bd.  iv.,  p.  89. 

2460.  Bacillus  phosphorescens  indigenus.    FISCHER,   Centralbl.   filr  Bakteriol.,  Bd. 

iii.,  p.  105. 

2461.  Bacillus  circulans.    JORDAN,  op.  cit.  (No.  2385),  p.  831. 
12462.  Bacillus  superficialis      JORDAN,  op.  cit.  (No.  2385),  p.  833. 

2463.  Bacillus  reticularis     JORDAN,  op.  cit.  (No.  2385),  p  834. 

2464.  Bacillus  hyalinus.    JORDAN,  op.  cit.  (No.  2385),  p  835. 

2465.  Bacillus  cloacae.    JORDAN,  op.  cit.  (No.  2385),  p.  836. 

2466.  Bacillus  delicatulus.     JORDAN,  op.  cit.  (No.  2385),  p.  837. 

2467.  Bacillus  aquatilis.     FRANKLAND,  op.  cit.  (No  2366),  p.  382. 

2468.  Bacillus  diffusus.     FRANKLAND,  op.  cit.  (No.  2366),  p.  396. 

2469.  Bacillus  liquidus.    FRANKLAND,  op.  cit.  (No.  2366),  p.  383. 

2470.  Bacillus  vermicularis.     FRANKLAND,  op.  cit.  (No.  2366),  p.  384. 

2471.  Bacillus  nubilus.     FRANKLAND,  op.  cit.  (No.  2366),  p.  387. 

2472.  Bacillus  pestifer.     FRANKLAND,  Phil.  Trans  ,  vol.  clxxviii.,  p.  27 Jc 

2473.  Bacillus  filiformis.     TILS,  op.  cit.  (No.  2397),  p.  294. 

2474.  Bacillus  devorans.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2475.  Bacillus  gracilis.     ZIMMEIIMANN,  op.  cit.  (No.  2296). 

2476.  Bacillus  guttatus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2477.  Bacillus  implexus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2478.  Bacillus  punctatus.     ZIMMERMANN,  op.  cit.  (No.  2296). 

2479.  Bacillus  radiatus.    ZIMMERMANN,  op.  cit.  (No.  2296). 

2480.  Bacillus  radiatus  aquatilis.    ZIMMERMANN,  op.  cit.  (No.  2296). 
:2481.  Bacillus  vermiculosus.     ZIMMERMANN,  op.  cit.  (No.  2296). 
2482.  Bacillus  aerophilus.     FLUGGE,  op.  cit.  (No.  2300),  p.  321. 


BIBLIOGRAPHY.  873 

2483.  Bacillus  my coides.     FLUGGE,  op.   cit.   (No.   2300),  p.  334.    ZIMMERMANN,  op. 

cit.  (No.  2296). 

2484.  Bacillus  mesentericus  vulgatus.     VIGNAL,   Le  bacille   mesentericus  vulgatus,. 

Paris,  1889— an  extended  monograph.     FLUGGE,  op.  cit.  (No.  2300),  p.  322. 

2485.  Bacillus  mesentericus  fuscus     FLUGGE,  op.  cit.  (No.  2300),  p.  321.     TILS,  op. 

cit.  (No.  2397),  p.  310. 

2486.  Bacillus  megatherium.     DE  BARY,  Vergl.  Morphologic   und  Biol.  der  Pilze, 

Leipzig,  1884.     TILS,  op.  cit.  (No.  2397),  p.  312. 

2487.  Bacillus  albus  putidus.     ADAMETZ,  op.  cit.  (No.  2294). 

2488.  Bacillus  brassicae.     POMMER,   Mitth.  des  botanischen  Inst.  zu  Gratz,  Bd.  i., 

p  95. 

2489.  Bacillus  butyricus  of  Hueppe.     HUEPPE,  Mitth.  aus  dem  K.  Geshundheits- 

amte,  Bd.  ii.,  1884. 

2490.  Bacillus  gasoformans.     EISENBERG,  op.  cit.  (No.  2297),  p.  107. 

2491.  Bacillus  carabiformis.     KACZYNSKY,  Diss.  der  militar-med.  Akad.  in  St.  Peters- 

burg, 1888. 

2492.  Bacillus  graveolens.     BORDONI-UFFREDUZZI,  Fortschr.  der  Med.,  1886,  p.  157. 

2493.  Bacillus  carotarum.     A.  KOCH,  Habilitationsschrift,  Gottingen,  1888. 

2494.  Bacillus  inflatus.     A.  KOCH,  op.  cit.  (No.  2493). 

2495.  Bacillus  ramosus.     EISENBERG,  op.  cit.  (No.  2297),  p.  126. 

2496.  Bacillus  subtilis.     PRAZMOWSKI,  Untersuchungen  fiber  die  Entwickluiigsge- 

schichte  und  Fermentwirkung  einiger  Bakterien,  Leipzig  1880.  FLUGGE, 
op  cit.  (No.  2300),  p.  315.  VIGNAL,  op.  cit.  (No.  2421),  p.  344.  BABES, 
Journ.  d'Anat.,  1884,  p.  41. 

2497.  Bacillus  subtilis  similis.    STERNBERG,  op.  cit.  (No.  2337),  p.  210. 

2498.  Bacillus  leptosporus.     L.  KLEIN,  Centralbl.  f ur  Bakteriol. ,  Bd.  vi.,  p  345. 

2499.  Bacillus  sessilis.     L.  KLEIN,  op.  cit.  (No.  2498),  p.  378. 

2500.  Bacillus  allantoides.    L.  KLEIN,  op.  cit.  (No.  2498),  p.  383. 

2501.  Bacillus  of  Scheiirlen.     SCHECRLEN,  Deutsche  med.  Wochenschr. ,  1888,  p. 

1033.  SENGER,  Berl.  klin.  Wochenschr.,  1888,  p.  186.  VAN  ERMENGEM, 
Bull.  Soc.  beige  de  Microscopic,  seances  de  janv.  28  et  du  mars  31,  1888. 
PFEIFFER,  Deutsche  med.  Wochenschr.,  1888,  No.  11.  ROSENTHAL,  Zeit- 
schr  fur  Hygiene,  Bd.  v.,  p.  161. 

2502.  Bacillus  lactis  albus.     LOFFLER,  Berliner  klin.  Wochenschr.,  1887,  p.  630 

2503.  Bacillus  liodermos.     LOFFLER,  op.  cit.  (No.  2502),  p.  630. 

2504.  Bacillus  ulna.     FLUGGE,  op.  cit.  (No.  2300),  p  329. 

2505.  Bacillus  ulna  of  Vignal.     VIGNAL,  op.  cit.  (No.  2421),  p.  360. 

2506  Bacillus  liquefaciens.     EISENBERG,  op.  cit.  (No.  2297),  p.  112. 

2507  Bacillus  mai'dis.     PALTATJF   UND  HEIDER,    Medicinische  Jahrbilcher,    1889, 

No.  8.    EISENBERG,  op.  cit.  (No.  2297),  p.  119. 

2508  Proteus    sulfureus     LINDENBORN    UND     HOLSCHEWNIKOFF,    Fortschr.    der 

Med.,  Bd.  vii.,  p.  201. 

2509.  Bacillus  thermophilus.     MIQUEL,  Ann  de  Micrographie,  1888,  p.  4. 

2510.  Bacillus  tumescens.     A.  KOCH,   op.   cit.   (No    2493).    ZOPF,  Die  Spaltpilze, 

Breslau,  1884,  p.  61. 

2511.  Bacillus  buccalis  maximus.     MILLER    The  microorganisms  of    the  human 

mouth,  Phila.,  1890,  p.  73  (English  translation  from  Ger.  ed.). 

2512.  Leptothrix  buccalis  of  Vignal.     VIGNAL,  op.  cit.  (No  2421),  p.  337. 

2513    Bacillus  b,  Bacillus/,  and  Bacillus^'  of  Vignal.     VIGNAL.,  op.  cit.  (No.  2421). 
2514.  Bacillus  Havaniensis  liquefaciens.     STERNBERG,  op.  cit.  (No.  2337).  p.  215. 

2515  Bacillus  liquefaciens  communis.     STERNBERG,  op.  cit.  (2337),  p.  209. 

2516  Bacillus  muscoides.     LIBORIUS,  Zeitschr.  filr  Hygiene,  Bd.  i.,  p.  163. 


•'874  BIBLIOGRAPHY. 

•2517.  Bacillus  polypiformis.     LIBORIUS,  op.  cit.  (No.  2516),  p.  162. 

2518.  Bacillus  solidus.     LUDERITZ,  Zeitschr.  fur  Hygiene,  Bd.  v.,  p.  152. 

.2519.  Bacillus butyricus.  PASTEUR,  Compt.  rend.  Acad.  des  Sc.,  lii.,  1861.  TRECUL, 
Compt.  rend.  Acad.  desSc.,  Ixi.,  1865;  ibid.,  Ixv.,  1867.  VAN  TIEGHEM, 
Compt.  rend.  Acad.  des  Sc.,  Ixxxviii.,  1879;  ibid.,  Ixxxix.,  1879;  ibid., 
1884  (No.  6).  TAPPEINER,  Fortschr.  der  Med.,  Bd.  i.,  p.  151  ;  Bd.  ii., 
pp.  377  and  416.  PRAZMOWSKI,  op.  cit.  (No.  2496). 

'2520.  Clostridium  fcetidum.     LIBORIUS,  op.  cit.  (No.  2516),  p.  160. 

2521.  Bacillus  liquefaciens  magnus.     LUDERITZ,  op.  cit.  (No.  2518),  p.  146. 

2532.  Bacillus  liquefaciens  parvus.     LUDERITZ,  op.  cit.  (No.  2518),  p.  148. 

2523.  Bacillus  radiatus.  .  LUDERITZ,  op.  cit.  (No.  2518),  p   149. 

2524.  Bacillus  spinosus.     LUDERITZ,  op.  cit.  (No.  2518),  p.  153. 

2525.  Bacillus  anaerobicus  liquefaciens.     STERNBERG,  op.  cit.  (No.  2337),  p.  214. 

X    NON-PATHOGENIC  SPIRILLA 

2526.  Spirillum  sputigenum.    MILLER,  Deutsche  med.  Wochenschr.,  1884,  No.  47. 
"2527.  Spirillum  dentium.     MILLER,  op.  cit.  (No.  2511). 

2528.  Spirillum  plicatile.     KOCH,  Beitrag  zur  Biol,  der  Pflanzen,  Bd.  ii.,  p.  420. 
:2529.  Spirillum  rugula.     PRAZMOWSKI,  op.   cit.  (No.  2496).    VIGNAL,  op.  cit.  (No. 

2421)  p.  347. 

'2530.  Spirillum  sanguineum.     COHN,  Beitrag  zur  Biol.  der  Pflanzen,  Bd.  i.,  p.  169. 
2531.  Spirilla  of  Weibel.     WEIBEL,  Centralbl.  fur  Bakteriol.,  Bd.  iv. 
'2532.  Spirillum  concentricum.     KITASATO,  Centralbl.  fiir  Bakteriol.,  Bd.  iii.,  p.  73. 
:2533.  Spirillum  rubrum.    VON  ESMARCH,  Centralbl  fllr  Bakteriol.,  Bd.  i.,  p.  225. 
2534.  Spirillum  of  Smith.     SMITH,  Centralbl  filr  Bakteriol.,  Bd.  x.,  p.  178. 
"2535.  Spirillum  of  Miller.   MILLER,  Deutsche  med.  Wochenschr.,  1884,  Nos.  34  and  48. 

XL     LEPTOTRICHE^E  AND   CLADROTRICH^E. 

'3536.  Crenothrix  Kilhniana.  COHN,  Max  Schultz's  Archiv,  Bd.  iii.  ZOPP,  Die 
Spaltpilze,  2d  ed. ,  p.  67. 

2537.  Beggiatoa  alba.     ZOPF,  op.  cit.  (No.  2536),  p.  71. 

2538.  Beggiatoa  roseo  persiciua.    ZOPF,  op.  cit.   (No.   2536),   p.   73.    LANKESTER, 

Quar  Journ.  Mic.  Sci.,  vol.  xiii.,  1873  ;  ibid.,  vol.  xvi.,  1876. 

2539.  Beggiatoa  mirabilis.     ZOPF,  op.  cit.  (No.  2536),  p.  74. 

2540.  Phragmidiothrix  multiseptata.    ENGLER,  Bericht  der  Kommission  zur  Erfor- 

schung  deutscher  Meere,  1881. 

2541.  Cladothrix  dichotoma.     COHN,  Beitrag  zur  Biol.  der  Pflanzen,  Bd.  i.,  Heft  3. 

CIENKOWSKI,  zur  Morph.  der  Bakterien,  St.  Petersburg,  1876.     ZOPF,  op. 
cit.  (No.  2536),  p.  77. 
5542.  Cladothrix  Foersteri.     COHN,  op.  cit.  (No.  2541),  Bd.  i.,  Heft 3. 

XII.     ADDITIONAL   SPECIES  OF  BACTERIA,  NOT  CLASSIFIED. 

.2543  WINOGRADSKY.  Recherchcs  sur  les  organismes  de  la  nitrification,  Ann.  de 
1'Institut  Pasteur,  t.  iv.,  1890,  p.  213;  2e  Memoire,  ibid.,  p  257;  3e  Me- 
moire,  ibid.,  p.  760  ;  4e  Memoire,  ibid.,  t.  v.,  1891,  p.  93  ;  5e  Memoire,  ibid., 
t.  v.,  p.  575. 

:2544.  FRANKLAND,  PERCY  F.  AND  GRACE  C.  The  nitrifying  process  and  its  spe- 
cific ferment.  Proc.  of  the  Royal  Soc.  of  London,  vol.  xlvii.,  1890,  p.  296. 

:2545  JORDAN,  E.  O.,  AND  RICHARDS,  ELLEN  H.  Investigations  upon  nitrification 
and  the  nitrifying  organism.  Rep.  Mass.  State  Board  of  Health,  Purifi- 
cation of  Sewage  and  Water,  vol.  ii.,  1890,  p.  865. 


BIBLIOGRAPHY.  875 

•2546.  MUNTZ.  De  la  formation  des  nitrates  dans  la  terre.  Compt.  rend.  Acad.  des 
Sc  ,  t.  cxii.,  No.  20. 

2547.  WARINGTON.     On  nitrification.     Journ.    of  the  Chem.    Soc.,    Lond.,    1890, 

p.  485. 

2548.  Streptococcus  conglomeratus.     KURTH,  Trans.  Ninth  Interuat.  Med.  Cong., 

Berlin,  1891,  p.  335. 
'2549.  RUSSELL.     Untersuchungen   liber    im   Golf    von  Neapel  lebende    Bakterien. 

Zeifschr.  fur  Hygiene,  Bd.  xi.,  1891,  p.  190. 
2550.  Bacillus  capsulatus  mucosus.     FASCHING,  S.  B.  K.  Akad.  Wiss.,  Wiener  Cen- 

tralbl.,  Ib91,  p.  295. 
'2551.  Bacillus  of  potato  rot.     KRAMER,  Bakteriologische  Untersuchungen  uber  die 

Nassfaille    der    Kartoffelknollen.     Oesterreichisches  landwirthschaft.  Cen- 

tralbl.,  1891,  p.  11. 
•2552.  Bacillus  vacuolosis.     STERNBERG,  op.  cit.  (No.  2337),  p.  208. 

2553.  Bacillus  of  Dantec.     DANTEC,  Etude  de  la  morue  rouge,  Ann.  de  1'Institut 

Pasteur,  t.  v.,  1891,  p.  659. 

2554.  Bacillus  Havaniensis.     STERNBERG,  op.  cit.  (No.  2337),  p.  207. 

2555.  Bacillus  amylozyma.     PERDRIX,  Sur  les  fermentations  produites  par  un  mi- 

crobe, anaerobic  de  1'eau.     Ann.  de  1'Institut  Pasteur,  t.  v.,  1891,  p.  287. 

2556.  Bacillus  rubellus.     OKADA,  Centralbl.  filr  Bakteriol.,  Bd.  xi.,  1892,  p.  1. 

2557.  Bacterium  ureoe.     JAKSCH,  Zeitschr.  fur  phys.  Chem.,  Bd.  v.,  p.  395.     LEUBE 

UND  GRASSER,  Virchow's  Archiv,  Bd.  c.,  p.  556. 

2158.  Sarcina  mobilis.     MAUREA,  Centralbl.  fur  Bakteriol.,  Bd.  xi.,  1892,  p.  228. 
•2159.  POHL.     Centralbl.  fur  Bakteriol.,  Bd.  xi.,  1892,  p.  142. 
2160.  Bacillus  butyricus  of  Botkin.     BOTKIN,  Zeitschr.  fur  Hygiene,  Bd.  xi.,  1892, 

p.  421. 

2561.  MIQCEL.     Etude  sur  la  fermentation  ammoniacale  et  sur  les  ferments  de  1'uree. 

Ann.  de  Micrographie,  vols.  ii.,  iii.,  iv.,  and  v.  (1889-1892). 

2562.  BOVET.     Contribution  a  1'etude  des  microbes  de  1'intestin  gre"le.     Ann.  de  Mi- 

crographie, vol.  iii.,  1891,  p.  353. 

•2563.  FREUDENREICH.  Sur  un  nouveau  bacille  trouve  dans  les  fromages  boursoufles. 
Ann.  de  Micrographie,  vol.  iii.,  1891,  p.  161. 

2564.  Sur  quelques  bacteries  produisent  le  boursouflement  des  frommages. 

Ann.  de  Micrographie,  vol.  ii.,  1890,  p.  353. 

3565.  GUILLEBEAU.  Description  de  deux  nouveaux  microbes  du  lait  filant.  Ann. 
de  Micrographie,  vol.  iv.,  1892,  p.  225. 

'2566.  Bacillus  denitrificans.  GILTAY  ET  ABERSON,  Arch.  Neerlandaises  Sci.  exact. 
et  nat.,  xxv.,  1891,  p.  341. 

:2567.  Bacillus  cyano-fuscus.     BEYERINCK,  Bot.  Ztg.,  1891,  vol.  xlix.,  Nos.  43-47. 

2568.  Description  of  a  pus-producing  bacillus  obtained  from  earth.  BOLTON,  Am. 
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:2569.  VAUGHAN.  A  bacteriological  study  of  drinking  water.  Am.  Journ.  Med.  Sc., 
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2570.  WELCH  AND  NTTTTALL.  A  gas-producing  bacillus  (Bacillus  afirogenes  capsu- 
latus, nov.  spec.)  capable  of  rapid  development  in  the  blood  vessels  after 
death.  Bull,  of  the  Johns  Hopkins  Hospital,  July,  1892. 

•2571.  CANON  UND  PrELiCKE.     Berliner  klin.  Wochenschr.,  No.  16,  1892. 

2572.  BRANNAN  AND  CHEESMAN.  A  study  of  typhus  fever,  clinical,  pathological, 
and  bacteriological.  Medical  Record,  New  York,  June  25th,  1892. 

•2573.  MENGE.  Uebereinen  Mikrokokkus  mit  Eigenbewegung.  Centralbl.  fur  Bak- 
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2574.  STERNBERG.    Op,  cit.  (No  2337),  p.  216. 


876  BIBLIOGRAPHY. 

SUPPLEMENT  TO  BIBLIOGRAPHY. 

2575.  PFUHL.     Beitrag  zur  .iEtiologie  der  Influenza.     Centralbl.  fiir  Bakteriol.,  Bd. 

xi.,  1892,  p.  398. 

2576.  FIOCCA.     Ueber  einen  im  Speichel  einiger  Hausthiere  gefundenen,  dem  In- 

fluenzabacillus  ahnlichen  Mikroorganismus.     Centralbl.  filr  Bakteriol.,  Bd. 
xi.,  1892,  p.  406. 

2577.  STERN.     Ueber  Desinfektion  des  Darmkanales.     Zeitschrift  fiir  Hygiene,  Bd. 

xii.,  1892,  p.  88. 

2578.  ROBB  AND  GHRISKY.     The  bacteria    in    wounds    and  skin  stitches.     Johns 

Hopkins  Hosp.  Bull.,  vol.  iii.,  1892,  p.  37. 

2579.  BRIEGER,  KITASATO  TTND    WASSERMANN.     Ueber  Immunitat  und  Giftfesti- 

gung.     Zeitschrift  fur  Hygiene,  Bd.  xii.,  1892,  p.  138. 

2580.  FREUDENREICH.     De  1'antagonism  des  bacteries.     Ann.  de  Micrographie,  vol. 

ii.,  1889,  p.  1. 

2581.  PARK.     Diphtheria  and  allied  pseudo-membranous  inflammations.     Medical 

Record,  New  York,  July  30th,  1892. 

2582.  STERNBERG.    Practical  results  of  bacteriological  researches.     Am.  Journ.  Med. 

Sc.,  vol.  civ.,  No.  1  (July,  1892). 


INDEX. 


Abrin,  pathogenic  action  of,  and  immu- 
nity from,  259 

Abscesses,  formation  of,  217,  264 
Acetone,  germicidal  value  of,  189 
Acetic  acid,  production  of,  130 

germicidal  value  of,  174 
Acids,  production  of,  129 

germicidal  action  of,  172 
Acne  contagiosa  of  horses,  bacillus  of, 

478 
Atsroscope  of  Maddox,  543 ;    of  Hesse, 

545 
Agar-agar  jelly,  43 

methods  of  filtering,  44 
Agar-gelatin,  43 

Agua  coco  as  a  culture  medium,  39 
Air,  bacteria  in,  541 
Alcohol,  germicidal  value  of,  189 
Alkalies,  germicidal  value  of,  175 
Alopecia,  bacteria  in,  514 
Alum,  antiseptic  value  of,  180 
Aluminum  acetate,  antiseptic  value  of, 

180 

Ammonia,  germicidal  value  of,  176 
Ammonium  carbonate,  germicidal  value 

of,  180 
Anaerobic  bacilli,  pathogenic,  482 

non- pathogenic,  687 

cultivation  of,  78 
Aniline  oil,  antiseptic  value  of,  190 

dyes,  germicidal  value  of,  189 
Anthrax,  327 

bacillus,  chemical  products  of,  333 

bacillus,  toxalbumin  of,  332 

bacillus,  formation  of  spores,  331 
Antiseptics,  action  of,  156 

comparative  value  of,  178 
Antiseptic  value,   method    of  determin- 
ing, 156,  157 
Antitoxine  of  pneumonia,  257,  308 

of  tetanus,  256 
Antitoxines,  256 
Arnold's  steam  sterilizer,  54 
Arsenious  acid,  germicidal  value  of,  175 
Arthrospores,  116 
Ascobacillus  citreus,  634 
Ascococcus,  generic  characters,  17 

Billrothii,  618 

Johnei,  315 

72 


Aseptol,  germicidal  value  of,  190 
Atmospheric  bacteria,  541 

methods  of  collecting,  541-560 
general  results  of  researches  made, 

550 

list  of  species  found,  552 
Miquel's  method  of  collecting,  546  ; 

Petri's  method,  548 
soluble  filter  for  collection  of,  549 
Attenuation  of  virulence,  123,  233 
by  antiseptic  agents,  124 
by  cultivation  in  blood  of  immune 

animal,  125 
by  heat,  124 

Bacilli,  general  characters  of,  18 

morphology  of,  23 
Bacillus,  generic  characters,  18 

acidiformans,  449 

acidi  lactici,  645 

of  acne  contagiosa  of  horses,  478 

aBrogenes  capsulatus,  731 

aerophilus,  672 

of  Afanassiew,  469 

agilis  oitreus,  733 

albus,  645 

albus  anafirobiescens,  729 

albus  cadaveris,  473 

albus  putidus,  675 

allantoides,  680 

allii,  629 

alvei,  477 

amylozyma,  718 

anae"robicus  liquefaciens,  693 

anthracis,  328 

aquatilis,  666 

aquatilis sulcatus  No.  I.,  646 

aquatilis  sulcatus  No.  II.,  647 

aquatilis  sulcatus  No.  III.,  647 

aquatilis  sulcatus  No.  IV.,  648 

aquatilis  sulcatus  No.  V. ,  648 

arborescens,  633 

argenteo-phosphorescens  No.  I.,  659 

argenteo-phosphorescens  No.  II.,  659 

argenteo-phosphorescens    No.    III., 
660 

argen  teo-  pi  i  osphorescens        1  iq  uef  a- 
cieiis,  661 

aurantiacus,  620 


878 


INDEX. 


Bacillus  aureus,  621 

of  Babes  and  Oprescu,  435 
of  Belfauti  and  Pascarola,  417 
beriolinensis  Indicus.  621 
of  Booker,  443-446,  463 
of  Bovet,  724 
brassicae,  675 
brunneus,  620 
buccalis  fortuitus,  685 
buccalis  maximus,  683 
buccalis  minutus,  643 
butjricus,  688 
butyricus  of  Botkin,  721 
butyricus  of  Hueppe,  675 
cadaveris,  492 
canalis  capsulatus,  476 
canalis  parvus,  476 
candicans.  644 
of  Canestrini .  643 
of  Canon  and  Pielicke,  731 
capsulatus,  431 
capsulatus  mucosus,  716 
carabiformis,  676 
carotarum,  676 
caviae  fortuitus,  650 
cavicida,  425 
cavicida  Havaniensis,  425 
of  Cazal  and  Vaillard,  435 
cholera?  gallinarum,  408 
chromo-aromaticus,  475 
circulans,  663 
citreus  cadaveris,  633 
cloaca? ,  065 
coeruleus,  635 
coli  communis,  439 
coli  similis,  650 
of  Colpmiatti,  656 
constrictus,  622 
coprogenes  parvus,  424 
coprogenes  fretidus,  468 
crassus  sputigenus,  426 
cuniculicida,  408 
cuniculicida  Havaniensis,  450 
cuticularis,  632 
cyanogenus,  626 
cyaneo  phosphorescens,  661 
cyano  fuscus,  727 
cystiformis,  649 
of  Dantec,  717 
delicatulus,  666 
of  Demme,  465 
denitrificans,  727 
dentalis  viridans,  471 
devorans,  669 
diffusus,  667 
diphtheria?,  360 
diphtheria?  columbrarum,  367 
diphtheria?  vitulorum,  368 
endocarditidis  capsulatus,  464 
endocarditidis  griseus,  463 
enteritidis,  429 
epidermidis,  651 
erysipelatos  suis,  420 
erythrosporus,  624 
figurans,  729 


Bacillus  filiformis,  669 

filiformis  Havaniensis,  650 

of  Fiocca,  456 

flavocoriaceus,  621 

flavescens,  721 

fluorescens  aureus,  622 

fluorescens  liquefaciens,  635 

fluorescens    liquefaciens    minutissi- 

mus,  636 

fluorescens  longus,  622 
fluorescens  nivalis,  636 
fluorescens  noii-liquefaciens,  623 
fluorescens  putidus,  624 
fluorescens  tenuis,  623 
foetidus  oza?na?,  466 
No.  I.  of  Fulles,  657 
No.  II.  of  Fulles,  657 
fulvus,  629 
f  uscus,  625 
fuscus  limbatus,  628 
gallinarum.  430 
gasoformans,  676 
of  Gessner,  475 
gingiva?  pyogenes,  471 
glaucus,  637 
gracilis,  670 

gracilis  anaerobiescens,  728 
gracilis  cadaveris,  733 
granulosus,  711 
graveolens,  676 
of  grouse  disease,  429 
of  Guillebeau,  a,  b,  c,  725 
guttatus,  670 
halophilus,  716 
Havaniensis,  718 
Havaniensis  liquefaciens,  686 
helvplus,  630 
heminecrobiophilus,  481 
hepaticus  fortuitus,  649 
Hessii,  727 
of  hog  cholera,  413 
hyacinthi  septicus,  651 
hyalinus,  665 
hydrophilus  fuscus,  432 
implexus,  671 
incanus,  720 
Indicus,  637 
indigogenus,  476 
inflatus,  677 
of  influenza,  371 
intestinus  motilis,  649 
of    intestinal  diphtheria  in  rabbits, 

368 

invisibilis,  729 
iuunctus,  721 
iris,  625 
janthinus,  631 
of  Jeffries,  448 
of  Kartulis,  477 
of  Koubasoff ,  405 
lactis  albus,  680 
lactis  erythrogenes,  636 
lactis  pituitosi,  645 
latericeus,  628 
of  Laser,  434 


I*DEX. 


879 


Bacillus  leporis  lethalis,  458 
leprse,  394 
leptosporus,  679 
of  Lesage,  464 
of  Let ze rich,  466 
limosus,  713 

limbatus  acidi  lactici,  645 
liodermos,  680 
liquefaciens,  682 
liquefaciens  comraunis,  686 
liquefaciens  magnus,  690 
liquefaciens  parvus,  690 
liquidus,  667 
litoralis,  714 
lividus.  637 
of  Loeb,  437 
of  Lucet,  436 
of  Lumnitzer,  467 
maidis.  682 
malar iae  of  Klebs  and  Tommasi-Cru- 

deli,  523 
mallei,  396 
marinus,  714 
Martinez.  651 
of  measles,  731 
megatherium,  674 
membranaceus  amethystinus,  634 
meningitidis  purulent*,  474 
mesentericus  fuscus,  674 
mesentericus  ruber,  639 
mesentericus  vulgatus,  673 
multipediculus,  648 
murisepticus  420 
murisepticus  pleomorphus,  460 
muscoides,  687 
mycoides,  673 
mycoides  roseus,  640 
Neapolitanus,  439 
necrophorus,  468 
of  Nocard,  406 
nodosus  parvus,  651 
nubilus,  668 
ochraceus,  630 
oedematis  afirobicus,  465 
cedematis  maligni,  488 
of  Okada,  479 
ovatus  miimtissimus,  652 
oxytocus  perniciosus,  469 
pestifer,  669 

phosphorescens  gelidus,  658 
phosphorescens  Indicus,  662 
phosphorescens  iudigenus,  663 
plicatus.  630 
pneumouiae,  296 
pneumosepticus,  431 
polypiformis,  687 
prodigiosus,  638 
pseudotuberculosis,  470 
pulpae  pyogenes,  471 
punctatus,  671 

of  purpura  haemorrhagica,  480,  48L 
putrificus  coli,  654 
pyocyanus,  454 
pyocyanus  fi,  639 
pyogenes  fcetidus,  427 


Bacillus  pyogenes  soli,  728 
radiatus,  691 
radiatus  aquatilis,  671 
ramosus,  677 
reticularis,  664 
of  rhinoscleroma,  404 
rosaceum  metalloides,  640 
of  Roth,  479 
rubefaciens,  625 
rubellus,  719 
rubescens,  629 
rubidus,  642 
salivarius  septicus,  298 
sauguinis  typhi,  732 
saprogenes  II.,  469 
Schafferi,  725 
of  Scheurlen,  680 
of  Schimmelbusch,  466 
of  Schou.  468 
scissus,  656 

septicaemias  hasmorrhagicae,  408 
septicus  acuurinatus,  472 
septicus  agrigenus,  419 
septicus  keratomalaciae,  472 
septicus  sputigenus,  298 
septicus  ulceris  gangraenosi,  472 
septicus  vesicae,  475 
sessilis,  679 

smaragdinus  foetidus,  430 
smaragdino- phosphorescens,  658 
solidus,  688 
spiniferus,  628 
spinosus,  693 
stolonatus,  654 
stoloniferus,  720 
striatus  albus,  654 
striatus  flavus,  626 
subflavus.  626 
subtilis,  677 

subtilis  simulans  No.  I.,  654 
subtilis  simulans  No.  II.,  654 
sulfureum,  641 
superficialis.  664 
of  swine  plague,  417 
of  symptomatic  anthrax,  493 
tenuis  sputigenus,  433 
tetani,  482 
thalassophilus,  711 
thermophilus,  682 
of  Tommasoli,  467 
tremelloides,  632 
of  Tricomi,  473 
tuberculosis,  375 
tuberculosis  gallinarum,  392 
tumescens,  683 
typhi  abdominalis,  346 
typhi  murium,  434 
typhosus,  346 
ubiquitus,  644 
ulna,  681 

ulna  of  Vignal,  681 
of  Utpadel,  477 
vacuolosis,  717 
varicosus  conjunctiva,  474 
venenosus,  729 


880 


INDEX. 


Bacillus  venenosus  breyis,  730 

venenosus  invisibilis,  730 

venenosus  liquefaciens,  730 

ventriculi,  655 

vermicularis,  668 

vermiculosus,  673 

b  of  Vignal,  684 

/of  Vignal,  685 

j  of  Vignal,  685 

violaceus,  641 

violaceus  Laurentius,  631 

virescens,  624 

viridis  pallescens,  624 

viscosus,  640 
Bacillus  coli  communis  in  peritonitis,  447 

tuberculosis,  spore  formation  (?),  379; 
thermal  death  point,  380 

tuberculosis  ;  staining  methods,  377 

typhi  abdominalis,  flagella  of,  347 

typhi  abdominalis,    in  spleen,    341  ; 
in  faeces,  341 ;  in  water,  350 

typhi  abdominalis;  chemical  products 

of,  344 

Bacteria  in  the  air,  541 
Bacterial  cells,  chemical  composition  of, 

117 

Bacteriological  diagnosis,  735 
Bacterium  afirogenes,  646 

coli  commune,  439 

gliscrogenum,  652 

lactis  aerogenes,  447 

luteum,  620 

termo  of  Vignal,  642 

tholoideum,  475 

ureae.  720 

Zopfii,  656 

Zuruianum,  656 

Baumgarten,  classification  of,  12 
Beggiatoa,  sulphur  grains  in,  24 

alba,  705 

mirabilis,  706 

roseo  persicina,  705 
Benzene,  germicidal  value  of,  190 
Benzoic  acid,  germicidal  value  of,  175 
Beri-beri,  bacteria  in,  514 
Bibliography,  735  to  876 
Biological  characters,   modifications  of, 

122 

Biskra  button,  micrococcus  of,  318 
Blood  serum,  collection  of,  37 

cultures  upon,  75 

germicidal  value  of,  198,  229 

sterilization  of,  5~> 
Booker's  bacilli,  443-446 
Boracic  acid,  germicidal  value  of,  174 
Bouillon,  41 
Bread  paste,  49 
Brieger's  bacillus,  425 
Bright's  disease,  micrococci  in,  319 
Bromine,  germicidal  value  of,  170 
Bronchitis,  bacteria  in,  467,  515 
Buchner's  method  of  cultivating  anae- 
robic bacteria,  83 
Bilffelseuche,  bacillus  of,  408 
Butter,  bacteria  in,  590 


Butyric  acid,  production  of,  130 
germicidal  value  of.  175 

Cadaverin,  139 
Cadavers,  bacteria  in,  585 
Calcium  hydroxide,  germicidal  value  of, 
176 

chloride,  antiseptic  value  of,  180 

hypochlorite,  germicidal  value  of ,  180 
Camphor,  germicidal  value  of,  190 
Capsule  bacilli  of  Smith,  652 
Carbolic  acid,  germicidal  value  of,  191 
Carbon  dioxide,  action  of,  16G 
Carbonic  oxide,  action  of,  166 
Carcinoma,  bacteria  in,  515 
Catarrhal  inflammations,  220 
Caucasian  milk  ferment,  132 
Cerebro-spinal    meningitis,    bacteria   in, 

518 

Chancroid,  bacteria  in,  515 
Charbon,  327 

symptomatique,  bacillus  of,  493 
Cheese,  bacteria  in,  590 
Chemiotaxis,  235 

Chloral  hydrate,  antiseptic  value  of,  181 
Chlorine,  antiseptic  and  germicidal  value 

of,  169 

Chloroform,  antiseptic  value  of,  169 
Cholera  in  ducks,  bacillus  of,  413 

infantum,  bacteria  4n,  515 

infantum,  Proteus  vulgaris  in,  4."»9 

nostras,  bacteria  in,  515 

ptomaines,  142 
Cholin,  140 

Chromic  acid,  germicidal  value  of,  173 
Chronic  infectious  diseases,  bacilli  in,  374 
Citric  acid,  germicidal  value  of,  174 
Cladothrix,  morphology  of,  24 

intricata,  708 

dichotoma,  706 

Foersteri,  707 
Cladotricheae,  703 

general  characters  of,  19 
Classification.  10 

biological,  14-16 

morphological,  13 

of  pathogenic  bacteria,  533 

of  Baumgarten,  12 

of  Cohn,  11 

of  Davaine,  10 

of  Dujardin,  10 

of  Ehrenberg,  10 

of  Hoffmann,  10 

of  Hueppe,  16 

of  Niljreli,  11 

of  Robin,  3 

of  Sachs,  11 

of  Zopf,  12 

Clathrocystis  roseo- persicina,  705 
Clostridium.  morphology  of,  23 

foetidum,  689 

Coal-tar  products,  germicidal  value  of,  139 
Coffee  infusion,  germicidal  value  of,  193 
Cohn,  classification  of,  1 1 
Colon  bacillus,  439 


INDEX. 


881 


Colonies  of  bacteria,  general  characters 

of,  71 

Comma  bacillus  of  Koch,  500 
Conjunctivitis,  bacteria  in,  517,  574 

bacilli  in.  474.  477 

pus  cocci  in,  282 
Contact  preparations.  27 
Corrosive  sublimate,  germicidal  value  of, 

182 

Coryza,  bacteria  in,  517 
Cotton  air  filter,  4 
Crenothrix  Kilhuiana,  703 
Creolin,  germicidal  value  of,  192 
Cresol,  germicidal  value  of,  193 
Croupous  pneumonia,  bacteria  in,  288 

etiology  of,  288-296 
Culture  media.  37 
Cultures  in  liquid  media,  60 

in  solid  media,  67 

Cupric sulphate,  germicidal  value  of,  181 
Cystitis,  bacilli  in,  475,  517 

Darmbacillus  of  Sehottelius,  468 
Davaine,  classification  of ,  10 
Davaine's  septicaemia,  bacillus  of,  408 
Uecolorization,  28 
Demme,  bacillus  of,  465 
Deneke,  spirillum  of,  511 
Dengue,  bacteria  iu,  519 
Defensive  proteids,  260 
Desiccation,  effect  of,  151 
Diagnosis,  bacteriological,  735 
Dimensions  of  bacteria,  20 
Diplococcus  albicans  amplus,  603 

coryzae,  608 

citreus  liquefaciens,  595 

citreus  conglomerate,  594 

fluorescens  foatidus,  596 

flavus  liquefaciens  tardus,  595 

intercellularis  meningitidis,  310 

luteus,  596 

pneumonia.  298 

of  pneumonia  in  horses,  322 

roseus,  596 

Disinfectants,  general  account  of  the  ac- 
tion of.  156 
Disinfection,  practical  directions  for,  201 

by  steam,  203 

of  clothing,  202 

of  ships,  203 

of  the  sick-room,  202 

in  diphtheria,  210 

of  excreta,  206 

Disiufektol,  germicidal  value  of,  194 
Diphtheria,  bacteria  in,  356 

experiments  on  animals,  359,  362 

bacillus,  toxalbumin  of,  364 

bacillus,  immunity  from,  364 
Diphtheritic  inflammations,  219 
Double  staining,  28 
Drop  cultures,  62 
Dujardin,  classification  of,  10 

Eczema  epizp5tica,  bacteria  in,  519 
Eggs,  bacteria  in,  591 


Ehrenberg,  classification  of,  10 
Ehrlich's  solution,  29 
Ehrlich-Weigert  solution,  29 
Electricity,  action  of,  upon  bacteria,  154 
Emmerich's  bacillus.  439 
Empyema,  bacteria  in,  520 
Endocarditis,  ulcerative,  271 

bacteria  in,  520 

micrococci  in,  320  ^^^ 

streptococcus  pyogenes  in,  2<4\278 
Enzymes,  tryptic,  129 
Erysipelas,  etiology  of,  274,  277 
Erythema,  bacteria  in,  521 

nodosum,  465 

Von  Esmarch's  roll  tubes,  74 
Esmarch's  method  of  cultivating  anafro- 

bic  bacteria,  82 

Essential  oils,  germicidal  value  of,  194 
Ether,  germicidal  value  of,  194 
Eucalyptol,  germicidal  value  of,  195 
Excreta,  disinfection  of ,  201,  206 
Experiments  upon  animals,  94 

Faeces,  bacteria  in,  583,  584 
Farcy  in  cattle,  406 
Fermentation,  putrefactive,  134 

of  urea,  132 

viscous,  133 
Ferments,  soluble,  136 
Ferric  chloride,  germicidal  value  of,  182 
Ferrous  sulphate,   germicidal  value   of, 

181 

Finkler  and  Prior,  spirillum  of,  509 
Fiocca,  bacillus  of,  456 
Fixing,  upon  cover  glass,  26 
Flagella,  methods  of  staining,  32 

of  bacilli,  24 

of  bacteria,  112 
Flesh-colored  bacillus,  632 
Flesh  peptone  gelatin,  41 

solution,  41 

Foot  and  mouth  disease,  bacteria  in,  519 
Formic  acid,  germicidal  value  of,  175 
Foul  brood,  bacillus  of,  477 
Fowl  cholera,  bacillus  of,  408 
Frankel's  method  of  cultivating  anaero- 
bic bacteria,  80 

Freezing,  action  of,  upon  bacteria,  145 
Friedlander's  bacillus,  296 

method  of  staining  tubercle  bacilli, 
30. 

Gabbett's  method  of  staining  tubercle  ba- 
cilli, 30 

Gallic  acid,  germicidal  value  of,  175 
Gases,  action  of,  upon  bacteria,  161 
Germicides,  action  of,  156 
Germicidal  value,  methods  of  determin- 
ing, 158 

Gibier,  bacillus  of,  453 
Glanders,  bacillus  of,  396 

bacillus,  staining  of,  397 

diagnosis  of,  401 
Glycerin,  germicidal  value  of,  195 

-agar,  43 


882 


INDEX. 


Gold  chloride,  germicidal  value  of,  182 

Gonococcus,  283 

Gram's  method,  29 

Granuloma  fungoides,  bacteria  in,  521 

Green  pus,  bacillus  of,  454 

Grouse  disease,  bacillus  of,  429 

Growth,  conditions  of,  118 

Hsematococcus  bovis,  322 

Hail,  bacteria  in.  559  . 

Hands,  disinfection  of,  205 

Heat,  action  of,  upon  bacteria,  145 
moist,  action  of,  146 
dry,  action  of,  146 

Helicobacterium  aerogenes,  646 

Heterogenesis,  5 

Historical,  3 

Hoffmann,  classification  of,  10 

Hog  cholera,  bacillus  of,  4i3 
erysipelas,  bacillus  of,  420 

Hot-air  ovens,  52 

Hydrant  water,  bacteria  in,  561 

Hydrochloric  acid,  germicidal  value  of, 
173 

Hydrofluoric  acid,  germicidal  value  of, 
171 

Hydrogen  peroxide,  antiseptic  and  ger- 
micidal value  of,  165 

Hydrophobia,  bacteria  in,  521 

Hydrosulphuric  acid,  action  of,  167 
formation  of,  134 

Hydroxylamin,  germicidal  value  of,  195 

Ice,  bacteria  in,  560 
Icterus,  bacteria  in,  523     . 
Immunity,  226 

acquired,  232 

from  injection  of  filtered  cultures, 
234 

theories  of,  237 
Impftetanus  bacillus,  417 
Incubating  ovens,  86 

oven  of  D'Arsonval,  82 

oven  of  Roux,  93 
Infection,  channels  of,  223 

mixed.  222 

secondary,  221 
Inflammations  of    mucous    membranes, 

pus  cocci  in.  281 
Influenza,  bacteria  in,  370 
Infusoria,  3 
Injections  into  the  eye,  97 

into  the  circulation.  96 

into  peritoneal  cavity,  96 

into  the  intestine,  97 
Intestine,  bacteria  in,  580,  582 
Involution  forms,  23 
Iodine,  germicidal  value  of,  169 

trichloride,  germicidal  value  of,  170 
lodoform,  germicidal  value  of,  170 
Iron,  sulphate  of,  antiseptic  value,  182 

Jeffries'  bacilli,  448 

Jequirity  solution,  as  culture  medium,  47 


Karliusky's  method  of  filtering  agar,  45 
Kartulis,  bacillus  of,  477 
Koch's  plate  method,  72 

method  of  staining  flagella,  32 

syringe,  95 

Kiihne's  method  of  staining  bacteria  in 
tissues,  34 

Lactic  acid,  germicidal  value  of,  174 

fermentation,  588 
Lake  water,  bacteria  in,  560 
Lanolin,  germicidal  value  of,  196 
Lead  chloride,  germicidal  value  of.  182 

nitrate,  germicidal  value  of,  182 
Leprosy,  bacillus  of,  394,  523 
Leptothrix  buccalis  of  Vignal,  684 
Leptotricheae,  703 

general  characters  of,  19 
Lesage,  bacillus  of,  464 
Leuconostoc,  generic  characters,  17 

mesenteroides,  619 
Liborius'  met  hod  of  cultivating  anaerobic 

bacteria,  83 

Light,  action  of,  upon  bacteria,  151 
Liquid  media,  cultures  in,  60 
Liquefaction  of  gelatin,  70,  128 
List  of  bacteria  described,  737 
Lochial  discharge,  bacteria  in,  578 
Loffler's  solution,  29 

method  of  staining  flagella,  32 
Lustgarten,  bacillus  of,  402 

Malachite  green,  germicidal  value  of,  190 

Malaria,  523 

Malic  acid,  germicidal  value  of,  175 

Malignant  pustule,  347 

Malignant  oedema,  bacillus  of,  488 

Mallein,  144 

Marsh  gas,  formation  of,  134 

Mastitis,  bovine,  micrococcus  of,  317 

Mastitis  in  sheep,  micrococci  in.  320 

in  cows,  streptococcus  of,  321 
Measles,  bacteria  in,  524 
Meats,  bacteria  in,  590 
Meatus-urinarius,  bacteria  of,  578 
Meningitis,  bacteria  in,  474,  524 
Mercuric  chloride,   germicidal  value  of, 
182 

cyanide,  germicidal  value  of,  184 

iodide,  antiseptic  value  of,  184 
Merismopedia,  generic  characters,  17 
Methane,  action  of,  167 
Methyl  violet,  germicidal  value  of,  189 
Methylamine.  140 
Methyl  guanidin,  141 
Metritis,  puerperal,  etiology  of,  274 
Micrococci,  general  characters  of,  17 
Micrococcus  acidi  lactici,  603 

acidi  lactici  liquefaciens,  C01 

aerogenes,  602 

agilis,  594 

albicans  tardus.  607 

albicans  tardissimus.  607 

albus  liquefaciens,  602 

of  Almquist,  325 


INDEX. 


Micrococcus  amylovorus,  618 

aquatilis,  604 

aquatilis  invisibilis,  728 

ascoforrnans,  315 

aurantiacus,  597 

botryogenus    3 1 5 

of  bovine  mastitis,  317 

of  bovine  pneumonia,  317 

candicans,  603 

candidus,  603 

carneus,  598 

cerasinus  siccus,  599 

cereus  albus,  599 

cereus  flavus,  599 

cinnabareus,  599 

citreus,  599 

concentricus,  604 

cremoides,  597 

cumulatus  tenuis,  605 

of  Dantec,  598 

of  Demme.  319 

endocarditidis  rugatus,  320 

fervidosus,  600 

Finlayensis,  608 

No.  II  of  Fischel,  324 

flavus  desidens,  594 

flavus  liquefaciens,  593 

flavus  tardigradus,  600 

foetidus,  604 

of  Forbes,  326 

of  Freire,  608 

Freudenreichi,  726 

fuscus,  594 

of  gangrenous  mastitis  in  sheep, 
320 

gingivae  pyogenes,  323 

gonorrho?ae,  283 

of  Heydeureich,  318 

of  Kirchner,  324 

lactis  riscosus,  604 

luteus,  600 

of  Manfredi,  316 

of  Manneberg,  319 

ocbroleucus,  601 

ovalis,  608 

ovatus,  318 

Pasteuri,  298 

plumosus.  605 

pneumonia?  crouposae,  298  ;  in  saliva 
of  healthy  persons,  298  ;  in  pneu- 
monic sputum,  299;  in  meningitis, 
300  in  otitis  media,  301  ;  in  ul- 
cerative  endocarditis,  301 ;  in  acute 
abscesses.  301 

of  pyaemia  in  rabbits,  312 

pyogenes  tenuis,  274 

radiatus.  602 

rosettaceus,  605 

roseus,  597 

salivarius  pyogenes,  311 

salivarius  septicus,  312 

of  septicaemia  in  rabbits,  312 

subflavus,  312 

tetragenus,  314 

tetragenus  mobilis  ventriculi,  615 


Micrococcus  tetrageuus  subflavus,  615 

tetragenus  versatilis,  613 

of  trachoma  (?),  313 

ureae,  606 

ureae  liquefaciens,  606 

versicolor,  598 

violaceus,  601 

viticulosus,  606 
Microzyma  bombycis,  318 
Milk,  bacteria  in,  588,  590 

as  a  culture  medium,  39 

germicidal  value  of,  200 

fermentation  of,  589 
Mil /brand,  327 

Miquel's    method    of    collecting    atmo- 
spheric bacteria,  546 
Mixed  infection,  222 
Modes  of  action  of  pathogenic  bacteria, 

215 
Modification    of    biological     characters. 

123 

Morphology  of  bacteria,  20 
Motions  of  bacteria,  113 
Mouse  septicaemia,  bacillus  of,  420 
Mouth,  bacteria  of,  575 

list  of  bacteria  found  in,  579 
Mucous  membranes,  bacteria  of,  573 
Miiller's  method  of  staining  spores,  32 
Muscarin,  140 

Mustard,  oil  of,  antiseptic  value,  196 
Mykoprotein,  117 

Nageli,  classification  of,  11 

Naphthol,  germicidal  value  of,  196 

Nares,  bacteria  of,  575 

Nasal  catarrh,  pus  cocci  in,  282 

Neisser's  method  of  staining  sporse,  31 

Nephritis,  bacteria  in,  466,  524 

Neuridin.  139 

Neurin,  140 

Nitrates,  reduction  of,  136 

Nitric  acid,  germicidal  value  of,  173 

Nitrification,  13ij 

Nitrifying  bacillus  of  Winogradsky,  710 

Nitrifying  bacilli.  709-711 

Nitromonas  of  Winogradsky,  709 

Nitrous  oxide,  action  of,  167 

Nitrous  acid,  germicidal  value  of,  173 

Noma,  bacilli  in,  466 

Nose,  list  of  bacteria  found  in,  579 

Nosema  bombycis,  318 

Nutrient  gelatin,  preparation  of,  42 

Okada,  bacillus  of,  479 
Ophidomonas  sanguinea,  705 
Otitis  media,  bacteria  in  525 

Micrococcus   pneumonias     crouposae 
in,  301 

pus  cocci  in,  281 

Osmic  acid,  germicidal  value  of,  173 
Osteomyelitis,  270 

bacteria  in,  525 

Oxalic  acid,  germicidal  value  of,  174 
Oxygen,  action  of,  upon  bacteria,  164 
Ozaena,  bacteria  in,  466,  526 
Ozone,  action  of,  upon  bacteria,  164 


INDEX. 


Panhistophyton  ovatum,  318 
Papin's  digester,  54 
Parasites,  facultative,  120 
Parasitic  bacteria,  215 
Parasitism,  120 
Parotitis,  bacteria  in,  526 
Pasteur-Chamberlain  filter,  57 
Pasteur's  solution,  46 

method  of  inoculating   rabbits   for 

rabies,  97 
Pathogenic  bacteria,  classification  of,  533 

in  water,  563,  565 
Pediococcus  albus,  614 

cerevisiae.  615 
Pemphigus,  bacteria  in,  526 

acutus,  micrococcus  of,  319 
Penicillum  glaucum,  542 
Peppermint,  oil  of,  antiseptic  value,  196 
Peptotoxin,  141 
Peritonitis,  bacteria  in,  526 

Bacillus  coli  communis  in,  447 
Perlsucht,  375 
Petri's  dishes,  73 

method    of   collecting    atmospheric 

bacteri»,  548 
Phagocytosis,  245 
Phosphorescence,  137 
Phosphoric  acid,  germicidal  value  of,  173 
Photographing  bacteria,  101 

by  sunlight,  105 ;  by  gaslight,  107; 
by  electric  light,  105  ;  by  calcium 
light,  105 

Phragmidiothrix  multiseptata,  706 
Phylaxins,  260 

Physical  agents,  influence  of,  145 
Pigment,  production  of ,  126 
Plate  method  of  Koch,  72 
Pleuritis,  bacteria  in,  527 
Plcuro- pneumonia  of  cattle,  bacteria  in, 

527 

Pneumobacillus  liquefaciens  bovis,  470 
Pneumonia,  bovine,  micrococcus  of,  317 
bovine,  bacilli  in,  470 
in  horses,  diplococcus  of,  322 
Pneumotoxin,  257,  308 
Post-mortem  examination  of  animals,  99 
Potassium  arsenite,  germicidal  value  of, 

185 

bichromate,  germicidal  value  of,  185 
bromide,  antiseptic  value  of,  185 
chlorate,  germicidal  value  of,  185 
cyanide,  antiseptic  value  of,  185 
hydroxide,  germicidal  value  of,  175 
iodide,  germicidal  value  of,  185 
permanganate,  germicidal  value  of 

186 

Potato,  preparation  of,  47 
paste,  49 
bacillus,  673 
cultures  upon,  76 
rot,  bacillus  of,  716 
Pregl's  method  of  staining  bacteria    in 

tissues,  35 

Pressure  regulator  of  Moitessier,  88 
Products  of  vital  activity,  126 


Proteus  capsulatus  septicus,  429 

hominis  capsulatus,  427 

of  Karlinsky,  460 

lethalis,  462 

mirabilis,  460 

septicus,  462 

sulfureus,  682 

Zenkeri,  462 

vulgaris,  457 

Pseudodiplococcus  pneumonia;,  323 
Pseudo-diphtheritic  bacillus,  365 
Ptomaines,  139 
Purpura  haamorrhagica,    bacilli  in,  480. 

481.  527 

Pus,  formation  of,  218,  263 
Putrefaction,  134 

Putrefying  material,  bacteria  in,  585 
Putrescin,  140 
Pyocyanin,  127 
Pyogenic  bacteria,  263 
Pyoktanin,  germicidal  value  of,  189 

Quinine  sulphate,   germicidal   value  of, 
186 

Rabbit  septicaemia,  bacillus  of,  408 
Rain  water,  bacteria  in,  559 
Ranvier's  moist  chamber,  63 
Rauschbrandbacillus  493 
Relapsing  fever,  spirillum  of,  497 
Reproduction  by  binary  division,  113 

by  spores,  114 

rapidity  of,  114 
Rhinoscleroma,  bacteria  in.  527 

bacillus  of,  404 
Ricin,  pathogenic  action  of,  and  immunity 

from  259 

Rinderseuche,  bacillus  of.  408 
River  water,  bacteria  in,  559 
Robin,  classification  of ,  3 
Roll  tubes  of  Von  Esmarch,  74 
Roth,  bacilli  of,  479 
Rotzbacillus.  396 
Rouget,  bacillus  of,  420 
Roux's  method  of  cultivating  anaerobic 
bacteria,  79 

Sachs,  classification  of,  11 

Salicylic  acid,  germicidal  value  of,  174 

Saliva,  bacteria  of,  575 

Saprin,  140 

Saprophytes,  definition  of,  215 

Sarcina  aurantiaca,  615 

alba.  617 

Candida,  617 

flava,  616 

lutea.  616 

mobilis,  720 

pulmonum,  617 

rosea.  616 

ventriculi,  617 
Sarcinse,  morphology  of,  22 

generic  characters,  17 
Scarlet  fever,  bacteria  in,  527 
Scheurlen's  bacillus,  680 
Schweinerothlauf ,  bacillus  of,  420 


INDEX. 


885 


Sea  water,  bacteria  iu,  564 

Secondary  infections,  221 

Senile  gangrene,  bacilli  in,  478 

Septicaemia,  bacilli  of,  407 

Sewers,  bacteria  in,  561 

Silicate  jelly,  46 

Silver  chloride,  germicidal  value  of ,  186 

nitrate,  germicidal  value  of,  186 
Smear  preparations,  26 
Smith,  capsule  bacilli  of,  652 
Smoke,  antiseptic  value  of,  196 
Snow,  bacteria  in,  559 
Sodium  borate,  germicidal  value  of,  187 

carbonate,  germicidal  value  of,  187 

chloride,  antiseptic  value  of,  187 

hydroxide,  germicidal  value  of,  176 

hyposulphite,  antiseptic  value  of,  187 

sulphite,  antiseptic  value  of,  187 
Soil,  bacteria  in,  567,  568,  571,  572 

pathogenic,  bacteria  in,  570 
Solid  culture  media,  41 

characters  of  growth  in,  68 
Sozins,  260 

Sphaerococcus  acidi  lactici,  604 
Spirilla,  general  characters  of,  18 

morphology  of,  24 

non-pathogenic,  694 
Spirillum  aureum,  700 

cholerse  Asiatic*,  500 

concentricum,  701 

denlium,  694 

of  Finkler  and  Prior,  509 

flavum,  700 

rlavescens,  700 

lingua,  687 

Metschnikovi,  511 

of  Miller,  702 

nasale,  897 

Obermeieri,  497 

plicatile,  695 

rubrum,  701 

sanguineum,  696 

serpens,  696 

of  Smith,  701 

sputigenum,  694    , 

tenue,  697 

tyrogenum,  511 

voluntans,  696 

a  of  Weibel,  698 

r  of  Weibel,  699 
Spirochaete  Obermeieri,  497 
Spirulina,  generic  characters,  18 
Spontaneous  generation,  4 
Spores,  5 

methods  of  staining,  31 

formation  of,  114 

germination  of,  115 

resistance  of,  to  heat,  116 

thermal  death-point  of,  149 
Staining  methods,  25 

upon  cover  glass,  25 

bacteria  in  tissues,  33 

sections  of  gelatin  stick  cultures,  36 
solutions,  29 
Staphylococci,  characters  of,  21 


Staphylococcus  albus  liquef  aciens,  607 

epidermidis  albus,  272 

pyogeues  albus,  272 

pyogenes  aureus,  265  ;  in  osteomye- 
litis, 270  ;  in  ulcerative  endocardi- 
tis, 271 

pyogenes  citreus,  273 

viridis  flavescens,  601 
Steam  sterilizers,  53 

disinfection  by,  203 
Sterilization  of  culture  media,  50 

by  discontinuous  heating,  51 

by  dry  heat,  52 

by  filtration,  56 

Sternberg's  method  of  cultivating   bac- 
teria in  liquid  media,  63 

method  of  cultivating  anaerobic  bac- 
teria, 81 

Stomach,  bacteria  in,  580 
Streak  cultures,  75 
Streptococci,  classification  of,  275 
Streptococcus  albus,  610 

acidi  lactici,  610 

articulorum,  278 

bombycis,  318 

of  Bpnome,  325 

brevis,  611 

cadaveris,  611 

coli  gracilis,  609 

conglomerate,  711 

coryzje  contagiosa?  equoruin,  322 

erysipelatos,  274 

generic  characters,  17 

giganteus  urethras,  610 

Havaniensis,  612 

lanceolatus  Pasteuri,  298 

liquefaciens,  613 

longus,  274 

of  mastitis  in  cows,  321 

perniciosus  psittacorum,  326 

pyogenes,  274 

pyogenes  in  diphtheritic  inflamma- 
tions, 278 

pyosepticus,  325 

septicus,  318 

septicus  liquefaciens,  323 

vermiformis,  611 
Structure  of  bacteria,  111 
Sulphur  grains,  in  genus  Beggiatoa,  24 

dioxide,    antiseptic    and    germicidal 

value  of,  168 

Sulphuric  acid,  germicidal  value  of.  172 
Sulphurous  acid,  germicidal  value  of,  172 
Surface  of  body,  bacteria  of,  573 
Swine  pest,  bacillus  of,  413 

plague,  bacillus  of,  417 
Sycosis,  bacilli  in,  467 
Symptomatic  anthrax,  bacillus  of,  493 
Syphilis,  bacteria  in,  528 

bacillus  of  Lustgarten,  402 

bacillus  of  Eve  and  Lingard,  403 
Syringes  for  injecting  bacteria  into  ani- 
mals, 95 

Taunic  acid,  germicidal  value  of,  175 


88(3 


INDEX. 


Tartaric  acid,  germicidal  value  of,  175 
Temperature  favorable  for  growth,  119 
Teianin,  142,  484 
Tetanotoxin,  485 
Tetanus  antitoxin,  488 

bacillus,  482 

toxalbumin,  143 
Tetrads,  definition  of,  22 
Texas  fever  of  cattle,  bacteria  in,  528 
Thermal  death-point  of  bacteria,  147  ;  of 

spores,  149 
Thermo- regulator  of  Bohr,  88 

electro-magnetic,  90 

of  Milncke,  90 

of  Reichert,  88 

of  Rohrbeck,  86 
Thermo-regulators,  86 
Thymic  acid,  germicidal  value  of,  175 
Thymol,  antiseptic  value  of,  196 
Thymus  bouillon,  230 
Tin  chloride,  germicidal  value  of,  187 
Tobacco  smoke,  antiseptic  value  of,  197 
Toxalbumins,  142 
Trachoma,  pus  cocci  in,  282 
Trimethylamine,  140 
Tubercle  bacillus,  cultivation  of,  381 

chemical  products  of,  3S6 

method  of  obtaining  pure  culture  of, 
383 

methods  of  staining,  30 

thermal  death-point  of,  380 
Tuberculin,  144,  3»7 
Tuberculosis,  bacillus  of,  375 

diagnosis  of,  in  cows,  389 

of  fowls,  3^3 

transmission  of,  391 

Turpentine,  oil  of,  antiseptic  value,  196 
Typhoid  bacillus,  detection  of,  in  water, 
353 

fever,  bacillus  of,  337 

fever,  bacillus  of,  in  spleen  of  man, 
340 

fever,  experiments  on  animals,  341 
Typhotoxin,  141,  351 
Typhus  fever,  bacteria  iu,  528 

Underclothing,  bacteria  of,  574 
Unna's  method  of  filtering  agar,  45 


Urea,  fermentation  of,  132 
Urine  as  a  culture  medium,  39 

germicidal  action  of,  200 
Urobacilli  of  Miquel.  722-724 
Urobacillus  Duclauxi,  723 

Freudenreichi,  723 

Maddoxi,  724 

Pasteuri   722 

Schiitzenbergi,  724 
Utpadel,  bacillus  of,  477 

Vaccinia,  bacteria  in,  528 

Vagina,  bacteria  of,  578 

Valerianic  acid,  germicidal  value  of,  175 

Varicella,  bacteria  in,  528 

Variola,  bacteria  in,  528 

Vibrio  Metschnikovi,  511 

proteus,  509 

rugula,  695 
Vibrion  septique,  488 
Virulence,  recovery  of,  125 

loss  of,  124 

Viscous  fermentation,  133 
Vital  activity,  products  of,  126 

Water,  bacteria  in,  553 

bacteria,  methods  of  collection,  554, 

555 

bacteria,  counting  colonies  of,  557 
list  of  bacteria  found  in,  565,  566 

Weigert's  method  of  staining  bacteria  in 
tissues,  34 

Well  water,  bacteria  in,  561 

Whooping  cough,  bacilli  in,  469 

Wildseuche,  bacillus  of,  408 

Winogradsky,  nitrifying  bacillus  of,  710 

Wurmkrankheit,  406 

Yellow  fever,  bacteria  in,  529-531 

Ziehl's  solution,  29 

Ziehl  Neelsen  method  of  staining  tubercle 

bacilli,  30 

Zinc  chloride,  germicidal  value  of,  187 
sulphate,  germicidal  value  of,  188 
Zooglcya,  definition  of,  21 
Zopf,  classification  of,  12 


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8  472. 


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